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August 23 | 1901–present | 1901–present
1924 – Heinrich Berté, Slovak-Austrian composer (b. 1856)
1926 – Rudolph Valentino, Italian actor (b. 1895)
1927 – Nicola Sacco, Italian anarchist convicted of murder (b. 1891)
1927 – Bartolomeo Vanzetti, Italian anarchist convicted of murder (b. 1888)
1933 – Adolf Loos, Austrian architect and theoretician, designed Villa Müller (b. 1870)
1937 – Albert Roussel, French composer (b. 1869)
1944 – Abdülmecid II, Ottoman sultan (b. 1868)
1944 – Stefan Filipkiewicz, Polish painter and illustrator (b. 1879)
1949 – Helen Churchill Candee, American geographer, journalist, and author (b. 1858)
1954 – Jaan Sarv, Estonian mathematician and scholar (b. 1877)
1960 – Oscar Hammerstein II, American director, producer, and composer (b. 1895)
1962 – Walter Anderson, Russian-German ethnologist and academic (b. 1885)
1962 – Hoot Gibson, American actor, director, and producer (b. 1892)
1964 – Edmond Hogan, Australian politician, 30th Premier of Victoria (b. 1883)
1966 – Francis X. Bushman, American actor, director, and screenwriter (b. 1883)
1967 – Georges Berger, Belgian race car driver (b. 1918)
1967 – Nathaniel Cartmell, American runner and coach (b. 1883)
1974 – Roberto Assagioli, Italian psychiatrist and author (b. 1888)
1975 – Faruk Gürler, Turkish general (b. 1913)
1977 – Naum Gabo, Russian sculptor and academic (b. 1890)
1982 – Stanford Moore, American biochemist and academic, Nobel Prize laureate (b. 1913)
1987 – Didier Pironi, French race car and boat driver (b. 1952)
1989 – Mohammed Abed Elhai, Sudanese poet and academic (b. 1944)
1989 – R. D. Laing, Scottish psychiatrist and author (b. 1927)
1990 – David Rose, American pianist and composer (b. 1910)
1994 – Zoltán Fábri, Hungarian director and screenwriter (b. 1917)
1995 – Alfred Eisenstaedt, German-American photographer and journalist (b. 1898)
1996 – Margaret Tucker, Australian author and activist (b. 1904)
1997 – Eric Gairy, Grenadian educator and politician, 1st Prime Minister of Grenada (b. 1922)
1997 – John Kendrew, English biochemist and crystallographer, Nobel Prize laureate (b. 1917)
1999 – Norman Wexler, American screenwriter (b. 1926)
1999 – James White, Irish author (b. 1928)
2000 – John Anthony Kaiser, American priest and missionary (b. 1932)
2001 – Kathleen Freeman, American actress (b. 1919)
2001 – Peter Maas, American journalist and author (b. 1929)
2002 – Hoyt Wilhelm, American baseball player and coach (b. 1922)
2003 – Bobby Bonds, American baseball player and manager (b. 1946)
2003 – Jack Dyer, Australian footballer and coach (b. 1913)
2003 – Jan Sedivka, Czech-Australian violinist and educator (b. 1917)
2003 – Michael Kijana Wamalwa, Kenyan lawyer and politician, 8th Vice President of Kenya (b. 1944)
2005 – Brock Peters, American actor (b. 1927)
2006 – Maynard Ferguson, Canadian trumpet player and bandleader (b. 1928)
2008 – John Russell, English-American author and critic (b. 1919)
2012 – Jerry Nelson, American puppeteer and voice actor (b. 1934)
2012 – Josepha Sherman, American anthologist and author (b. 1946)
2013 – Richard J. Corman, American businessman, founded the R.J. Corman Railroad Group (b. 1955)
2013 – William Glasser, American psychiatrist and author (b. 1925)
2013 – Charles Lisanby, American production designer and set director (b. 1924)
2013 – Konstanty Miodowicz, Polish ethnographer and politician (b. 1951)
2013 – Vesna Rožič, Slovenian chess player (b. 1987)
2013 – Tatyana Zaslavskaya, Russian sociologist and economist (b. 1927)
2014 – Albert Ebossé Bodjongo, Cameroonian footballer (b. 1989)
2014 – Annefleur Kalvenhaar, Dutch cyclist (b. 1994)
2014 – Birgitta Stenberg, Swedish author and illustrator (b. 1932)
2014 – Jaume Vallcorba Plana, Spanish philologist and publisher (b. 1949)
2015 – Augusta Chiwy, Congolese-Belgian nurse (b. 1921)
2015 – Guy Ligier, French rugby player and race car driver (b. 1930)
2015 – Enrique Reneau, Honduran footballer (b. 1971)
2015 – Paul Royle, Australian lieutenant and pilot (b. 1914)
2021 – Elizabeth Blackadder, Scottish painter and printmaker (b. 1931)
2023 – Dmitry Utkin, Russian army officer, founder of Wagner Group (b. 1970)
2023 – Yevgeny Prigozhin, Russian businessman, chief of Wagner Group (b. 1961)
2023 – Terry Funk, American professional wrestler (b. 1944) |
August 23 | Holidays and observances | Holidays and observances
Battle of Kursk Day (Russia)
Christian feast day:
Ascelina
Asterius, Claudius, and Neon
Éogan of Ardstraw
Lupus (Luppus) of Novae
Philip Benitius
Quiriacus and companions, of Ostia
Rose of Lima
Tydfil
Zacchaeus of Jerusalem
August 23 (Eastern Orthodox liturgics)
Day of the National Flag (Ukraine)
European Day of Remembrance for Victims of Stalinism and Nazism or Black Ribbon Day (European Union and other countries), and related observances:
Liberation from Fascist Occupation Day (Romania)
International Day for the Remembrance of the Slave Trade and its Abolition
National Day for Physicians (Iran) |
August 23 | References | References |
August 23 | External links | External links
Category:Days of August |
August 23 | Table of Content | For, Events, Pre-1600, 1601–1900, 1901–present, Births, Pre-1600, 1601–1900, 1901–present, Deaths, Pre-1600, 1601–1900, 1901–present, Holidays and observances, References, External links |
August 24 | pp-move | |
August 24 | Events | Events |
August 24 | Pre-1600 | Pre-1600
367 – Gratian, son of Roman Emperor Valentinian I, is named co-Augustus at the age of eight by his father.
394 – The Graffito of Esmet-Akhom, the latest known inscription in Egyptian hieroglyphs, is written.Richard Parkinson, Cracking Codes: The Rosetta Stone and Decipherment (1999), p. 178.
410 – The Visigoths under King Alaric I begin to pillage Rome.
1185 – Sack of Thessalonica by the Normans.
1200 – King John of England, signer of the first Magna Carta, marries Isabella of Angoulême in Angoulême Cathedral. Roger of Howden, iv, 120.
1215 – Pope Innocent III issues a bull declaring Magna Carta invalid.
1349 – Six thousand Jews are killed in Mainz after being blamed for the bubonic plague.
1482 – The town and castle of Berwick-upon-Tweed is captured from Scotland by an English army.
1516 – The Ottoman Empire under Selim I defeats the Mamluk Sultanate and captures present-day Syria at the Battle of Marj Dabiq.
1561 – Willem of Orange marries duchess Anna of Saxony. |
August 24 | 1601–1900 | 1601–1900
1608 – The first official English representative to India lands in Surat.
1643 – A Dutch fleet establishes a new colony in the ruins of Valdivia in southern Chile.
1662 – The 1662 Book of Common Prayer is legally enforced as the liturgy of the Church of England, precipitating the Great Ejection of Dissenter ministers from their benefices.
1682 – William Penn receives the area that is now the state of Delaware, and adds it to his colony of Pennsylvania.
1690 – Job Charnock of the East India Company establishes a factory in Calcutta, an event formerly considered the founding of the city (in 2003 the Calcutta High Court ruled that the city's foundation date is unknown).
1743 – The War of the Hats: The Swedish army surrenders to the Russians in Helsinki, ending the war and starting Lesser Wrath.
1781 – American Revolutionary War: A small force of Pennsylvania militia is ambushed and overwhelmed by an American Indian group, which forces George Rogers Clark to abandon his attempt to attack Detroit.
1789 – The first naval battle of the Svensksund began in the Gulf of Finland.
1812 – Peninsular War: A coalition of Spanish, British, and Portuguese forces succeed in lifting the two-and-a-half-year-long Siege of Cádiz.
1814 – British troops capture Washington, D.C. and set the Presidential Mansion, Capitol, Navy Yard and many other public buildings ablaze.
1815 – The modern Constitution of the Netherlands is signed.
1816 – The Treaty of St. Louis is signed in St. Louis, Missouri.
1820 – Constitutionalist insurrection at Oporto, Portugal.
1821 – The Treaty of Córdoba is signed in Córdoba, now in Veracruz, Mexico, concluding the Mexican War of Independence from Spain.
1857 – The Panic of 1857 begins, setting off one of the most severe economic crises in United States history.
1870 – The Wolseley expedition reaches Manitoba to end the Red River Rebellion.
1898 – Count Muravyov, Foreign Minister of Russia presents a rescript that convoked the First Hague Peace Conference. |
August 24 | 1901–present | 1901–present
1909 – Workers start pouring concrete for the Panama Canal.
1911 – Manuel de Arriaga is elected and sworn in as the first President of Portugal.
1914 – World War I: German troops capture Namur.
1914 – World War I: The Battle of Cer ends as the first Allied victory in the war.
1929 – Second day of two-day Hebron massacre during the 1929 Palestine riots: Arab attacks on the Jewish community in Hebron in the British Mandate of Palestine, result in the death of 65–68 Jews; the remaining Jews are forced to flee the city.
1931 – Resignation of the United Kingdom's Second Labour Government. Formation of the UK National Government.
1932 – Amelia Earhart becomes the first woman to fly across the United States non-stop (from Los Angeles to Newark, New Jersey).
1933 – The Crescent Limited train derails in Washington, D.C., after the bridge it is crossing is washed out by the 1933 Chesapeake–Potomac hurricane.
1936 – The Australian Antarctic Territory is created.
1937 – Spanish Civil War: the Basque Army surrenders to the Italian Corpo Truppe Volontarie following the Santoña Agreement.
1937 – Spanish Civil War: Sovereign Council of Asturias and León is proclaimed in Gijón.
1938 – Kweilin incident: A Japanese warplane shoots down the Kweilin, a Chinese civilian airliner, killing 14. It is the first recorded instance of a civilian airliner being shot down.
1941 – The Holocaust: Adolf Hitler orders the cessation of Nazi Germany's systematic T4 euthanasia program of the mentally ill and the handicapped due to protests, although killings continue for the remainder of the war.
1942 – World War II: The Battle of the Eastern Solomons. Japanese aircraft carrier Ryūjō is sunk, with the loss of seven officers and 113 crewmen. The US carrier is heavily damaged.
1944 – World War II: Allied troops begin the attack on Paris.
1949 – The treaty creating the North Atlantic Treaty Organization goes into effect.
1950 – Edith Sampson becomes the first black U.S. delegate to the United Nations.
1951 – United Air Lines Flight 615 crashes near Decoto, California, killing 50 people.
1954 – The Communist Control Act goes into effect, outlawing the Communist Party in the United States.
1954 – Vice president João Café Filho takes office as president of Brazil, following the suicide of Getúlio Vargas.
1963 – Buddhist crisis: As a result of the Xá Lợi Pagoda raids, the US State Department cables the United States Embassy, Saigon to encourage Army of the Republic of Vietnam generals to launch a coup against President Ngô Đình Diệm if he did not remove his brother Ngô Đình Nhu.
1967 – Led by Abbie Hoffman, the Youth International Party temporarily disrupts trading at the New York Stock Exchange by throwing dollar bills from the viewing gallery, causing trading to cease as brokers scramble to grab them.
1970 – Vietnam War protesters bomb Sterling Hall at the University of Wisconsin–Madison, leading to an international manhunt for the perpetrators.
1981 – Mark David Chapman is sentenced to 20 years to life in prison for murdering John Lennon.
1989 – Colombian drug barons declare "total war" on the Colombian government.
1989 – Tadeusz Mazowiecki is chosen as the first non-communist prime minister in Central and Eastern Europe.
1991 – Mikhail Gorbachev resigns as head of the Communist Party of the Soviet Union.
1991 – Ukraine declares itself independent from the Soviet Union.
1992 – Hurricane Andrew makes landfall in Homestead, Florida as a Category 5 hurricane, causing up to $25 billion (1992 USD) in damages.
1995 – Microsoft Windows 95 was released to the public in North America.
1998 – First radio-frequency identification (RFID) human implantation tested in the United Kingdom.
2001 – Air Transat Flight 236 loses all engine power over the Atlantic Ocean, forcing the pilots to conduct an emergency landing in the Azores.
2004 – Ninety passengers die after two airliners explode after flying out of Domodedovo International Airport, near Moscow. The explosions are caused by suicide bombers from Chechnya.
2006 – The International Astronomical Union (IAU) redefines the term "planet" such that Pluto is now considered a dwarf planet.
2008 – Sixty-five passengers are killed when Iran Aseman Airlines Flight 6895 crashes during an emergency landing at Manas International Airport in Bishkek, Kyrgyzstan.
2008 – A Cessna 208 Caravan crashes in Cabañas, Zacapa, Guatemala, killing 11 people.
2010 – In San Fernando, Tamaulipas, Mexico, 72 illegal immigrants are killed by Los Zetas and eventually found dead by Mexican authorities.
2010 – Henan Airlines Flight 8387 crashes at Yichun Lindu Airport in Yichun, Heilongjiang, China, killing 44 out of the 96 people on board.
2010 – Agni Air Flight 101 crashes near Shikharpur, Makwanpur, Nepal, killing all 14 people on board.
2012 – Anders Behring Breivik, perpetrator of the 2011 Norway attacks, is sentenced to 21 years of preventive detention.
2014 – A magnitude 6.0 earthquake strikes the San Francisco Bay Area; it is the largest in that area since 1989.
2016 – An earthquake strikes Central Italy with a magnitude of 6.2, with aftershocks felt as far as Rome and Florence. Around 300 people are killed."Terremoto Centro Italia: aggiornamento del numero di vittime, feriti e popolazione assistita" , Protezione Civile, 26 August 2016.
2016 – Proxima Centauri b, the closest exoplanet to Earth, is discovered by the European Southern Observatory.
2017 – The National Space Agency of Taiwan successfully launches the observation satellite Formosat-5 into space.
2020 – Erin O’Toole is elected leader of the Conservative Party of Canada.
2023 – Japan officially begins discharging treated radioactive water from the Fukushima Daiichi Nuclear Power Plant into the Pacific Ocean, sparking international concerns and condemnation. |
August 24 | Births | Births |
August 24 | Pre-1600 | Pre-1600
1016 – Fujiwara no Genshi, Japanese empress consort (d. 1039)
1113 – Geoffrey Plantagenet, Count of Anjou (d. 1151)
1198 – Alexander II of Scotland (d. 1249)
1358 – John I of Castile (d. 1390)
1393 – Arthur III, Duke of Brittany (d. 1458)
1423 – Thomas Rotherham, English cleric (d. 1500)
1498 – John, Hereditary Prince of Saxony (d. 1537)
1510 – Elisabeth of Brandenburg, Duchess of Brunswick-Calenberg-Göttingen (d. 1558)
1552 – Lavinia Fontana, Italian painter and educator (d. 1614)
1556 – Sophia Brahe, Danish horticulturalist and astronomer (d. 1643)
1561 – Thomas Howard, 1st Earl of Suffolk (d. 1626)
1578 – John Taylor, English poet and author (d. 1653)
1591 – Robert Herrick, English poet and cleric (d. 1674) |
August 24 | 1601–1900 | 1601–1900
1631 – Philip Henry, English minister (d. 1696)
1635 – Peder Griffenfeld, Danish lawyer and politician (d. 1699)
1684 – Sir Robert Munro, 6th Baronet, British politician (d. 1746)
1714 – Alaungpaya, Burmese king (d. 1760)
1758 – Duchess Sophia Frederica of Mecklenburg-Schwerin (d. 1794)
1759 – William Wilberforce, English philanthropist and politician (d. 1833)
1772 – William I of the Netherlands (d. 1840)
1787 – James Weddell, Belgian-English sailor, hunter, and explorer (d. 1834)
1824 – Antonio Stoppani, Italian geologist and scholar (d. 1891)
1837 – Théodore Dubois, French organist, composer, and educator (d. 1924)
1843 – Boyd Dunlop Morehead, Australian politician, 10th Premier of Queensland (d. 1905)
1845 – James Calhoun, American lieutenant (d. 1876)
1851 – Tom Kendall, Australian cricketer and journalist (d. 1924)
1852 – Agnes Marshall, English culinary entrepreneur, inventor, and celebrity chef (d. 1905)Jenkins, Terry: "The Truth about Mrs Marshall", Petits Propos Culinaires 112, November 2018, pp. 100–112.
1860 – David Bowman, Australian lawyer and politician (d. 1916)
1862 – Zonia Baber, American geographer and geologist (d. 1956)
1863 – Dragutin Lerman, Croatian explorer (d. 1918)
1865 – Ferdinand I of Romania (d. 1927)
1872 – Max Beerbohm, English essayist, parodist, and caricaturist (d. 1956)
1884 – Earl Derr Biggers, American author and playwright (d. 1933)
1887 – Harry Hooper, American baseball player (d. 1974)
1888 – Valentine Baker, Welsh co-founder of the Martin-Baker Aircraft Company (d. 1942)
1890 – Duke Kahanamoku, American swimmer, actor, and surfer (d. 1968)
1890 – Jean Rhys, Dominican-British novelist (d. 1979)
1893 – Haim Ernst Wertheimer, German-Israeli biochemist and academic (d. 1978)
1895 – Richard Cushing, American cardinal (d. 1970)
1897 – Fred Rose, American pianist, songwriter, and publisher (d. 1954)
1898 – Malcolm Cowley, American novelist, poet, literary critic (d. 1989)
1899 – Jorge Luis Borges, Argentine short-story writer, essayist, poet and translator (d. 1986)
1899 – Albert Claude, Belgian biologist and academic, Nobel Prize laureate (d. 1983)
1900 – Preston Foster, American actor (d. 1970) |
August 24 | 1901–present | 1901–present
1902 – Fernand Braudel, French historian and academic (d. 1985)
1902 – Carlo Gambino, Italian-American mob boss (d. 1976)
1903 – Karl Hanke, German businessman and politician (d. 1945)
1904 – Ida Cook, English campaigner for Jewish refugees, and romantic novelist as Mary Burchell (d. 1986)
1905 – Arthur "Big Boy" Crudup, American singer-songwriter and guitarist (d. 1974)
1905 – Siaka Stevens, Sierra Leonean police officer and politician, 1st President of Sierra Leone (d. 1988)
1907 – Bruno Giacometti, Swiss architect, designed the Hallenstadion (d. 2012)
1908 – Shivaram Rajguru, Indian activist (d. 1931)
1909 – Ronnie Grieveson, South African cricketer and soldier (d. 1998)
1913 – Charles Snead Houston, American physician and mountaineer (d. 2009)
1915 – Wynonie Harris, American singer and guitarist (d. 1969)
1915 – James Tiptree Jr. (Alice Bradley Sheldon), American psychologist and science fiction author (d. 1987)
1918 – Sikander Bakht, Indian field hockey player and politician, Indian Minister of External Affairs (d. 2004)
1919 – Tosia Altman, member of the Polish resistance in World War II (d. 1943)
1919 – J. Gordon Edwards, American entomologist, mountaineer, and DDT advocate (d. 2004)
1919 – Enrique Llanes, Mexican wrestler (d. 2004)
1919 – Niels Viggo Bentzon, Danish composer and pianist (d. 2000)
1920 – Alex Colville, Canadian painter and academic (d. 2013)
1921 – Eric Simms, English ornithologist and conservationist (d. 2009)
1922 – René Lévesque, Canadian journalist and politician, 23rd Premier of Quebec (d. 1987)
1922 – Howard Zinn, American historian, author, and activist (d. 2010)
1923 – Arthur Jensen, American psychologist and academic (d. 2012)
1924 – Alyn Ainsworth, English singer and conductor (d. 1990)
1924 – Louis Teicher, American pianist (d. 2008)
1926 – Nancy Spero, American painter and academic (d. 2009)
1927 – Anjali Devi, Indian actress and producer (d. 2014)
1927 – David Ireland, Australian author and playwright (d. 2022)
1927 – Harry Markowitz, American economist and academic, Nobel Prize laureate (d. 2023)
1929 – Betty Dodson, American author and educator (d. 2020)
1930 – Jackie Brenston, American singer-songwriter and saxophonist (d. 1979)
1930 – Roger McCluskey, American race car driver (d. 1993)
1932 – Robert D. Hales, American captain and religious leader (d. 2017)
1932 – Richard Meale, Australian pianist and composer (d. 2009)
1932 – Cormac Murphy-O'Connor, English cardinal (d. 2017)
1933 – Prince Rupert Loewenstein, Spanish-English banker and manager (d. 2014)
1934 – Kenny Baker, English actor (d. 2016)
1936 – A. S. Byatt, English novelist and poet (d. 2023)
1936 – Kenny Guinn, American banker and politician, 27th Governor of Nevada (d. 2010)
1936 – Arthur B. C. Walker Jr., American physicist and academic (d. 2001)
1937 – Moshood Abiola, Nigerian businessman and politician (d. 1998)
1937 – Susan Sheehan, Austrian-American journalist and author
1938 – David Freiberg, American singer and bass player
1938 – Mason Williams, American guitarist and composer
1940 – Madsen Pirie, British academic, President and co-founder of the Adam Smith Institute
1940 – Francine Lalonde, Canadian educator and politician (d. 2014)
1940 – Keith Savage, English rugby player
1941 – Alan M. Roberts, English academic, Professor of Zoology at the University of Bristol
1942 – Max Cleland, American captain and politician (d. 2021)
1942 – Jimmy Soul, American pop-soul singer (d. 1988)
1942 – Karen Uhlenbeck, American mathematician
1942 – Hans Peter Korff, German actor (d. 2025)
1943 – John Cipollina, American rock guitarist (d. 1989)
1944 – Bill Goldsworthy, Canadian-American ice hockey player and coach (d. 1996)
1944 – Gregory Jarvis, American engineer, and astronaut (d. 1986)
1944 – Rocky Johnson, Canadian-American wrestler and trainer (d. 2020)
1945 – Ronee Blakley, American singer-songwriter, producer, and actress
1945 – Molly Duncan, Scottish saxophonist (d. 2019)
1945 – Ken Hensley, English rock singer-songwriter and musician (d. 2020)
1945 – Marsha P. Johnson, American gay liberation activist and drag queen (d. 1992)
1945 – Vince McMahon, American wrestler, promoter, and entrepreneur; co-founded WWE
1947 – Anne Archer, American actress and producer
1947 – Paulo Coelho, Brazilian author and songwriter
1947 – Roger De Vlaeminck, Belgian cyclist and coach
1947 – Joe Manchin, American politician, 34th Governor of West Virginia
1947 – Vladimir Masorin, Russian admiral
1948 – Kim Sung-il, South Korean commander and pilot
1948 – Jean Michel Jarre, French pianist, composer, and producer
1948 – Sauli Niinistö, Finnish captain and politician, 12th President of Finland
1948 – Alexander McCall Smith, Rhodesian-Scottish author and educator
1949 – Stephen Paulus, American composer and educator (d. 2014)
1949 – Joe Regalbuto, American actor and director
1951 – Danny Joe Brown, American southern rock singer-songwriter and musician (d. 2005)
1951 – Orson Scott Card, American novelist, critic, public speaker, essayist, and columnist;
1951 – Oscar Hijuelos, American author and academic (d. 2013)
1952 – Marion Bloem, Dutch author, director, and painter
1952 – Linton Kwesi Johnson, Jamaican dub poet
1953 – Sam Torrance, Scottish golfer and sportscaster
1954 – Alain Daigle, Canadian ice hockey player
1954 – Heini Otto, Dutch footballer, coach, and manager
1955 – Kevin Dunn, American actor
1955 – Mike Huckabee, American minister and politician, 44th Governor of Arkansas
1956 – Gerry Cooney, American boxer
1957 – Jeffrey Daniel, American singer-songwriter and dancer
1957 – Stephen Fry, English actor, journalist, producer, and screenwriter
1958 – Steve Guttenberg, American actor and producer
1960 – Cal Ripken Jr., American baseball player and coach
1961 – Jared Harris, English actor
1962 – Craig Kilborn, American television host
1962 – Emile Roemer, Dutch educator and politician
1963 – John Bush, American singer-songwriter
1963 – Hideo Kojima, Japanese director, screenwriter and video game designer
1964 – Éric Bernard, French racing driver
1964 – Mark Cerny, American video game designer, programmer, producer and business executive
1964 – Salizhan Sharipov, Kyrgyzstani-Russian lieutenant, pilot, and astronaut
1965 – Marlee Matlin, American actress and producer
1965 – Reggie Miller, American basketball player and sportscaster
1965 – Brian Rajadurai, Sri Lankan-Canadian cricketer
1967 – Michael Thomas, English footballer
1968 – Benoît Brunet, Canadian ice hockey player and sportscaster
1968 – Shoichi Funaki, Japanese-American wrestler and sportscaster
1968 – Andreas Kisser, Brazilian guitarist, songwriter, and producer
1968 – Tim Salmon, American baseball player and sportscaster
1969 – Jans Koerts, Dutch cyclist
1970 – Rich Beem, American golfer
1970 – David Gregory, American journalist
1970 – Tugay Kerimoğlu, Turkish footballer and manager
1972 – Jean-Luc Brassard, Canadian skier and radio host
1972 – Ava DuVernay, American director and screenwriter
1972 – Todd Young, American politician
1973 – Andrew Brunette, Canadian ice hockey player and coach
1973 – Dave Chappelle, American comedian, actor, producer and screenwriter
1973 – James D'Arcy, English actor
1973 – Inge de Bruijn, Dutch swimmer
1973 – Carmine Giovinazzo, American actor
1974 – Jennifer Lien, American actress
1975 – Roberto Colombo, Italian footballer
1975 – Mark de Vries, Surinamese-Dutch footballer
1976 – Simon Dennis, English rower and academic
1976 – Alex O'Loughlin, Australian actor, writer, director, and producer
1977 – Denílson de Oliveira Araújo, Brazilian footballer
1977 – Robert Enke, German footballer (d. 2009)
1977 – Per Gade, Danish footballer
1977 – John Green, American author and vlogger
1977 – Jürgen Macho, Austrian footballer
1978 – Derek Morris, Canadian ice hockey player
1979 – Vahur Afanasjev, Estonian author and poet
1979 – Orlando Engelaar, Dutch footballer
1979 – Michael Redd, American basketball player
1981 – Chad Michael Murray, American actor, model, and author
1982 – José Bosingwa, Portuguese footballer
1982 – Kim Källström, Swedish footballer
1983 – Brett Gardner, American baseball player
1983 – Marcel Goc, German ice hockey player
1984 – Erin Molan, Australian journalist and sportscaster
1984 – Charlie Villanueva, Dominican-American basketball player
1984 – Yesung, South Korean singer
1986 – Joseph Akpala, Nigerian footballer
1986 – Arian Foster, American football player, rapper, and actor
1987 – Anže Kopitar, Slovenian ice hockey player
1988 – Rupert Grint, English actor
1988 – Brad Hunt, Canadian ice hockey player
1988 – Manu Ma'u, New Zealand rugby league player
1988 – Maya Yoshida, Japanese footballer
1989 – Reynaldo, Brazilian footballer
1989 – Rocío Igarzábal, Argentinian actress and singer
1990 – Juan Pedro Lanzani, Argentinian actor and singer
1991 – Enrique Hernández, Puerto Rican baseball player
1991 – Wang Zhen, Chinese race walker
1992 – Jemerson, Brazilian footballer
1993 – Maryna Zanevska, Belgian tennis player
1994 – Kelsey Plum, American basketball player
1995 – Noah Vonleh, American basketball player
1995 – Lady Amelia Windsor, member of the British royal family
1997 – Alan Walker, British-Norwegian DJ and record producer
1998 – Sofia Richie, American model and social media personality
2000 – Griffin Gluck, American actor
2001 – Mildred Maldonado, Mexican rhythmic gymnast |
August 24 | Deaths | Deaths |
August 24 | Pre-1600 | Pre-1600
691 – Fu Youyi, official of the Tang Dynasty
842 – Saga, Japanese emperor (b. 786)Varley, H. Paul. (1980). Jinnō Shōtōki, p. 151–163
895 – Guthred, king of Northumbria
927 – Doulu Ge, chancellor of Later Tang
927 – Wei Yue, chancellor of Later TangZizhi Tongjian, vol. 276.Academia Sinica Chinese-Western Calendar Converter.August 24, 927 was the date that the Later Tang emperor Li Siyuan issued the edict ordering Wei's death; it was not clear whether the order was carried out the same day or later.
942 – Liu, empress dowager of Later Jin
948 – Zhang Ye, Chinese general and chancellor
1042 – Michael V Kalaphates, Byzantine emperor (b. 1015)
1103 – Magnus Barefoot, Norwegian king (b. 1073)
1217 – Eustace the Monk, French pirate (b. 1170)
1313 – Henry VII, Holy Roman Emperor (b. 1275)
1372 – Casimir III, Duke of Pomerania (b. 1348)
1497 – Sophie of Pomerania, Duchess of Pomerania (b. 1435)
1507 – Cecily of York, English princess (b. 1469)
1540 – Parmigianino, Italian painter and etcher (b. 1503)
1542 – Gasparo Contarini, Italian cardinal (b. 1483)
1572 – Gaspard II de Coligny, French admiral (b. 1519)
1572 – Charles de Téligny, French soldier and diplomat (b. 1535)
1595 – Thomas Digges, English mathematician and astronomer (b. 1546) |
August 24 | 1601–1900 | 1601–1900
1617 – Rose of Lima, Peruvian saint (b. 1586)
1647 – Nicholas Stone, English sculptor and architect (b. 1586)
1679 – Jean François Paul de Gondi, French cardinal and author (b. 1614)
1680 – Thomas Blood, Irish colonel (b. 1618)
1680 – Ferdinand Bol, Dutch painter and etcher (b. 1616)
1683 – John Owen, English theologian and academic (b. 1616)
1759 – Ewald Christian von Kleist, German poet and soldier (b. 1715)
1770 – Thomas Chatterton, English poet and prodigy (b. 1752)
1779 – Cosmas of Aetolia, Greek monk and saint (b. 1714)
1798 – Thomas Alcock, English priest and author (b. 1709)
1804 – Peggy Shippen, American wife of Benedict Arnold and American Revolutionary War spy (b. 1760)
1818 – James Carr, American lawyer and politician (b. 1777)
1821 – John William Polidori, English writer and physician (b. 1795)
1832 – Nicolas Léonard Sadi Carnot, French physicist and engineer (b. 1796)
1832 – Richard Weymouth, British Royal Navy commander (b. 1780/81)
1838 – Ferenc Kölcsey, Hungarian poet, critic, and politician (b. 1790)
1841 – Theodore Hook, English civil servant and composer (b. 1788)
1841 – John Ordronaux, French-American soldier (b. 1778)
1888 – Rudolf Clausius, German physicist and mathematician (b. 1822)
1895 – Albert F. Mummery, English mountaineer and author (b. 1855) |
August 24 | 1901–present | 1901–present
1923 – Kate Douglas Wiggin, American author and educator (b. 1856)
1930 – Tom Norman, English businessman and showman (b. 1860)
1932 – Kate M. Gordon, American activist (b. 1861)
1939 – Frederick Carl Frieseke, American painter and educator (b. 1874)
1940 – Paul Gottlieb Nipkow, Polish-German technician and inventor, invented the Nipkow disk (b. 1860)
1943 – Antonio Alice, Argentinian painter and educator (b. 1886)
1943 – Ettore Muti Italian aviator, adventurer and politician (b. 1902)
1943 – Simone Weil, French philosopher and activist (b. 1909)
1946 – James Clark McReynolds, American lawyer and judge, 48th United States Attorney General (b. 1862)
1954 – Getúlio Vargas, Brazilian lawyer and politician, 14th President of Brazil (b. 1882)
1956 – Kenji Mizoguchi, Japanese director and screenwriter (b. 1898)
1957 – Ronald Knox, English Catholic priest (b. 1888)
1958 – Paul Henry, Irish painter and educator (b. 1876)
1967 – Henry J. Kaiser, American businessman, founded Kaiser Shipyards and Kaiser Aluminum (b. 1882)
1974 – Alexander P. de Seversky, Russian-American pilot and businessman, co-founded Republic Aviation (b. 1894)
1977 – Buddy O'Connor, Canadian ice hockey player (b. 1916)
1978 – Louis Prima, American singer-songwriter, trumpet player, and actor (b. 1910)
1979 – Hanna Reitsch, German soldier and pilot (b. 1912)
1980 – Yootha Joyce, English actress (b. 1927)
1982 – Félix-Antoine Savard, Canadian priest and author (b. 1896)
1983 – Kalevi Kotkas, Estonian-Finnish high jumper and discus thrower (b. 1913)
1983 – Scott Nearing, American economist, educator, and activist (b. 1883)
1985 – Paul Creston, American composer and educator (b. 1906)
1987 – Malcolm Kirk, English rugby player and wrestler (b. 1936)
1990 – Sergei Dovlatov, Russian-American journalist and author (b. 1941)
1990 – Gely Abdel Rahman, Sudanese-Egyptian poet and academic (b. 1931)
1991 – Bernard Castro, Italian-American inventor (b. 1904)
1992 – André Donner, Dutch academic and judge (b. 1918)
1997 – Luigi Villoresi, Italian racing driver (b. 1907)
1998 – E. G. Marshall, American actor (b. 1910)
1999 – Mary Jane Croft, American actress (b. 1916)
1999 – Alexandre Lagoya, Egyptian guitarist and composer (b. 1929)
2000 – Andy Hug, Swiss martial artist and kick-boxer (b. 1964)
2001 – Jane Greer, American actress (b. 1924)
2001 – Roman Matsov, Estonian violinist, pianist, and conductor (b. 1917)
2002 – Nikolay Guryanov, Russian priest and mystic (b. 1909)
2003 – Wilfred Thesiger, Ethiopian-English explorer and author (b. 1910)
2004 – Elisabeth Kübler-Ross, Swiss-American psychiatrist and academic (b. 1926)
2006 – Rocco Petrone, American soldier and engineer (b. 1926)
2006 – Léopold Simoneau, Canadian tenor and educator (b. 1916)
2007 – Andrée Boucher, Canadian educator and politician, 39th Mayor of Quebec City (b. 1937)
2007 – Aaron Russo, American director and producer (b. 1943)
2010 – Satoshi Kon, Japanese director and screenwriter (b. 1963)
2011 – Seyhan Erözçelik, Turkish poet and author (b. 1962)
2011 – Mike Flanagan, American baseball player, coach, and sportscaster (b. 1951)
2012 – Dadullah, Pakistani Taliban leader (b. 1965)
2012 – Pauli Ellefsen, Faroese surveyor and politician, 6th Prime Minister of the Faroe Islands (b. 1936)
2012 – Steve Franken, American actor (b. 1932)
2012 – Félix Miélli Venerando, Brazilian footballer and manager (b. 1937)
2013 – Gerry Baker, American soccer player and manager (b. 1938)
2013 – Nílton de Sordi, Brazilian footballer and manager (b. 1931)
2013 – Julie Harris, American actress (b. 1925)
2013 – Muriel Siebert, American businesswoman and philanthropist (b. 1928)
2014 – Richard Attenborough, English actor, director, producer, and politician (b. 1923)
2014 – Antônio Ermírio de Moraes, Brazilian businessman (b. 1928)
2015 – Charlie Coffey, American football player and coach (b. 1934)
2015 – Joseph F. Traub, German-American computer scientist and academic (b. 1932)
2015 – Justin Wilson, English racing driver (b. 1978)
2016 – Walter Scheel, German politician, 4th President of Germany (b. 1919)
2017 – Jay Thomas, American actor, comedian, and radio talk show host (b. 1948)
2020 – Gail Sheehy, American author, journalist, and lecturer (b. 1936)
2021 – Charlie Watts, English musician (b. 1941)
2023 – Bray Wyatt, American wrestler (b. 1987)
2024 – Christoph Daum, German footballer and manager (b. 1953) |
August 24 | Holidays and observances | Holidays and observances
Christian feast day:
Abbán of Ireland
Aurea of Ostia
Bartholomew the Apostle (Roman Catholic, Anglican)
Jeanne-Antide Thouret
Maria Micaela Desmaisieres
Massa Candida (Martyrs of Utica)
Owen (Audoin)
August 24 (Eastern Orthodox liturgics)
Flag Day (Liberia)
Independence Day or Den' Nezalezhnosti, celebrates the independence of Ukraine from the Soviet Union in 1991.
International Strange Music Day
National Waffle Day (United States)
Nostalgia Night (Uruguay)
Willka Raymi (Cusco, Peru) |
August 24 | References | References |
August 24 | External links | External links
Category:Days of August |
August 24 | Table of Content | pp-move, Events, Pre-1600, 1601–1900, 1901–present, Births, Pre-1600, 1601–1900, 1901–present, Deaths, Pre-1600, 1601–1900, 1901–present, Holidays and observances, References, External links |
Antipope | short description | An antipope () is a person who claims to be Bishop of Rome and leader of the Roman Catholic Church in opposition to the officially elected pope. Between the 3rd and mid-15th centuries, antipopes were supported by factions within the Church itself and secular rulers.
Sometimes it was difficult to distinguish which of two claimants should be called pope and which antipope, as in the case of Pope Leo VIII and Pope Benedict V.Of Pope Leo VIII, the Annuario Pontificio, the Holy See's yearbook, says: "At this point, as again in the mid-eleventh century, we come across elections in which problems of harmonizing historical criteria and those of theology and canon law make it impossible to decide clearly which side possessed the legitimacy whose factual existence guarantees the unbroken lawful succession of the Successors of Saint Peter. The uncertainty that in some cases results has made it advisable to abandon the assignation of successive numbers in the list of the Popes" (note 19 to the list of popes in the Annuario Pontificio). Of Pope Benedict V it says: "If Pope Leo VIII was lawful Pope, [...] Benedict V is an antipope" (note 20 to the list of popes). |
Antipope | History | History
Hippolytus of Rome (d. 235) is commonly considered to be the earliest antipope, as he headed a separate group within the Church in Rome against Pope Callixtus I. Hippolytus was reconciled to Callixtus's second successor, Pope Pontian, and both he and Pontian are honoured as saints by the Catholic Church with a shared feast day on 13 August. Whether two or more persons have been confused in this account of Hippolytus and whether Hippolytus actually declared himself to be the Bishop of Rome remains unclear, since no such claim by Hippolytus has been cited in the writings attributed to him.
Eusebius quotesHistoria Ecclesiastica, V, 28 from an unnamed earlier writer the story of Natalius, a 3rd-century priest who accepted the bishopric of the Adoptionists, a heretical group in Rome. Natalius soon repented and tearfully begged Pope Zephyrinus to receive him into communion.Dictionary of Christian Biography and Literature: Zephyrinus
Novatian (d. 258), another third-century figure, certainly claimed the See of Rome in opposition to Pope Cornelius, and if Natalius and Hippolytus were excluded because of the uncertainties concerning them, Novatian could then be said to be the first antipope.
The period in which antipopes were most numerous was during the struggles between the popes and the Holy Roman Emperors of the 11th and 12th centuries. The emperors frequently imposed their own nominees to further their own causes. The popes, likewise, sometimes sponsored rival imperial claimants (anti-kings) in Germany to overcome a particular emperor.
The Western Schism – which began in 1378, when the French cardinals, claiming that the election of Pope Urban VI was invalid, elected antipope Clement VII as a rival to the Roman Pope – led eventually to two competing lines of antipopes: the Avignon line as Clement VII moved back to Avignon, and the Pisan line. The Pisan line, which began in 1409, was named after the town of Pisa, Italy, where the (Pisan) council had elected antipope Alexander V as a third claimant. To end the schism, in May 1415, the Council of Constance deposed antipope John XXIII of the Pisan line. Pope Gregory XII of the Roman line resigned in July 1415. In 1417, the council also formally deposed antipope Benedict XIII of Avignon, but he adamantly refused to resign. Afterwards, Pope Martin V was elected and was accepted everywhere except in the small and rapidly diminishing area of influence of Benedict XIII. |
Antipope | List of historical antipopes | List of historical antipopes
The following table gives the names of the antipopes included in the list of popes and antipopes in the Annuario Pontificio, with the addition of the names of Natalius (in spite of doubts about his historicity) and Antipope Clement VIII (whose following was insignificant).
An asterisk marks those who were included in the conventional numbering of later popes who took the same name. More commonly, the antipope is ignored in later papal regnal numbers; for example, there was an Antipope John XXIII, but the new Pope John elected in 1958 was also called John XXIII. For the additional confusion regarding popes named John, see Pope John numbering.
The list of popes and antipopes in the Annuario Pontificio attaches the following note to the name of Pope Leo VIII (963–965):
At this point, as again in the mid-11th century, we come across elections in which problems of harmonising historical criteria and those of theology and canon law make it impossible to decide clearly which side possessed the legitimacy whose factual existence guarantees the unbroken lawful succession of the successors of Saint Peter. The uncertainty that in some cases results has made it advisable to abandon the assignation of successive numbers in the list of the popes.
Thus, because of the obscurities about mid-11th-century canon law and the historical facts, the Annuario Pontificio lists Sylvester III as a pope, without thereby expressing a judgement on his legitimacy. The Catholic Encyclopedia places him in its List of Popes, but with the annotation: "Considered by some to be an antipope". Other sources classify him as an antipope.
As Celestine II resigned before being consecrated and enthroned in order to avoid a schism, Oxford's A Dictionary of Popes (2010) considers he "...is classified, unfairly, as an antipope", an opinion historian Salvador Miranda also shares.
Those with asterisks (*) were counted in subsequent papal numbering.
Pontificate Common English name Regnal (Latin) name Personal name Place of birth Age at election/Death or resigned Years asantipope(days) Notes In opposition to Natalius Natalius Natalius c. 159 Rome, Roman Empire 38 / 48 () Later reconciled (see above) Zephyrinus 20 Dec 217 – 28 Sep 235 Saint Hippolytus Hippolytus Hippolytus 170 Rome. Roman Empire 45 / 65 (†66) () Later reconciled with Pope Pontian (see above) Callixtus IUrban IPontian Mar 251 – Aug 258 Novatian Novatianus Novatian c. 200 Rome, Roman Empire 51 / 58 (†93) () Founder of Novatianism CorneliusLucius IStephen ISixtus II20 Apr 309 – 16 Aug 310 Heraclius Heraclius Heraclius c. 265 Rome, Roman Empire 45 / 46 () Eusebius355 – 26 Nov 365 Felix II* Felix secundus Felix c. 270 Rome, Roman Empire 80 / 90 () Installed by Roman emperor Constantius II Liberius1 Oct 366 – 16 Nov 367 Ursicinus Ursicinus Ursinus c. 300 Rome, Roman Empire 66 / 67 () Damasus I27 Dec 418 – 3 Apr 419 Eulalius Eulalius Eulalius c. 370 Rome, Roman Empire 38 / 39 (†42) () Boniface I22 Nov 498 – Aug 506/08 Laurentius Laurentius Lorenzo Celio c. 460 Rome, Roman Empire 38 / 46 (†48) () Supported by Byzantine emperor Anastasius I Symmachus22 Sep 530 – 14 Oct 530 Dioscorus Dioscurus Dióskoros c. 450 Alexandria 70 / 70 () Boniface II21 Sep 687 Theodore Theodorus Theodore c. 599 Rome, Duchy of Rome 88 / 88 (†92) () Sergius I21 Sep 687 Paschal (I) Paschalis Pascale c. 598 Rome, Duchy of Rome 89 / 89 (†94) () 28 Jun 767 – 6 Aug 768 Constantine II Constantinus secundus Konstantinus c. 700 Rome, Duchy of Rome 67 / 68 (†69) () Between Paul I and Stephen III31 Jul 768 Philip Philippus Philip c. 701 Rome, Duchy of Rome 68 / 68 (†99) () Installed by envoy of Lombard King Desiderius Stephen III25 Jan – 31 May 844 John VIII Joannes octavus Giovanni c. 800 Rome, Papal States 44 / 44 (†91) () Elected by acclamation Sergius IIJan 855 – 31 Mar 855 Anastasius III Bibliothecarius Anastasius tertius Anastasius c. 810 Rome, Papal States 45 / 45 (†68) () Benedict III3 Oct 903 – 27 Jan 904 Christopher Christophorus Christoforo c. 850 Rome, Papal States 53 / 54 () Between Leo V and Sergius III6 December 963 – 26 February 964 Leo VIII* Leo octavus Leone c. 915 Rome, Papal States 48 / 49 () Installed by emperor Otto the Great, opposed to John XII, later succeeded Benedict V as a legitimate Pope John XIIJul 974 Boniface VII* Bonifacius Franco Ferrucci c. 900 Rome, Papal States 73 / 73 and 84 / 85 () () total 364 days (364 days) Between Benedict VI and Benedict VII20 Aug 984 – 20 Jul 985 Between John XIV and John XVApr 997 – Feb 998 John XVI* Joannes John Filagatto c. 941 Rossano, Calabria, Papal States (Italy) 56 / 56 (†59) () Supported by Byzantine emperor Basil II Gregory VJun 1012 Gregory VI Gregorius Sextus Gregorio c. 960 Rome, Papal States 52 / 52 (†60) () Benedict VIII4 Apr 1058 – 24 Jan 1059 Benedict X* Benedictus Decimus Giovanni Mincio dei Conti di Tusculo c. 1000 Rome, Papal States, 58 / 59 (†80) ( ) Supported by the Counts of Tusculum Nicholas IIJuly 1061 – 31 May 1064 Honorius II Honorius Secundus Pietro Cadalus 1010 Verona, Papal States 51 / 54 (†62) () Supported by Agnes, regent of the Holy Roman Empire Alexander II 25 Jun 1080, 21 Mar 1084 – 8 Sep 1100Clement III Clemens Tertius Guibert of Ravenna c. 1029 Parma, Papal States 51 / 51, 54 / 71 () Supported by Henry IV, Holy Roman Emperor Gregory VIIVictor IIIUrban IIPaschal II8 Sep 1100 – Jan 1101 Theodoric Theodoricus Theodoro c. 1030 Rome, Papal States, 70 / 71 (†72) () Successor to Clement III Paschal IIJan 1101 – Feb 1102 Adalbert or Albert Adalbertus Albert c. 1046 Atella, Campania, Papal States, 55 / 56 (†85) () Successor to Theodoric8 Nov 1105 – 11 Apr 1111 Sylvester IV Sylvester Quartus Maginulf c. 1050 Rome, Papal States 49 / 55 (†56) () Supported by Henry V, Holy Roman Emperor10 Mar 1118 – 22 Apr 1121 Gregory VIII Gregorius Octavus Maurice Burdain c. 1057 Limousin, Occitania, France 61 / 65 (†72) () Gelasius IICallixtus II16 Dec 1124 Celestine II Cœlestinus Secundus Teobaldo Boccapecci c. 1050 Rome, Papal States 74 / 74 (†86) () Honorius II14 Feb 1130 – 25 Jan 1138 Anacletus II Anacletus Secundus Pietro Pierleoni c. 1090 Rome, Papal States 48 / 48 () Innocent II23 Mar 1138 Victor IV Victor Quartus Gregorio Conti c. 1057 Ceccano, Papal States 81 / 81 (†90) () Successor to Anacletus II7 Sep 1159 – 20 Apr 1164 Victor IV Victor Quartus Ottavio di Montecelio c. 1095 Tivoli, Papal States 64 / 69 () Supported by Frederick I, Holy Roman Emperor Alexander III22 Apr 1164 – 28 Sep 1168 Paschal III Paschalis Tertius Guido di Crema c. 1110 Crema, Lombardy, Papal States 54 / 58 ( days)Sep 1168 – 29 Aug 1178 Callixtus III Callixtus Tertius Giovanni of Struma c. 1090 Arezzo, Papal States 78 / 88 (†90) ( days)29 Sep 1179 – Jan 1180 Innocent III Innocentius Tertius Lanzo of Sezza c. 1120 Sezze, Papal States 59 / 60 (†63) ( days)12 May 1328 – 12 Aug 1330 Nicholas V Nicolaus Quintus Pietro Rainalducci c. 1258 Corvaro, Papal States 70 / 74 ( days) Supported by Louis IV, Holy Roman Emperor John XXII 20 Sep 1378 – 16 Sep 1394 Clement VII Clemens Robert of Geneva 1342 Annecy, France 36/52 ( days) Avignon Urban VI Boniface IX 28 Sep 1394 – 23 May 1423 Benedict XIII Benedictus Pedro de Luna 25 November 1328 Illueca, Aragon 65/94 ( days) AvignonInnocent VIIGregory XIIMartin V25 Jun 1409 – 3 May 1410 Alexander V* Alexander Pietro Philarghi c. 1339 Crete, Republic of Venice 70 / 71 ( days) Pisa Gregory XII 25 May 1410 – 29 May 1415 John XXIII Ioannes Vicecimus Tertius Baldassare Cossa c. 1365 45 / 50 (†54) ( days) Pisa10 Jun 1423 – 26 Jul 1429 Clement VIII Clemens Octavus Gil Sánchez Muñoz y Carbón 1370 Teruel, Aragon 52 / 59 (†77) ( days) Avignon Martin V1424–1430 Benedict XIV Benedictus Quartus Decimus Bernard Garnier 1370 France 54 / 59 (†89) ( days) Claimed successor to Benedict XIII – aka "The hidden pope" 1430–1437 Benedict XIV Benedictus Quartus Decimus Jean Carrier c. 1370 France 59 / 66 ( days) 5 Nov 1439 – 7 Apr 1449 Felix V Fœlix Duke Amadeus VIII of Savoy 4 September 1383 Chambéry, Savoy 56/65 (†67) () Elected by the Council of Basel Eugene IV Nicholas V |
Antipope | Quasi-cardinal-nephews | Quasi-cardinal-nephews
Many antipopes created cardinals, known as quasi-cardinals, and a few created cardinal-nephews, known as quasi-cardinal-nephews.
Quasi-cardinal Nephew of Elevated NotesGiacomo AlbertiAntipope Nicholas V15 May 1328Excommunicated by Pope John XXII.Amedeo SaluzzoAntipope Clement VII23 Dec 1383Abandoned Antipope Benedict XIII after having been deposed by him on 21 October 1408; participated in the Council of Pisa, the election of Pope Alexander V (now regarded as an antipope), the Council of Constance, and the conclave of Pope Martin V.Tommaso BrancaccioAntipope John XXIII6 Jun 1411Attended the Council of Constance, and the conclave of Pope Martin V.Gil Sánchez MuñozAntipope Clement VIII26 Jul 1429Submitted to Pope Martin V after his uncle abdicated. |
Antipope | Modern minor claimants | Modern minor claimants
Antipopes still exist today, but all are minor claimants, without the support of any Cardinal. Examples include Palmarians, Apostles of Infinite Love Antipopes, and an unknown number of many other Conclavist claimants. |
Antipope | Antipope of Alexandria | Antipope of Alexandria
As the Patriarch of Alexandria (Egypt) has historically also held the title of pope, a person who, in opposition to someone who is generally accepted as a legitimate pope of Alexandria, claims to hold that position may also be considered an antipope. Coptic lector Max Michel became an antipope of Alexandria, calling himself Maximos I. His claim to the Alexandrine papacy was dismissed by both the Coptic Orthodox Pope Shenouda III and Pope Theodore II of the Greek Orthodox Church of Alexandria. The Coptic pope of Alexandria and the Greek pope of Alexandria currently view one another, not as antipopes, but rather as successors to differing lines of apostolic succession that formed as a result of christological disputes in the fifth century. |
Antipope | In fiction | In fiction
Antipopes have appeared as fictional characters. These may be either in historical fiction, as fictional portraits of well-known historical antipopes or as purely imaginary antipopes.
Jean Raspail's novel l'Anneau du pêcheur ("The Fisherman's Ring").Jean Raspail, L'Anneau du pêcheur, Paris: Albin Michel, 1994. 403 p.
Gérard Bavoux's novel Le Porteur de lumière ("The Light-bringer").Gérard Bavoux, Le Porteur de lumière, Paris: Pygmalion, 1996. p. 329
The fictional synth-pop artist Zladko Vladcik claims to be "The Anti-Pope" in one of his songs.
Dan Simmons's novels Endymion and The Rise of Endymion feature the character of Father Paul Duré, who becomes Pope Teilhard I, but a few years later he is deposed and murdered by a secret group of high-ranking cardinals who disagree with his policies. They install a more tractable successor, and Duré is subsequently referred to by church leadership as the antipope. At the end of the last novel, it is mentioned that another person calling himself the pope of the Technocore loyal Catholics is recognized by very few even among that group, and he is also referred to as an antipope.
In the Girl Genius comics series, set in a gaslamp fantasy version of Europe thrown into chaos by mad science (among other things), there is a brief reference to the existence of seven popes—all of whom apparently ordered a particular text burned.
Ralph McInerny's novel The Red Hat features a schism between liberals and conservatives following the election of a conservative African Pope; the liberal faction elect an Italian cardinal who calls himself "Pius XIII".
In the video game Crusader Kings II by Swedish developer Paradox Interactive, Catholic rulers may appoint one of their bishops as an antipope. An emperor-tier ruler such as the Holy Roman Emperor may declare war on the Papal States to install their antipope as the "true" pope, thereby vassalizing the papacy.
In the video game Age of Empires II, the third scenario in the game's Barbarossa campaign is called "Pope and Antipope" and is based on the Siege of Crema and the subsequent Wars of the Guelphs and Ghibellines.
In episode 3 of The Black Adder (set in the late 15th century), "The Archbishop", Baldrick remarks on selling counterfeit papal pardons, that one for the highest crimes requires the signatures of "both popes" (implying one pope and one antipope). At the end of the episode, the Mother Superior of the local convent informs Edmund that he has been excommunicated by "all three popes".
The Last Fisherman by Randy England features an anti-pope John XXIV elected in opposition to Pope Brendan I.
Bud McFarlane's Pierced by a Sword includes an anti-pope John XXIV who is elected when the assassination attempt on Pope Patrick (fictional successor to John Paul II) is believed to have succeeded. He commits suicide at the end of the book.
Chilling Adventures of Sabrina features an antipope who leads the Churches of Darkness. This antipope reigns in the Vatican Necropolis beneath Rome.
In the TV series The New Pope, after the fictional Pius XIII is put in a coma, Pope Francis II is elected as a replacement. Francis II later dies and is replaced by John Paul III, the titular protagonist. Pius XIII later wakes up, creating a situation where both men have a claim on the Papacy. |
Antipope | See also | See also
Benevacantism
List of papal elections
Papal conclave
Papal selection before 1059
Sedevacantism
Pretender |
Antipope | References | References |
Antipope | External links and bibliography | External links and bibliography
Catholic Encyclopedia: "Antipope"
Encyclopædia Britannica: "Antipope"
The Pope Encyclopaedia: "Antipope"
Kelly, J.N.D, The Oxford Dictionary of Popes, Oxford University Press, US (1986), .
Raspail, Jean, 'L'Anneau du pêcheur, Paris: Albin Michel, 1994. 403 pp. .
Bavoux, Gérard, Le Porteur de lumière, Paris: Pygmalion, 1996. 329 pp. .
Category:Ecclesiastical titles
Category:History of the papacy
Category:Lists of Catholic popes |
Antipope | Table of Content | short description, History, List of historical antipopes, Quasi-cardinal-nephews, Modern minor claimants, Antipope of Alexandria, In fiction, See also, References, External links and bibliography |
Aquaculture | Short description | thumb|300px|Aquaculture fish farming in the fjords south of Castro, Chile
Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. lotus). Aquaculture involves cultivating freshwater, brackish water, and saltwater populations under controlled or semi-natural conditions and can be contrasted with commercial fishing, which is the harvesting of wild fish. Aquaculture is also a practice used for restoring and rehabilitating marine and freshwater ecosystems. Mariculture, commonly known as marine farming, is aquaculture in seawater habitats and lagoons, as opposed to freshwater aquaculture. Pisciculture is a type of aquaculture that consists of fish farming to obtain fish products as food.
Aquaculture can also be defined as the breeding, growing, and harvesting of fish and other aquatic plants, also known as farming in water. It is an environmental source of food and commercial products that help to improve healthier habitats and are used to reconstruct the population of endangered aquatic species. Technology has increased the growth of fish in coastal marine waters and open oceans due to the increased demand for seafood.
Aquaculture can be conducted in completely artificial facilities built on land (onshore aquaculture), as in the case of fish tank, ponds, aquaponics or raceways, where the living conditions rely on human control such as water quality (oxygen), feed or temperature. Alternatively, they can be conducted on well-sheltered shallow waters nearshore of a body of water (inshore aquaculture), where the cultivated species are subjected to relatively more naturalistic environments; or on fenced/enclosed sections of open water away from the shore (offshore aquaculture), where the species are either cultured in cages, racks or bags and are exposed to more diverse natural conditions such as water currents (such as ocean currents), diel vertical migration and nutrient cycles.
According to the Food and Agriculture Organization (FAO), aquaculture "is understood to mean the farming of aquatic organisms including fish, molluscs, crustaceans and aquatic plants. Farming implies some form of intervention in the rearing process to enhance production, such as regular stocking, feeding, protection from predators, etc. Farming also implies individual or corporate ownership of the stock being cultivated."Global Aquaculture Production Fishery Statistical Collections, FAO, Rome. Retrieved 2 October 2011. The reported output from global aquaculture operations in 2019 was over 120 million tonnes valued at US$274 billion, by 2022, it had risen to 130.9 million tonnes, valued at USD 312.8 billion.FAO FIGIS Database (2022) Global Aquaculture Production 1950–2019 . Retrieved 2 February 2022 However, there are issues with the reliability of the reported figures. Further, in current aquaculture practice, products from several kilograms of wild fish are used to produce one kilogram of a piscivorous fish like salmon. Plant and insect-based feeds are also being developed to help reduce wild fish being used for aquaculture feed.
Particular kinds of aquaculture include fish farming, shrimp farming, oyster farming, mariculture, pisciculture, algaculture (such as seaweed farming), and the cultivation of ornamental fish. Particular methods include aquaponics and integrated multi-trophic aquaculture, both of which integrate fish farming and aquatic plant farming. The FAO describes aquaculture as one of the industries most directly affected by climate change and its impacts. Some forms of aquaculture have negative impacts on the environment, such as through nutrient pollution or disease transfer to wild populations. |
Aquaculture | Overview | Overview
thumb|right|300px|Global capture fisheries and aquaculture production reported by FAO, 1990–2030
thumb|right|300px|World aquaculture production of food fish and aquatic plants, 1990–2016
Harvest stagnation in wild fisheries and overexploitation of popular marine species, combined with a growing demand for high-quality protein, encouraged aquaculturists to domesticate other marine species."'FAO: 'Fish farming is the way forward.'(Big Picture)(Food and Agriculture Administration's 'State of Fisheries and Aquaculture' report)." The Ecologist 39.4 (2009): 8–9. Gale Expanded Academic ASAP. Web. 1 October 2009. <http://find.galegroup.com/gtx/start.do?prodId=EAIM.>."The Case for Fish and Oyster Farming ," Carl Marziali, University of Southern California Trojan Family Magazine, May 17, 2009. At the outset of modern aquaculture, many were optimistic that a "Blue Revolution" could take place in aquaculture, just as the Green Revolution of the 20th century had revolutionized agriculture."The Economist: 'The promise of a blue revolution', Aug. 7, 2003. <http://www.economist.com/node/1974103> Although land animals had long been domesticated, most seafood species were still caught from the wild. Concerned about the impact of growing demand for seafood on the world's oceans, prominent ocean explorer Jacques Cousteau wrote in 1973: "With earth's burgeoning human populations to feed, we must turn to the sea with new understanding and new technology.""Jacques Cousteau, The Ocean World of Jacques Cousteau: The Act of life, World Pub: 1973."
About 430 (97%) of the species cultured were domesticated during the 20th and 21st centuries, of which an estimated 106 came in the decade to 2007. Given the long-term importance of agriculture, to date, only 0.08% of known land plant species and 0.0002% of known land animal species have been domesticated, compared with 0.17% of known marine plant species and 0.13% of known marine animal species. Domestication typically involves about a decade of scientific research. Domesticating aquatic species involves fewer risks to humans than do land animals, which took a large toll in human lives. Most major human diseases originated in domesticated animals, including diseases such as smallpox and diphtheria, that like most infectious diseases, move to humans from animals. No human pathogens of comparable virulence have yet emerged from marine species.
Biological control methods to manage parasites are already being used, such as cleaner fish (e.g. lumpsuckers and wrasse) to control sea lice populations in salmon farming. Models are being used to help with spatial planning and siting of fish farms in order to minimize impact.
thumb|300x300px|Aquaculture production (2019)
The decline in wild fish stocks has increased the demand for farmed fish. However, finding alternative sources of protein and oil for fish feed is necessary so the aquaculture industry can grow sustainably; otherwise, it represents a great risk for the over-exploitation of forage fish.
Aquaculture production now exceeds capture fishery production and together the relative GDP contribution has ranged from 0.01 to 10%. Singling out aquaculture's relative contribution to GDP, however, is not easily derived due to lack of data.
Another recent issue following the banning in 2008 of organotins by the International Maritime Organization is the need to find environmentally friendly, but still effective, compounds with antifouling effects.
Many new natural compounds are discovered every year, but producing them on a large enough scale for commercial purposes is almost impossible.
It is highly probable that future developments in this field will rely on microorganisms, but greater funding and further research is needed to overcome the lack of knowledge in this field. |
Aquaculture | Species groups | Species groups
thumb|300px|World capture fisheries and aquaculture production by main producers (2018), from FAO's Statistical Yearbook 2020 |
Aquaculture | Aquatic plants | Aquatic plants
thumb|300px|Cultivating emergent aquatic plants in floating containers|alt=Aquatic plants in floating containers
Microalgae, also referred to as phytoplankton, microphytes, or planktonic algae, constitute the majority of cultivated algae. Macroalgae commonly known as seaweed also have many commercial and industrial uses, but due to their size and specific requirements, they are not easily cultivated on a large scale and are most often taken in the wild.
In 2016, aquaculture was the source of 96.5 percent by volume of the total 31.2 million tonnes of wild-collected and cultivated aquatic plants combined. Global production of farmed aquatic plants, overwhelmingly dominated by seaweeds, grew in output volume from 13.5 million tonnes in 1995 to just over 30 million tonnes in 2016. |
Aquaculture | Seaweed farming | Seaweed farming |
Aquaculture | Fish | Fish
The farming of fish is the most common form of aquaculture. It involves raising fish commercially in tanks, fish ponds, or ocean enclosures, usually for food. A facility that releases juvenile fish into the wild for recreational fishing or to supplement a species' natural numbers is generally referred to as a fish hatchery. Worldwide, the most important fish species used in fish farming are, in order, carp, salmon, tilapia, and catfish.
In the Mediterranean, young bluefin tuna are netted at sea and towed slowly towards the shore. They are then interned in offshore pens (sometimes made from floating HDPE pipe) where they are further grown for the market. In 2009, researchers in Australia managed for the first time to coax southern bluefin tuna to breed in landlocked tanks. Southern bluefin tuna are also caught in the wild and fattened in grow-out sea cages in southern Spencer Gulf, South Australia.
A similar process is used in the salmon-farming section of this industry; juveniles are taken from hatcheries and a variety of methods are used to aid them in their maturation. For example, as stated above, some of the most important fish species in the industry, salmon, can be grown using a cage system. This is done by having netted cages, preferably in open water that has a strong flow, and feeding the salmon a special food mixture that aids their growth. This process allows for year-round growth of the fish, thus a higher harvest during the correct seasons. An additional method, known sometimes as sea ranching, has also been used within the industry. Sea ranching involves raising fish in a hatchery for a brief time and then releasing them into marine waters for further development, whereupon the fish are recaptured when they have matured. |
Aquaculture | Crustaceans | Crustaceans
Commercial shrimp farming began in the 1970s, and production grew steeply thereafter. Global production reached more than 1.6 million tonnes in 2003, worth about US$9 billion. About 75% of farmed shrimp is produced in Asia, in particular in China and Thailand. The other 25% is produced mainly in Latin America, where Brazil is the largest producer. Thailand is the largest exporter.
Shrimp farming has changed from its traditional, small-scale form in Southeast Asia into a global industry. Technological advances have led to ever higher densities per unit area, and broodstock is shipped worldwide. Virtually all farmed shrimp are penaeids (i.e., shrimp of the family Penaeidae), and just two species of shrimp, the Pacific white shrimp and the giant tiger prawn, account for about 80% of all farmed shrimp. These industrial monocultures are very susceptible to disease, which has decimated shrimp populations across entire regions. Increasing ecological problems, repeated disease outbreaks, and pressure and criticism from both nongovernmental organizations and consumer countries led to changes in the industry in the late 1990s and generally stronger regulations. In 1999, governments, industry representatives, and environmental organizations initiated a program aimed at developing and promoting more sustainable farming practices through the Seafood Watch program.
Freshwater prawn farming shares many characteristics with, including many problems with, marine shrimp farming. Unique problems are introduced by the developmental lifecycle of the main species, the giant river prawn.New, M. B.: Farming Freshwater Prawns; FAO Fisheries Technical Paper 428, 2002. .
The global annual production of freshwater prawns (excluding crayfish and crabs) in 2007 was about 460,000 tonnes, exceeding 1.86 billion dollars. Additionally, China produced about 370,000 tonnes of Chinese river crab.Data extracted from the FAO Fisheries Global Aquaculture Production Database for freshwater crustaceans. The most recent data are from 2003 and sometimes contain estimates. Retrieved June 28, 2005.
In addition astaciculture is the freshwater farming of crayfish (mostly in the US, Australia, and Europe). |
Aquaculture | Molluscs | Molluscs
thumb|300px|Abalone farm|alt=Abalone farm
thumb|300px|Sturgeon farm|alt=Sturgeon farm
Aquacultured shellfish include various oyster, mussel, and clam species. These bivalves are filter and/or deposit feeders, which rely on ambient primary production rather than inputs of fish or other feed. As such, shellfish aquaculture is generally perceived as benign or even beneficial.
Depending on the species and local conditions, bivalve molluscs are either grown on the beach, on longlines, or suspended from rafts and harvested by hand or by dredging. In May 2017 a Belgian consortium installed the first of two trial mussel farms on a wind farm in the North Sea.
Abalone farming began in the late 1950s and early 1960s in Japan and China. Since the mid-1990s, this industry has become increasingly successful. Overfishing and poaching have reduced wild populations to the extent that farmed abalone now supplies most abalone meat. Sustainably farmed molluscs can be certified by Seafood Watch and other organizations, including the World Wildlife Fund (WWF). WWF initiated the "Aquaculture Dialogues" in 2004 to develop measurable and performance-based standards for responsibly farmed seafood. In 2009, WWF co-founded the Aquaculture Stewardship Council with the Dutch Sustainable Trade Initiative to manage the global standards and certification programs.
After trials in 2012, a commercial "sea ranch" was set up in Flinders Bay, Western Australia, to raise abalone. The ranch is based on an artificial reef made up of 5000 () separate concrete units called abitats (abalone habitats). The 900 kg abitats can host 400 abalone each. The reef is seeded with young abalone from an onshore hatchery. The abalone feed on seaweed that has grown naturally on the habitats, with the ecosystem enrichment of the bay also resulting in growing numbers of dhufish, pink snapper, wrasse, and Samson fish, among other species.
Brad Adams, from the company, has emphasised the similarity to wild abalone and the difference from shore-based aquaculture. "We're not aquaculture, we're ranching, because once they're in the water they look after themselves." |
Aquaculture | Other groups | Other groups
Other groups include aquatic reptiles, amphibians, and miscellaneous invertebrates, such as echinoderms and jellyfish. They are separately graphed at the top right of this section, since they do not contribute enough volume to show clearly on the main graph.
Commercially harvested echinoderms include sea cucumbers and sea urchins. In China, sea cucumbers are farmed in artificial ponds as large as . |
Aquaculture | Global fish production | Global fish production
Global fish production peaked at about 171 million tonnes in 2016, with aquaculture representing 47 percent of the total and 53 percent if non-food uses (including reduction to fishmeal and fish oil) are excluded. With capture fishery production relatively static since the late 1980s, aquaculture has been responsible for the continuing growth in the supply of fish for human consumption. Global aquaculture production (including aquatic plants) in 2016 was 110.2 million tonnes, with the first-sale value estimated at US$244 billion. Three years later, in 2019 the reported output from global aquaculture operations was over 120 million tonnes valued at US$274 billion and by 2022 it had reached 130.9 million tonnes, valued at USD 312.8 billion. For the first time, aquaculture surpassed capture fisheries in aquatic animal production with 94.4 million tonnes, representing 51 percent of the world total and a record 57 percent of the production destined for human consumption.
In 2022 most aquaculture workers were in Asia (95%), followed by Africa (3%) and Latin America and the Caribbean (2%).
The contribution of aquaculture to the global production of capture fisheries and aquaculture combined has risen continuously, reaching 46.8 percent in 2016, up from 25.7 percent in 2000. With 5.8 percent annual growth rate during the period 2001–2016, aquaculture continues to grow faster than other major food production sectors, but it no longer has the high annual growth rates experienced in the 1980s and 1990s.
In 2012, the total world production of fisheries was 158 million tonnes, of which aquaculture contributed 66.6 million tonnes, about 42%.FAO (2014) The State of World Fisheries and Aquaculture 2014 (SOFIA) The growth rate of worldwide aquaculture has been sustained and rapid, averaging about 8% per year for over 30 years, while the take from wild fisheries has been essentially flat for the last decade. The aquaculture market reached $86 billion$86 thousand million in 2009.
Aquaculture is an especially important economic activity in China. Between 1980 and 1997, the Chinese Bureau of Fisheries reports, aquaculture harvests grew at an annual rate of 16.7%, jumping from 1.9 million tonnes to nearly 23 million tonnes. In 2005, China accounted for 70% of world production. Aquaculture is also currently one of the fastest-growing areas of food production in the U.S.
About 90% of all U.S. shrimp consumption is farmed and imported. In recent years, salmon aquaculture has become a major export in southern Chile, especially in Puerto Montt, Chile's fastest-growing city.
A United Nations report titled The State of the World Fisheries and Aquaculture released in May 2014 maintained fisheries and aquaculture support the livelihoods of some 60 million people in Asia and Africa. FAO estimates that in 2016, overall, women accounted for nearly 14 percent of all people directly engaged in the fisheries and aquaculture primary sector.
In 2021, global fish production reached 182 million tonnes, with approximately equal amounts coming from capture (91.2 million tonnes) and aquaculture (90.9 million tonnes). Aquaculture has experienced rapid growth in recent decades, increasing almost sevenfold from 1990 to 2021.
Category201120122013201420152016ProductionCaptureInland10.711.211.211.311.411.6Marine81.578.479.479.981.279.3Total capture92.289.590.691.292.790.9AquacultureInland38.64244.846.948.651.4Marine23.224.425.426.827.528.7Total aquaculture61.866.470.273.776.180Total world fisheries and aquaculture154156160.7164.9168.7170.9UtilizationHuman consumption130136.4140.1144.8148.4151.2Non-food uses2419.620.62020.319.7Population (billions)77.17.27.37.37.4Per capita apparent consumption (kg)18.519.219.519.920.220.3thumb|300px|Aquaculture production by region |
Aquaculture | Over-reporting by China | Over-reporting by China
China overwhelmingly dominates the world in reported aquaculture output, reporting a total output which is double that of the rest of the world put together. However, there are some historical issues with the accuracy of China's returns.
In 2001, scientists Reg Watson and Daniel Pauly expressed concerns that China was over reporting its catch from wild fisheries in the 1990s. They said that made it appear that the global catch since 1988 was increasing annually by 300,000 tonnes, whereas it was really shrinking annually by 350,000 tonnes. Watson and Pauly suggested this may have been related to Chinese policies where state entities that monitored the economy were also tasked with increasing output. Also, until more recently, the promotion of Chinese officials was based on production increases from their own areas.
China disputed this claim. The official Xinhua News Agency quoted Yang Jian, director general of the Agriculture Ministry's Bureau of Fisheries, as saying that China's figures were "basically correct".China disputes claim it over reports fish catch Associated Press, 17 December 2002. However, the FAO accepted there were issues with the reliability of China's statistical returns, and for a period treated data from China, including the aquaculture data, apart from the rest of the world. |
Aquaculture | Aquacultural methods | Aquacultural methods |
Aquaculture | Mariculture | Mariculture
Mariculture is the cultivation of marine organisms in seawater, variously in sheltered coastal waters ("inshore"), open ocean ("offshore"), and on land ("onshore"). Farmed species include algae (from microalgae (such as phytoplankton) to macroalgae (such as seaweed); shellfish (such as shrimp), lobster, oysters), and clams, and marine finfish. Channel catfish (Ictalurus punctatus), hard clams (Mercenaria mercenaria) and Atlantic salmon (Salmo salar) are prominent in the U.S. mariculture.
Mariculture may consist of raising the organisms on or in artificial enclosures such as in floating netted enclosures for salmon, and on racks or in floating cages for oysters. In the case of enclosed salmon, they are fed by the operators; oysters on racks filter feed on naturally available food. Abalone have been farmed on an artificial reef consuming seaweed which grows naturally on the reef units. |
Aquaculture | Integrated | Integrated
Integrated multi-trophic aquaculture (IMTA) is a practice in which the byproducts (wastes) from one species are recycled to become inputs (fertilizers, food) for another. Fed aquaculture (for example, fish, shrimp) is combined with inorganic extractive and organic extractive (for example, shellfish) aquaculture to create balanced systems for environmental sustainability (biomitigation), economic stability (product diversification and risk reduction) and social acceptability (better management practices).
"Multi-trophic" refers to the incorporation of species from different trophic or nutritional levels in the same system.Chopin T. 2006. Integrated multi-trophic aquaculture. What it is, and why you should care ... and don't confuse it with polyculture. Northern Aquaculture, Vol. 12, No. 4, July/August 2006, pg. 4. This is one potential distinction from the age-old practice of aquatic polyculture, which could simply be the co-culture of different fish species from the same trophic level. In this case, these organisms may all share the same biological and chemical processes, with few synergistic benefits, which could potentially lead to significant shifts in the ecosystem. Some traditional polyculture systems may, in fact, incorporate a greater diversity of species, occupying several niches, as extensive cultures (low intensity, low management) within the same pond. A working IMTA system can result in greater total production based on mutual benefits to the co-cultured species and improved ecosystem health, even if the production of individual species is lower than in a monoculture over a short-term period.
Sometimes the term "integrated aquaculture" is used to describe the integration of monocultures through water transfer. For all intents and purposes, however, the terms "IMTA" and "integrated aquaculture" differ only in their degree of descriptiveness. Aquaponics, fractionated aquaculture, integrated agriculture-aquaculture systems, integrated peri-urban-aquaculture systems, and integrated fisheries-aquaculture systems are other variations of the IMTA concept. |
Aquaculture | Urban aquaculture | Urban aquaculture |
Aquaculture | Netting materials | Netting materials
Various materials, including nylon, polyester, polypropylene, polyethylene, plastic-coated welded wire, rubber, patented rope products (Spectra, Thorn-D, Dyneema), galvanized steel and copper are used for netting in aquaculture fish enclosures around the world.Offshore Aquaculture in the United States: Economic considerations, implications, and opportunities, U.S. Department of Commerce, National Oceanic & Atmospheric Administration, July 2008, p. 53Southern Regional Aquaculture Center at All of these materials are selected for a variety of reasons, including design feasibility, material strength, cost, and corrosion resistance.
Recently, copper alloys have become important netting materials in aquaculture because they are antimicrobial (i.e., they destroy bacteria, viruses, fungi, algae, and other microbes) and they therefore prevent biofouling (i.e., the undesirable accumulation, adhesion, and growth of microorganisms, plants, algae, tubeworms, barnacles, mollusks, and other organisms). By inhibiting microbial growth, copper alloy aquaculture cages avoid costly net changes that are necessary with other materials. The resistance of organism growth on copper alloy nets also provides a cleaner and healthier environment for farmed fish to grow and thrive. |
Aquaculture | Technology | Technology
Uncrewed vessels, like ROVs and AUVs, are now being used in aquaculture in various ways, such as site planning, cage or net inspection, environmental monitoring, disaster assessment, and risk reduction. The use of uncrewed vessels aims to increase safety, efficiency, and accuracy of aquaculture operations. Aquaculture is a multi-million-dollar business that relies on net and cage maintenance. Inspections used to be conducted by divers manually inspecting the nets, but uncrewed vessels are now being used to conduct faster and more efficient inspections.
Biofloc technology is also used to simultaneously improve water quality and generate bacterial biomass as food for the cultured animals. |
Aquaculture | Issues | Issues
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If performed without consideration for potential local environmental impacts, aquaculture in inland waters can result in more environmental damage than wild fisheries, though with less waste produced per kg on a global scale.Diamond, Jared, Collapse: How societies choose to fail or succeed, Viking Press, 2005, pp. 479–485 Local concerns with aquaculture in inland waters may include waste handling, side-effects of antibiotics, competition between farmed and wild animals, and the potential introduction of invasive plant and animal species, or foreign pathogens, particularly if unprocessed fish are used to feed more marketable carnivorous fish. If non-local live feeds are used, aquaculture may introduce exotic plants or animals with disastrous effects. Improvements in methods resulting from advances in research and the availability of commercial feeds has reduced some of these concerns since their greater prevalence in the 1990s and 2000s .Costa-Pierce, B.A., 2002, Ecological Aquaculture, Blackwell Science, Oxford, UK.
Fish waste is organic and composed of nutrients necessary in all components of aquatic food webs. In-ocean aquaculture often produces much higher than normal fish waste concentrations. The waste collects on the ocean bottom, damaging or eliminating bottom-dwelling life. Waste can also decrease dissolved oxygen levels in the water column, putting further pressure on wild animals. An alternative model to food being added to the ecosystem, is the installation of artificial reef structures to increase the habitat niches available, without the need to add any more than ambient feed and nutrient. This has been used in the "ranching" of abalone in Western Australia. |
Aquaculture | Impacts on wild fish | Impacts on wild fish
Some carnivorous and omnivorous farmed fish species are fed wild forage fish. Although carnivorous farmed fish represented only 13 percent of aquaculture production by weight in 2000, they represented 34 percent of aquaculture production by value.
Farming of carnivorous species like salmon and shrimp leads to a high demand for forage fish to match the nutrition they get in the wild. Fish do not actually produce omega-3 fatty acids, but instead accumulate them from either consuming microalgae that produce these fatty acids, as is the case with forage fish like herring and sardines, or, as is the case with fatty predatory fish, like salmon, by eating prey fish that have accumulated omega-3 fatty acids from microalgae. To satisfy this requirement, more than 50 percent of the world fish oil production is fed to farmed salmon.
Farmed salmon consume more wild fish than they generate as a final product, although the efficiency of production is improving. To produce one kilograms of farmed salmon, products from several kilograms of wild fish are fed to them – this can be described as the "fish-in-fish-out" (FIFO) ratio. In 1995, salmon had a FIFO ratio of 7.5 (meaning 7.5 kilograms of wild fish feed were required to produce one kilogram of salmon); by 2006 the ratio had fallen to 4.9. Additionally, a growing share of fish oil and fishmeal come from residues (byproducts of fish processing), rather than dedicated whole fish. In 2012, 34 percent of fish oil and 28 percent of fishmeal came from residues. However, fishmeal and oil from residues instead of whole fish have a different composition with more ash and less protein, which may limit its potential use for aquaculture.
As the salmon farming industry expands, it requires more wild forage fish for feed, at a time when seventy-five percent of the world's monitored fisheries are already near to or have exceeded their maximum sustainable yield.Seafood Choices Alliance (2005) The industrial-scale extraction of wild forage fish for salmon farming then impacts the survivability of the wild predator fish who rely on them for food. An important step in reducing the impact of aquaculture on wild fish is shifting carnivorous species to plant-based feeds. Salmon feeds, for example, have gone from containing only fishmeal and oil to containing 40 percent plant protein. The USDA has also experimented with using grain-based feeds for farmed trout. When properly formulated (and often mixed with fishmeal or oil), plant-based feeds can provide proper nutrition and similar growth rates in carnivorous farmed fish.NOAA/USDA: The Future of Aquafeeds (2011)
Another impact aquaculture production can have on wild fish is the risk of fish escaping from coastal pens, where they can interbreed with their wild counterparts, diluting wild genetic stocks. Escaped fish can become invasive, out-competing native species."Aquaculture's growth continuing: improved management techniques can reduce environmental effects of the practice. (UPDATE)." Resource: Engineering & Technology for a Sustainable World 16.5 (2009): 20–22. Gale Expanded Academic ASAP. Web. 1 October 2009. |
Aquaculture | Animal welfare | Animal welfare
As with the farming of terrestrial animals, social attitudes influence the need for humane practices and regulations in farmed marine animals. Under the guidelines advised by the Farm Animal Welfare Council good animal welfare means both fitness and a sense of well-being in the animal's physical and mental state. This can be defined by the Five Freedoms:
Freedom from hunger and thirst
Freedom from discomfort
Freedom from pain, disease, or injury
Freedom to express normal behaviour
Freedom from fear and distress
However, the controversial issue in aquaculture is whether fish and farmed marine invertebrates are actually sentient, or have the perception and awareness to experience suffering. Although no evidence of this has been found in marine invertebrates, recent studies conclude that fish do have the necessary receptors (nociceptors) to sense noxious stimuli and so are likely to experience states of pain, fear and stress. Consequently, welfare in aquaculture is directed at vertebrates, finfish in particular. |
Aquaculture | Common welfare concerns | Common welfare concerns
Welfare in aquaculture can be impacted by a number of issues such as stocking densities, behavioural interactions, disease and parasitism. A major problem in determining the cause of impaired welfare is that these issues are often all interrelated and influence each other at different times.
Optimal stocking density is often defined by the carrying capacity of the stocked environment and the amount of individual space needed by the fish, which is very species specific. Although behavioural interactions such as shoaling may mean that high stocking densities are beneficial to some species, in many cultured species high stocking densities may be of concern. Crowding can constrain normal swimming behaviour, as well as increase aggressive and competitive behaviours such as cannibalism, feed competition, territoriality and dominance/subordination hierarchies. This potentially increases the risk of tissue damage due to abrasion from fish-to-fish contact or fish-to-cage contact. Fish can suffer reductions in food intake and food conversion efficiency. In addition, high stocking densities can result in water flow being insufficient, creating inadequate oxygen supply and waste product removal. Dissolved oxygen is essential for fish respiration and concentrations below critical levels can induce stress and even lead to asphyxiation. Ammonia, a nitrogen excretion product, is highly toxic to fish at accumulated levels, particularly when oxygen concentrations are low.
Many of these interactions and effects cause stress in the fish, which can be a major factor in facilitating fish disease. For many parasites, infestation depends on the host's degree of mobility, the density of the host population and vulnerability of the host's defence system. Sea lice are the primary parasitic problem for finfish in aquaculture, high numbers causing widespread skin erosion and haemorrhaging, gill congestion, and increased mucus production. There are also a number of prominent viral and bacterial pathogens that can have severe effects on internal organs and nervous systems. |
Aquaculture | Improving welfare | Improving welfare
The key to improving welfare of marine cultured organisms is to reduce stress to a minimum, as prolonged or repeated stress can cause a range of adverse effects. Attempts to minimise stress can occur throughout the culture process. Understanding and providing required environmental enrichment can be vital for reducing stress and benefit aquaculture objects such as improved growth body condition and reduced damage from aggression. During grow-out it is important to keep stocking densities at appropriate levels specific to each species, as well as separating size classes and grading to reduce aggressive behavioural interactions. Keeping nets and cages clean can assist positive water flow to reduce the risk of water degradation.
Not surprisingly disease and parasitism can have a major effect on fish welfare and it is important for farmers not only to manage infected stock but also to apply disease prevention measures. However, prevention methods, such as vaccination, can also induce stress because of the extra handling and injection. Other methods include adding antibiotics to feed, adding chemicals into water for treatment baths and biological control, such as using cleaner wrasse to remove lice from farmed salmon.
Many steps are involved in transport, including capture, food deprivation to reduce faecal contamination of transport water, transfer to transport vehicle via nets or pumps, plus transport and transfer to the delivery location. During transport water needs to be maintained to a high quality, with regulated temperature, sufficient oxygen and minimal waste products. In some cases anaesthetics may be used in small doses to calm fish before transport.
Aquaculture is sometimes part of an environmental rehabilitation program or as an aid in conserving endangered species. |
Aquaculture | Coastal ecosystems | Coastal ecosystems
Aquaculture is becoming a significant threat to coastal ecosystems. About 20 percent of mangrove forests have been destroyed since 1980, partly due to shrimp farming. An extended cost–benefit analysis of the total economic value of shrimp aquaculture built on mangrove ecosystems found that the external costs were much higher than the external benefits. Over four decades, of Indonesian mangroves have been converted to shrimp farms. Most of these farms are abandoned within a decade because of the toxin build-up and nutrient loss.Meat and Fish American Association for the Advancement of Science Atlas of Population and Environment. Retrieved 4 January 2010. |
Aquaculture | Pollution from sea cage aquaculture | Pollution from sea cage aquaculture
thumb|Salmon aquaculture, Norway
Salmon farms are typically sited in pristine coastal ecosystems which they then pollute. A farm with 200,000 salmon discharges more fecal waste than a city of 60,000 people. This waste is discharged directly into the surrounding aquatic environment, untreated, often containing antibiotics and pesticides." There is also an accumulation of heavy metals on the benthos (seafloor) near the salmon farms, particularly copper and zinc.
In 2016, mass fish kill events impacted salmon farmers along Chile's coast and the wider ecology. Increases in aquaculture production and its associated effluent were considered to be possible contributing factors to fish and molluscan mortality.
Sea cage aquaculture is responsible for nutrient enrichment of the waters in which they are established. This results from fish wastes and uneaten feed inputs. Elements of most concern are nitrogen and phosphorus which can promote algal growth, including harmful algal blooms which can be toxic to fish. Flushing times, current speeds, distance from the shore and water depth are important considerations when locating sea cages in order to minimize the impacts of nutrient enrichment on coastal ecosystems.
The extent of the effects of pollution from sea-cage aquaculture varies depending on where the cages are located, which species are kept, how densely cages are stocked and what the fish are fed. Important species-specific variables include the species' food conversion ratio (FCR) and nitrogen retention. |
Aquaculture | Freshwater ecosystems | Freshwater ecosystems
Whole-lake experiments carried out at the Experimental Lakes Area in Ontario, Canada, have displayed the potential for cage aquaculture to source numerous changes in freshwater ecosystems. Following the initiation of an experimental rainbow trout cage farm in a small boreal lake, dramatic reductions in mysis concentrations associated with a decrease in dissolved oxygen were observed. Significant increases in ammonium and total phosphorus, a driver for eutrophication in freshwater systems, were measured in the hypolimnion of the lake. Annual phosphorus inputs from aquaculture waste exceeded that of natural inputs from atmospheric deposition and inflows, and phytoplankton biomass has had a fourfold annual increase following the initiation of the experimental farm. |
Aquaculture | Genetic modification | Genetic modification
A type of salmon called the AquAdvantage salmon has been genetically modified for faster growth, although it has not been approved for commercial use, due to controversy.Mcleod C, J Grice, H Campbell and T Herleth (2006) Super Salmon: The Industrialisation of Fish Farming and the Drive Towards GM Technologies in Salmon Production CSaFe, Discussion paper 5, University of Otago. The altered salmon incorporates a growth hormone from a Chinook salmon that allows it to reach full size in 16–28 months, instead of the normal 36 months for Atlantic salmon, and while consuming 25 percent less feed.Robynne Boyd, Would you eat AquAdvantage salmon if approved? Scientific American online, 26 April 2013. The U.S. Food and Drug Administration reviewed the AquAdvantage salmon in a draft environmental assessment and determined that it "would not have a significant impact (FONSI) on the U.S. environment."FDA: AquAdvantage Salmon |
Aquaculture | Fish diseases, parasites and vaccines | Fish diseases, parasites and vaccines
A major difficulty for aquaculture is the tendency towards monoculture and the associated risk of widespread disease. Aquaculture is also associated with environmental risks; for instance, shrimp farming has caused the destruction of important mangrove forests throughout southeast Asia.
In the 1990s, disease wiped out China's farmed Farrer's scallop and white shrimp and required their replacement by other species."An Overview of China's Aquaculture", page 6. Netherlands Business Support Office (Dalian), 2010. |
Aquaculture | Needs of the aquaculture sector in vaccines | Needs of the aquaculture sector in vaccines
Aquaculture has an average annual growth rate of 9.2%, however, the success and continued expansion of the fish farming sector is highly dependent on the control of fish pathogens including a wide range of viruses, bacteria, fungi, and parasites. In 2014, it was estimated that these parasites cost the global salmon farming industry up to 400 million Euros. This represents 6–10% of the production value of the affected countries, but it can go up to 20% (Fisheries and Oceans Canada, 2014). Since pathogens quickly spread within a population of cultured fish, their control is vital for the sector.
Historically, the use of antibiotics was against bacterial epizootics but the production of animal proteins has to be sustainable, which means that preventive measures that are acceptable from a biological and environmental point of view should be used to keep disease problems in aquaculture at an acceptable level. So, this added to the efficiency of vaccines resulted in an immediate and permanent reduction in the use of antibiotics in the 90s. In the beginning, there were fish immersion vaccines efficient against the vibriosis but proved ineffective against the furunculosis, hence the arrival of injectable vaccines: first water-based and after oil-based, much more efficient (Sommerset, 2005). |
Aquaculture | Development of new vaccines | Development of new vaccines
It is the important mortality in cages among farmed fish, the debates around DNA injection vaccines, although effective, their safety and their side effects but also societal expectations for cleaner fish and security, lead research on new vaccine vectors. Several initiatives are financed by the European Union to develop a rapid and cost-effective approach to using bacteria in feed to make vaccines, in particular thanks to lactic bacteria whose DNA is modified (Boudinot, 2006). In fact, vaccinating farmed fish by injection is time-consuming and costly, so vaccines can be administered orally or by immersion by being added to feed or directly into water. This allows vaccinating many individuals at the same time while limiting the associated handling and stress.
Indeed, many tests are necessary because the antigens of the vaccines must be adapted to each species or not present a certain level of variability or they will not have any effect. For example, tests have been done with two species: Lepeophtheirus salmonis (from which the antigens were collected) and Caligus rogercresseyi (which was vaccinated with the antigens), although the homology between the two species is important, the level of variability made the protection ineffective (Fisheries and Oceans Canada, 2014). |
Aquaculture | Recent vaccines development in aquaculture | Recent vaccines development in aquaculture
There are 24 vaccines available and one for lobsters. The first vaccine was used in the USA against enteric red mouth in 1976. However, there are 19 companies and some small stakeholders are producing vaccines for aquaculture nowadays. The novel approaches are a way forward to prevent the loss of 10% of aquaculture through disease. Genetically modified vaccines are not being used in the EU due to societal concerns and regulations. Meanwhile, DNA vaccines are now authorised in the EU.
There are challenges in fish vaccine development, immune response due to lack of potent adjuvants. Scientists are considering microdose application in future. But there are also opportunities in aquaculture vaccinology due to the low cost of technology, regulations change and novel antigen expression and delivery systems.
In Norway subunit vaccine (VP2 peptide) against infectious pancreatic necrosis is being used. In Canada, a licensed DNA vaccine against Infectious hematopoietic necrosis has been launched for industry use.
Fish have large mucosal surfaces, so the preferred route is immersion, intraperitoneal and oral respectively. Nanoparticles are in progress for delivery purposes. The common antibodies produced are IgM and IgT. Normally booster is not required in fish because more memory cells are produced in response to the booster rather than an increased level of antibodies.
mRNA vaccines are alternative to DNA vaccines because they are more safe, stable, easily producible at a large scale and mass immunization potential. Recently these are used in cancer prevention and therapeutics. Studies in rabies has shown that efficacy depends on dose and route of administration. These are still in infancy. |
Aquaculture | Economic gains | Economic gains
In 2014, the aquaculture produced fish overtook wild caught fish, in supply for human food. This means there is a huge demand for vaccines, in prevention of diseases. The reported annual loss fish, calculates to >10 billion USD. This is from approximately 10% of all fishes dying from infectious diseases.
The high annual losses increases the demand for vaccines. Even though there are about 24 traditionally used vaccines, there is still demand for more vaccines. The breakthrough of DNA-vaccines has sunk the cost of vaccines.
The alternative to vaccines would be antibiotics and chemotherapy, which are more expensive and with bigger drawbacks. DNA-vaccines have become the most cost-efficient method of preventing infectious diseases. This bodes well for DNA-vaccines becoming the new standard both in fish vaccines, and in general vaccines. |
Aquaculture | Salinization/acidification of soils | Salinization/acidification of soils
Sediment from abandoned aquaculture farms can remain hypersaline, acidic and eroded. This material can remain unusable for aquaculture purposes for long periods thereafter. Various chemical treatments, such as adding lime, can aggravate the problem by modify the physicochemical characteristics of the sediment. |
Aquaculture | Plastic pollution | Plastic pollution
Aquaculture produces a range of marine debris, depending on the product and location. The most frequently documented type of plastic is expanded polystyrene (EPS), used extensively in floats and sea cage collars (MEPC 2020). Other common waste items include cage nets and plastic harvest bins. A review of aquaculture as a source of marine litter in the North, Baltic and Mediterranean Seas identified 64 different items, 19 of which were unique to aquaculture . Estimates of the amount of aquaculture waste entering the oceans vary widely, depending on the methodologies used. For example, in the European Economic Area loss estimates have varied from a low of 3,000 tonnes to 41,000 tonnes per year. |
Aquaculture | Ecological benefits | Ecological benefits
While some forms of aquaculture can be devastating to ecosystems, such as shrimp farming in mangroves, other forms can be beneficial. Shellfish aquaculture adds substantial filter feeding capacity to an environment which can significantly improve water quality. A single oyster can filter 15 gallons of water a day, removing microscopic algal cells. By removing these cells, shellfish are removing nitrogen and other nutrients from the system and either retaining it or releasing it as waste which sinks to the bottom. By harvesting these shellfish, the nitrogen they retained is completely removed from the system. Raising and harvesting kelp and other macroalgae directly remove nutrients such as nitrogen and phosphorus. Repackaging these nutrients can relieve eutrophic, or nutrient-rich, conditions known for their low dissolved oxygen which can decimate species diversity and abundance of marine life. Removing algal cells from the water also increases light penetration, allowing plants such as eelgrass to reestablish themselves and further increase oxygen levels.
Aquaculture in an area can provide for crucial ecological functions for the inhabitants. Shellfish beds or cages can provide habitat structure. This structure can be used as shelter by invertebrates, small fish or crustaceans to potentially increase their abundance and maintain biodiversity. Increased shelter raises stocks of prey fish and small crustaceans by increasing recruitment opportunities in turn providing more prey for higher trophic levels. One study estimated that 10 square meters of oyster reef could enhance an ecosystem's biomass by 2.57 kg Herbivore shellfish will also be preyed on. This moves energy directly from primary producers to higher trophic levels potentially skipping out on multiple energetically costly trophic jumps which would increase biomass in the ecosystem.
Seaweed farming is a carbon negative crop, with a high potential for climate change mitigation. The IPCC Special Report on the Ocean and Cryosphere in a Changing Climate recommends "further research attention" as a mitigation tactic. Regenerative ocean farming is a polyculture farming system that grows a mix of seaweeds and shellfish while sequestering carbon, decreasing nitrogen in the water and increasing oxygen, helping to regenerate and restore local habitat like reef ecosystems. |
Aquaculture | Prospects | Prospects
Global wild fisheries are in decline, with valuable habitat such as estuaries in critical condition.Tietenberg, Tom (2006) Environmental and Natural Resource Economics: A Contemporary Approach. Page 28. Pearson/Addison Wesley. The aquaculture or farming of piscivorous fish, like salmon, does not help the problem because they need to eat products from other fish, such as fish meal and fish oil. Studies have shown that salmon farming has major negative impacts on wild salmon, as well as the forage fish that need to be caught to feed them.Knapp G, Roheim CA and Anderson JL (2007) The Great Salmon Run: Competition Between Wild And Farmed Salmon World Wildlife Fund. Fish that are higher on the food chain are less efficient sources of food energy.
Apart from fish and shrimp, some aquaculture undertakings, such as seaweed and filter-feeding bivalve mollusks like oysters, clams, mussels and scallops, are relatively benign and even environmentally restorative. Filter-feeders filter pollutants as well as nutrients from the water, improving water quality. Seaweeds extract nutrients such as inorganic nitrogen and phosphorus directly from the water, and filter-feeding mollusks can extract nutrients as they feed on particulates, such as phytoplankton and detritus.
Some profitable aquaculture cooperatives promote sustainable practices. New methods lessen the risk of biological and chemical pollution through minimizing fish stress, fallowing netpens, and applying integrated pest management. Vaccines are being used more and more to reduce antibiotic use for disease control.
Onshore recirculating aquaculture systems, facilities using polyculture techniques, and properly sited facilities (for example, offshore areas with strong currents) are examples of ways to manage negative environmental effects.
Recirculating aquaculture systems (RAS) recycle water by circulating it through filters to remove fish waste and food and then recirculating it back into the tanks. This saves water and the waste gathered can be used in compost or, in some cases, could even be treated and used on land. While RAS was developed with freshwater fish in mind, scientists associated with the Agricultural Research Service have found a way to rear saltwater fish using RAS in low-salinity waters. Although saltwater fish are raised in off-shore cages or caught with nets in water that typically has a salinity of 35 parts per thousand (ppt), scientists were able to produce healthy pompano, a saltwater fish, in tanks with a salinity of only 5 ppt. Commercializing low-salinity RAS are predicted to have positive environmental and economical effects. Unwanted nutrients from the fish food would not be added to the ocean and the risk of transmitting diseases between wild and farm-raised fish would greatly be reduced. The price of expensive saltwater fish, such as the pompano and cobia used in the experiments, would be reduced. However, before any of this can be done researchers must study every aspect of the fish's lifecycle, including the amount of ammonia and nitrate the fish will tolerate in the water, what to feed the fish during each stage of its lifecycle, the stocking rate that will produce the healthiest fish, etc.
Some 16 countries now use geothermal energy for aquaculture, including China, Israel, and the United States. In California, for example, 15 fish farms produce tilapia, bass, and catfish with warm water from underground. This warmer water enables fish to grow all year round and mature more quickly. Collectively these California farms produce 4.5 million kilograms of fish each year. |
Aquaculture | Global goals | Global goals
The UN Sustainable Development Goal 14 ("life below water"), Target 14.7 includes aquaculture: "By 2030, increase the economic benefits to small island developing states and least developed countries from the sustainable use of marine resources, including through sustainable management of fisheries, aquaculture and tourism".United Nations (2017) Resolution adopted by the General Assembly on 6 July 2017, Work of the Statistical Commission pertaining to the 2030 Agenda for Sustainable Development (A/RES/71/313)Ritchie, Roser, Mispy, Ortiz-Ospina. "SDG 14 – Measuring progress towards the Sustainable Development Goals." SDG-Tracker.org, website (2018). Aquaculture's contribution to GDP is not included in SDG Target 14.7 but methods for quantifying this have been explored by FAO. |
Aquaculture | National laws, regulations, and management | National laws, regulations, and management
Laws governing aquaculture practices vary greatly by country and are often not closely regulated or easily traceable.
In the United States, land-based and nearshore aquaculture is regulated at the federal and state levels; however, no national laws govern offshore aquaculture in U.S. exclusive economic zone waters. In June 2011, the Department of Commerce and National Oceanic and Atmospheric Administration released national aquaculture policies to address this issue and "to meet the growing demand for healthy seafood, to create jobs in coastal communities, and restore vital ecosystems." Large aquaculture facilities (i.e. those producing per year) which discharge wastewater are required to obtain permits pursuant to the Clean Water Act. Facilities that produce at least of fish, molluscs or crustaceans a year are subject to specific national discharge standards. Other permitted facilities are subject to effluent limitations that are developed on a case-by-case basis. |
Aquaculture | By country | By country
Aquaculture by Country: |
Aquaculture | History | History
thumb|left|Workers harvest catfish from the Delta Pride Catfish farms in Mississippi|alt= Photo of dripping, cup-shaped net, approximately in diameter and equally tall, half-full of fish, suspended from crane boom, with four workers on and around larger, ring-shaped structure in water
The Gunditjmara, a local Aboriginal Australian people in south-western Victoria, Australia, may have raised short-finned eels as early as about 4,580 BCE. See also attached documents: National Heritage List Location and Boundary Map, and Government Gazette, 20 July 2004. Evidence indicates they developed about of volcanic floodplains in the vicinity of Lake Condah into a complex of channels and dams, and used woven traps to capture eels, and to preserve them to eat all year round.Aborigines may have farmed eels, built huts ABC Science News, 13 March 2003.Lake Condah Sustainability Project . Retrieved 18 February 2010. The local Budj Bim Cultural Landscape, a World Heritage Site, is one of the oldest known aquaculture sites in the world.
Oral tradition in China tells of the culture of the common carp, Cyprinus carpio, as long ago as 2000–2100 BCE (around 4,000 years BP), but the earliest significant evidence lies in the literature, in the earliest monograph on fish culture called The Classic of Fish Culture, by Fan Li, written around 475 BCE ( BP). Another ancient Chinese guide to aquaculture , wriiten by Yang Yu Jing around 460 BCE, shows that carp farming was becoming more sophisticated. The Jiahu site in China has circumstantial archeological evidence as possibly the oldest aquaculture locations, dating from 6200BCE (about 8,200 years BP), but this is speculative. When the waters subsided after river floods, some fish, mainly carp, were trapped in lakes. Early aquaculturists fed their brood using nymphs and silkworm faeces, and ate them.
Ancient Egyptians might have farmed fish (especially gilt-head bream) from Lake Bardawil about 1,500 BCE (about 3,500 BP), and they traded them with Canaan.
Gim cultivation is the oldest aquaculture in Korea. Early cultivation methods used bamboo or oak sticks; newer methods utilizing nets replaced them in the 19th century. Floating rafts have been used for mass production since the 1920s.
Japanese people cultivated seaweed by providing bamboo poles and, later, nets and oyster shells to serve as anchoring-surfaces for spores.
Romans bred fish in ponds and farmed oysters in coastal lagoons before 100 CE.
thumb|right|Fish pond of the La Cambre Abbey in Brussels, Belgium
In medieval Europe, early Christian monasteries adopted Roman aquacultural practices.Jhingran, V.G., Introduction to aquaculture. 1987, United Nations Development Programme, Food and Agriculture Organization of the United Nations, Nigerian Institute for Oceanography and Marine Research. Aquaculture spread because people away from coasts and big rivers were otherwise dependant on fish which required salting in order to be preserved. Fish was an important food source in medieval Europe, when in average 150 days per year were days of fasting and abstinence, and meat was prohibited. Improvements in transportation during the 19th century made fresh fish easily available and inexpensive, even in inland areas, rendering aquaculture less popular. The 15th-century fishponds of the Trebon Basin in the present-day Czech Republic are maintained as a tentative UNESCO World Heritage Site.
Samoans practised "a traditional form of giant clam ranching".
Hawaiians constructed oceanic fish ponds. A remarkable example is the "Menehune" fishpond dating from at least 1,000 years ago, at Alekoko. Legend records its construction by the mythical Menehune dwarf-people.
In the first half of the 18th century, German Stephan Ludwig Jacobi experimented with external fertilization of brown trout and salmon. He wrote an article "" (On the Artificial Production of Trout and Salmon) summarizing his findings, and earning him a reputation as the founder of artificial fish-rearing. By the latter decades of the 18th century, oyster-farming had begun in estuaries along the Atlantic Coast of North America.
The word "aquaculture" appeared in an 1855 newspaper article in reference to the harvesting of ice. It also appeared in descriptions of the terrestrial agricultural practise of sub-irrigation in the late-19th century before becoming associated primarily with the cultivation of aquatic plant- and animal-species. (The Oxford English Dictionary records the common modern usage of "aquaculture" from 1887;
and that of "aquiculture" from 1867.)
In 1859, Stephen Ainsworth of West Bloomfield, New York, began experiments with brook trout. By 1864, Seth Green had established a commercial fish-hatching operation at Caledonia Springs, near Rochester, New York. By 1866, with the involvement of W. W. Fletcher of Concord, Massachusetts, artificial fish-hatcheries operated both in both Canada and in the United States.Milner, James W. (1874). "The Progress of Fish-culture in the United States". United States Commission of Fish and Fisheries Report of the Commissioner for 1872 and 1873. 535 – 544 <http://penbay.org/cof/cof_1872_1873.html> When the Dildo Island fish hatchery opened in Newfoundland in 1889, it was the largest and most advanced in the world. The word "aquaculture" was used in descriptions of the hatcheries experiments with cod and lobster in 1890.
By the 1920s, the American Fish Culture Company of Carolina, Rhode Island, founded in the 1870s, was one of the leading producers of trout. During the 1940s, they perfected the method of manipulating the day- and night-cycle of fish so that they could be artificially spawned year-round.Rice, M.A. 2010. "A brief history of the American Fish Culture Company 1877–1997". Rhode Island History 68(1):20–35. web version
Californians harvested wild kelp and attempted to manage supply around 1900, later labeling it a wartime resource. |
Aquaculture | See also | See also
Agroecology
Alligator farm
Certification for Aquaculture Professionals
Fisheries science
Fishery
Industrial aquaculture
List of commercially important fish species
Maggots used as food for fish
Oyster farming
Recirculating aquaculture system
Resource decoupling |
Aquaculture | Sources | Sources |
Aquaculture | References | References |
Aquaculture | Sources | Sources
podcast
GESAMP (2008) Assessment and communication of environmental risks in coastal aquaculture FAO Reports and Studies No 76.
Hepburn, J. 2002. Taking Aquaculture Seriously. Organic Farming, Winter 2002 © Soil Association.
The Scottish Association for Marine Science and Napier University. 2002. Review and synthesis of the environmental impacts of aquaculture
Higginbotham James Piscinae: Artificial Fishponds in Roman Italy University of North Carolina Press (June 1997)
Wyban, Carol Araki (1992) Tide and Current: Fishponds of Hawai'I University of Hawaiʻi Press::
Timmons, M.B., Ebeling, J.M., Wheaton, F.W., Summerfelt, S.T., Vinci, B.J., 2002. Recirculating Aquaculture Systems: 2nd edition. Cayuga Aqua Ventures.
|
Aquaculture | Free content work | Free content work |
Aquaculture | Further reading | Further reading
Holmer, Marianne. Aquaculture in the Ecosystem. Dordrecht, Netherlands: Springer, 2008.
Molyneaux, Paul. Swimming in Circles: Aquaculture and the End of Wild Oceans. New York: Thunder's Mouth Press, 2006.
Stickney, Robert R. Aquaculture: An Introductory Text. Oxford, UK; Cambridge, MA: CABI Publishing, 2005.
World Bank. Changing the Face of the Waters: The Promise and Challenge of Sustainable Aquaculture. Washington, DC: World Bank, 2007. |
Aquaculture | External links | External links
Aquaculture topic page from Woods Hole Oceanographic Institution
The Coastal Resources Center
NOAA aquaculture
The University of Hawaiʻi's AquacultureHub
Category:Domesticated animals
Category:Buildings and structures used to confine animals
Category:Sustainable food system |
Aquaculture | Table of Content | Short description, Overview, Species groups, Aquatic plants, Seaweed farming, Fish, Crustaceans, Molluscs, Other groups, Global fish production, Over-reporting by China, Aquacultural methods, Mariculture, Integrated, Urban aquaculture, Netting materials, Technology, Issues, Impacts on wild fish, Animal welfare, Common welfare concerns, Improving welfare, Coastal ecosystems, Pollution from sea cage aquaculture, Freshwater ecosystems, Genetic modification, Fish diseases, parasites and vaccines, Needs of the aquaculture sector in vaccines, Development of new vaccines, Recent vaccines development in aquaculture, Economic gains, Salinization/acidification of soils, Plastic pollution, Ecological benefits, Prospects, Global goals, National laws, regulations, and management, By country, History, See also, Sources, References, Sources, Free content work, Further reading, External links |
Kolmogorov complexity | short description | right|thumb|upright=1.4|This image illustrates part of the Mandelbrot set fractal. Simply storing the 24-bit color of each pixel in this image would require 23 million bytes, but a small computer program can reproduce these 23 MB using the definition of the Mandelbrot set and the corner coordinates of the image. Thus, the Kolmogorov complexity of this image is much less than 23 MB in any pragmatic model of computation. PNG's general-purpose image compression only reduces it to 1.6 MB, smaller than the raw data but much larger than the Kolmogorov complexity.
In algorithmic information theory (a subfield of computer science and mathematics), the Kolmogorov complexity of an object, such as a piece of text, is the length of a shortest computer program (in a predetermined programming language) that produces the object as output. It is a measure of the computational resources needed to specify the object, and is also known as algorithmic complexity, Solomonoff–Kolmogorov–Chaitin complexity, program-size complexity, descriptive complexity, or algorithmic entropy. It is named after Andrey Kolmogorov, who first published on the subject in 1963 and is a generalization of classical information theory.
The notion of Kolmogorov complexity can be used to state and prove impossibility results akin to Cantor's diagonal argument, Gödel's incompleteness theorem, and Turing's halting problem.
In particular, no program P computing a lower bound for each text's Kolmogorov complexity can return a value essentially larger than P's own length (see section ); hence no single program can compute the exact Kolmogorov complexity for infinitely many texts. Kolmogorov complexity is the length of the ultimately compressed version of a file (i.e., anything which can be put in a computer). Formally, it is the length of a shortest program from which the file can be reconstructed. While Kolmogorov complexity is uncomputable, various approaches have been proposed and reviewed. |
Kolmogorov complexity | Definition | Definition |
Kolmogorov complexity | Intuition | Intuition
Consider the following two strings of 32 lowercase letters and digits:
abababababababababababababababab , and
4c1j5b2p0cv4w1x8rx2y39umgw5q85s7
The first string has a short English-language description, namely "write ab 16 times", which consists of 17 characters. The second one has no obvious simple description (using the same character set) other than writing down the string itself, i.e., "write 4c1j5b2p0cv4w1x8rx2y39umgw5q85s7" which has 38 characters. Hence the operation of writing the first string can be said to have "less complexity" than writing the second.
More formally, the complexity of a string is the length of the shortest possible description of the string in some fixed universal description language (the sensitivity of complexity relative to the choice of description language is discussed below). It can be shown that the Kolmogorov complexity of any string cannot be more than a few bytes larger than the length of the string itself. Strings like the abab example above, whose Kolmogorov complexity is small relative to the string's size, are not considered to be complex.
The Kolmogorov complexity can be defined for any mathematical object, but for simplicity the scope of this article is restricted to strings. We must first specify a description language for strings. Such a description language can be based on any computer programming language, such as Lisp, Pascal, or Java. If P is a program which outputs a string x, then P is a description of x. The length of the description is just the length of P as a character string, multiplied by the number of bits in a character (e.g., 7 for ASCII).
We could, alternatively, choose an encoding for Turing machines, where an encoding is a function which associates to each Turing Machine M a bitstring <M>. If M is a Turing Machine which, on input w, outputs string x, then the concatenated string <M> w is a description of x. For theoretical analysis, this approach is more suited for constructing detailed formal proofs and is generally preferred in the research literature. In this article, an informal approach is discussed.
Any string s has at least one description. For example, the second string above is output by the pseudo-code:
function GenerateString2()
return "4c1j5b2p0cv4w1x8rx2y39umgw5q85s7"
whereas the first string is output by the (much shorter) pseudo-code:
function GenerateString1()
return "ab" × 16
If a description d(s) of a string s is of minimal length (i.e., using the fewest bits), it is called a minimal description of s, and the length of d(s) (i.e. the number of bits in the minimal description) is the Kolmogorov complexity of s, written K(s). Symbolically,
K(s) = |d(s)|.
The length of the shortest description will depend on the choice of description language; but the effect of changing languages is bounded (a result called the invariance theorem). |
Kolmogorov complexity | Plain Kolmogorov complexity ''C'' | Plain Kolmogorov complexity C
There are two definitions of Kolmogorov complexity: plain and prefix-free. The plain complexity is the minimal description length of any program, and denoted while the prefix-free complexity is the minimal description length of any program encoded in a prefix-free code, and denoted . The plain complexity is more intuitive, but the prefix-free complexity is easier to study.
By default, all equations hold only up to an additive constant. For example, really means that , that is, .
Let be a computable function mapping finite binary strings to binary strings. It is a universal function if, and only if, for any computable , we can encode the function in a "program" , such that . We can think of as a program interpreter, which takes in an initial segment describing the program, followed by data that the program should process.
One problem with plain complexity is that , because intuitively speaking, there is no general way to tell where to divide an output string just by looking at the concatenated string. We can divide it by specifying the length of or , but that would take extra symbols. Indeed, for any there exists such that .(Downey and Hirschfeldt, 2010), Theorem 3.1.4
Typically, inequalities with plain complexity have a term like on one side, whereas the same inequalities with prefix-free complexity have only .
The main problem with plain complexity is that there is something extra sneaked into a program. A program not only represents for something with its code, but also represents its own length. In particular, a program may represent a binary number up to , simply by its own length. Stated in another way, it is as if we are using a termination symbol to denote where a word ends, and so we are not using 2 symbols, but 3. To fix this defect, we introduce the prefix-free Kolmogorov complexity.(Downey and Hirschfeldt, 2010), Section 3.5 |
Kolmogorov complexity | Prefix-free Kolmogorov complexity ''K'' | Prefix-free Kolmogorov complexity K
A prefix-free code is a subset of such that given any two different words in the set, neither is a prefix of the other. The benefit of a prefix-free code is that we can build a machine that reads words from the code forward in one direction, and as soon as it reads the last symbol of the word, it knows that the word is finished, and does not need to backtrack or a termination symbol.
Define a prefix-free Turing machine to be a Turing machine that comes with a prefix-free code, such that the Turing machine can read any string from the code in one direction, and stop reading as soon as it reads the last symbol. Afterwards, it may compute on a work tape and write to a write tape, but it cannot move its read-head anymore.
This gives us the following formal way to describe K.
Fix a prefix-free universal Turing machine, with three tapes: a read tape infinite in one direction, a work tape infinite in two directions, and a write tape infinite in one direction.
The machine can read from the read tape in one direction only (no backtracking), and write to the write tape in one direction only. It can read and write the work tape in both directions.
The work tape and write tape start with all zeros. The read tape starts with an input prefix code, followed by all zeros.
Let be the prefix-free code on , used by the universal Turing machine.
Note that some universal Turing machines may not be programmable with prefix codes. We must pick only a prefix-free universal Turing machine.
The prefix-free complexity of a string is the shortest prefix code that makes the machine output : |
Kolmogorov complexity | Invariance theorem | Invariance theorem |
Kolmogorov complexity | Informal treatment | Informal treatment
There are some description languages which are optimal, in the following sense: given any description of an object in a description language, said description may be used in the optimal description language with a constant overhead. The constant depends only on the languages involved, not on the description of the object, nor the object being described.
Here is an example of an optimal description language. A description will have two parts:
The first part describes another description language.
The second part is a description of the object in that language.
In more technical terms, the first part of a description is a computer program (specifically: a compiler for the object's language, written in the description language), with the second part being the input to that computer program which produces the object as output.
The invariance theorem follows: Given any description language L, the optimal description language is at least as efficient as L, with some constant overhead.
Proof: Any description D in L can be converted into a description in the optimal language by first describing L as a computer program P (part 1), and then using the original description D as input to that program (part 2). The
total length of this new description D′ is (approximately):
|D′ | = |P| + |D|
The length of P is a constant that doesn't depend on D. So, there is at most a constant overhead, regardless of the object described. Therefore, the optimal language is universal up to this additive constant. |
Kolmogorov complexity | A more formal treatment | A more formal treatment
Theorem: If K1 and K2 are the complexity functions relative to Turing complete description languages L1 and L2, then there is a constant c – which depends only on the languages L1 and L2 chosen – such that
∀s. −c ≤ K1(s) − K2(s) ≤ c.
Proof: By symmetry, it suffices to prove that there is some constant c such that for all strings s
K1(s) ≤ K2(s) + c.
Now, suppose there is a program in the language L1 which acts as an interpreter for L2:
function InterpretLanguage(string p)
where p is a program in L2. The interpreter is characterized by the following property:
Running InterpretLanguage on input p returns the result of running p.
Thus, if P is a program in L2 which is a minimal description of s, then InterpretLanguage(P) returns the string s. The length of this description of s is the sum of
The length of the program InterpretLanguage, which we can take to be the constant c.
The length of P which by definition is K2(s).
This proves the desired upper bound. |
Kolmogorov complexity | History and context | History and context
Algorithmic information theory is the area of computer science that studies Kolmogorov complexity and other complexity measures on strings (or other data structures).
The concept and theory of Kolmogorov Complexity is based on a crucial theorem first discovered by Ray Solomonoff, who published it in 1960, describing it in "A Preliminary Report on a General Theory of Inductive Inference" as part of his invention of algorithmic probability. He gave a more complete description in his 1964 publications, "A Formal Theory of Inductive Inference," Part 1 and Part 2 in Information and Control.
Andrey Kolmogorov later independently published this theorem in Problems Inform. Transmission in 1965. Gregory Chaitin also presents this theorem in J. ACM – Chaitin's paper was submitted October 1966 and revised in December 1968, and cites both Solomonoff's and Kolmogorov's papers.
The theorem says that, among algorithms that decode strings from their descriptions (codes), there exists an optimal one. This algorithm, for all strings, allows codes as short as allowed by any other algorithm up to an additive constant that depends on the algorithms, but not on the strings themselves. Solomonoff used this algorithm and the code lengths it allows to define a "universal probability" of a string on which inductive inference of the subsequent digits of the string can be based. Kolmogorov used this theorem to define several functions of strings, including complexity, randomness, and information.
When Kolmogorov became aware of Solomonoff's work, he acknowledged Solomonoff's priority. For several years, Solomonoff's work was better known in the Soviet Union than in the Western World. The general consensus in the scientific community, however, was to associate this type of complexity with Kolmogorov, who was concerned with randomness of a sequence, while Algorithmic Probability became associated with Solomonoff, who focused on prediction using his invention of the universal prior probability distribution. The broader area encompassing descriptional complexity and probability is often called Kolmogorov complexity. The computer scientist Ming Li considers this an example of the Matthew effect: "...to everyone who has, more will be given..."
There are several other variants of Kolmogorov complexity or algorithmic information. The most widely used one is based on self-delimiting programs, and is mainly due to Leonid Levin (1974).
An axiomatic approach to Kolmogorov complexity based on Blum axioms (Blum 1967) was introduced by Mark Burgin in the paper presented for publication by Andrey Kolmogorov.
In the late 1990s and early 2000s, methods developed to approximate Kolmogorov complexity relied on popular compression algorithms like LZW, which made difficult or impossible to provide any estimation to short strings until a method based on Algorithmic probability was introduced, offering the only alternative to compression-based methods.Zenil, Hector; Soler Toscano, Fernando; Gauvrit, Nicolas (2022). "Methods and Applications of Algorithmic Complexity: Beyond Statistical Lossless Compression". Emergence, Complexity and Computation. Springer Berlin, Heidelberg. doi:10.1007/978-3-662-64985-5. ISBN 978-3-662-64983-1. |
Kolmogorov complexity | Basic results | Basic results
We write to be , where means some fixed way to code for a tuple of strings x and y. |
Kolmogorov complexity | Inequalities | Inequalities
We omit additive factors of . This section is based on.
Theorem.
Proof. Take any program for the universal Turing machine used to define plain complexity, and convert it to a prefix-free program by first coding the length of the program in binary, then convert the length to prefix-free coding. For example, suppose the program has length 9, then we can convert it as follows:where we double each digit, then add a termination code. The prefix-free universal Turing machine can then read in any program for the other machine as follows:The first part programs the machine to simulate the other machine, and is a constant overhead . The second part has length . The third part has length .
Theorem: There exists such that . More succinctly, . Similarly, , and .
Proof. For the plain complexity, just write a program that simply copies the input to the output. For the prefix-free complexity, we need to first describe the length of the string, before writing out the string itself.
Theorem. (extra information bounds, subadditivity)
Note that there is no way to compare and or or or . There are strings such that the whole string is easy to describe, but its substrings are very hard to describe.
Theorem. (symmetry of information) .
Proof. One side is simple. For the other side with , we need to use a counting argument (page 38 ).
Theorem. (information non-increase) For any computable function , we have .
Proof. Program the Turing machine to read two subsequent programs, one describing the function and one describing the string. Then run both programs on the work tape to produce , and write it out. |
Kolmogorov complexity | Uncomputability of Kolmogorov complexity | Uncomputability of Kolmogorov complexity |
Kolmogorov complexity | A naive attempt at a program to compute ''K'' | A naive attempt at a program to compute K
At first glance it might seem trivial to write a program which can compute K(s) for any s, such as the following:
function KolmogorovComplexity(string s)
for i = 1 to infinity:
for each string p of length exactly i
if isValidProgram(p) and evaluate(p) == s
return i
This program iterates through all possible programs (by iterating through all possible strings and only considering those which are valid programs), starting with the shortest. Each program is executed to find the result produced by that program, comparing it to the input s. If the result matches then the length of the program is returned.
However this will not work because some of the programs p tested will not terminate, e.g. if they contain infinite loops. There is no way to avoid all of these programs by testing them in some way before executing them due to the non-computability of the halting problem.
What is more, no program at all can compute the function K, be it ever so sophisticated. This is proven in the following. |
Kolmogorov complexity | Formal proof of uncomputability of ''K'' | Formal proof of uncomputability of K
Theorem: There exist strings of arbitrarily large Kolmogorov complexity. Formally: for each natural number n, there is a string s with K(s) ≥ n.However, an s with K(s) = n need not exist for every n. For example, if n is not a multiple of 7, no ASCII program can have a length of exactly n bits.
Proof: Otherwise all of the infinitely many possible finite strings could be generated by the finitely manyThere are 1 + 2 + 22 + 23 + ... + 2n = 2n+1 − 1 different program texts of length up to n bits; cf. geometric series. If program lengths are to be multiples of 7 bits, even fewer program texts exist. programs with a complexity below n bits.
Theorem: K is not a computable function. In other words, there is no program which takes any string s as input and produces the integer K(s) as output.
The following proof by contradiction uses a simple Pascal-like language to denote programs; for sake of proof simplicity assume its description (i.e. an interpreter) to have a length of bits.
Assume for contradiction there is a program
function KolmogorovComplexity(string s)
which takes as input a string s and returns K(s). All programs are of finite length so, for sake of proof simplicity, assume it to be bits.
Now, consider the following program of length bits:
function GenerateComplexString()
for i = 1 to infinity:
for each string s of length exactly i
if KolmogorovComplexity(s) ≥ 8000000000
return s
Using KolmogorovComplexity as a subroutine, the program tries every string, starting with the shortest, until it returns a string with Kolmogorov complexity at least bits,By the previous theorem, such a string exists, hence the for loop will eventually terminate. i.e. a string that cannot be produced by any program shorter than bits. However, the overall length of the above program that produced s is only bits,including the language interpreter and the subroutine code for KolmogorovComplexity which is a contradiction. (If the code of KolmogorovComplexity is shorter, the contradiction remains. If it is longer, the constant used in GenerateComplexString can always be changed appropriately.)If KolmogorovComplexity has length n bits, the constant m used in GenerateComplexString needs to be adapted to satisfy , which is always possible since m grows faster than log10(m).
The above proof uses a contradiction similar to that of the Berry paradox: "The smallest positive integer that cannot be defined in fewer than twenty English words". It is also possible to show the non-computability of K by reduction from the non-computability of the halting problem H, since K and H are Turing-equivalent.Stated without proof in:
There is a corollary, humorously called the "full employment theorem" in the programming language community, stating that there is no perfect size-optimizing compiler. |
Kolmogorov complexity | Chain rule for Kolmogorov complexity | Chain rule for Kolmogorov complexity
The chain rule for Kolmogorov complexity states that there exists a constant c such that for all X and Y:
K(X,Y) = K(X) + K(Y|X) + c*max(1,log(K(X,Y))).
It states that the shortest program that reproduces X and Y is no more than a logarithmic term larger than a program to reproduce X and a program to reproduce Y given X. Using this statement, one can define an analogue of mutual information for Kolmogorov complexity. |
Kolmogorov complexity | Compression | Compression
It is straightforward to compute upper bounds for K(s) – simply compress the string s with some method, implement the corresponding decompressor in the chosen language, concatenate the decompressor to the compressed string, and measure the length of the resulting string – concretely, the size of a self-extracting archive in the given language.
A string s is compressible by a number c if it has a description whose length does not exceed |s| − c bits. This is equivalent to saying that . Otherwise, s is incompressible by c. A string incompressible by 1 is said to be simply incompressible – by the pigeonhole principle, which applies because every compressed string maps to only one uncompressed string, incompressible strings must exist, since there are 2n bit strings of length n, but only 2n − 1 shorter strings, that is, strings of length less than n, (i.e. with length 0, 1, ..., n − 1).As there are strings of length L, the number of strings of lengths is = , which is a finite geometric series with sum =
For the same reason, most strings are complex in the sense that they cannot be significantly compressed – their K(s) is not much smaller than |s|, the length of s in bits. To make this precise, fix a value of n. There are 2n bitstrings of length n. The uniform probability distribution on the space of these bitstrings assigns exactly equal weight 2−n to each string of length n.
Theorem: With the uniform probability distribution on the space of bitstrings of length n, the probability that a string is incompressible by c is at least .
To prove the theorem, note that the number of descriptions of length not exceeding n − c is given by the geometric series:
1 + 2 + 22 + ... + 2n − c = 2n−c+1 − 1.
There remain at least
2n − 2n−c+1 + 1
bitstrings of length n that are incompressible by c. To determine the probability, divide by 2n. |
Kolmogorov complexity | Chaitin's incompleteness theorem | Chaitin's incompleteness theorem
thumb|right|600px|Kolmogorov complexity , and two computable lower bound functions , . The horizontal axis (logarithmic scale) enumerates all strings s, ordered by length; the vertical axis (linear scale) measures Kolmogorov complexity in bits. Most strings are incompressible, i.e. their Kolmogorov complexity exceeds their length by a constant amount. 9 compressible strings are shown in the picture, appearing as almost vertical slopes. Due to Chaitin's incompleteness theorem (1974), the output of any program computing a lower bound of the Kolmogorov complexity cannot exceed some fixed limit, which is independent of the input string s.
By the above theorem (), most strings are complex in the sense that they cannot be described in any significantly "compressed" way. However, it turns out that the fact that a specific string is complex cannot be formally proven, if the complexity of the string is above a certain threshold. The precise formalization is as follows. First, fix a particular axiomatic system S for the natural numbers. The axiomatic system has to be powerful enough so that, to certain assertions A about complexity of strings, one can associate a formula FA in S. This association must have the following property:
If FA is provable from the axioms of S, then the corresponding assertion A must be true. This "formalization" can be achieved based on a Gödel numbering.
Theorem: There exists a constant L (which only depends on S and on the choice of description language) such that there does not exist a string s for which the statement
K(s) ≥ L (as formalized in S)
can be proven within S. Here: Thm.4.1b
Proof Idea: The proof of this result is modeled on a self-referential construction used in Berry's paradox. We firstly obtain a program which enumerates the proofs within S and we specify a procedure P which takes as an input an integer L and prints the strings x which are within proofs within S of the statement K(x) ≥ L. By then setting L to greater than the length of this procedure P, we have that the required length of a program to print x as stated in K(x) ≥ L as being at least L is then less than the amount L since the string x was printed by the procedure P. This is a contradiction. So it is not possible for the proof system S to prove K(x) ≥ L for L arbitrarily large, in particular, for L larger than the length of the procedure P, (which is finite).
Proof:
We can find an effective enumeration of all the formal proofs in S by some procedure
function NthProof(int n)
which takes as input n and outputs some proof. This function enumerates all proofs. Some of these are proofs for formulas we do not care about here, since every possible proof in the language of S is produced for some n. Some of these are complexity formulas of the form K(s) ≥ n where s and n are constants in the language of S. There is a procedure
function NthProofProvesComplexityFormula(int n)
which determines whether the nth proof actually proves a complexity formula K(s) ≥ L. The strings s, and the integer L in turn, are computable by procedure:
function StringNthProof(int n)
function ComplexityLowerBoundNthProof(int n)
Consider the following procedure:
function GenerateProvablyComplexString(int n)
for i = 1 to infinity:
if NthProofProvesComplexityFormula(i) and ComplexityLowerBoundNthProof(i) ≥ n
return StringNthProof(i)
Given an n, this procedure tries every proof until it finds a string and a proof in the formal system S of the formula K(s) ≥ L for some L ≥ n; if no such proof exists, it loops forever.
Finally, consider the program consisting of all these procedure definitions, and a main call:
GenerateProvablyComplexString(n0)
where the constant n0 will be determined later on. The overall program length can be expressed as U+log2(n0), where U is some constant and log2(n0) represents the length of the integer value n0, under the reasonable assumption that it is encoded in binary digits. We will choose n0 to be greater than the program length, that is, such that n0 > U+log2(n0). This is clearly true for n0 sufficiently large, because the left hand side grows linearly in n0 whilst the right hand side grows logarithmically in n0 up to the fixed constant U.
Then no proof of the form "K(s)≥L" with L≥n0 can be obtained in S, as can be seen by an indirect argument:
If ComplexityLowerBoundNthProof(i) could return a value ≥n0, then the loop inside GenerateProvablyComplexString would eventually terminate, and that procedure would return a string s such that
K(s) ≥ n0 by construction of GenerateProvablyComplexString > U+log2(n0) by the choice of n0 ≥ K(s) since s was described by the program with that length
This is a contradiction, Q.E.D.
As a consequence, the above program, with the chosen value of n0, must loop forever.
Similar ideas are used to prove the properties of Chaitin's constant. |
Kolmogorov complexity | Minimum message length | Minimum message length
The minimum message length principle of statistical and inductive inference and machine learning was developed by C.S. Wallace and D.M. Boulton in 1968. MML is Bayesian (i.e. it incorporates prior beliefs) and information-theoretic. It has the desirable properties of statistical invariance (i.e. the inference transforms with a re-parametrisation, such as from polar coordinates to Cartesian coordinates), statistical consistency (i.e. even for very hard problems, MML will converge to any underlying model) and efficiency (i.e. the MML model will converge to any true underlying model about as quickly as is possible). C.S. Wallace and D.L. Dowe (1999) showed a formal connection between MML and algorithmic information theory (or Kolmogorov complexity). |
Kolmogorov complexity | Kolmogorov randomness | Kolmogorov randomness
Kolmogorov randomness defines a string (usually of bits) as being random if and only if every computer program that can produce that string is at least as long as the string itself. To make this precise, a universal computer (or universal Turing machine) must be specified, so that "program" means a program for this universal machine. A random string in this sense is "incompressible" in that it is impossible to "compress" the string into a program that is shorter than the string itself. For every universal computer, there is at least one algorithmically random string of each length.There are 2n bit strings of length n but only 2n-1 shorter bit strings, hence at most that much compression results. Whether a particular string is random, however, depends on the specific universal computer that is chosen. This is because a universal computer can have a particular string hard-coded in itself, and a program running on this universal computer can then simply refer to this hard-coded string using a short sequence of bits (i.e. much shorter than the string itself).
This definition can be extended to define a notion of randomness for infinite sequences from a finite alphabet. These algorithmically random sequences can be defined in three equivalent ways. One way uses an effective analogue of measure theory; another uses effective martingales. The third way defines an infinite sequence to be random if the prefix-free Kolmogorov complexity of its initial segments grows quickly enough — there must be a constant c such that the complexity of an initial segment of length n is always at least n−c. This definition, unlike the definition of randomness for a finite string, is not affected by which universal machine is used to define prefix-free Kolmogorov complexity. |
Kolmogorov complexity | Relation to entropy | Relation to entropy
For dynamical systems, entropy rate and algorithmic complexity of the trajectories are related by a theorem of Brudno, that the equality holds for almost all .
It can be shown that for the output of Markov information sources, Kolmogorov complexity is related to the entropy of the information source. More precisely, the Kolmogorov complexity of the output of a Markov information source, normalized by the length of the output, converges almost surely (as the length of the output goes to infinity) to the entropy of the source.
Theorem. (Theorem 14.2.5 ) The conditional Kolmogorov complexity of a binary string satisfieswhere is the binary entropy function (not to be confused with the entropy rate). |
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