– 300,000 km2 Gulf of Carpentaria – 300,000 km2 Celebes Sea – 280,000 km2 Tyrrhenian Sea – 275,000 km2 Sulu Sea – 260,000 km2 Cooperation Sea – 258,000 km2 Persian Gulf – 251,000 km2 Flores Sea – 240,000 km2 Gulf of Saint Lawrence – 226,000 km2 Bay of Biscay – 223,000 km2 Aegean Sea – 214,000 km2 Gulf of Anadyr – 200,000 km2 Molucca Sea – 200,000 km2 Oman Sea – 181,000 km2 Ionian Sea – 169,000 km2 Gulf of California – 160,000 km2 Balearic Sea – 150,000 km2 Adriatic Sea – 138,000 km2 Marginal seas by ocean Seas may be considered marginal between ocean and land, or between oceans in which case they may be treated as marginal parts of either. There is no single ultimate authority on the matter. Arctic Ocean (clockwise from 180°) Chukchi Sea East Siberian Sea Laptev Sea Kara Sea Barents Sea (connected to the Kara Sea by the Kara Strait) Pechora Sea White Sea Queen Victoria Sea Wandel Sea Greenland Sea Lincoln Sea (recognized by the IHO but not the IMO) Baffin Bay The Northwest Passages Prince Gustav Adolf Sea Amundsen Gulf (more to be listed) Hudson Bay Foxe Basin Bowman Bay Wager Bay Roes Welcome Sound Foxe Channel Bay of Gods Mercy Hudson Strait Ungava Bay Native Bay Evans Strait Fisher Strait James Bay Beaufort Sea Atlantic Ocean In addition to the marginal seas listed in the three sub-sections below, the Arctic Ocean itself is sometimes also considered a marginal sea of the Atlantic. Africa and Eurasia Norwegian Sea North Sea Kattegat Skagerrak Wadden Sea Dogger Bank Baltic Sea Gulf of Bothnia Kvarken Bothnian Sea South Kvarken Sea of Åland Archipelago Sea Gulf of Finland Vyborg Bay Neva Bay Koporye Bay Luga Bay Narva Bay Väinameri Sea Gulf of Riga Curonian Lagoon Vistula Lagoon Gdańsk Bay Bay of Pomerania Szczecin Lagoon Bay of Greifswald Rügischer Bodden Strelasund Bay of Lübeck Bay of Kiel Kalmar Strait Bight of Hanö Danish straits Oresund Strait Fehmarn Belt Great Belt Little Belt English Channel Strait of Dover Irish Sea Celtic Sea Iroise Sea Bay of Biscay Cantabrian Sea Gulf of Cádiz Mediterranean Sea Alboran Sea Mar Menor Balearic (Catalan) Sea Gulf of Valencia Gulf of Lion Étang de Thau Ligurian Sea Gulf of Genoa Tyrrhenian Sea Gulf of Naples Gulf of Salerno Gulf of Cagliari Adriatic Sea Bay of Kotor Gulf of Venice Gulf of Trieste Venetian