earlier studies – despite calling both estimates "conservative" as coastal areas are known to contain much more microplastic pollution. These estimates are about one to two times the amount of plastic thought – per Jambeck et al., 2015 – to currently enter the oceans annually. Exploitation In art and culture Some children's play songs include elements such as "There's a hole at the bottom of the sea", or "A sailor went to sea... but all that he could see was the bottom of the deep blue sea". On and under the seabed are archaeological sites of historic interest, such as shipwrecks and sunken towns. This underwater cultural heritage is protected by the UNESCO Convention on the Protection of the Underwater Cultural Heritage. The convention aims at preventing looting and the destruction or loss of historic and cultural information by providing an international legal framework. See also References Further reading Roger Hekinian: Sea Floor Exploration: Scientific Adventures Diving into the Abyss. Springer, 2014. (print); (eBook) Stéphane Sainson: Electromagnetic Seabed Logging. A new tool for geoscientists. Springer, 2016. (print); (eBook) External links Understanding the Seafloor presentation from Cosee – the Center for Ocean Sciences Educational Excellence. Ocean Explorer (www.oceanexplorer.noaa.gov) – Public outreach site for explorations sponsored by the Office of Ocean Exploration. NOAA, Ocean Explorer Gallery, Submarine Ring of Fire 2006 Gallery, Submarine Ring of Fire 2004 Gallery – A rich collection of images, video, audio and podcast. NOAA, Ocean Explorer YouTube Channel Submarine Ring of Fire, Mariana Arc – Explore the volcanoes of the Mariana Arc, Submarine Ring of Fire. Age of the Ocean Floor National Geophysical Data Center Astonishing deep sea life on TED (conference) Oceanography Fisheries science Articles containing video clips