The World's Enclosed Coastal Seas

The Environmental Management of Enclosed Coastal Seas Protecting Our Coastal Seas for Future Generations

In many parts of the world there are bodies of sea water that are almost entirely enclosed by land. These bodies of water are called enclosed coastal seas. Examples include the Mediterranean Sea, the Baltic Sea, Chesapeake Bay, the Gulf of Thailand, the Bo Hai in northern China and, in Japan, the Seto Inland Sea, Tokyo Bay and Ise Bay. Since ancient times, enclosed coastal seas have been known for their great scenic beauty. Their outstanding natural attributes have spurred the development of transportation networks and many types of industry in the ocean and coastal regions, and they have been the setting for cultural and recreational activities throughout the ages. But man’s activities have exceeded the natural ability of the seas to cleanse themselves, giving rise to problems of pollution in the world’s enclosed coastal seas such as eutrophication, “red tides” and “blue tides”. We must work to preserve these priceless natural treasures if we are to pass them onto future generations.

Major Enclosed Coastal Seas of the World

Chesapeake Bay（11,603km²，6.4m）
San Francisco Bay（1,040km²，6m）
Gulf of Mexico（1,592,800km²，1,486m）
Mediterranean Sea（2,536,000km²,>5,150m）
North Sea（575,200km²，94m）
Baltic Sea（422,200km²，55m）
Persian Sea（233,000km²，35m）
Gulf of Thailand（320,000km²，45m）
Bohai Sea（77,284km²，26m）
Seto Inland Sea（23,203km²，38m）
Black Sea（508,000km²，1,240m）
Puget Sound（2,600km²,>300m）
Hudson Bay（1,232,300km²，128m）
Gulf of California（153,000km²，1,200m）
Caribbean Sea（2,718,200km²，2,647m）
Red Sea（438,000km²，491m）
Bay of Bengal（2,173,000km²,2,600m）
South China Sea（2,319,000km²，1,652m）
Yellow Sea（466,200km²，40m）
East China Sea（735,800km²，175m）
Sea of Japan（978,000km²，1,752m）
Gulf of Carpentaria(370,000km²，60m)

※area, average depth, > maximum depth

Environmental Guidebook on the Enclosed Coastal Seas of the World（9MB/PDF）

Enclosed Coastal Seas in the World.pdf

No	Sea area	Dimensions	Main Environmental Problems	Environmental Protection Measures	Related Organizations and NGOs	1.Area Guide 2.Current Status and New Directions
1	Chesapeake Bay	Surface Area 11,603km² Volume 68.1km³ Average Depth 6.4m	29 % were met the water quality standards (DO, transparency, Chl-a, underwater grasses) Overabundance of N & P from air, land and water Sedimentation into sea floor Toxic chemicals (pesticides, pharmaceuticals, PCBs)	EO 13508 for Chesapeake Bay Protection and Restoration Total Maximum Daily Load (TMDL)	Chesapeake Bay Program Chesapeake　Bay Foundation Maryland Department of National Resources Virginia Department of Environmental Quality NOAA Chesapeake Bay Office USGS Chesapeake Bay Features	1.Area Guide 2. Robert M. Summers, 2018.
2	San Francisco Bay	Surface Area 1,040km² Volume 7km³ Average Depth 6m	Water quality of Bay has improved Bottom sediment (70% were toxic to aquatic organisms) PCBs, methyl mercury and dioxin are highly detected in fish Decrease and regeneration of Habitats Decline of biological resources	San Francisco Estuary Project(SFEP)	San Francisco Bay　Conservation and Development Commission San Francisco Estuary Partnership Friends of the San Francisco Estuary San Francisco Estuary Institute Save the Bay	1.Area Guide
3	Gulf of Mexico	Surface Area 1,592,800km² Volume 2,366,901km³ Average Depth 1,486m	Loss of coastal wetland Fish contaminants Sediment quality Oil spills	Federal Fishery Management Council (stop overfishing, reduce bycatch, protect deep water coral reefs)	US EPA Gulf of Mexico Program Centro de Ecologia, Pesquerias y Oceanografia del Golfo Mexico (EPOMEX) Centro de Investigaciones Marinas (CIM)	1.Area Guide
4	Mediterranean Sea	Surface Area 2,536,000km² Volume 3,750,000km³ Average Depth -	Eutrophication, heavy metals pollution, organic pollution, microbial pollution (coastal areas) POPs Marine litter Marine noise	Barcelona Convention (22 countries surrounding Mediterranean Sea) Mediteranean Strategy for Sustainable Development (MSSD)	MEDCOAST MEDASSET UNEP Mediterranean Action Plan	1.Area Guide
5	North Sea	Surface Area 575,200km² Volume 54,069km³ Average Depth 94m	Eutrophication Contamination by trace organic compounds Marine litter Impacts of climate change Damage to shallow sediment habitats	Convention for the Protection of the Marine Environment of the North-EastAtlantic (OSPAR Convention)	Bonn Agreement The North Sea Commission European Environment Agency (EEA) International Council for the Exploration of the Sea (ICES) Risk assessment for marine pollution in the Greater North Sea and its wider approaches	1.Area Guide 2. Jean-Paul Ductoroy, 2018.
6	Baltic Sea	Surface Area 422,200km² Volume 23,221km³ Average Depth 55m	Eutrophication Pollution by hazardous substances Oil pollution Threat to biodiversity	Convention on the Protection of the Marine Environment of the Baltic Sea Area (Helsinki Convention)	Helsinki Commission (HELCOM) International Council for the Exploration of the Sea (ICES) Coalition Clean Baltic (CCB) Baltic Sea Research Institute Warnemunde	1.Area Guide
7	Persian Gulf	Surface Area 233,000km² Volume 8,155km³ Average Depth 35m	Oil pollution Land-based pollution Destruction of habitats	Kuwait Convention and Action Plan Regional Organization for the Protection of the Marine Environment (ROPME)	Regional Organization for the Protection of the Marine Environment (ROPME9) the Marine Emergency Mutual Aid Centre (MEMAC) UN Division for Ocean Affairs Commission on Sustainable Development (CSD) Economic and Social Commission for Western Asia (ESCWA) Global Programme of Action (GPA) Regional Office for West Asia (ROWA) United Nations Industrial Development Organization (UNIDO) United Nations Development Programme (UNDP) International Maritime Organization (IMO) etc.	1.Area Guide
8	Gulf of Thailand	Surface Area 320,000km² Volume 14,400km³ Average Depth 45m	Water quality of Main river Chao Praya; deteriorated Tha Chin; deteriorated Mae Klong; fair Bangpakong; fair Pollution in the Gulf (mercury) Sediment quality (heavy metals) Degradation and decline of habitats Reduction of coral reefs	Project "Reversing Environmental Degradation Trends in the South China Sea and Gulf of Thailand"	Partnership in Environmental Management for the seas of East Asia (PEMSEA) CORE sea Mangroves for the Future Bird Conservation Society of Thailand (BCST)	1.Area Guide 2. Menasveta, P.,Chavanich, S., Jarupongskul, T., 2019.
9	Bohai Sea	Surface Area 77,284km² Volume 2,009km³ Average Depth 26m	Nearshore areas (pollution of organic matters, active phosphate, petroleum hydrocarbon, inorganic nitrogen and heavy metals) Red tides Oil spills Coastal erosion	Blue Sea Action Plan for the Bohai Sea		1.Area Guide 2. Yanfang Li, 2019.
10	Seto Inland Sea	Surface Area 23,203km² Volume 881.5km³ Average Depth 38m	Water quality (COD, TP and TN pollution from land has been greatly reduced) Red tides (200-300 in 1975, 100 in recent year) Reduction of neritic region	Water Pollution Control Law (Control of Total Maximum Daily Load, Environmental Standards of Nitrogen and Phosphorus) Seto Inland Sea Environmental Protection Temporary Measure Law	Seto Inland Sea Environmental Conservation Governor, Mayor Meeting Health Organizations Federation the Association for the Environmental Conservation of Seto inland Sea	1.Area Guide 2.Osamu Matuda, 2017.
11	Black Sea	Surface Area 508,000km² Volume 629,920km³ Average Depth 1,240m	Invasive species Land reclamation Change wettland to agricultural polder	Environmental Protection Measure by the Black Sea Economic Cooperation (BSEC) Natura 2000 programme	Black Sea NGO Network Agreement for the Conservation of the Black Sea, Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS) Mediterranean Coastal Foundation (MEDCOAST)	1.Area Guide 2.Ruben Kosyan, 2019.
12	Puget Sound	Surface Area 2,600km² Volume 169km³ Average Depth -	Low dissolved oxygen High fecal coliform bacteria contamination Eutrophication Chemical contamination (PCBs, DDT) Sediment (arsenic, copper, mercury, lead and zinc) Shoreline modification	Puget Sound Water Quality Management Plan Puget Sound/Georgia Basin International Task Force	Puget Sound Partnership The Association of National Estuary Programs (ANEP) People for Puget Sound	1.Area Guide
13	Hudson Bay	Surface Area 1,232,300km² Volume 157,734km³ Average Depth 128m	Ecosystem pollution (organochlorine; DDT, PCBs radionuclides; Cs-137) Climate change	Canadian Ocean Act Nunavut Wildlife Management Board (NWMB) the Committee on the Status of Endangered Wildlife in Canada (COSEWIC)	Canadian Arctic Resource Committee	1.Area Guide
14	Gulf of California	Surface Area 153,000km² Volume 183,600km³ Average Depth 1,200m	Fish reproduction (high salinity) Pesticide input from agricultural area Species in danger of economic extinction	Greater local control over marine resources more law enforcement in the government USA provides finantial assistance for the environmental protection of the Gulf To develop public educational materials	Sea of Cortez International Preservation Foundation	1.Area Guide
15	Caribbean Sea	Surface Area 2,718,200km² Volume 7,195,075km³ Average Depth 2,647m	Water pollution (sewage, eutrophication) Degradation of seagrass and coral reefs POPs Solid waste Offshore oil and gas exploitation are sources of pollution Habitat destruction due to coastal development	Cartagena Convention (Cooperation in Combating Oil Spill, Special Protected Areas and Wildlife (SPAW), Pollution from Land-based Source sand Activities (LBS)) Caribbian Action Plan Caribbean Environment Programme (CEP) Assessment and Management of Environmet Pollution (AMEP)	Caribbean Environment Programme (CEP) Caribbean Regional Fund for Wastewater Management Caribbean Natural Resource Institute (CANARI) UNEP Global Programme of Action for the Protection of the Marine Environment from Land-based Activities	1.Area Guide
16	Red Sea	Surface Area 438,000km² Volume 215,058km³ Average Depth 491m	Pollution comes from land-based activities Oil exploitation Destraction of habitat Over exploitation of marine resources	Jeddah Convention (Regional Convention for the Conservation of the Environment of the Red Sea and Gulf of Aden Environment) A Strategic Action Plan (SAP)	Regional Organization for the Conservation of the Environment of the Red Sea and Gulf of Aden (PERSGA) Friends of the Earth Middle East (FoEME)	1.Area Guide
17	Bay of Bengal	Surface Area 2,173,000km² Volume 5,649,800km³ Average Depth 2,600m	Pollution in the Bay is localized (eutrophication, POPs) 1,800 ton/year of pesticides enter the Bay Oil pollution (offshore oil and gas exploration) Seabed mining	Bay of Bengal Program (BOBP)	Bangladesh, India, Myanmar, Sri Lanka, Thailand Economic Cooperation (BIMST-EC) South Asia Association for Regional Co-operation (SAARC) United Nations Economic and Social Commission for Asia and Pacific (ESCAP) South Asia Co-operative Environment Programme (SACEP) Indian Ocean Marine Affairs Co-operation (IOMA) Indian Ocean Tuna Commission (IOTC) Indian Ocean Rim Association (IORA) Asia-Pacific Fishery Commission (APFIC) Network of Aquaculture Centres in Asia -Pacific (NACA)	1.Area Guide
18	South China Sea	Surface Area 2,319,000km² Volume 3,830,988km³ Average Depth 1,652m	Water pollution (sewage, BOD, eutrophication) Trans Boundary Issues associated with Regional Food Security Threats to coral reefs			1.Area Guide
19	Yellow Sea	Surface Area 466,200km² Volume 18,648km³ Average Depth 40m	Water Quality (general good) Sediment Quality (High organic concentration) Over exploitation of fishery resources Harmuful Algal Blooms (HAB)	Strict controls on fishing efforts Transboundary cooperation (NOWPAP, TRADP, APEC, GEF/UNDP/IMO)	Northwest Pacific Action Plan (NOWPAP) UNDP/GEF Yellow Sea LME Project Korean Institute of Ocean Science & Technology (KIOST) World Wildlife Fund (WWF) China	1.Area Guide
20	East China Sea	Surface Area 735,800km² Volume 128,765km³ Average Depth 175m	Urbanization and industrialization accerated environmental pollution and water quality deterioration Sediment quality (not serious polluted)		Environmental Protection Law of the People's Republic of China	1.Area Guide 2.Zhongyuan Chen, 2019.
21	Sea of Japan	Surface Area 978,000km² Volume 1,713,456km³ Average Depth 1,752m	Red Tides Influence of global warming Marine litter Radioactive pollution Oil spill	Ongoing environmental protection measure Northwest Pacific Action Plan (NOWPAP) Coastal Marine litter Survey	Northwest Pacific Regional Environmental Cooperation (NPEC) the Economic Research Institute for Northeast Asia (ERINA) Japan Seaology Promotion Organization Ocean Energy of Japan Sea Governments The Association of North East Asia Regional Governments (NEAR) Association for Northeast Asia Regional Studies	1.Area Guide
22	Gulf of Carpentaria	Surface Area 370,000km² Volume 22,200km³ Average Depth 60m	Marine debris Rising sea temperature by climate change		Anindilyakwa Land Council Carpentaria Land Council Aboriginal Corporation Cape York Land Council Torres Strait Regional Authority Northern Territory Government Queensland Government Australian Fisheries Management Authority Arafura Timor Sea Ecosystem Action Programme	1. Ruth Patterson, 2019. New! 2. Improving certainty in marine ecosystems: A biophysical modelling approach in the remote, data-limited Gulf of Carpentaria