Marine pollution#Plastic debris

{{Pollution sidebar|Water}}

{{See also|Water pollution}}There are many ways to categorize and examine the inputs of pollution into marine ecosystems. There are three main types of inputs of pollution into the ocean: direct discharge of waste into the oceans, runoff into the waters due to rain, and pollutants released from the atmosphere.{{Cite web |url=http://www.offshore-environment.com/anthropogenicimpact.html |title=Anthropogenic impact in the sea and marine pollution |last=Patin, S.A. |website=offshore-environment.com |access-date=1 February 2018}}

One common path of entry by contaminants to the sea are rivers. The evaporation of water from oceans exceeds precipitation. The balance is restored by rain over the continents entering rivers and then being returned to the sea. The Hudson River in New York State and the Raritan River in New Jersey, which empty at the northern and southern ends of Staten Island, are a source of mercury contamination of zooplankton (copepods) in the open ocean. The highest concentration in the filter-feeding copepods is not at the mouths of these rivers but {{convert|70|mi|km}} south, nearer Atlantic City, because water flows close to the coast. It takes a few days before toxins are taken up by the plankton. Ohio River and Tennessee River both join Mississippi River ultimately drains organic contaminants from several northern states into the Gulf of Mexico.{{cite journal | url=https://doi.org/10.1016/j.marpolbul.2024.116833 | doi=10.1016/j.marpolbul.2024.116833 | title=Assessment of toxicity potential of freely dissolved PAHs using passive sampler in Kentucky Lake and Ohio River | date=2024 | last1=Kim | first1=Na Yeong | last2=Loganathan | first2=Bommanna G. | last3=Kim | first3=Gi Beum | journal=Marine Pollution Bulletin | volume=207 | pmid=39159572 | bibcode=2024MarPB.20716833K }}

Pollution is often classed as point source or nonpoint source pollution. Point source pollution occurs when there is a single, identifiable, localized source of the pollution. An example is directly discharging sewage and industrial waste into the ocean. Pollution such as this occurs particularly in developing nations.{{citation needed|date=August 2021}} Nonpoint source pollution occurs when the pollution is from ill-defined and diffuse sources. These can be difficult to regulate. Agricultural runoff and wind blown debris are prime examples.

File:Rio tinto river CarolStoker NASA Ames Research Center.jpg in the Rio Tinto River]]

{{See also|Sewerage|Industrial waste|Environmental impact of mining}}

Pollutants enter rivers and the sea directly from urban sewerage and industrial waste discharges, sometimes in the form of hazardous and toxic wastes, or in the form of plastics.{{citation needed|date=April 2023}}

In a study published by Science, Jambeck et al. (2015) estimated that the 10 largest emitters of oceanic plastic pollution worldwide are, from the most to the least, China, Indonesia, Philippines, Vietnam, Sri Lanka, Thailand, Egypt, Malaysia, Nigeria, and Bangladesh.{{cite journal |last1=Jambeck |first1=J. R. |last2=Geyer |first2=R. |last3=Wilcox |first3=C. |last4=Siegler |first4=T. R. |last5=Perryman |first5=M. |last6=Andrady |first6=A. |last7=Narayan |first7=R. |last8=Law |first8=K. L. |title=Plastic waste inputs from land into the ocean |journal=Science |date=12 February 2015 |volume=347 |issue=6223 |pages=768–771 |doi=10.1126/science.1260352 |pmid=25678662 |bibcode=2015Sci...347..768J |s2cid=206562155 }}

Inland mining for copper, gold, etc., is another source of marine pollution. Most of the pollution is simply soil, which ends up in rivers flowing to the sea. However, some minerals discharged in the course of the mining can cause problems, such as copper, a common industrial pollutant, which can interfere with the life history and development of coral polyps.{{cite web |last=Young |first=Emma |title=Copper decimates coral reef spawning |url=https://www.newscientist.com/article/dn4391-copper-decimates-coral-reef-spawning |date=2003-11-18 |publisher=New Scientist |location=London}} Mining has a poor environmental track record. For example, according to the United States Environmental Protection Agency, mining has contaminated portions of the headwaters of over 40% of watersheds in the western continental US.{{cite web |title=Liquid Assets 2000: Americans Pay for Dirty Water |url=http://www.epa.gov/water/liquidassets/dirtywater.html |access-date=23 January 2007 |archive-url=https://web.archive.org/web/20080515191140/http://www.epa.gov/water/liquidassets/dirtywater.html |archive-date=15 May 2008 |publisher=U.S. Environmental Protection Agency (EPA)}} Much of this pollution ends up in the sea.{{citation needed|date=April 2023}}

{{Main|Surface runoff}}

{{See also|Urban runoff|Stormwater|Nutrient pollution}}

Surface runoff from farming, as well as urban runoff and runoff from the construction of roads, buildings, ports, channels, and harbours, can carry soil and particles laden with carbon, nitrogen, phosphorus, and minerals. This nutrient-rich water can cause fleshy algae and phytoplankton to thrive in coastal areas; known as algal blooms, which have the potential to create hypoxic conditions by using all available oxygen. In the coast of southwest Florida, harmful algal blooms have existed for over 100 years.{{Cite book |jstor=j.ctt5hj4c2.10 |date=2009|publisher=Rutgers University Press|isbn=978-0-8135-4548-6|editor-last=Weis|editor-first=Judith S.|series=A Natural and Unnatural History|pages=117–149|editor-last2=Butler|editor-first2=Carol A.|last1=Weis|first1=Judith S.|last2=Butler|first2=Carol A.|title=Salt Marshes|chapter=Pollution}} These algal blooms have been a cause of species of fish, turtles, dolphins, and shrimp to die and cause harmful effects on humans who swim in the water.

Polluted runoff from roads and highways can be a significant source of water pollution in coastal areas. About 75% of the toxic chemicals that flow into Puget Sound are carried by stormwater that runs off paved roads and driveways, rooftops, yards and other developed land.{{cite web|publisher=Washington State Department of Ecology |title=Control of Toxic Chemicals in Puget Sound, Phase 2: Development of Simple Numerical Models |date=2008|url=http://www.ecy.wa.gov/Programs/wq/pstoxics/index.html |archive-url=https://web.archive.org/web/20170302010119/http://www.ecy.wa.gov/programs/wq/pstoxics/index.html|archive-date=2 March 2017}} In California, there are many rainstorms that runoff into the ocean. These rainstorms occur from October to March, and these runoff waters contain petroleum, heavy metals, pollutants from emissions, etc.{{cite journal |last1=Holt |first1=Benjamin |last2=Trinh |first2=Rebecca |last3=Gierach |first3=Michelle M. |title=Stormwater runoff plumes in the Southern California Bight: A comparison study with SAR and MODIS imagery |journal=Marine Pollution Bulletin |date=May 2017 |volume=118 |issue=1–2 |pages=141–154 |doi=10.1016/j.marpolbul.2017.02.040 |pmid=28238485 |bibcode=2017MarPB.118..141H }}

In China, there is a large coastal population that pollutes the ocean through land runoff. This includes sewage discharge and pollution from urbanization and land use. In 2001, more than 66,795 mi² of the Chinese coastal ocean waters were rated less than Class I of the Sea Water Quality Standard of China.{{Cite journal|last1=Daoji|first1=Li|last2=Daler|first2=Dag|date=2004|title=Ocean Pollution from Land-Based Sources: East China Sea, China|jstor=4315461|journal=Ambio|volume=33|issue=1/2|pages=107–113|doi=10.1579/0044-7447-33.1.107|pmid=15083656 |bibcode=2004Ambio..33..107D |s2cid=12289116}} Much of this pollution came from Ag, Cu, Cd, Pb, As, DDT, PCBs, etc., which occurred from contamination through land runoff.

{{Main|Environmental impact of shipping}}

{{See also|Ballast water discharge and the environment}}

File:Ship pumping ballast water.jpg

Ships can pollute waterways and oceans in many ways including through their ballast, bilge, and fuel tanks. Oil spills can have devastating effects. In addition to being toxic to marine life, polycyclic aromatic hydrocarbons (PAHs), found in crude oil, are very difficult to clean up, and last for years in the sediment and marine environment.{{Cite book |author=Panetta, L.E. (Chair) |year=2003 |title=America's living oceans: charting a course for sea change |url=https://nauticalcharts.noaa.gov/hsrp/admin/nov2004/oceans_report.pdf |publisher=Pew Oceans Commission |page=64}}{{Cite journal |last1=Van Landuyt |first1=Josefien |last2=Kundu |first2=Kankana |last3=Van Haelst |first3=Sven |last4=Neyts |first4=Marijke |last5=Parmentier |first5=Koen |last6=De Rijcke |first6=Maarten |last7=Boon |first7=Nico |date=2022-10-18 |title=80 years later: Marine sediments still influenced by an old war ship |journal=Frontiers in Marine Science |volume=9 |page=1017136 |doi=10.3389/fmars.2022.1017136 |issn=2296-7745|doi-access=free |bibcode=2022FrMaS...917136V |hdl=1854/LU-01GKS4PJA2JJ06GXN0FQHFMB4D |hdl-access=free }} Additionally, bilge pollution can be toxic to the surrounding environment when bilge water is released from a ship's bilge.{{Cite web |title=Bilge dumping: Illegal pollution you've never heard of – DW – 04/28/2022 |url=https://www.dw.com/en/bilge-dumping-how-cargo-carriers-cut-corners-and-contaminate-the-oceans/audio-61622516 |access-date=2023-03-29 |website=dw.com |language=en}}

Oil spills are one of the most emotive of marine pollution events. However, while a tanker wreck may result in extensive newspaper headlines, much of the oil in the world's seas comes from other smaller sources, such as tankers discharging ballast water from oil tanks used on return ships, leaking pipelines or engine oil disposed of down sewers.{{cite book |author=Farmer, Andrew |year=1997 |title=Managing Environmental Pollution |publisher=Psychology Press |isbn=978-0-415-14515-2 }}{{page needed|date=January 2018}}

Discharge of cargo residues from bulk carriers can pollute ports, waterways, and oceans. In many instances vessels intentionally discharge illegal wastes despite foreign and domestic regulation prohibiting such actions. An absence of national standards provides an incentive for some cruise liners to dump waste in places where the penalties are inadequate.{{cite journal |last1=Schulkin |first1=Andrew |title=Safe harbors: Crafting an international solution to cruise ship pollution |journal=Georgetown International Environmental Law Review |url=https://www.proquest.com/openview/408bf9d53e951415fbc9bbef80bfce9c/1 |volume=15 |issue=1 |year=2002 |pages=105–132 }} It has been estimated that container ships lose over 10,000 containers at sea each year (usually during storms).{{cite web |url=http://news.nationalgeographic.com/news/2001/06/0619_seacargo.html |archive-url=https://web.archive.org/web/20010703073644/http://news.nationalgeographic.com/news/2001/06/0619_seacargo.html |archive-date=3 July 2001 |title=Lost Sea Cargo: Beach Bounty or Junk? |access-date=8 April 2008 |date=19 June 2001 |author=Podsadam, Janice |publisher=National Geographic News}} Ships also create noise pollution that disturbs natural wildlife, and water from ballast tanks can spread harmful algae and other invasive species.Meinesz, A. (2003) [https://www.pbs.org/wgbh/nova/algae/impact.html Deep Sea Invasion: The Impact of Invasive Species] PBS: NOVA. Retrieved 26 November 2009

Ballast water taken up at sea and released in port is a major source of unwanted exotic marine life. The invasive freshwater zebra mussels, native to the Black, Caspian, and Azov seas, were probably transported to the Great Lakes via ballast water from a transoceanic vessel.[http://www.wsg.washington.edu/mas/pdfs/leastwanted.pdf Aquatic invasive species. A Guide to Least-Wanted Aquatic Organisms of the Pacific Northwest] {{webarchive|url=https://web.archive.org/web/20080725040002/http://www.wsg.washington.edu/mas/pdfs/leastwanted.pdf |date=25 July 2008}}. 2001. University of Washington Meinesz believes that one of the worst cases of a single invasive species causing harm to an ecosystem can be attributed to a seemingly harmless jellyfish. Mnemiopsis leidyi, a species of comb jellyfish that spread so it now inhabits estuaries in many parts of the world, was first introduced in 1982, and thought to have been transported to the Black Sea in a ship's ballast water. The population of the jellyfish grew exponentially and, by 1988, it was wreaking havoc upon the local fishing industry. "The anchovy catch fell from 204,000 tons in 1984 to 200 tons in 1993; sprat from 24,600 tons in 1984 to 12,000 tons in 1993; horse mackerel from 4,000 tons in 1984 to zero in 1993." Now that the jellyfish have exhausted the zooplankton, including fish larvae, their numbers have fallen dramatically, yet they continue to maintain a stranglehold on the ecosystem.

Invasive species can take over once occupied areas, facilitate the spread of new diseases, introduce new genetic material, alter underwater seascapes, and jeopardize the ability of native species to obtain food. Invasive species are responsible for about $138 billion annually in lost revenue and management costs in the US alone.{{cite journal |last1=Pimentel |first1=David |last2=Zuniga |first2=Rodolfo |last3=Morrison |first3=Doug |title=Update on the environmental and economic costs associated with alien-invasive species in the United States |journal=Ecological Economics |date=February 2005 |volume=52 |issue=3 |pages=273–288 |doi=10.1016/j.ecolecon.2004.10.002 |bibcode=2005EcoEc..52..273P }}

File:Barbadosdustgraph.gif and Florida.[http://coastal.er.usgs.gov/african_dust/barbados.html Coral Mortality and African Dust: Barbados Dust Record: 1965–1996] {{webarchive|url=https://web.archive.org/web/20090806184410/http://coastal.er.usgs.gov/african_dust/barbados.html |date=6 August 2009 }} US Geological Survey. Retrieved 10 December 2009]]

Another pathway of pollution occurs through the atmosphere. The ocean has long been affected by the passage of chemicals from the atmosphere (e.g. nutrient source; pH influence).{{Cite web |date=2015-11-12 |title=The Impacts of Atmospheric Deposition to the Ocean on Marine Ecosystems and Climate |url=https://public-old.wmo.int/en/bulletin/impacts-atmospheric-deposition-ocean-marine-ecosystems-and-climate |archive-url=https://web.archive.org/web/20231218175210/https://public-old.wmo.int/en/bulletin/impacts-atmospheric-deposition-ocean-marine-ecosystems-and-climate |archive-date=18 December 2023 |access-date=2022-08-11 |website=public.wmo.int |language=en}} Wind-blown dust and debris, including plastic bags, are blown seaward from landfills and other areas. Dust from the Sahara moving around the southern periphery of the subtropical ridge moves into the Caribbean and Florida during the warm season as the ridge builds and moves northward through the subtropical Atlantic. Dust can also be attributed to a global transport from the Gobi and Taklamakan deserts across Korea, Japan, and the Northern Pacific to the Hawaiian Islands.{{cite journal |last1=Duce |first1=RA |last2=Unni |first2=CK |last3=Ray |first3=BJ |last4=Prospero |first4=JM |last5=Merrill |first5=JT |title=Long-Range Atmospheric Transport of Soil Dust from Asia to the Tropical North Pacific: Temporal Variability |journal=Science |date=26 September 1980 |volume=209 |issue=4464 |pages=1522–1524 |doi=10.1126/science.209.4464.1522 |pmid=17745962 |s2cid=30337924 |bibcode=1980Sci...209.1522D |s2cid-access=free }}

Since 1970, dust outbreaks have worsened due to periods of drought in Africa. There is a large variability in dust transport to the Caribbean and Florida from year to year;Usinfo.state.gov. [http://www.gcrio.org/OnLnDoc/pdf/african_dust.pdf Study Says African Dust Affects Climate in U.S., Caribbean.] {{webarchive|url=https://web.archive.org/web/20070620013708/http://www.gcrio.org/OnLnDoc/pdf/african_dust.pdf |date=20 June 2007}}. Retrieved 10 June 2007 however, the flux is greater during positive phases of the North Atlantic Oscillation.{{cite journal |doi= 10.1038/320735a0 |title= Impact of the North African drought and El Niño on mineral dust in the Barbados trade winds |journal= Nature |volume= 320 |issue= 6064 |pages= 735–738 |year= 1986 |last1= Prospero |first1= J. M. |last2= Nees |first2= R. T. |bibcode= 1986Natur.320..735P|s2cid= 33094175 }} The USGS links dust events to a decline in the health of coral reefs across the Caribbean and Florida, primarily since the 1970s.U. S. Geological Survey. [http://coastal.er.usgs.gov/african_dust/ Coral Mortality and African Dust.] {{Webarchive|url=https://web.archive.org/web/20120502091350/http://coastal.er.usgs.gov/african_dust/ |date=2 May 2012 }}. Retrieved 10 June 2007

Climate change is raising ocean temperatures[http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter5.pdf Observations: Oceanic Climate Change and Sea Level] {{Webarchive|url=https://web.archive.org/web/20170513164252/http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter5.pdf |date=13 May 2017 }} In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. (15MB) and raising levels of carbon dioxide in the atmosphere. These rising levels of carbon dioxide are acidifying the oceans.Doney, S. C. (2006) "[http://www.precaution.org/lib/06/ocean_acidification_from_c02_060301.pdf The Dangers of Ocean Acidification]" Scientific American, March 2006 This, in turn, is altering aquatic ecosystems and modifying fish distributions,Cheung, W.W.L., et al. (2009) "[http://www.seaaroundus.org/ClimateChange/images/Pew%20OSS%20Final%20climate%20change%20and%20fisheries.pdf Redistribution of Fish Catch by Climate Change. A Summary of a New Scientific Analysis] {{webarchive|url=https://web.archive.org/web/20110726113553/http://www.seaaroundus.org/ClimateChange/images/Pew%20OSS%20Final%20climate%20change%20and%20fisheries.pdf |date=26 July 2011}}" Pew Ocean Science Series with impacts on the sustainability of fisheries and the livelihoods of the communities that depend on them. Healthy ocean ecosystems are also important for the mitigation of climate change.[http://www.climatefish.org/index_en.htm PACFA] {{webarchive|url=https://web.archive.org/web/20091215221120/http://www.climatefish.org/index_en.htm |date=15 December 2009 }} (2009) [http://www.fao.org/climatechange/17789-1-0.pdf Fisheries and Aquaculture in a Changing Climate]

{{excerpt|Deep sea mining#Environmental impacts|paragraphs=1|file=no}}Some of the potential toxic metals include copper, zinc, cadmium, lead as well as rare earth elements such as lanthanum and yttrium.{{Cite journal |last1=Hauton |first1=Chris |last2=Brown |first2=Alastair |last3=Thatje |first3=Sven |last4=Mestre |first4=Nélia C. |last5=Bebianno |first5=Maria J. |last6=Martins |first6=Inês |last7=Bettencourt |first7=Raul |last8=Canals |first8=Miquel |last9=Sanchez-Vidal |first9=Anna |last10=Shillito |first10=Bruce |last11=Ravaux |first11=Juliette |date=2017-11-16 |title=Identifying Toxic Impacts of Metals Potentially Released during Deep-Sea Mining—A Synthesis of the Challenges to Quantifying Risk |journal=Frontiers in Marine Science |volume=4 |page=368 |doi=10.3389/fmars.2017.00368 |issn=2296-7745|doi-access=free |bibcode=2017FrMaS...4..368H |hdl=2445/138040 |hdl-access=free }} Following the release of toxins there is an increase of noise, light, sediment le dan plumes and elements that have the potential to impact the ecosystems.{{Cite journal |last1=Lopes |first1=Carina L. |last2=Bastos |first2=Luísa |last3=Caetano |first3=Miguel |last4=Martins |first4=Irene |last5=Santos |first5=Miguel M. |last6=Iglesias |first6=Isabel |date=2019-02-10 |title=Development of physical modelling tools in support of risk scenarios: A new framework focused on deep-sea mining |url=https://www.sciencedirect.com/science/article/pii/S004896971833852X |journal=Science of the Total Environment |language=en |volume=650 |issue=Pt 2 |pages=2294–2306 |doi=10.1016/j.scitotenv.2018.09.351 |pmid=30292122 |bibcode=2019ScTEn.650.2294L |s2cid=52945921 |issn=0048-9697}}

Deep sea minerals (DSM) can be extremely beneficial, it can cause wealth, raising living standards as well as economic opportunities for both current and future generations.{{Cite journal |last1=Ovesen |first1=Vidar |last2=Hackett |first2=Ron |last3=Burns |first3=Lee |last4=Mullins |first4=Peter |last5=Roger |first5=Scott |date=2018-09-01 |title=Managing deep sea mining revenues for the public good – ensuring transparency and distribution equity |url=https://www.sciencedirect.com/science/article/pii/S0308597X17301264 |journal=Marine Policy |language=en |volume=95 |pages=332–336 |doi=10.1016/j.marpol.2017.02.010 |bibcode=2018MarPo..95..332O |s2cid=111380724 |issn=0308-597X}} In addition, if the wealth is poorly managed it can have the potential to cause great economic and social damage. The instability of price and production levels of minerals can cause an external economic shock leading to a significant backlash on the domestic economy.

File:Caribbean Jetsam.jpg

{{excerpt|Marine debris|paragraphs=1-2|file=no}}

File:Polluted Beach.jpg

File:The breakdown of a plastic bottle into smaller fragments, eventually ending up as micro- and nano-plastics.png]]

{{excerpt|Marine plastic pollution|paragraphs=1-3|file=no}}

{{excerpt|Ocean acidification|paragraphs=1-3|file=no}}

File:Maldives - Kurumba Island.jpg in the Maldives. Coral reefs are dying around the world.[https://www.theguardian.com/environment/interactive/2009/sep/02/coral-world-interactive Coral reefs around the world] The Guardian, 2 September 2009]]

{{Main|Eutrophication}}

{{See also|Nutrient pollution}}

File:Aguas del lago de Maracaibo contaminadas por Lemna 03.JPG

File:Scheme eutrophication-en.svg]]

Eutrophication is an increase in chemical nutrients, typically compounds containing nitrogen or phosphorus, in an ecosystem. It can result in an increase in the ecosystem's primary productivity (excessive plant growth and decay), and further effects including lack of oxygen and severe reductions in water quality, fish, and other animal populations. Nutrient pollution, a form of water pollution, refers to contamination by excessive inputs of nutrients. It is a primary cause of eutrophication of surface waters, in which excess nutrients, usually nitrates or phosphates, stimulate algae growth. Such blooms are naturally occurring but may be increasing as a result of anthropogenic inputs or alternatively may be something that is now more closely monitored and so more frequently reported.{{Cite journal|last1=Hallegraeff|first1=Gustaaf M.|last2=Anderson|first2=Donald M.|last3=Belin|first3=Catherine|last4=Bottein|first4=Marie-Yasmine Dechraoui|last5=Bresnan|first5=Eileen|last6=Chinain|first6=Mireille|last7=Enevoldsen|first7=Henrik|last8=Iwataki|first8=Mitsunori|last9=Karlson|first9=Bengt|last10=McKenzie|first10=Cynthia H.|last11=Sunesen|first11=Inés|date=2021|title=Perceived global increase in algal blooms is attributable to intensified monitoring and emerging bloom impacts|journal=Communications Earth & Environment|language=en|volume=2|issue=1|page=117|doi=10.1038/s43247-021-00178-8|pmid=37359131 |pmc=10289804 |bibcode=2021ComEE...2..117H|issn=2662-4435|s2cid=235364600|doi-access=free}}

The biggest culprit are rivers that empty into the ocean, and with it the many chemicals used as fertilizers in agriculture as well as waste from livestock and humans. An excess of oxygen-depleting chemicals in the water can lead to hypoxia and the creation of a dead zone.Gerlach, S. A. (1975) Marine Pollution, Springer, Berlin

Estuaries tend to be naturally eutrophic because land-derived nutrients are concentrated where runoff enters the marine environment in a confined channel. The World Resources Institute has identified 375 hypoxic coastal zones around the world, concentrated in coastal areas in Western Europe, the Eastern and Southern coasts of the US, and East Asia, particularly in Japan.

Selman, Mindy (2007) Eutrophication: An Overview of Status, Trends, Policies, and Strategies. World Resources Institute In the ocean, there are frequent red tide algae blooms{{cite web

|url=http://www.tulane.edu/~bfleury/envirobio/enviroweb/DeadZone.htm

|title=The Gulf of Mexico Dead Zone and Red Tides

|access-date=27 December 2006

}} that kill fish and marine mammals and cause respiratory problems in humans and some domestic animals when the blooms reach close to shore.

In addition to land runoff, atmospheric anthropogenic fixed nitrogen can enter the open ocean. A study in 2008 found that this could account for around one third of the ocean's external (non-recycled) nitrogen supply and up to three per cent of the annual new marine biological production.{{cite journal |last1=Duce |first1=R. A. |last2=LaRoche |first2=J. |last3=Altieri |first3=K. |last4=Arrigo |first4=K. R. |last5=Baker |first5=A. R. |last6=Capone |first6=D. G. |last7=Cornell |first7=S. |last8=Dentener |first8=F. |last9=Galloway |first9=J. |last10=Ganeshram |first10=R. S. |last11=Geider |first11=R. J. |last12=Jickells |first12=T. |last13=Kuypers |first13=M. M. |last14=Langlois |first14=R. |last15=Liss |first15=P. S. |last16=Liu |first16=S. M. |last17=Middelburg |first17=J. J. |last18=Moore |first18=C. M. |last19=Nickovic |first19=S. |last20=Oschlies |first20=A. |last21=Pedersen |first21=T. |last22=Prospero |first22=J. |last23=Schlitzer |first23=R. |last24=Seitzinger |first24=S. |last25=Sorensen |first25=L. L. |last26=Uematsu |first26=M. |last27=Ulloa |first27=O. |last28=Voss |first28=M. |last29=Ward |first29=B. |last30=Zamora |first30=L. |title=Impacts of Atmospheric Anthropogenic Nitrogen on the Open Ocean |journal=Science |date=16 May 2008 |volume=320 |issue=5878 |pages=893–897 |doi=10.1126/science.1150369 |pmid=18487184 |s2cid=11204131 |bibcode=2008Sci...320..893D |s2cid-access=free |hdl=21.11116/0000-0001-CD7A-0 |hdl-access=free }} It has been suggested that accumulating reactive nitrogen in the environment may have consequences as serious as putting carbon dioxide in the atmosphere.[http://www.eurekalert.org/pub_releases/2008-05/uov-at051208.php Addressing the nitrogen cascade] Eureka Alert, 2008

One proposed solution to eutrophication in estuaries is to restore shellfish populations, such as oysters. Oyster reefs remove nitrogen from the water column and filter out suspended solids, subsequently reducing the likelihood or extent of harmful algal blooms or anoxic conditions.{{cite web |last1=Kroeger |first1=Timm |date=May 2012 |title=Dollars and Sense: Economic Benefits and Impacts from two Oyster Reef Restoration Projects in the Northern Gulf of Mexico |url=https://www.conservationgateway.org/Files/Pages/dollars-and-sense-economi.aspx |website=The Nature Conservancy }} Filter feeding activity is considered beneficial to water qualityBurkholder, JoAnn M. and Shumway, Sandra E. (2011). "Bivalve shellfish aquaculture and eutrophication". In: Shellfish Aquaculture and the Environment. Ed. Sandra E. Shumway. John Wiley & Sons by controlling phytoplankton density and sequestering nutrients, which can be removed from the system through shellfish harvest, buried in the sediments, or lost through denitrification.{{cite journal |last1=Kaspar |first1=H. F. |last2=Gillespie |first2=P. A. |last3=Boyer |first3=I. C. |last4=MacKenzie |first4=A. L. |title=Effects of mussel aquaculture on the nitrogen cycle and benthic communities in Kenepuru Sound, Marlborough Sounds, New Zealand |journal=Marine Biology |date=1985 |volume=85 |issue=2 |pages=127–136 |doi=10.1007/BF00397431 |bibcode=1985MarBi..85..127K |s2cid=83551118 }}{{cite journal |last1=Newell |first1=Roger I. E. |last2=Cornwell |first2=Jeffrey C. |last3=Owens |first3=Michael S. |title=Influence of simulated bivalve biodeposition and microphytobenthos on sediment nitrogen dynamics: A laboratory study |journal=Limnology and Oceanography |date=September 2002 |volume=47 |issue=5 |pages=1367–1379 |doi=10.4319/lo.2002.47.5.1367 |s2cid=6589732 |bibcode=2002LimOc..47.1367N |doi-access=free }} Foundational work toward the idea of improving marine water quality through shellfish cultivation to was conducted by Odd Lindahl et al., using mussels in Sweden.{{cite journal |last1=Lindahl |first1=Odd |last2=Hart |first2=Rob |last3=Hernroth |first3=Bodil |last4=Kollberg |first4=Sven |last5=Loo |first5=Lars-Ove |last6=Olrog |first6=Lars |last7=Rehnstam-Holm |first7=Ann-Sofi |last8=Svensson |first8=Jonny |last9=Svensson |first9=Susanne |last10=Syversen |first10=Ulf |title=Improving Marine Water Quality by Mussel Farming: A Profitable Solution for Swedish Society |journal=Ambio: A Journal of the Human Environment |date=March 2005 |volume=34 |issue=2 |pages=131–138 |doi=10.1579/0044-7447-34.2.131 |pmid=15865310 |bibcode=2005Ambio..34..131L |citeseerx= 10.1.1.589.3995 |s2cid=25371433 }}

{{See also|Mercury in fish}}

Apart from plastics, there are particular problems with other toxic pollutants that either do not break down or only very slowly in the marine environment. Examples of persistent toxicants are PCBs, DDT, TBT, pesticides, furans, dioxins, phenols, radioactive waste, and PFAS. Heavy metals are metallic chemical elements that have a relatively high density and are toxic or poisonous at low concentrations. Examples are mercury, lead, copper and cadmium. Some toxicants can accumulate in the tissues of many species of aquatic life in a process called bioaccumulation. They are also known to accumulate in benthic environments, such as estuaries and bay muds: a geological record of human activities of the last century.

DDT is a very toxic chemical that was used as a pesticide in mass quantities{{Cite web |date=July 1975 |title=DDT Regulatory History: A Brief Survey (to 1975) |url=https://www.epa.gov/archive/epa/aboutepa/ddt-regulatory-history-brief-survey-1975.html#:~:text=During%20the%2030%20years%20prior,pounds%20in%20the%20early%201970s. |access-date=2023-11-10 |website=United States Environmental Protection Agency}} throughout the United States and is known to be neurotoxic, a reproductive toxin, an endocrine disruptor, and a carcinogen.{{Cite journal |last1=Harada |first1=Takanori |last2=Takeda |first2=Makio |last3=Kojima |first3=Sayuri |last4=Tomiyama |first4=Naruto |date=2016-01-31 |title=Toxicity and Carcinogenicity of Dichlorodiphenyltrichloroethane (DDT) |journal=Toxicological Research |language=en |volume=32 |issue=1 |pages=21–33 |doi=10.5487/TR.2016.32.1.021 |issn=1976-8257 |pmc=4780236 |pmid=26977256|bibcode=2016ToxRe..32...21H }} DDT is a major focus of the book Silent Spring published by Rachel Carson in 1962. This is often attributed to launching the modern environmental movement{{Cite web |title=Legacy of Rachel Carsons Silent Spring National Historic Chemical Landmark |url=https://www.acs.org/education/whatischemistry/landmarks/rachel-carson-silent-spring.html |access-date=2023-11-10 |website=American Chemical Society |language=en}} and setting the stage for the creation of the EPA in 1970.{{Cite web |date=2022-04-22 |title=How Rachel Carson's 'Silent Spring' Awakened the World to Environmental Peril |url=https://www.history.com/news/rachel-carson-silent-spring-impact-environmental-movement |access-date=2023-11-10 |website=HISTORY |language=en}} DDT was banned in the U.S. two years later in 1972.{{Cite web |date=2021-09-02 |title=Dichlorodiphenyltrichloroethane (DDT) Factsheet {{!}} National Biomonitoring Program {{!}} CDC |url=https://www.cdc.gov/biomonitoring/DDT_FactSheet.html |access-date=2023-11-10 |website=www.cdc.gov |language=en-us}} Unfortunately, large quantities had already entered the ocean through runoff and had been dumped directly into the ocean.{{Cite web |date=2022-09-26 |title=Chemical Dumpsite Offshore Southern California |url=https://scripps.ucsd.edu/ddtcoastaldumpsite |access-date=2023-11-10 |website=scripps.ucsd.edu |language=en}} This toxin impacts marine ecosystems by accumulating from lower trophic levels{{Cite journal |last1=Wang |first1=Xinhong |last2=Wang |first2=Wen-Xiong |date=2005-08-01 |title=Uptake, absorption efficiency and elimination of DDT in marine phytoplankton, copepods and fish |url=https://www.sciencedirect.com/science/article/pii/S0269749105000655 |journal=Environmental Pollution |volume=136 |issue=3 |pages=453–464 |doi=10.1016/j.envpol.2005.01.004 |pmid=15862399 |bibcode=2005EPoll.136..453W |issn=0269-7491}} and up the food chain into higher trophic levels such as from arctic cod into seals,{{Cite journal |last1=Muir |first1=Derek C. G. |last2=Norstrom |first2=Ross J. |last3=Simon |first3=Mary. |date=September 1988 |title=Organochlorine contaminants in arctic marine food chains: accumulation of specific polychlorinated biphenyls and chlordane-related compounds |url=https://pubs.acs.org/doi/abs/10.1021/es00174a012 |journal=Environmental Science & Technology |language=en |volume=22 |issue=9 |pages=1071–1079 |doi=10.1021/es00174a012 |pmid=22148662 |bibcode=1988EnST...22.1071M |issn=0013-936X}} from fish then eaten by dolphins,{{Cite journal |title=Distribution and Total Burdens of Chlorinated Hydrocarbons in Bodies of Striped Dolphins (Stenella coeruleoalba) |journal=Agricultural and Biological Chemistry |volume=45 |issue=11 |date=1 November 1981 |pages=2569–2578 |doi=10.1271/bbb1961.45.2569 |last1=Tanabe |first1=Shinsuke |last2=Tatsukawa |first2=Ryo |last3=Tanaka |first3=Hiroyuki |last4=Maruyama |first4=Kohji |last5=Miyazaki |first5=Nobuyuki |last6=Fujiyama |first6=Toraya |doi-access=free }}{{Cite journal |last1=Tanabe |first1=Shinsuke |last2=Tanaka |first2=Hiroyuki |last3=Tatsukawa |first3=Ryo |date=1984-11-01 |title=Polychlorobiphenyls, ΣDDT, and hexachlorocyclohexane isomers in the western North Pacific ecosystem |journal=Archives of Environmental Contamination and Toxicology |language=en |volume=13 |issue=6 |pages=731–738 |doi=10.1007/BF01055937 |bibcode=1984ArECT..13..731T |s2cid=85012745 |issn=1432-0703}} and from cod and eels into seals.{{Cite journal |last1=Ruus |first1=A |last2=Ugland |first2=K. I |last3=Espeland |first3=O |last4=Skaare |first4=J. U |date=1999-08-01 |title=Organochlorine contaminants in a local marine food chain from Jarfjord, Northern Norway |url=https://www.sciencedirect.com/science/article/pii/S0141113699000379 |journal=Marine Environmental Research |volume=48 |issue=2 |pages=131–146 |doi=10.1016/S0141-1136(99)00037-9 |bibcode=1999MarER..48..131R |issn=0141-1136}}

Shortly after Rachel Carson's publication of Silent Spring, PCBs were identified as another persistent, toxic chemical that has been released in extensive quantities to the environment. PCBs are a very well-studied class of chemicals that are manufactured from oil.{{Cite journal |last1=Montano |first1=Luigi |last2=Pironti |first2=Concetta |last3=Pinto |first3=Gabriella |last4=Ricciardi |first4=Maria |last5=Buono |first5=Amalia |last6=Brogna |first6=Carlo |last7=Venier |first7=Marta |last8=Piscopo |first8=Marina |last9=Amoresano |first9=Angela |last10=Motta |first10=Oriana |date=2022-07-01 |title=Polychlorinated Biphenyls (PCBs) in the Environment: Occupational and Exposure Events, Effects on Human Health and Fertility |journal=Toxics |language=en |volume=10 |issue=7 |page=365 |doi=10.3390/toxics10070365 |issn=2305-6304 |pmc=9323099 |pmid=35878270 |doi-access=free |bibcode=2022Toxic..10..365M }} These chemicals are banned in the United States under the Toxic Substance Control Act,{{Cite web |date=August 8, 2023 |title=Toxic Substances Control Act (TSCA) and Federal Facilities |url=https://www.epa.gov/enforcement/toxic-substances-control-act-tsca-and-federal-facilities#:~:text=Six%20chemical%20substances%20receive%20special,to%20promulgate%20PCB%20disposal%20regulations. |access-date=2023-11-10 |website=United States Environmental Protection Agency}} but are still found in the soil, air, sediments, and biota. PCBs are known to accumulate in the fatty tissues of animals. In particular, PCBs build up and are stored in the blubber of marine mammals including dolphins and killer whales.{{Cite journal |last1=Jepson |first1=Paul D. |last2=Deaville |first2=Rob |last3=Barber |first3=Jonathan L. |last4=Aguilar |first4=Àlex |last5=Borrell |first5=Asunción |last6=Murphy |first6=Sinéad |last7=Barry |first7=Jon |last8=Brownlow |first8=Andrew |last9=Barnett |first9=James |last10=Berrow |first10=Simon |last11=Cunningham |first11=Andrew A. |last12=Davison |first12=Nicholas J. |last13=ten Doeschate |first13=Mariel |last14=Esteban |first14=Ruth |last15=Ferreira |first15=Marisa |date=2016-01-14 |title=PCB pollution continues to impact populations of orcas and other dolphins in European waters |journal=Scientific Reports |language=en |volume=6 |issue=1 |page=18573 |doi=10.1038/srep18573 |issn=2045-2322 |pmc=4725908 |pmid=26766430|bibcode=2016NatSR...618573J }} These chemicals cause reproductive issues for many species. In mud crabs, PCBs have been discovered to be immunotoxic by reducing resistance to bacterial disease, reducing antioxidant enzyme activity, and damaging DNA responsible for immune system functions.{{Cite journal |last1=Xiao |first1=Chongyang |last2=Zhang |first2=Yunfei |last3=Zhu |first3=Fei |date=2021-12-15 |title=Immunotoxicity of polychlorinated biphenyls (PCBs) to the marine crustacean species, Scylla paramamosain |url=https://www.sciencedirect.com/science/article/pii/S026974912101811X |journal=Environmental Pollution |volume=291 |page=118229 |doi=10.1016/j.envpol.2021.118229 |pmid=34582922 |bibcode=2021EPoll.29118229X |s2cid=238218223 |issn=0269-7491}}

PFAS are an important emerging class of man-made persistent toxicants that contain extremely strong carbon-fluorine bonds which make these chemicals extremely difficult to break down. They have unique properties that make them useful for manufacturing a wide variety of products such as firefighting foams, clothing, carpets, and fast food wrappers.{{Cite journal |last=Mahmoudnia |first=Ali |date=2023-01-18 |title=The role of PFAS in unsettling ocean carbon sequestration |journal=Environmental Monitoring and Assessment |language=en |volume=195 |issue=2 |page=310 |doi=10.1007/s10661-023-10912-8 |issn=1573-2959 |pmc=9848026 |pmid=36652110|bibcode=2023EMnAs.195..310M }} These useful properties in manufacturing unfortunately translate to problematic properties in the environment and organisms from plants to people. Because PFAS are not broken down in the environment, they have been circulated through the air and water to essentially all regions of the atmosphere, land, and ocean.{{Cite journal |last1=Panieri |first1=Emiliano |last2=Baralic |first2=Katarina |last3=Djukic-Cosic |first3=Danijela |last4=Buha Djordjevic |first4=Aleksandra |last5=Saso |first5=Luciano |date=February 2022 |title=PFAS Molecules: A Major Concern for the Human Health and the Environment |journal=Toxics |language=en |volume=10 |issue=2 |page=44 |doi=10.3390/toxics10020044 |issn=2305-6304 |pmc=8878656 |pmid=35202231 |doi-access=free |bibcode=2022Toxic..10...44P }}{{Cite journal |last1=Muir |first1=Derek |last2=Miaz |first2=Luc T. |date=2021-07-20 |title=Spatial and Temporal Trends of Perfluoroalkyl Substances in Global Ocean and Coastal Waters |journal=Environmental Science & Technology |language=en |volume=55 |issue=14 |pages=9527–9537 |doi=10.1021/acs.est.0c08035 |pmid=33646763 |bibcode=2021EnST...55.9527M |s2cid=232090620 |issn=0013-936X|doi-access=free }} These chemicals have many negative effects on marine life, such as significantly inhibited growth of phytoplankton over time{{Cite journal |last1=Niu |first1=Zhiguang |last2=Na |first2=Jing |last3=Xu |first3=Wei'an |last4=Wu |first4=Nan |last5=Zhang |first5=Ying |date=2019-09-01 |title=The effect of environmentally relevant emerging per- and polyfluoroalkyl substances on the growth and antioxidant response in marine Chlorella sp. |url=https://www.sciencedirect.com/science/article/pii/S0269749118357920 |journal=Environmental Pollution |volume=252 |issue=Pt A |pages=103–109 |doi=10.1016/j.envpol.2019.05.103 |pmid=31146223 |bibcode=2019EPoll.252..103N |s2cid=171092231 |issn=0269-7491}} and accumulation in seals, polar bears,{{Cite journal |last1=Boisvert |first1=Gabriel |last2=Sonne |first2=Christian |last3=Rigét |first3=Frank F. |last4=Dietz |first4=Rune |last5=Letcher |first5=Robert J. |date=2019-09-01 |title=Bioaccumulation and biomagnification of perfluoroalkyl acids and precursors in East Greenland polar bears and their ringed seal prey |url=https://www.sciencedirect.com/science/article/pii/S0269749119319438 |journal=Environmental Pollution |volume=252 |issue=Pt B |pages=1335–1343 |doi=10.1016/j.envpol.2019.06.035 |pmid=31252131 |bibcode=2019EPoll.252.1335B |s2cid=195764669 |issn=0269-7491}} and dolphins.{{Cite journal |last1=Stockin |first1=K. A. |last2=Yi |first2=S. |last3=Northcott |first3=G. L. |last4=Betty |first4=E. L. |last5=Machovsky-Capuska |first5=G. E. |last6=Jones |first6=B. |last7=Perrott |first7=M. R. |last8=Law |first8=R. J. |last9=Rumsby |first9=A. |last10=Thelen |first10=M. A. |last11=Graham |first11=L. |last12=Palmer |first12=E. I. |last13=Tremblay |first13=L. A. |date=2021-12-01 |title=Per- and polyfluoroalkyl substances (PFAS), trace elements and life history parameters of mass-stranded common dolphins (Delphinus delphis) in New Zealand |journal=Marine Pollution Bulletin |volume=173 |issue=Pt A |page=112896 |doi=10.1016/j.marpolbul.2021.112896 |pmid=34601248 |bibcode=2021MarPB.17312896S |s2cid=238258920 |issn=0025-326X|doi-access=free |hdl=2292/58033 |hdl-access=free }} Current research is underway investigating the full extent of the harm to marine ecosystems caused by PFAS.

;Specific examples:

• Chinese and Russian industrial pollution such as phenols and heavy metals in the Amur River have devastated fish stocks and damaged its estuary soil.[http://www.npolar.no/ansipra/english/Indexpages/Ethnic_groups.html#19 "Indigenous Peoples of the Russian North, Siberia and Far East: Nivkh" ] by Arctic Network for the Support of the Indigenous Peoples of the Russian Arctic
• Acute and chronic pollution events have been shown to impact southern California kelp forests, though the intensity of the impact seems to depend on both the nature of the contaminants and duration of exposure.{{cite journal |author=Grigg, R.W. |author2=Kiwala, R.S. |year=1970|title= Some ecological effects of discharged wastes on marine life|journal= California Department of Fish and Game|volume= 56|pages= 145–155}}{{cite book |doi= 10.1109/OCEANS.1989.586780 |chapter= Contaminants in Sediments Near a Major Marine Outfall: History, Effects, and Future |title= Proceedings OCEANS |volume= 2 |pages= 481–484 |year= 1989 |last1= Stull |first1= J. K.|s2cid= 111153399 }}{{cite book |doi= 10.1007/978-94-011-1998-6_33 |chapter= History of kelp beds (Macrocystis) in Orange and San Diego Counties, California |title= Fourteenth International Seaweed Symposium |page= 277 |year= 1993 |last1= North |first1= W. J. |last2= James |first2= D. E. |last3= Jones |first3= L. G. |isbn= 978-94-010-4882-8}}{{cite journal |doi= 10.1016/0141-1136(94)00008-D |title= Effects of a large sewage spill on a kelp forest community: Catastrophe or disturbance? |journal= Marine Environmental Research |volume= 40 |issue= 2 |pages= 181–224 |year= 1995 |last1= Tegner |first1= M. J. |last2= Dayton |first2= P. K. |last3= Edwards |first3= P. B. |last4= Riser |first4= K. L. |last5= Chadwick |first5= D. B. |last6= Dean |first6= T. A. |last7= Deysher |first7= L.|bibcode= 1995MarER..40..181T |url= https://zenodo.org/record/1258321 }}{{cite journal |last1=Carpenter |first1=S. R. |last2=Caraco |first2=N. F. |last3=Correll |first3=D. L. |last4=Howarth |first4=R. W. |last5=Sharpley |first5=A. N. |last6=Smith |first6=V. H. |title=Nonpoint Pollution of Surface Waters with Phosphorus and Nitrogen |journal=Ecological Applications |date=August 1998 |volume=8 |issue=3 |pages=559–568 |doi=10.1890/1051-0761(1998)008[0559:NPOSWW]2.0.CO;2 |hdl=1808/16724 |hdl-access=free }}
• Due to their high position in the food chain and the subsequent accumulation of heavy metals from their diet, mercury levels can be high in larger species such as bluefin and albacore. As a result, in March 2004 the United States FDA issued guidelines recommending that pregnant women, nursing mothers and children limit their intake of tuna and other types of predatory fish.{{cite web |title=Advice about Eating Fish For Women Who Are or Might Become Pregnant, Breastfeeding Mothers, and Young Children |url=https://www.fda.gov/food/consumers/advice-about-eating-fish |website=FDA |date=24 February 2020 }}
• Some shellfish and crabs can survive polluted environments, accumulating heavy metals or toxins in their tissues. For example, mitten crabs have a remarkable ability to survive in highly modified aquatic habitats, including polluted waters.{{cite web |url=http://www.issg.org/database/species/ecology.asp?si=38&fr=1&sts= |title=Ecology of Eriocheir sinensis |author=Gollasch, Stephen |date=3 March 2006}} The farming and harvesting of such species needs careful management if they are to be used as a food.{{cite journal |last1=Hui |first1=Clifford A. |last2=Rudnick |first2=Deborah |last3=Williams |first3=Erin |title=Mercury burdens in Chinese mitten crabs (Eriocheir sinensis) in three tributaries of southern San Francisco Bay, California, USA |journal=Environmental Pollution |date=February 2005 |volume=133 |issue=3 |pages=481–487 |doi=10.1016/j.envpol.2004.06.019 |pmid=15519723 |bibcode=2005EPoll.133..481H }}{{cite journal |last1=Silvestre |first1=F |last2=Trausch |first2=G |last3=Péqueux |first3=A |last4=Devos |first4=P |title=Uptake of cadmium through isolated perfused gills of the Chinese mitten crab, Eriocheir sinensis |journal=Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology |date=January 2004 |volume=137 |issue=1 |pages=189–196 |doi=10.1016/s1095-6433(03)00290-3 |pmid=14720604 }}
• Surface runoff of pesticides can alter the gender of fish species genetically, transforming male into female fish.{{cite news |last1=Saey |first1=Tina Hesman |date=12 August 2002 |title=DDT treatment turns male fish into mothers |url=https://www.sciencenews.org/article/ddt-treatment-turns-male-fish-mothers |work=Science News |url-access=subscription }}
• Heavy metals enter the environment through oil spills – such as the Prestige oil spill on the Galician coast and Gulf of Mexico which unleashed an estimated 3.19 million barrels of oil{{cite web |title=Gulf Oil Spill |url=https://ocean.si.edu/conservation/pollution/gulf-oil-spill |website=Smithsonian Ocean |date=30 April 2018 }} – or from other natural or anthropogenic sources.
• In 2005, the 'Ndrangheta, an Italian mafia syndicate, was accused of sinking at least 30 ships loaded with toxic waste, much of it radioactive. This has led to widespread investigations into radioactive waste disposal rackets.Bocca, Riccardo (5 August 2005) [http://www.archivio900.it/it/articoli/art.aspx?r=relauto&id=5978 Parla un boss: Così lo Stato pagava la 'ndrangheta per smaltire i rifiuti tossici]. L'Espresso
• Since the end of World War II, various nations, including the Soviet Union, the United Kingdom, the United States, and Germany, have disposed of chemical weapons in the Baltic Sea, raising concerns of environmental contamination.{{cite news |title=Chemical Weapon Time Bomb Ticks in the Baltic Sea |url=https://www.dw.com/en/chemical-weapon-time-bomb-ticks-in-the-baltic-sea/a-3102728 |work=DW |date=1 February 2008 }}{{cite web |url=https://helcom.fi/wp-content/uploads/2019/10/BSEP114.pdf |title=Activities 2007 Overview |series=Baltic Sea Environment Proceedings No. 112. |publisher=Helsinki Commission }}
• The Fukushima Daiichi nuclear disaster in 2011 caused radioactive toxins from the damaged power plant to leak into the air and ocean. There are still many isotopes in the ocean, which directly affects the benthic food web and also affects the whole food chain. The concentration of 137Cs in the bottom sediment that was contaminated by water with high concentrations in April–May 2011 remains quite high and is showing signs of very slow decrease with time.{{cite journal |last1=Bezhenar |first1=Roman |last2=Jung |first2=Kyung Tae |last3=Maderich |first3=Vladimir |last4=Willemsen |first4=Stefan |last5=de With |first5=Govert |last6=Qiao |first6=Fangli |title=Transfer of radiocaesium from contaminated bottom sediments to marine organisms through benthic food chains in post-Fukushima and post-Chernobyl periods |journal=Biogeosciences |date=23 May 2016 |volume=13 |issue=10 |pages=3021–3034 |doi=10.5194/bg-13-3021-2016 |bibcode=2016BGeo...13.3021B |doi-access=free }}
• During the 20th century, large amounts of DDT, petroleum products, radioactive materials, sulphuric acid, and other toxins were dumped in the Pacific Ocean off the coast of Southern California.

{{Clear}}

{{See also|Noise pollution|Acoustic ecology|The Effects of Noise on Aquatic Life|Marine mammals and sonar}}

Marine life can be susceptible to noise or the sound pollution from sources such as passing ships, oil exploration seismic surveys, and naval low-frequency active sonar. Sound travels more rapidly and over larger distances in the sea than in the atmosphere. Between 1950 and 1975, ambient noise at one location in the Pacific Ocean increased by about ten decibels (that is a tenfold increase in intensity).Ross, (1993) On Ocean Underwater Ambient Noise. Institute of Acoustics Bulletin, St Albans, Herts, UK: Institute of Acoustics, 18 Underwater noise pollution is unevenly distributed across marine environments, with the highest con-centrations occurring in shipping lanes, port areas, and densely trafficked ocean routes. These areas experience sustained high ambient noise levels due to the dominance of older and larger vessels, which emit significant low-frequency noise (10 to 500 Hz) caused by engine vibrations, propeller cavitation, and hull turbulence.Erbe, C., MacGillivray, A., & Williams, R. (2012). Mapping cumulative noise from shipping to inform marine spatial planning. The Journal of the Acoustical Society of America, 132(5), 423-428. DOI: https://doi.org/10.1121/1.4758779 While advancements in ship design have shown potential to reduce noise emissions, older, noisier vessels remain prevalent in major shipping routes, largely due to economic and logistical constraints.Hildebrand, J. A. (2009). Anthropogenic and natural sources of ambient noise in the ocean. Marine Ecology Progress Series, 395, 5-20. DOI: 10.3354/meps08353 Additionally, the overall increase in global shipping activity in recent decades has contributed to a rise of approximately 12 decibels in ambient noise levels, particularly in the low-frequency range, which propagates over long distances with minimal attenuation.Hildebrand, J. A. (2009). Anthropogenic and natural sources of ambient noise in the ocean. Marine Ecology Progress Series, 395, 5-20. [DOI: 10.3354/meps08353] The cumulative effects of concentrated noise pollution pose a unique risk to localised ecosystems, particularly for species with limited mobility or specific habitat requirements, as they are unable to escape these high-noise regions. Research also highlights variations in noise behaviour across marine environments, with factors such as water depth, salinity, and seabed composition influencing how noise propagates in coastal areas versus open seas.Merchant, N. D., Pirotta, E., Barton, T. R., & Thompson, P. M. (2014). Monitoring ship noise to assess the impact of coastal developments on marine mammals. Marine Pollution Bulletin, 78(1-2), 85-95. [DOI: 10.1016/j.marpolbul.2013.10.058] The localised nature of underwater noise pollution amplifies its ecological consequences, particularly for species that rely on sound for survival.

The ecological impacts of underwater noise are most prevalent for marine mammals like whales and dolphins, which rely heavily on sound for communication, navigation, and foraging. Cetaceans, such as whales and dolphins, are especially vulnerable because they rely on echolocation and acoustic signals for communication and navigation. They experience disrupted communication patterns, altered migration routes, and stress-related behavioural changes as some of the consequences of chronic exposure to ship noise.Weilgart, L. S. (2007). The impacts of anthropogenic ocean noise on cetaceans and implications for management. Canadian Journal of Zoology, 85(11), 1091-1116. [DOI: 10.1139/Z07-101] For example, endangered whale populations in the Saguenay–St. Lawrence Marine Park experience considerable acoustic space reduction, limiting their communication ranges and altering their natural behaviours.Gervaise, C., Simard, Y., Roy, N., Kinda, G. & Ménard, N. (2012). Shipping noise in whale habitat: Characteristics, sources, budget, and impact on belugas in Saguenay-St. Lawrence Marine Park hub. The Journal of the Acoustical Society of America. 132. 76-89. [DOI: 10.1121/1.4728190] Studies have shown that underwater noise can reduce communication ranges, impairing essential behaviours such as mating and social cohesion.Merchant, N. D., Pirotta, E., Barton, T. R., & Thompson, P. M. (2014). Monitoring ship noise to assess the impact of coastal developments on marine mammals. Marine Pollution Bulletin, 78(1-2), 85-95. [DOI: 10.1016/j.marpolbul.2013.10.058] Beyond marine mammals, fish and invertebrates are also affected, though they are less frequently studied. Fish use acoustic signals for mating, predator avoidance, and territory defence.Popper, A. N., & Hastings, M. C. (2009). The effects of anthropogenic sources of sound on fishes. Journal of fish biology, 75(3), 455–489. https://doi.org/10.1111/j.1095-8649.2009.02319.x Noise interference can cause habitat avoidance, reduced reproductive success, and disrupted predator-prey relationships, destabilising local food webs.Solan, M., Hauton, C., Godbold, J. A., et al. (2016). Anthropogenic sources of underwater sound can modify how sediment-dwelling invertebrates mediate ecosystem properties. Scientific Reports, 6, 20540. [DOI: 10.1038/srep20540] These cumulative effects of URN contribute to the destabilisation of nutrient cycling and broader eco-system processes.

Noise also makes species communicate louder, which is called the Lombard vocal response.[http://www.dosits.org/glossary/pop/lvr.htm Glossary] {{Webarchive|url=https://web.archive.org/web/20170629202711/http://www.dosits.org/glossary/pop/lvr.htm |date=29 June 2017 }} Discovery of Sounds in the Sea. Retrieved 23 December 2009 Whale songs are longer when submarine-detectors are on.{{cite journal |doi= 10.1121/1.1573637|pmid=12822811|url=https://www.researchgate.net/publication/10693892 |title= Variation in humpback whale (Megaptera novaeangliae) song length in relation to low-frequency sound broadcasts |journal= The Journal of the Acoustical Society of America |volume= 113 |issue= 6 |pages= 3411–3424 |year= 2003 |last1= Fristrup |first1= K. M. |last2= Hatch |first2= L. T. |last3= Clark |first3= C. W. |bibcode=2003ASAJ..113.3411F}} If creatures don't "speak" loud enough, their voice can be masked by anthropogenic sounds. These unheard voices might be warnings, finding of prey, or preparations of net-bubbling. When one species begins speaking louder, it will mask other species voices, causing the whole ecosystem to eventually speak louder.[http://www.dosits.org/tutorials/animalt-masking.htm Effects of Sound on Marine Animals] {{Webarchive|url= https://web.archive.org/web/20100113232329/http://www.dosits.org/tutorials/animalt-masking.htm |date=13 January 2010 }} Discovery of Sounds in the Sea. Retrieved 23 December 2009 Noise from ships and human activity can damage Cnidarians and Ctenophora, which are very important organisms in the marine ecosystem. They promote high diversity and they are used as models for ecology and biology because of their simple structures. When there is underwater noise, the vibrations in the water damage the cilia hairs in the Coelenterates. In a study, the organisms were exposed to sound waves for different numbers of times and the results showed that damaged hair cells were extruded or missing or presented bent, flaccid or missed kinocilia and stereocilia.{{cite journal |last1=Solé |first1=Marta |last2=Lenoir |first2=Marc |last3=Fontuño |first3=José Manuel |last4=Durfort |first4=Mercè |last5=van der Schaar |first5=Mike |last6=André |first6=Michel |title=Evidence of Cnidarians sensitivity to sound after exposure to low frequency noise underwater sources |journal=Scientific Reports |date=21 December 2016 |volume=6 |issue=1 |page=37979 |doi=10.1038/srep37979 |pmid=28000727 |pmc=5175278 |bibcode=2016NatSR...637979S }} Ships can be certified to meet certain noise criteria.{{cite web |title=HSHI Delivers World's First Product Carrier With 'SILENT-E' Underwater Noise Notation |url=https://www.marineinsight.com/shipping-news/hshi-delivers-worlds-first-product-carrier-with-silent-e-underwater-noise-notation/ |website=www.marineinsight.com |date=19 April 2021 |last1=Network |first1=MI News }}

According to the oceanographer Sylvia Earle, "Undersea noise pollution is like the death of a thousand cuts. Each sound in itself may not be a matter of critical concern, but taken all together, the noise from shipping, seismic surveys, and military activity is creating a totally different environment than existed even 50 years ago. That high level of noise is bound to have a hard, sweeping impact on life in the sea."Natural Resources Defense Council Press Release (1999) Sounding the Depths: Supertankers, Sonar, and the Rise of Undersea Noise, Executive Summary. New York, N.Y.: www.nrdc.org

Efforts to address underwater noise pollution remain limited. The International Maritime Organisation (IMO) introduced voluntary guidelines in 2014, encouraging measures such as the adoption of quieter ship designs, optimized propellers, and improved hull forms to reduce noise emissions.Leaper, R., Renilson, M., & Ryan, Conor. (2014). Reducing underwater noise from large commercial ships: Current status and future directions. Journal of Ocean Technology. 9. 65-83. However, the non-mandatory nature of these guidelines has resulted in inconsistent adoption across the shipping industry. In contrast, the European Union’s Marine Strategy Framework Directive (MSFD) mandates the assessment and reduction of underwater noise levels as part of achieving Good Environmental Status (GES).{{cite web | url=https://environment.ec.europa.eu/topics/marine-environment/descriptors-under-marine-strategy-framework-directive_en | title=Descriptors under the Marine Strategy Framework Directive - European Commission }} Scholars argue that a combination of technical and economic measures is needed to tackle the issue effectively. These include mandatory noise limits, subsidies for retrofitting ships with quieter technologies, and spatially informed policies, such as the creation of quiet zones or Marine Protected Areas (MPAs), to safeguard sensitive ecosystems.Vakili, S. V., Olcer, A. I., & Ballini, F. (2020). The development of a policy framework to mitigate underwater noise pollution from commercial vessels. Marine Policy, 118, 104004. https://doi.org/10.1016/j.marpol.2020.104004Van der Graaf, A. J., Ainslie, M. A., André, M., & Dekeling, R. P. A. (2012). European Marine Strategy Framework Directive: Task Group 11 underwater noise and other forms of energy. European Commission.Merchant, N. D. (2019). Underwater noise abatement: Economic factors and policy options. Environmental Science & Policy, 92, 116-123. https://doi.org/10.1016/j.envsci.2018.11.014

There are a variety of secondary effects stemming not from the original pollutant, but a derivative condition. An example is silt-bearing surface runoff, which can inhibit the penetration of sunlight through the water column, hampering photosynthesis in aquatic plants.{{Cite web|last=Queensland Government|date=2019-02-13|title=How does sediment affect the Great Barrier Reef?|url=https://www.reefplan.qld.gov.au/resources/explainers/how-does-sediment-affect-the-gbr|access-date=2021-08-04|website=Reef 2050 Water Quality Improvement Plan|language=en-AU}} Dredge plumes can contain silt and thus have similar effects on aquatic life.{{Cite journal |last1=Erftemeijer |first1=Paul L. A. |last2=Riegl |first2=Bernhard |last3=Hoeksema |first3=Bert W. |last4=Todd |first4=Peter A. |date=2012-09-01 |title=Environmental impacts of dredging and other sediment disturbances on corals: A review |journal=Marine Pollution Bulletin |volume=64 |issue=9 |pages=1737–1765 |doi=10.1016/j.marpolbul.2012.05.008 |issn=0025-326X|doi-access=free |pmid=22682583 |bibcode=2012MarPB..64.1737E }}

Much anthropogenic pollution ends up in the ocean. The 2011 edition of the United Nations Environment Programme Year Book identifies as the main emerging environmental issues the loss to the oceans of massive amounts of phosphorus, "a valuable fertilizer needed to feed a growing global population", and the impact billions of pieces of plastic waste are having globally on the health of marine environments.[http://www.unep.org/Documents.Multilingual/Default.asp?DocumentID=659&ArticleID=6897&l=en Fertilizer and plastic pollution are the main emerging issues in 2011 UNEP Year Book] {{Webarchive|url=http://webarchive.loc.gov/all/20150615190610/http://unep.org/Documents.Multilingual/Default.asp?DocumentID=659&ArticleID=6897&l=en |date=15 June 2015 }}, 17 February 2011. News Centre, United Nations Environment Programme, The Hague

Bjorn Jennssen (2003) notes in his article, "Anthropogenic pollution may reduce biodiversity and productivity of marine ecosystems, resulting in reduction and depletion of human marine food resources".{{cite journal |last1=Jenssen |first1=Bjørn Munro |title=Marine pollution: the future challenge is to link human and wildlife studies. |journal=Environmental Health Perspectives |date=April 2003 |volume=111 |issue=4 |pages=A198-9 |doi=10.1289/ehp.111-a198 |pmid=12676633 |pmc=1241462 }} There are two ways the overall level of this pollution can be mitigated: either the human population is reduced, or a way is found to reduce the ecological footprint left behind by the average human. If the second way is not adopted, then the first way may be imposed as the world ecosystems falter.{{citation needed|date=April 2023}}

The second way is for humans, individually, to pollute less. That requires social and political will, together with a shift in awareness so more people respect the environment and are less disposed to abuse it.{{cite journal |last1=Kullenberg |first1=G. |title=Approaches to addressing the problems of pollution of the marine environment: an overview |journal=Ocean & Coastal Management |date=December 1999 |volume=42 |issue=12 |pages=999–1018 |doi=10.1016/S0964-5691(99)00059-9 |bibcode=1999OCM....42..999K }} At an operational level, regulations, and international government participation is needed.{{cite journal |last1=Matthews |first1=Gwenda |title=Pollution of the oceans: An international problem? |journal=Ocean Management |date=January 1973 |volume=1 |pages=161–170 |doi=10.1016/0302-184X(73)90010-3 |bibcode=1973OcMan...1..161M }} It is often very difficult to regulate marine pollution because pollution spreads over international barriers, thus making regulations hard to create as well as enforce.{{cite book |last1=Warner |first1=Robin |title=Protecting the Oceans Beyond National Jurisdiction: Strengthening the International Law Framework |date=2009 |publisher=Brill |isbn=978-90-04-17262-3 }}{{page needed|date=July 2020}}

Without appropriate awareness of marine pollution, the necessary global will to effectively address the issues may prove inadequate. Balanced information on the sources and harmful effects of marine pollution need to become part of general public awareness, and ongoing research is required to fully establish, and keep current, the scope of the issues. As expressed in Daoji and Dag's research,{{cite journal |last1=Daoji |first1=Li |last2=Daler |first2=Dag |title=Ocean Pollution from Land-based Sources: East China Sea, China |journal=Ambio: A Journal of the Human Environment |date=February 2004 |volume=33 |issue=1 |pages=107–113 |doi=10.1579/0044-7447-33.1.107 |jstor=4315461 |bibcode=2004Ambio..33..107D |s2cid=12289116 }} one of the reasons why environmental concern is lacking among the Chinese is because the public awareness is low and therefore should be targeted.{{citation needed|date=April 2023}}

File:Marine Debris Removal ...Hawaiian Islands.jpg's tiny islands and atolls, sensitive coral reefs and shallow waters).]]

The amount of awareness on marine pollution is vital to the support of keeping the prevention of trash from entering waterways and ending up in our oceans. The EPA reports that in 2014 Americans generated about 258 million tons of waste, and only a third was recycled or composted. In 2015, there was over 8 million tons of plastic that made it into the ocean. The Ocean Conservancy reported that China, Indonesia, Philippines, Thailand, and Vietnam dump more plastic in the sea than all other countries combined.{{cite news |last1=Leung |first1=Hannah |title=Five Asian Countries Dump More Plastic Into Oceans Than Anyone Else Combined: How You Can Help |url=https://www.forbes.com/sites/hannahleung/2018/04/21/five-asian-countries-dump-more-plastic-than-anyone-else-combined-how-you-can-help/ |work=Forbes |date=21 April 2018 |quote=China, Indonesia, Philippines, Thailand, and Vietnam are dumping more plastic into oceans than the rest of the world combined, according to a 2017 report by Ocean Conservancy }} Through more sustainable packing this could lead to; eliminating toxic constituents, using fewer materials, making more readily available recyclable plastic. However, awareness can only take these initiatives so far. The most abundant plastic is PET (Polyethylene terephthalate) and is the most resistant to biodegradables. Researchers have been making great strides in combating this problem. In one way has been by adding a special polymer called a tetrablock copolymer. The tetrablock copolymer acts as a laminate between the PE and iPP which enables for an easier breakdown but still be tough. Through more awareness, individuals will become more cognizant of their carbon footprints. Also, from research and technology, more strides can be made to aid in the plastic pollution problem.{{cite journal |last1=Austin |first1=Harry P. |last2=Allen |first2=Mark D. |last3=Donohoe |first3=Bryon S. |last4=Rorrer |first4=Nicholas A. |last5=Kearns |first5=Fiona L. |last6=Silveira |first6=Rodrigo L. |last7=Pollard |first7=Benjamin C. |last8=Dominick |first8=Graham |last9=Duman |first9=Ramona |last10=El Omari |first10=Kamel |last11=Mykhaylyk |first11=Vitaliy |last12=Wagner |first12=Armin |last13=Michener |first13=William E. |last14=Amore |first14=Antonella |last15=Skaf |first15=Munir S. |last16=Crowley |first16=Michael F. |last17=Thorne |first17=Alan W. |last18=Johnson |first18=Christopher W. |last19=Woodcock |first19=H. Lee |last20=McGeehan |first20=John E. |last21=Beckham |first21=Gregg T. |title=Characterization and engineering of a plastic-degrading aromatic polyesterase |journal=Proceedings of the National Academy of Sciences of the United States of America |date=8 May 2018 |volume=115 |issue=19 |pages=E4350–E4357 |doi=10.1073/pnas.1718804115 |pmid=29666242 |pmc=5948967 |bibcode=2018PNAS..115E4350A |doi-access=free }}{{cite web |title=Trash Free Waters |url=https://www.epa.gov/trash-free-waters |date=2022-09-15 |publisher=EPA}}Jellyfish have been considered a potential mitigating organism for pollution.{{cite news |last1=Fourneris |first1=Cyril |title=Could jellyfish be the answer to fighting ocean pollution? |url=https://www.euronews.com/2020/01/20/could-jellyfish-be-the-answer-to-the-fight-against-ocean-pollution |work=euronews |date=20 January 2020 }}{{Cite web |url=https://gojelly.eu |title=GoJelly; a gelatinous solution to plastic pollution |access-date=2022-09-21 |publisher=SDU University of Southern Denmark |location=Odense, Denmark}}

In 2017, the United Nations adopted a resolution establishing Sustainable Development Goals, including reduced marine pollution as a measured goal under Goal 14. The international community has agreed that reducing pollution in the oceans is a priority, which is tracked as part of Sustainable Development Goal 14 which actively seeks to undo these human impacts on the oceans.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 ([https://undocs.org/A/RES/71/313 A/RES/71/313]) The title of Target 14.1 is: "By 2025, prevent and significantly reduce marine pollution of all kinds, in particular from land-based activities, including marine debris and nutrient pollution."

File:MARPOL 73-78 signatories.png convention on marine pollution (as of April 2008)]]

Although marine pollution has a long history, significant international laws to counter it were not enacted until the twentieth century. Marine pollution was a concern during several United Nations Conventions on the Law of the Sea beginning in the 1950s. Most scientists believed that the oceans were so vast that they had unlimited ability to dilute, and thus render pollution harmless.{{citation needed|date=April 2023}}

In the late 1950s and early 1960s, there were several controversies about dumping radioactive waste off the coasts of the United States by companies licensed by the Atomic Energy Commission, into the Irish Sea from the British reprocessing facility at Windscale, and into the Mediterranean Sea by the French Commissariat à l'Energie Atomique. After the Mediterranean Sea controversy, for example, Jacques Cousteau became a worldwide figure in the campaign to stop marine pollution. Marine pollution made further international headlines after the 1967 crash of the oil tanker Torrey Canyon, and after the 1969 Santa Barbara oil spill off the coast of California.{{citation needed|date=April 2023}}

Marine pollution was a major area of discussion during the 1972 United Nations Conference on the Human Environment, held in Stockholm. That year also saw the signing of the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, sometimes called the London Convention. The London Convention did not ban marine pollution, but it established black and gray lists for substances to be banned (black) or regulated by national authorities (gray). Cyanide and high-level radioactive waste, for example, were put on the black list. The London Convention applied only to waste dumped from ships, and thus did nothing to regulate waste discharged as liquids from pipelines.{{cite book|author=Hamblin, Jacob Darwin|title=Poison in the Well: Radioactive Waste in the Oceans at the Dawn of the Nuclear Age|publisher=Rutgers University Press|year=2008|isbn=978-0-8135-4220-1}}

File:Beach trash (30870156434).jpg causes vast quantities of trash to wash ashore at the south end of Hawaii.]]

There are different ways for the ocean to get polluted, therefore there have been multiple laws, policies, and treaties put into place throughout history. In order to protect the ocean from marine pollution, policies have been developed internationally.

• In 1948, Harry Truman signed a law formerly known as the Federal Water Pollution Control Act{{cite book |last1=Davies |first1=J. Clarence |title=Pollution Control in United States: Evaluating the System |last2=Mazurek |first2=Jan |date=2014 |publisher=Routledge |isbn=978-1-135-89166-4}}{{page needed|date=July 2020}} that allowed the federal government to control marine pollution in United States of America.
• In 1972, the Marine Protection, Research, and Sanctuaries Act of 1972 (MPRSA) was passed by the United States Congress, and regulates ocean dumping of waste in US waters.{{cite web |title=Learn About Ocean Dumping |url=https://www.epa.gov/ocean-dumping/learn-about-ocean-dumping |date=2022-06-08 |publisher=EPA}}{{cite journal |last1=Lang |first1=Gregory E. |date=1990 |title=Plastics, the Marine Menace: Causes and Cures |journal=Journal of Land Use & Environmental Law |volume=5 |issue=2 |pages=729–752 |jstor=42842563}}
• The 1954 Convention for the Prevention of Pollution of the Sea by Oil and the 1973 International Convention for the Prevention of Pollution by Ships were weakly enforced due to a lack of respect for the laws from flag states.{{Cite journal |last1=Rand |first1=Gary M. |last2=Carriger |first2=John F. |date=2001-01-01 |title=U.S. environmental law statutes in coastal zone protection |journal=Environmental Toxicology and Chemistry |volume=20 |issue=1 |pages=115–121 |doi=10.1002/etc.5620200111 |pmid=11351397 |bibcode=2001EnvTC..20..115R |s2cid=40130385 |issn=0730-7268}}
• In 1973 and 1978, MARPOL 73/78 was a treaty written to control vessel pollution, especially regarding oil. In 1983, the International Convention for the Prevention of Pollution from Ships enforced the MARPOL 73/78 treaty internationally.{{cite journal|last1=Griffin|first1=Andrew|date=1994|title=MARPOL 73/78 and Vessel Pollution: A Glass Half Full or Half Empty?|journal=Indiana Journal of Global Legal Studies|volume=1|issue=2|pages=489–513|jstor=20644564}}
• The 1982 United Nations Convention on the Law of the Sea (UNCLOS) was established to protect the marine environment by governing states to control their pollution to the ocean. It put restrictions on the amount of toxins and pollutants that come from all ships internationally.{{cite journal|last1=Darmody|first1=Stephen J.|date=1995|title=The Law of the Sea: A Delicate Balance for Environmental Lawyers|journal=Natural Resources & Environment|volume=9|issue=4|pages=24–27|jstor=40923485}}
• In 2006, the Marine Debris Research, Prevention and Reduction Ac.{{Cite book |last=(U.S.) |first=Marine Debris Program |title=Boating and marine debris: boater's guide to marine debris and conservation. |date=c. 2007 |publisher=U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration |oclc=700946101}} It was established by the National Oceanic and Atmospheric Administration (NOAA) to help identify, determine the source of, reduce and prevent marine debris.
• In December 2017, the UN Environmental Agency (UNEA) established the Ad Hoc Open-Ended Expert Group on Marine Litter and Microplastics with the purpose of examining marine plastic pollutions and to evaluate ways to handle the issue.{{Cite journal |last1=Maljean-Dubois |first1=Sandrine |last2=Mayer |first2=Benoît |date=2020 |title=Liability and Compensation for Marine Plastic Pollution: Conceptual Issues and Possible Ways Forward |journal=AJIL Unbound |language=en |volume=114 |pages=206–211 |doi=10.1017/aju.2020.40 |s2cid=225630731 |issn=2398-7723|doi-access=free }}
• In August 2023, the International Maritime Organization introduced [https://www.imo.org/en/GoogleSearch/SearchPosts/Default.aspx?q=noise#:~:text=Revised%20guidelines%20for,on%20the%20species%2C%C2%A0... Revised guidelines for the reduction of underwater radiated noise from shipping to address adverse impacts on marine life] containing provisions to help limit the noise resulting from the ships, to ensure the impact of noise on the marine life is addressed.

{{portal|Environment|Oceans}}

{{col div|colwidth=25em}}

• Aquatic toxicology
• Environmental impact of pesticides
• Mercury pollution in the ocean
• Oil pollution toxicity to marine fish
• Plasticosis
• Stockholm Convention on Persistent Organic Pollutants
• Sea snot
• World Oceans Day

{{colend}}

{{Reflist}}

• [https://oceandecade.org/ UN Ocean Decade]
• [https://marinedebris.noaa.gov/ US NOAA Marine Debris Program]

{{Marine pollution|state=expanded}}

{{Pollution}}

{{Physical oceanography|expanded=none}}

{{Authority control}}

{{DEFAULTSORT:Marine Pollution}}

Pollution

Category:Sanitation