Types of pollution Marine pollution

1 types of pollution

1.1 acidification
1.2 eutrophication
1.3 plastic debris
1.4 toxins
1.5 underwater noise

types of pollution
acidification


island fringing reef in maldives. coral reefs dying around world.

the oceans natural carbon sink, absorbing carbon dioxide atmosphere. because levels of atmospheric carbon dioxide increasing, oceans becoming more acidic. potential consequences of ocean acidification not understood, there concerns structures made of calcium carbonate may become vulnerable dissolution, affecting corals , ability of shellfish form shells.

oceans , coastal ecosystems play important role in global carbon cycle , have removed 25% of carbon dioxide emitted human activities between 2000 , 2007 , half anthropogenic co2 released since start of industrial revolution. rising ocean temperatures , ocean acidification means capacity of ocean carbon sink gradually weaker, giving rise global concerns expressed in monaco , manado declarations.

a report noaa scientists published in journal science in may 2008 found large amounts of relatively acidified water upwelling within 4 miles of pacific continental shelf area of north america. area critical zone local marine life lives or born. while paper dealt areas vancouver northern california, other continental shelf areas may experiencing similar effects.

a related issue methane clathrate reservoirs found under sediments on ocean floors. these trap large amounts of greenhouse gas methane, ocean warming has potential release. in 2004 global inventory of ocean methane clathrates estimated occupy between 1 , 5 million cubic kilometres. if these clathrates spread uniformly across ocean floor, translate thickness between 3 , fourteen metres. estimate corresponds 500–2500 gigatonnes carbon (gt c), , can compared 5000 gt c estimated other fossil fuel reserves.

eutrophication



polluted lagoon.



effect of eutrophication on marine benthic life

eutrophication increase in chemical nutrients, typically compounds containing nitrogen or phosphorus, in ecosystem. can result in increase in ecosystem s primary productivity (excessive plant growth , decay), , further effects including lack of oxygen , severe reductions in water quality, fish, , other animal populations.

the biggest culprit rivers empty ocean, , many chemicals used fertilizers in agriculture waste livestock , humans. excess of oxygen-depleting chemicals in water can lead hypoxia , creation of dead zone.

estuaries tend naturally eutrophic because land-derived nutrients concentrated runoff enters marine environment in confined channel. world resources institute has identified 375 hypoxic coastal zones around world, concentrated in coastal areas in western europe, eastern , southern coasts of us, , east asia, particularly in japan. in ocean, there frequent red tide algae blooms kill fish , marine mammals , cause respiratory problems in humans , domestic animals when blooms reach close shore.

in addition land runoff, atmospheric anthropogenic fixed nitrogen can enter open ocean. study in 2008 found account around 1 third of ocean s external (non-recycled) nitrogen supply , 3 per cent of annual new marine biological production. has been suggested accumulating reactive nitrogen in environment may have consequences serious putting carbon dioxide in atmosphere.

one proposed solution eutrophication in estuaries restore shellfish populations, such oysters. oyster reefs remove nitrogen water column , filter out suspended solids, subsequently reducing likelihood or extent of harmful algal blooms or anoxic conditions. filter feeding activity considered beneficial water quality controlling phytoplankton density , sequestering nutrients, can removed system through shellfish harvest, buried in sediments, or lost through denitrification. foundational work toward idea of improving marine water quality through shellfish cultivation conducted odd lindahl et al., using mussels in sweden.

plastic debris



a mute swan builds nest using plastic garbage.

marine debris discarded human rubbish floats on, or suspended in ocean. eighty percent of marine debris plastic – component has been rapidly accumulating since end of world war ii. mass of plastic in oceans may high 100,000,000 tonnes (98,000,000 long tons; 110,000,000 short tons).

discarded plastic bags, 6 pack rings, , other forms of plastic waste finish in ocean present dangers wildlife , fisheries. aquatic life can threatened through entanglement, suffocation, , ingestion. fishing nets, made of plastic, can left or lost in ocean fishermen. known ghost nets, these entangle fish, dolphins, sea turtles, sharks, dugongs, crocodiles, seabirds, crabs, , other creatures, restricting movement, causing starvation, laceration, infection, and, in need return surface breathe, suffocation.

remains of albatross containing ingested flotsam

many animals live on or in sea consume flotsam mistake, looks similar natural prey. plastic debris, when bulky or tangled, difficult pass, , may become permanently lodged in digestive tracts of these animals. when evolutionary adaptions make impossible likes of turtles reject plastic bags, resemble jellyfish when immersed in water, have system in throat stop slippery foods otherwise escaping. thereby blocking passage of food , causing death through starvation or infection.

plastics accumulate because don t biodegrade in way many other substances do. photodegrade on exposure sun, under dry conditions, , water inhibits process. in marine environments, photodegraded plastic disintegrates ever-smaller pieces while remaining polymers, down molecular level. when floating plastic particles photodegrade down zooplankton sizes, jellyfish attempt consume them, , in way plastic enters ocean food chain. many of these long-lasting pieces end in stomachs of marine birds , animals, including sea turtles, , black-footed albatross.

plastic debris tends accumulate @ centre of ocean gyres. in particular, great pacific garbage patch has high level of plastic particulate suspended in upper water column. in samples taken in 1999, mass of plastic exceeded of zooplankton (the dominant animal life in area) factor of six. midway atoll, in common hawaiian islands, receives substantial amounts of debris garbage patch. ninety percent plastic, debris accumulates on beaches of midway becomes hazard bird population of island. midway atoll home two-thirds (1.5 million) of global population of laysan albatross. of these albatross have plastic in digestive system , one-third of chicks die.

toxic additives used in manufacture of plastic materials can leach out surroundings when exposed water. waterborne hydrophobic pollutants collect , magnify on surface of plastic debris, making plastic far more deadly in ocean on land. hydrophobic contaminants known bioaccumulate in fatty tissues, biomagnifying food chain , putting pressure on apex predators. plastic additives known disrupt endocrine system when consumed, others can suppress immune system or decrease reproductive rates. floating debris can absorb persistent organic pollutants seawater, including pcbs, ddt, , pahs. aside toxic effects, when ingested of these affect animal brain cells estradiol, causing hormone disruption in affected wildlife. saido, chemist college of pharmacy, conducted study in nihon unversity, chiba, japan], discovered, when plastics decompose, produce potentially toxic bisphenol (bpa) , ps oligomer water. these toxins believed bring harm marine life living in area.

a growing concern regarding plastic pollution in marine ecosystem use of microplastics. microplastics little beads of plastic less 5 millimeters wide, , commonly found in hand soaps, face cleansers, , other exfoliators. when these products used, microplastics go through water filtration system , ocean, because of small size escape capture preliminary treatment screens on wastewater plants. these beads harmful organisms in ocean, filter feeders, because can ingest plastic , become sick. microplastics such concern because difficult clean them due size, humans can try avoid using these harmful plastics purchasing products use natural, environmentally safe exfoliates.

toxins

apart plastics, there particular problems other toxins not disintegrate rapidly in marine environment. examples of persistent toxins pcbs, ddt, tbt, pesticides, furans, dioxins, phenols, , radioactive waste. heavy metals metallic chemical elements have relatively high density , toxic or poisonous @ low concentrations. examples mercury, lead, nickel, arsenic, , cadmium. such toxins can accumulate in tissues of many species of aquatic life in process called bioaccumulation. known accumulate in benthic environments, such estuaries , bay muds: geological record of human activities of last century.

specific examples


chinese , russian industrial pollution such phenols , heavy metals in amur river have devastated fish stocks , damaged estuary soil.
wabamun lake in alberta, canada, once best whitefish lake in area, has unacceptable levels of heavy metals in sediment , fish.
acute , chronic pollution events have been shown impact southern california kelp forests, though intensity of impact seems depend on both nature of contaminants , duration of exposure.
due high position in food chain , subsequent accumulation of heavy metals diet, mercury levels can high in larger species such bluefin , albacore. result, in march 2004 united states fda issued guidelines recommending pregnant women, nursing mothers , children limit intake of tuna , other types of predatory fish.
some shellfish , crabs can survive polluted environments, accumulating heavy metals or toxins in tissues. example, mitten crabs have remarkable ability survive in highly modified aquatic habitats, including polluted waters. farming , harvesting of such species needs careful management if used food.
surface runoff of pesticides can alter gender of fish species genetically, transforming male female fish.
heavy metals enter environment through oil spills – such prestige oil spill on galician coast – or other natural or anthropogenic sources.
in 2005, ndrangheta, italian mafia syndicate, accused of sinking @ least 30 ships loaded toxic waste, of radioactive. has led widespread investigations radioactive waste disposal rackets.
since end of world war ii, various nations, including soviet union, united kingdom, united states, , germany, have disposed of chemical weapons in baltic sea, raising concerns of environmental contamination.
the damaging of fukushima dai-ichi nuclear power plant in 2011 caused radioactive toxins leak air , ocean. there still many isotopes in ocean, directly affects benthic food web , affects whole food chain. concentration of 137cs in bottom sediment contaminated water high concentrations in april–may 2011 remains quite high , showing signs of slow decrease time.


underwater noise

marine life can susceptible noise or sound pollution sources such passing ships, oil exploration seismic surveys, , naval low-frequency active sonar. sound travels more rapidly , on larger distances in sea in atmosphere. marine animals, such cetaceans, have weak eyesight, , live in world largely defined acoustic information. applies many deeper sea fish, live in world of darkness. between 1950 , 1975, ambient noise @ 1 location in pacific ocean increased ten decibels (that tenfold increase in intensity).

noise makes species communicate louder, called lombard vocal response. whale songs longer when submarine-detectors on. if creatures don t speak loud enough, voice can masked anthropogenic sounds. these unheard voices might warnings, finding of prey, or preparations of net-bubbling. when 1 species begins speaking louder, mask other species voices, causing whole ecosystem speak louder.

according oceanographer sylvia earle, undersea noise pollution death of thousand cuts. each sound in may not matter of critical concern, taken together, noise shipping, seismic surveys, , military activity creating totally different environment existed 50 years ago. high level of noise bound have hard, sweeping impact on life in sea.

noise ships , human activity can damage cnidarians , ctenophora, important organisms in marine ecosystem. promote high diversity , used models ecology , biology because of simple structures. when there underwater noise, vibrations in water damage cilia hairs in coelenterates. in study, organisms exposed sound waves different numbers of times , results showed damaged hair cells extruded or missing or presented bent, flaccid or missed kinocilia , stereocilia.