Marine Pollution

Marine Pollution is defined as "Introduction by man,directly or indirectly,of substances or energy into the marine environment resulting in such destructive effects as harm to living resources,hazard to human health,hindrance to marine activities including fishing,impairment of quality for use of sea-water,and reduction of amenities ."

Sources of Marine Pollution

1.Land based sources:
About 80% of marine pollution comes from land based activities.Land based sources of marine pollution are those types of pollution introduced into the marine environment from a variety of land sources.

2.Storm water:Storm water flow depends on rainfall,and the first flows following a dry spell often contain high levels of pollutions,such as heavy metals oil residues,nutrients,micro organisms,such as viruses,bacteria and protozoa from faecal material.

3.Pipelines:Disposal of fully or partially treated municipal and industrial wastes into rivers and/or bays,through pipe lines,also contributing to total land based marine pollution.Pipelines usually discharge below the low water mark.

4.Rivers:Rivers carry to the sea water containing contaminants such as nutrients and pesticides from agricultural runoff,faecal pollution resulting from poor sanitation,and industrial discharges.

Effects of Marine Pollution

1. Organic matter:Decomposition of organic matter present in the untreated or partially treated waste causes depletion of dissolved oxygen content of the marine water.This can cause the death of marine plants and animals,and may lead to changes in biodiversity.

2.Eutrophication:Disposal of effluent with more nitrogen and phosphorus causes 'eutrophication',which may cause algal blooms.These blooms can discolour the water,clog fish gills, or even be toxic.

3.Pathogenic micro-organisms:These cause gastric and ear-nose-throat infections,hepatitis,and even cholera and typhoid.

4.Toxic chemicals:Substances causing toxic effects that damage the physiological processes and functions of reproduction,feeding and respiration.

5.Pesticides:Pesticides such as DDT(Dichlorodiphenyltrichloroehane),and other persistent chemicals accumulate in the fatty tissu of animals.These chemicals can cause reproductive failure in marine mammals and birds

6.Human health:Many pollutants such as dioxins,furans,polychlorinated biphenyls(PCB's),and some heavy metals are accumulating in the marine organisms.When humans are consuming sea foods from the polluted areas they are exposes to those pollutants

7.Radioactive wastes:Any leakage of failure of radioactive waste containers,which are used to dispose low level radioactive wastes in deep sea causes more effects that could be devastating.

Preventions/control of Marine Pollution

Following are some of the preventive measures of marine pollution:

1.Careful handling of oil and petroleum products.
2.Ban ocean dumping of sludge and hazardous dredged materials.
3. Dispose fully treated municipal and industrial wastes.
4. Regulate coastal development.
5. Hygienic and aesthetic maintenance of recreational beaches.
6. Controlled use of pesticides and chemicals in agricultural activities in delta portions.
7. Separate sewage and storm water lines.
8.Ban on dumping of radioactive wastes.