Extreme climatic events, population growth and coastal fisheries account for major causes of coral reef decline – excessive domestic and agricultural waste pouring into ocean waters, poor land use practices that increase sedimentation of rivers and then of reefs, and over exploitation of reef resources, often in combination with practices such as harvesting with dynamite and poison, all degrade reefs. These factors, however, also make it far harder for coral reefs to recover from bleaching events. Major observed threats to the world’s coral reefs include extreme climate events, unsustainable 160 tourism practices, poison fishing for ornamental fish, overexploitation by fisheries, sedimentation, coral harvesting, dynamite fishing and pollution not in order of priority. This graphic explains which activities or conditions are affecting various coral reefs throughout the world. The graphic ‘major threats to reefs’ shows the percentage of reefs that are threatened by overexploitation, coastal development, inland pollution and marine pollution, and the degree to which they are under threat.

The graphic ‘destroyed coral reefs’ shows the percentage of coral reefs that have been destroyed in the world’s major regions. Around 60% of the wastewater discharged into the caspian sea is untreated, in latin america and the caribbean the figure is close to 80%, and in large parts of africa and the indo pacific the proportion is as high as 80 90% unep, 2006. An estimated us$ 56 billion is needed annually to address this enormous wastewater problem. However, the costs to coral reefs, tourism and losses in fisheries and human health risks may be far more expensive. Together with agricultural run off to the sea or into major rivers and eventually into the ocean, nitrogen mainly nitrate and ammonium exports to the marine environment are projected to increase at least 14% globally by 2030 unep, 2006.

In southeast asia more than 600,0 tons of nitrogen are discharged annually from the major rivers. These numbers may become further exacerbated as coastal populations are depicted to increase from 77 people/km2 to 115 people per km2 in 2025. Wetlands and mangroves are also declining rapidly, typically by 50 90% in most regions in the past 4 decades unep, 2006. All of the above, together with changes in salinity, melting sea ice, increased sea temperatures and future changes in sea currents may severely affect marine life and its ability to recover from extreme climatic events.

Also, it will severely exacerbate the effects of extreme weather and the productivity of coastal ecosystems to supply livelihoods and basic food to impoverished. Hence, the poor management of sewage not only presents a dire threat to health and ecosystems services, it may increase poverty, malnutrition and security for over a billion people unep 2006 in these two landsat images shrimp farms appear as bluish purple squares located near the streams. Between the earlier image acquired in january, 1990 and the later image acquired approximately 11 years later there is an explosion in shrimp farming throughout the estuary.

These landsat satellite images from 1974 and 2005 show the gradual spread of development and the loss of mangrove forest that has resulted. As thirty years pass, the agricultural areas expanded and more mangroves were converted to farms. At the same time, these images show the agricultural areas being converted to industrial and urban land use.

Elsewhere along the malaysian coastline, mangroves are rapidly being converted to commercial shrimp farms. Forestry department statistics show that peninsular malaysia had 85,800 hectares 214,500 acres of mangrove swamp forests in 2003, down from 86,497 hectares just one year earlier. Sea pollution the pollution of the ocean is rapidly becoming a crucial problem on earth. The major causes of sea pollution are oil spills, toxic waste, and dumping of other harmful materials into the ocean. This pollution will directly affect the living organisms in the ocean and indirectly affect human’s. Water pollution and its effects on the environment water is probably the most important resource we as people have.

Law of Persons Past Exam Papers

Humans can survive without food for several weeks, but without water we would die in less than a week. essay on marine pollution: sources, effects and control! marine pollution is defined as the introduction of substances to the marine environment directly or indirectly by man resulting in adverse effects such as hazardous to human health, obstruction of marine activities and lowering the quality of sea water. Municipal waste and sewage from residences and hotels in coastal towns are directly discharged into sea. Pesticides and fertilizers from agriculture which are washed off by rain enter water courses and finally to sea. India is estimated to use 55,0 tons of pesticides annually and about 25 percent of it is carried to ocean. Petroleum and oil washed off from roads normally enter sewage system and finally into seas.

Argumentative Essay Huck Finn

Ship accidents and accidental spillage at sea can therefore be very damaging to the marine environment. During this period when cargo compartments are emptied, residual oil goes into sea. Pollution due to organic wastes: when o₂ concentration falls 1.5 mg/l, the rate of aerobic oxidants reduced and replaced by the anaerobic bacteria that can oxidize the organic molecules without the use of oxygen. Pollution due to oil: crude oil is transported by sea after a tanker has unloaded its cargo of oil it has to take on sea water ballast for return journey. This ballast water is stored in cargo compartments that previously contained oil. During unloading of cargo certain amount of oil remains clinging to the walls of container and this may amount to 800t in a 200,0t tankers.

When fresh crag of oil is to be loaded these compartments are clean with water which discharges the dirty ballast along with oil into sea. Deep sea mining is a relatively new mineral retrieval process that takes place on the ocean floor. Ocean mining sites are usually done at about 1,400 3,700 meters below the oceans surface.

Dissertation Phd Philosophy

The vents create sulfide deposits, which contain precious metals such as silver, gold, copper, manganese, cobalt, and zinc. Removal of parts of the sea floor will result in disturbances to the benthic layer, and habitat of benthic organisms. Beside from direct impact of mining the area, leakage, spills and corrosion would alter the mining areas chemical makeup.

Papers on Operating System

Apart from causing eutrophication, a large amount of organic wastes can also result in the development of red tides. Commercially important marine species are also killed due to clogging of gills and other structures. When oil is spilled on the sea, it spreads over the surface of the water to form a thin film called as oil slick.

Commercial damage to fish by tainting which gives unpleasant flavor to fish and sea food reduces market values of sea food and causes death of birds through its effect on feathers. Birds often clean their plumage by pruning and in the process consume oil which can lead to intestinal, renal and liver failure. For salt marshy plants oil slick can affect the flowering, fruiting and germination. Organic waste addition results in end products such as hydrogen sulphide, ammonia and methane which are toxic to many organisms.