SAVING THE OCEANS
The oceans of the world occupy over 70% of the earth’s surface.They provide food for billions of people,serve as places of recreation,and facilitate the transportation of passangers and cargo.For all human history,people regarded the oceans as indestructible and infinite resource.Until recently,humans had little impact on the oceans.However,as the earth’s population increases,human activity will ultimately destroy the oceans unless immediate steps are taken.
Over-fishing is one major threat.Fish are being taken out of the oceans faster than the remaining fish can reproduce.A big fish-tuna,cod,shark,or swordfish- yields many pounds of delicious seafood when it reaches maturity.However,to meet the increasing demand for these fish, commercial fishermen began catching small,immature fish.In the process,they depleted the species.Ocean scientists estimate that 90% of these big fish are now gone from the oceans,and about 30% of all fished species have been destroyed.
Of the earth’s 6.5 billion people,over one billion rely on fish as a source of protein.Billions more eat fish frequently because of its health benefits and good taste.Throughout the world ,food from the sea provides between 5% and 10% of the total food supply.But when fish diappear from oceans,they will also disappear from our dinner plates.The impact on those who rely on fish could be malnutrition or even starvation.
Humans are impacting ocean life not only by what they take out of the oceans,but also by what they put into the oceans.Carelessly discarded cans,bottles,plastic cups and baby diapers find their way into the stomachs of fish,often killing them.Toxic chemicals and industrial trash are also discarded into the oceans,either accidentally or thoughtlessly.Such conduct pollutes the water and kills the sea life.Spills from a single oil tanker can contribute 200,000 tons of oil to the already polluted oceans.In the United States,an estimated 15,000 tons of automobile oil annually washes off roads into rivers and streams and ultimately in to the sea.
Along with the harmful oil,however,runoff also carries tons of nutrients in the form of plant matter,fertilizers,animal waste,and garbage that can be traced to cities,farms,factories,and forests.These nutrients may seem like a good thing at first,but poisonous algae and bacteria(microscobic plants and animals)in the ocean feed on nutrients.As the run-off increases,the aggregation of algae and bacteria increases,further eroding the marine environment.Small fish that feed on algea and bacteria are sickened or killed by the poisons they contain.When larger fish feed on smaller ones,they too are sickened by the poisons.Ultimately,humans who ate the flesh of poisoned fish will be sickened,too.
Are healthy oceans compatible with an industrialized world?What can be done to terminate the steady destruction of the oceans?Among other steps,countries can set limits on the number of fish that fishermen can legally catch.Goverments can also create sea reserves,areas where fishing is temporarily banned until the fish population increases.Commercial enterprises can develop open ocean aquaculture to grow fish in under watercages miles from land.And individuals can refuse to buy fish in restaurants and markets if the species is threatened.
Goverments can also protect the sea by enacting strict controls on ocean dumping.They can demand that oil tankers have higher safety standards.They can process run-off water to remove toxic substances.Individuals can properly dispose of leftover household and garden chemicals so they do not to the toxic run-off into the oceans.
