Environmental Problems, Their Causes, and Sustainability 1

Before commercial whaling began an estimated200,000 blue whales roamed the Antarctic Ocean. Todaythe species has been hunted to near biological extinctionfor its oil, meat, and bone. There are probablyfewer than 10,000 of these whales left.A combination of prolonged overharvesting andcertain natural characteristics of blue whales caused itsdecline. Their huge size made them easy to spot. Theywere caught in large numbers because they groupedtogether in their Antarctic feeding grounds. They alsotake 25 years to mature sexually and have only one offspringevery 2–5 years. This low reproductive ratemakes it difficult for the species to recover once itspopulation falls beneath a certain threshold.Blue whales have not been hunted commerciallysince 1964 and have been classified as an endangeredspecies since 1975. Despite this protection, some marinebiologists fear that too few blue whales remain forthe species to recover and avoid extinction. Others believethat with continued protection they will make aslow comeback.What Is the Role of InternationalAgreements and Protected MarineSanctuaries? Hopeful but LimitedProgressNations have established various types ofmarine sanctuaries, but most receive only partialprotection and fully protected areas make upless than 0.01% of the world’s ocean area.Under the United Nations Law of the Sea, all coastalnations have sovereignty over the waters and seabedup to 19 kilometers (12 miles) offshore. They also havealmost total jurisdiction over their Exclusive EconomicZone (EEZ), which extends 320 kilometers (200 miles)offshore. Taken together, the nations of the world havejurisdiction over 36% of the ocean surface and 90% ofthe world’s fish stocks. However, instead of using thislaw to protect their fishing grounds, many governmentspromoted overfishing, subsidized new fishingfleets, and failed to establish and enforce stricter regulationof fish catchesSince 1986 the World Conservation Union (IUCN)has helped establish a global system of marine protectedareas (MPAs), mostly at the national level. An MPA isan area of ocean protected from some or all human activities.The 1,300 existing MPAs provide partial protectionfor about 0.2% of the earth’s total ocean area.In addition, the United Nations EnvironmentProgramme has spearheaded efforts to develop 12 regionalagreements to protect large marine areas sharedby several countries.And about 90 of the world’s 350 biosphere reserves(p. 217) include coastal or marine habitats. Marinereserves—also known as fully protected areas orno-take MPAs—are areas where no extraction andalteration of any living or nonliving resources is allowed.More than 20 coastal nations, including theUnited States, have established marine reserves thatvary widely in size. In 2002, the Australian governmentestablished the world’s largest marine reserve.Scientific studies show that within fully protectedmarine reserves, fish populations double, fish sizegrows by almost a third, fish reproduction triples, andspecies diversity increases by almost one-fourth. Furthermore,this improvement happens within 2–4 yearsafter strict protection begins and lasts for decades.However, less than 0.01% of the world’s oceanarea consists of fully protected marine reserves. In theUnited States the total area of fully protected marinehabitat is only about 130 square kilometers (50 squaremiles). In other words, we have failed to strictly protect99.99% of the world’s ocean area from human exploitation.In 1997, a group of international marine scientistscalled for governments to increase fully protectedmarine reserves to at least 20% of the ocean’s surfaceby 2020. The 2003 Pew Fisheries Commission studyrecommended establishing many more protected marinereserves in U.S. coastal waters and connectingthem with protected corridors so fish can move backand forth. In 2004 marine biologist Elliott Norse proposedestablishment of moveable marine reserves thatmove with the animals as they migrate through theoceans.What Is the Role of Integrated CoastalManagement? Cooperation Can WorkSome communities have worked togetherto develop integrated plans for managing theircoastal areas.Integrated coastal management is a community-based effortto develop and use coastal resources more sustainably.The overall aim is for groups competing for theuse of coastal resources to identify shared problemsand goals. Then they attempt to develop workable,cost-effective, and adaptable solutions that preservebiodiversity and environmental quality while meetingeconomic and social needs. In other words, developand implement integrated plans using the principlesof adaptive ecosystem management (Figure 11-23, p. 218).Ideally, the overall goal is to zone the land and seaportions of an entire coastal area. Such zoning wouldinclude some fully protected marine reserves whereno exploitive human activities are allowed and otherzones where different kinds and levels of human activitiesare permitted. Australia’s huge Great Barrier ReefMarine Park is managed this way. Currently, morethan 100 integrated coastal management programs arebeing developed throughout the world.In the United States, 90 coastal counties are workingto establish coastal management systems, butfewer than 20 of these plans have been implemented.262 CHAPTER 13 Sustaining Aquatic Biodiversity