Tim Allman. World at Risk: A Global Issues Sourcebook. CQ Press, A Division of Sage Publications. 2010.
Biodiversity, a contraction of the term biological diversity, refers to the variety observed within the biosphere, or living world. This richness and variety of life are perhaps Earth’s greatest wonder and one of its most important resources because human survival completely depends on the effective functioning of global biological systems. Most of Earth’s diversity remains undiscovered, as science has classified only a small portion of the large number of species estimated to exist.
The study of biodiversity has been divided into three categories: genetic, species, and ecosystem. Genetic diversity is the inheritable variation that derives ultimately from variations in DNA sequence; species diversity characterizes the variety of different species observed in an area; and ecosystem diversity is the patterns of variation seen in ecosystems. Biodiversity in all these categories is declining ever more rapidly due to habitat destruction and other human activities. For example, eminent biologist Edward O. Wilson has predicted that half the planet’s species face extinction in the next one hundred years if current trends continue. With global biodiversity under such overwhelming attack, the struggle to conserve it becomes all the more urgent.
Historical Background and Development
Given that many early societies exhibited an interest in and affinity with nature and its diversity, it seems quite probable that human societies have long sought to classify to some degree the species that they have encountered. Such cultural analyses of diversity are invariably related to the importance of the various species to the society. In a classic study, the eminent German biologist Ernst Mayr visited the remote Arfak mountains of New Guinea in 1928 and noted that the indigenous inhabitants gave names to 136 species of birds, many of which they depend on for food. Interestingly, these 136 correspond almost exactly to the species recognized by Western taxonomy, the science of the classification of organisms. However, the New Guineans had little interest in certain other groups; for instance, they did not distinguish among any of the numerous species of ants by which they are surrounded.
Recorded attempts at taxonomic classification began with the ancient civilizations of Europe and Asia, with philosophers from Greece, Rome, and Arabia proposing basic schemes. The classification and compilation of species inventories have been a theme of various scientific inquiries ever since, but studies of biological diversity really began in earnest in eighteenth-century Europe as scientific exploration, specimen collection, and classification came into vogue. The outstanding figure of this period was Carolus Linnaeus, who established the foundations for the binomial system of scientific naming of organisms that is still used today and who is thus considered the father of modern taxonomy. A century later, studies of the natural world were advanced sufficiently for Charles Darwin to develop his theory of evolution. This theory revolutionized the biological sciences by providing a coherent mechanism for explaining the staggering variety of life on Earth and provided the theoretical foundation for modern studies of the living world.
The modern conservation movement began to coalesce in the late nineteenth century as a reaction to the damage to natural landscapes by industrialization, urban growth, and resource extraction. This period saw the establishment of the world’s first national parks, such as Yellowstone in 1872, Royal (in Australia) in 1879, and Banff (in Canada) in 1885.
Although scientific understanding of biology and ecology developed greatly throughout the twentieth century, biodiversity is a relatively new field of study; the term itself was coined in 1985. The concept of biodiversity had begun gaining currency against a background of increasing concern about the environment in many parts of the world two decades before the term was coined. This concern was reflected by the signing of such important agreements as the 1963 Convention on International Trade in Endangered Species (CITES), the 1972 World Heritage Convention, the 1983 Convention on Migratory Species, and the 1971 Ramsar Convention on Wetlands.
Research and policy focused specifically on biodiversity, and its conservation came to the fore only in the 1990s. Such initiatives were given great impetus by the Earth Summit held in Rio de Janeiro in 1992 and the resulting Convention on Biological Diversity, which came into force in December 1993. Recognition of the threats to global biodiversity and their possible repercussions helped create a general consensus about the urgency of the problem, often with scientists at the forefront of this concern; biologists Jared Diamond and Robert May, writing for the scientific journal Nature in 1985, memorably dubbed conservation biology a “discipline with a time limit.” The critical question for the future is whether sufficient time, financial support, and political will exist to fight biodiversity decline at local, national, and international levels.
There is no single, universally applicable unit of measure for biodiversity, only the requirement that the parameters used be appropriate to the situation. Biodiversity, however, is most often studied and described by scientists and policymakers at the species level. In particular, species richness—the number of species in an area or community, ideally relative to the total number of individuals of each species present—is a widely used measure of diversity.
However biodiversity is characterized and despite differing estimates of its degree, it is clear that human activity threatens and reduces biodiversity in numerous ways. Today, habitat destruction is the primary driver of biodiversity decline in almost every area of the world, with overexploitation, introduction of alien species, and pollution also contributing. In addition, impacts on biodiversity are likely to become increasingly dominated by climate change resulting from global warming, which is expected to have dramatic effects on species and ecosystems everywhere.
The depletion of biodiversity has reached an alarming rate. Although quantifying extinction rates involves many assumptions, the California Academy of Sciences estimates that some 10,000 species become extinct every year. This is 1,000 times the background extinction rate indicated in fossil records. Most biologists now agree that the biosphere is facing an extinction crisis; indeed, it is widely accepted that we are experiencing a sixth mass extinction period in the history of life on Earth, the greatest upheaval in the living world since the extinction event that wiped out the dinosaurs at the end of the Mesozoic Era, some 65 million years ago.
The current mass extinction is unique for having been precipitated by human activities. Biologist E. O. Wilson has suggested that the human effects on the development of life are now so profound that the Earth may be considered to be leaving the Cenozoic Era (the period dominated by mammals, which followed the Mesozoic) and entering what he calls the Eremozoic Era, the age of loneliness.
Living on a severely biologically impoverished planet will present humanity with problems far beyond loneliness, however. Healthy natural systems provide us with ecosystem services—essential attributes such as food, fuel, water, fiber, medicine, recycling of nutrients, purification of air and water, and pollination of crops. In 1997, economists writing in Nature estimated the total monetary value to humanity of the Earth’s ecosystem services at $33 trillion or more per year, almost twice the global gross domestic product (GDP). But, given their crucial importance for life on Earth, global ecosystems can justifiably be considered as priceless. Vital ecosystem services are damaged by biodiversity decline, with potentially catastrophic consequences for human societies.
Clearly, the need for ongoing accurate biodiversity research is urgent if ways to tackle the biodiversity crisis are to be found. The field is complex and broad, and it tends to rely on three scientific disciplines: genetics, taxonomy, and ecology. Each discipline approaches the analysis of diversity at a different level of organization, but they are all intimately related. For example, the geneticist studying DNA variation in a population of organisms might provide the taxonomist with knowledge that enables a revised classification of organisms to be made; this, in turn, could improve the ecologist’s understanding of the ecosystem of which the organisms are a part.
Most research focuses on the estimation of the diversity that exists in an area or community and on the scientific assessment of which components of this diversity are of most significance to overall biodiversity, especially with regard to prioritizing conservation efforts. Objective comparisons of biodiversity are often difficult to make, however, and tackling these questions for even a small wildlife reserve is a considerable task. The work required on a global scale is extremely daunting.
Global estimates of biodiversity are often done by extrapolating from samples of smaller systems. Given the complexity of the project, species richness is the best measure of diversity because it is relatively simple to measure in most situations and easily compared between ecosystems (see Table 1). It is no surprise that estimates of the number of species on Earth differ greatly, ranging from 4 million to 100 million according to the assumptions made; remarkably, we have a better idea of the number of stars in the galaxy than of the number of species on our own planet. The International Union for the Conservation of Nature (IUCN) quotes a working estimate of between 8 and 14 million species in its “Review of the 2008 Red List of Threatened Species.” However, only a small portion has been studied; the IUCN states that only about 1.8 million species are currently known to science and that the ecology of only a small portion of these has been studied in any detail. Around half of known species—950,000—are insects. Higher plants (seed plants and ferns) constitute the next largest group, with around 285,000 species.
It is certain that the discovery and classification of the majority of species will not keep pace with extinction rates. The scale of the task is too immense, and there are not enough taxonomic researchers, especially those specializing in poorly understood groups of organisms. Efforts are being made, however, to assist and coordinate taxonomic research. The most notable of these projects is the Catalog of Life, a joint project of two agencies, Species 2000 and the Integrated Taxonomic Information System (ITIS), both of which are themselves collaborative organizations involving many scientific bodies from all over the world. The Catalog of Life aims to establish an authoritative standardized index of all currently identified species, which can be accessed via the Internet. It is estimated that just over 60 percent of all known species are cataloged in existing databases, but the Catalog of Life aims to index all known species by 2011.
It is also important for scientists to understand how specific changes in biological diversity affect the functioning of ecosystems. For instance, it is generally accepted that more diverse communities are more productive. That is, they produce more organic matter, such as plant growth, in a given time and are more robust than less diverse ones, being better able to withstand disturbances. It is also generally agreed that more diverse ecosystems tend to be more resilient in the face of environmental change. Other research has attempted to explain the various interrelationships between geographical factors and biodiversity, the best known of which is the general increase in diversity in the latitudes approaching the equator. Exploring patterns such as these in more detail can lead to better understanding of the effects of conservation practices.
One attempt to highlight those areas most in need of conservation action is by designating biodiversity hotspots, a concept originated by British scientist Norman Myers. This analysis identifies areas that have very high biodiversity indicators (such as high levels of endemism, the occurrence of organisms that are unique to a particular area) and also a high risk of habitat destruction and, thus, are most in need of protection. Similarly, the Global 200 project of the World Wide Fund for Nature identifies two hundred regions of natural habitat with the most biodiversity significance. Of course, like all assessments of biodiversity, such classifications will always involve simplifications and subjective assumptions or judgments and, thus, attract debate; for example, the concept of biodiversity hotspots has been criticized for relying too heavily on endemic plants (those unique to an area) as a diversity indicator. Nonetheless, such analyses can play a useful role in conservation efforts.
Another important research project is the IUCN’s “Red List,” the world’s most comprehensive inventory of the conservation status of the world’s plant and animal species. The extinction risk of thousands of species and subspecies is assessed, and threatened species are then categorized in the list as vulnerable, endangered, or critically endangered. This informs policymakers about which species are most in need of conservation action and documents the urgency and scale of the extinction threat; for example, the 2008 list reported that nearly one-third of the world’s remaining amphibian species were threatened (see Table 3).
Policies and Programs
The decline in biodiversity was one of the issues that dominated the 1992 Earth Summit (formally known as the United Nations Conference on Environment and Development). At the conference, 168 countries signed the Convention on Biological Diversity, the first global agreement on biodiversity conservation. The convention has three objectives: the conservation of biodiversity, the sustainable use of biodiversity’s components, and the equitable sharing of genetic resources. A key challenge for its signatories is achieving a balance between the first two objectives. This means conserving biodiversity and all its components—such biological resources as species and habitats—while allowing sustainable human exploitation of these resources. The third objective also applies to human use of a component of diversity—genetic variation. In this respect, the convention aims to ensure that genetic resources (for example, wild plants whose genes may be of use to biotechnologists in the development of new drugs) provide as wide a benefit to humanity as possible.
Many policy approaches to biodiversity conservation tend to be utilitarian; that is, they seek to protect diversity because of its actual and potential value to humanity and the biosphere and, therefore, aim primarily to protect the most “valuable” elements of biodiversity. Although this pragmatic resource-value approach is necessary because of the scale of the problem and limits on time and resources, many groups involved in conservation programs point out that placing value on diversity will always be subjective and argue that biodiversity should deserve protection in its own right. Indeed, the Convention on Biological Diversity affirms the intrinsic value of biodiversity in its first line of text. Furthermore, because of the sheer complexity of the living world, even the most utilitarian-minded analysts would agree that any loss to biodiversity might have serious, unpredictable, and irreversible effects.
There are two broad approaches to biodiversity conservation: ex situ and in situ. Ex situ, or off-site, conservation measures focus on individual species and include the use of zoos, seed banks, and DNA storage facilities to preserve species. Because of the expense and effort required for ex situ conservation, especially for animals, such measures are generally limited to particularly rare, valued, or threatened species. A notable ex situ project with a comprehensive focus is the Svalbard Global Seed Vault, a secure underground storage facility in the Arctic permafrost. This aims to back up the work of seed banks around the world by storing the seeds of crop plant varieties, thus maintaining a reservoir of genetic diversity even in the face of catastrophic events.
In situ, or on-site, conservation aims to conserve biodiversity in its natural environment. This is the preferred approach and involves programs for the establishment of protected areas such as wildlife reserves and the legal protection of endangered species (see Table 2; map, p. 222). It is generally accepted that the most effective in situ paradigm is the ecosystem approach; this is favored by the Convention on Biological Diversity, which endorsed it at a 2000 meeting and defined it as “a strategy for the integrated management of land, water and living resources that promotes conservation and sustainable use in an equitable way.” The crucial advantage of the ecosystem approach is its focus on integration; by recognizing that healthy ecosystems cannot exist in isolation from other factors (geographical, hydrological, social, and cultural), it aims to address conservation problems in a more holistic way. The challenge of translating this approach into success is now a major concern of many biodiversity policies.
The Convention on Biological Diversity has provided the policy framework for numerous projects relating to the full scope of its aims by national governments and international organizations. The convention is legally binding, and countries that ratify it are obliged to implement it. The vast majority of the world’s nations—191 countries—were party to the convention by 2008. Although the convention has a scientific advisory body and a permanent secretariat, its ultimate authority derives from decisions made at the Conference of the Parties (COP) sessions, which are meetings of the signatory states.
COP sessions have approved important initiatives for achieving the objectives of the convention. Some of these initiatives are classed as thematic programs, such as studying inland waters, forests, mountains, and agricultural lands. Other initiatives are broader and are classed as cross-cutting issues, such as the analyses of invasive species and the effects of tourism on biodiversity. Also, COP2 called for the periodic production of Global Biodiversity Outlook (GBO) reports that, in effect, stand as status reports on the progress made in achieving the aims of the biodiversity convention. The first GBO was published in November 2001 and the second in March 2006 (see Document 2).
One of the most significant policy goals to emerge from the COP sessions is called the 2010 Biodiversity Target; in 2002, COP6 resolved “to achieve by 2010 a significant reduction of the current rate of biodiversity loss at the global, regional and national level as a contribution to poverty alleviation and to the benefit of all life on earth.” This is an ambitious and hugely challenging target; GBO2 admitted in 2006 that “unprecedented additional efforts” were required at all levels if this target is to be met.
As with all international agreements, the success of the Convention on Biological Diversity depends mainly on actions taken by the signatory countries. Among the commitments under the convention, governments are required to draft National Biodiversity Strategies and Action Plans (NBSAPs) and to integrate these into broader national plans for the environment and development. These plans vary, but they tend to be based on surveys of existing biodiversity resources coupled with evaluations of their importance and vulnerability. This permits governments to set targets for the conservation and sustainable use of local biodiversity and to craft strategies for meeting them. Other governmental obligations under the convention include the prevention of the spread of invasive species, restoration of degraded ecosystems, and promotion of public participation in conservation measures. Each government is required to submit a report at COP meetings describing what it has done in fulfillment of its treaty obligations. These reports are another important means by which the progress toward the convention’s objectives can be judged.
The Convention on Biological Diversity has produced a specific subsidiary agreement, the Cartagena Protocol on Biosafety, which deals with issues in the field of biotechnology. Advances in the biotech industry have led to the increasing introduction of living modified organisms (LMOs), also called genetically modified organisms (GMOs), as foodstuffs, pharmaceuticals, and other products. There are concerns about LMOs because the creation of organisms with entirely novel genetic combinations may pose unknown risks to the genetic diversity of wild populations of similar organisms. Such concerns led to the negotiation of the protocol, which was adopted in January 2000. The Cartagena Protocol on Biosafety allows countries to restrict imports of agricultural products that contain LMOs and requires commodities containing LMOs to be labeled as such before export. The protocol also establishes mechanisms facilitating the exchange of information on LMOs and assisting countries in the implementation of the protocol.
Biodiversity tends to be greatest in the equatorial regions, although numerous other factors of geography and climate also exert influences. Many different types of ecosystems occur across the globe, and pressures on the living world, and hence priorities for conservation, vary from region to region. Unfortunately, the same underlying theme prevails everywhere—there is no region where biodiversity is not in general decline. The story is much the same in the deep oceans, which cover the majority of the planet, with the collapse of wild fish stocks highlighting the serious damage to marine ecosystems; the United Nations Food and Agriculture Organization reported in 2005 that around three-quarters of fish stocks are being harvested at or above their ecological capacity.
The United States and Canada have per capita consumption rates of energy and resources that are among the highest in the world, creating enormous pressure on natural resources across the region (and, indeed, contributing disproportionately to pressures globally). A wide and important range of species and habitats is nonetheless found across this vast area, with Canada possessing one-quarter of the world’s wetlands and one-quarter of its ancient forest. This is despite high rates of habitat depletion. For example, Canada has drained 65 percent of its coastal marshes, and the United States has destroyed half of its original wetlands. Biodiversity is in decline throughout North America; 660 species of higher plants in Canada are at some degree of risk according to “Wild Species 2005: The General Status of Species in Canada”; in addition, the U.S. Fish and Wildlife Service estimated in November 2008 that 746 plant species are endangered or threatened in the United States. The U.S. Geological Survey reported in 2008 that nearly 40 percent of fish species in North American streams, rivers, and lakes are now imperiled, and the National Audubon Society reported that a quarter of U.S. bird species are at risk of extinction. The main causes of such alarming declines are intensive agriculture, development, resource extraction, and clearance of old-growth forest. The introduction of exotic species has also affected biodiversity. According to a 2004 study from Cornell University, there are approximately 50,000 foreign species in the United States, which together cause environmental damage and losses estimated at almost $120 billion per year; furthermore, 42 percent of the species on the Threatened or Endangered Species lists are at risk primarily because of alien or invasive species.
Marine ecosystems in the area are also being degraded; pollution from agriculture, industry, and sewage is affecting areas such as the Florida Keys and the Gulf of Mexico, with the latter now displaying a dead zone where oxygen levels in the water are too low to support fish. Overfishing is a problem in many coastal waters, and some very important fish stocks, such as the cod fisheries of the Grand Banks (off Newfoundland, Canada) have collapsed and not recovered.
Policy initiatives to conserve biodiversity are generally well developed in North America; Yellowstone National Park, founded in 1872 and located mostly in Wyoming, is generally reckoned to have been the world’s first national park. Some 11 percent of the North American land area is now legally protected. However, there have been land-use controversies in some protected areas, such as proposed oil drilling in the Arctic National Wildlife Refuge in Alaska. The United States remains one of the very few signatory nations not to have ratified the Convention on Biological Diversity, casting a shadow over the prospects for long-term biodiversity conservation in the region.
Latin America and the Caribbean
Latin America is exceptionally biologically rich. It includes five of the world’s ten most biodiverse countries (Brazil, Colombia, Peru, Mexico, and Ecuador) as well as the single most biodiverse area in the world—the tropical Andes. Latin America is home to approximately 27 percent of the world’s mammals, 34 percent of its plants, 37 percent of its reptiles, 43 percent of its birds, and 47 percent of its amphibians. The region has the highest diversity of plants on Earth. The World Wide Fund for Nature estimated that 80,000 species are found in the Amazon rainforest alone; yet the ecology of Latin America is still relatively poorly studied, especially in the tropical zones.
Habitat destruction across the region is the primary threat to biodiversity, with agricultural conversion, resource extraction, and infrastructure construction the main causes. The rapid depletion of the region’s tropical forests is well known as a serious global problem, but other habitats are also declining. Caribbean coral reefs are suffering from the effects of coastal development, pollution, overfishing, and rising sea temperatures, and mangrove forests are being cleared for agriculture, shrimp farming, and development. Ecuador has lost over two-thirds of its original mangroves, according to the International Mangrove Network. Species across the region are at risk; the IUCN’s “2008 Red List” cites 738 species nearing extinction in Brazil, 897 in Mexico, and 2,208 in Ecuador. Because of gaps in ecological knowledge about the region, such figures probably understate the true scale of the problem.
Countries throughout the region have responded to biodiversity depletion by establishing protected areas; approximately 20 percent of the region is thus designated, more than in any other region. One of the most high-profile conservation projects in Latin America is the Mesoamerican Biological Corridor, a network of protected areas linking southern Mexico to Panama. Such conservation measures will need to be very robust if they are to help ease the continuing pressures on Latin American biodiversity, especially forest loss.
Europe (including the Russian Federation)
Europe, the region with the longest history of industrialization, has suffered a lengthy decline in biodiversity, which greatly accelerated during the last century. Biodiversity is under strain from infrastructure development, forestry, agriculture, air and water pollution, wetland drainage, and the impact of introduced species. Large areas of wild land are rare, especially in the west of the region; due to the relatively small size and high population densities of most European countries, ecosystems tend to suffer from fragmentation, being split into smaller sections by developments such as highways or by farmland, further stressing wildlife. The European Environment Agency reports that butterfly populations in the region have declined by around 30 percent in the last twenty years. Species biodiversity is threatened everywhere; for instance, Spain risks losing 19 percent of its amphibians, 20 percent of its mammals and 27 percent of its reptiles, according to the IUCN. Marine ecosystems are also under stress, with the North Sea in serious trouble, mostly due to overfishing; the 2006 GBO reported that the number of large fish in the North Atlantic has declined by two-thirds in the last fifty years.
Europe has a relatively strong and popular green movement, and an awareness of Europe’s declining biodiversity is well established among the public and policymakers. Protected areas have been increasing in size and number since the middle of the twentieth century, and they now cover around 9 percent of Europe’s land area. Twelve national parks have been designated in England and Wales since 1949, for instance, with one more currently in the process of being created. Nonetheless, biodiversity seems likely to continue to decline across the region, with an important test being the ability of conservation measures to protect the relatively undeveloped habitats of Eastern Europe from the pressures of rapid economic expansion.
North Africa and the Middle East
This predominantly arid or subarid region is home to a variety of wildlife, including many rare species and a notably high proportion of endemic plants. The coastal and freshwater zones are especially important, with more than 1,200 species of fish and 200 species of crab in the Arabian and Red seas. The Mediterranean coastal fringe of North Africa is also an important center of biodiversity in the region. Habitats, and therefore species, face an intimidating suite of pressures; overgrazing, desertification, oil drilling, deforestation, drainage, water pollution and soil salinization, unsustainable hunting and fishing, military action, and urban development all take a toll. The Arabian Oryx became extinct in the wild in 1972 because of overhunting across the Middle East; it was reintroduced to Oman (from captive stock) in 1982, but it still suffers from poaching and remains among the most threatened of animals in the world. Degradation due to these pressures seems likely to grow as the human population increases and development spreads. Protected areas cover some 10 percent of the region, but this is not enough to reverse these trends.
Sub-Saharan Africa possesses a vast richness of habitats and species, with notable concentrations of biodiversity in the equatorial zone, on the southern cape, and on the island of Madagascar (which has a very high proportion of endemic species). The most extensive habitat type in Africa is savannah (a tropical grassland with scattered trees), which covers almost half the land area of the continent. The savannah supports the world’s largest concentration of large mammals, including iconic animals such as elephant, lion, giraffe, zebra, and a host of other species from other groups. Biodiversity is in decline across the continent; for example, South Africa’s Department of Environmental Affairs and Tourism states that half the country’s original wetlands have been destroyed. Deforestation, wetland drainage, desertification, mining, water scarcity, urbanization, and agriculture all contribute to habitat loss and biodiversity decline. Violent conflicts also play a significant role, as does, increasingly, the hunting of bushmeat (see Case Study—Primate Conservation and Bushmeat in the Congo Basin).
Although around 11 percent of the continent is protected for conservation, intense competition for land use outside (and sometimes within) protected areas means that the rates of species decline are likely to increase. As the human population grows rapidly and the great majority remains poor, it is difficult to see how the pressures on biodiversity can fail to increase dramatically.
Asia encompasses an enormous variety of habitat types, has climate zones ranging from equatorial to subarctic, and contains the world’s highest mountain system, the world’s second largest rainforest complex, and over half of the world’s coral reefs. There are concentrations of extremely high biodiversity, with some of the most biodiverse nations on Earth (such as Indonesia, China, Malaysia, and India) in this region. The region is also the world’s most densely populated and most rapidly developing, so biodiversity is under ever-increasing stress. For example, Indonesia has a greater variety of mammals than any other country on Earth, but the IUCN “2008 Red List” classed over one-quarter of these at risk of extinction. The IUCN also warned that, in Asia as a whole, 79 percent of monkeys and other primates face extinction. Deforestation, urbanization, agricultural expansion, mining, and pollution have all taken their toll. Wildlife also suffers directly from uncontrolled harvesting, hunting, and fishing.
Asia also displays a great richness of marine and coastal habitats, with very significant areas of coral reefs, mangroves, and seagrass beds. The greatest concentration of marine biodiversity in the world is found here—the Coral Triangle, which includes ocean areas around Indonesia, Malaysia, Papua New Guinea, Philippines, Solomon Islands, and Timor-Leste. Covering an area of 1.4 billion acres (570 million hectares) and hosting over six hundred reef building coral species—75 percent of all those known to science—and over 3,000 species of reef fish, the Coral Triangle is a special priority for conservation. Nonetheless, it is not immune from the problems facing marine habitats all over the region, such as overfishing, pollution, sedimentation, and mangrove clearance for aquaculture.
Inadequate data collection in many parts of Asia means that the true extent of the decline in most species remains uncertain. Conservation problems are compounded by the patchy effectiveness of the protected areas across the region, which cover some 8 percent of the region’s land area. For example, the Tanjung Puting reserve in Indonesia has suffered badly from illegal logging and poaching, and associated allegations of corruption have been made against the ranger staff. It seems that biodiversity conservation is likely to be a low priority in this poor region as its population and economies continue to grow rapidly, increasing pressure on scarce land.
The main feature of biodiversity in this area is the extraordinarily high levels of endemism. Around 80 percent of Australia’s plants and animals are endemic, according to the Australian Museum; every native amphibian, reptile, and mammal in New Zealand is endemic; and many of the other islands in this region also feature very high endemism. The rich biological resources of this region are declining; in the two centuries since European colonization of Australia, 11 out of the country’s 142 marsupial species disappeared—the worst mammal extinction in modern times. The IUCN “2008 Red List” detailed fifty-seven more as threatened with extinction. The introduction of many species has been particularly devastating to biodiversity in the region. In New Zealand, for example, stoats, weasels, and ferrets were introduced in the nineteenth century to control rabbits (themselves a problematic introduced species), but these species have preyed on and seriously reduced the native bird populations. Other pressures on biodiversity in the region include vegetation clearance (mainly for agriculture), wetland drainage, pollution, and soil salinization. Protected areas cover some 8 percent of Australia and 25 percent of New Zealand; most of the Pacific islands tend to have a smaller proportion of their land protected.
Rich marine life in all parts of Oceania, including the valuable coral reef systems, is being depleted by commercial overfishing and pollution. The largest coral reef system in the world, the Great Barrier Reef, is showing signs of degradation despite being protected by a marine park. Climate change is especially significant in Oceania; rising sea levels directly imperil many of the smaller island nations in the region, and warmer seas impact marine biodiversity.
|Table 1 Species Richness of Animals and Vascular Plants for Selected Countries|
|Source: World Resources Institute (WRI), “EarthTrends: Environmental Information,” World Resources Institute, Washington, D.C., 2007, available at http://earthtrends.wri.org. (Original data supplied to WRI by UNEP/WCMC, 2004.)|
|Note: DRC, Democratic Republic of Congo.|
|Papua New Guinea||11,544||720||260|
|Table 2 Extent of the Protection of the World’s Major Terrestrial Biomes|
|Protected areas||Biome protected (%)|
|Biome name||Area (km2)||Number||Extent (km2)||2003||1997|
|Source: Stuart Chape et al., United Nations List of Protected Areas (Cambridge, UK: IUCN/WCMC, 2003).|
|Tropical humid forests||10,513,210||3,422||2,450,344||23.31||8.77|
|Temperate needle-leaf forests/woodlands||15,682,817||13,297||1,350,221||8.61||5.72|
|Tropical dry forests/woodlands||17,312,538||5,746||2,210,563||12.77||7.07|
|Temperate broad-leaf forests||11,216,659||35,735||856,502||7.64||3.60|
|Evergreen sclerophyllous forests||3,757,144||5,334||399,587||10.64||4.39|
|Mixed mountain systems||10,633,145||9,345||1,735,828||16.32||9.10|
|Mixed island systems||3,252,563||3,425||967,129||29.73||16.32|
|Table 3 Threatened Species in Selected Animal Groups|
|Threatened status||Total threatened|
|Source: International Union for the Conservation of Nature, “2008 IUCN Red List of Threatened Species,” IUCN, Gland, Switzerland, and Cambridge, UK, 2008.|
|Notes: EX, extinct; EW, extinct in the wild (known only in captivity); CR, critically endangered (extremely high risk of extinction in the wild); EN, endangered (very high risk of extinction in the wild); VU, vulnerable (high risk of extinction in the wild).|
Case Study—Primate Conservation and Bushmeat In the Congo Basin
The Congo Basin of west central Africa holds a very important block of tropical rainforest covering nearly 500 million acres (200 million hectares) and spread over six countries: Cameroon, Central African Republic, Congo, Democratic Republic of Congo (DRC), Equatorial Guinea, and Gabon. These forests are well known for their wildlife diversity, with primates such as chimpanzees and gorillas—humankind’s closest evolutionary relatives—among the most celebrated residents of the forests. The main threat to biodiversity in the region is deforestation, but humans’ hunting for food (bushmeat) is increasingly threatening the survival of larger animals, in general, and primates, in particular.
There is a long tradition of hunting within the Congo Basin, with hunted forest meat an important food source, meeting between 30 and 80 percent of the dietary protein needs of rural dwellers in central Africa. Hunted animals also meet cultural and nonfood needs. However, the scale of hunting has rocketed in recent decades, with noticeable effects on wildlife. For example, the IUCN stated that the population of Lowland Gorilla (Gorilla gorilla) fell by 56 percent between 1983 and 2000 in Gabon, mostly attributed to hunting; because Gabon has the lowest density of human habitation in the Congo Basin, other countries are presumed to have experienced rates of loss even greater than this. The Lowland Gorilla is now classed as Critically Endangered in the IUCN “2008 Red List.” Similar patterns have been observed with other primates, with an estimated 7 million Red Colobus Monkeys (Piliocolobus species) taken from the Congo Basin for food every year, for instance.
The bushmeat trade is of high economic importance in the region, with sales both within forest communities at local markets and, increasingly, exported to urban centers and sometimes abroad. There is a growing market for bushmeat in the rapidly expanding cities, with a growing number of commercial hunters serving this market, often via illegal hunting. An important additional factor driving the huge increase in hunting is the logging industry, which has opened up large areas of previously poorly accessible land by construction of roads, thus facilitating access into the forest for hunters and providing routes for the transport of carcasses to cities; in fact, logging trucks have been used for the direct transport of bushmeat carcasses in many areas. Also, camps set up by corporations undertaking logging, mining, or drilling operations in the forest to accommodate their workers increase the local demand for wild meat. Political instability and lawlessness have exacerbated primate decline in the area, especially because of increased hunting after influxes of combatants or refugees into remote areas.
Unfortunately, legislative protection of endangered species in the region has often proved ineffective, and protected areas in the Congo Basin have failed to maintain safe primate populations even within their borders. Surveys within Salonga National Park in the DRC between 2003 and 2006 found evidence that Bonobo Chimpanzees (Pan paniscus) were being regularly poached in many parts of the park.
Hunting for bushmeat is now so extensive that it may finally drive the threatened primates in the Congo Basin to extinction. Large apes are particularly vulnerable due to their slow reproduction rate, which means that their populations recover slowly from depletion. Human populations in the forest also face a precarious future as the wild animal populations decline; the explosion of commercial hunting, much of which is for export to urban centers, means that, as bushmeat resources are exhausted, forest-dwellers face a loss both of their main protein supply and of an important source of basic income.
Solving the bushmeat crisis will be a very difficult and complex task. Because of the ingrained importance of bushmeat to the people of the Congo Basin and the lack of effective enforcement measures in much of the area, a total ban on the bushmeat trade—advocated by some conservationists—is unlikely to be achieved. A more integrated approach, involving a combination of regulation, education, protection of local land rights, and poverty alleviation, would be more likely to succeed. As with many examples of ecological degradation, social, political, and economic factors must be crucial components in any attempt to prevent the bushmeat trade from wiping out threatened primate species in this troubled and poor region.