Endangered Species — A Global Threat

The Clean Air Act, scheduled for reauthorization this year, seems hopelessly mired in Congress and environmental groups feel singled out for special wrath by the Reagan administration, but in the extension of the Endangered Species Act environmentalists can claim a signal victory during 1982. After the controversy and ridicule surrounding past applications of the act to the snail darter in Tennessee and Furbish's lousewort in Maine, those concerned with slowing the loss of species must have experienced both satisfaction and relief as Congress's renewal of the legislation was signed into law by the president.

But however sweet to the environmental movement, the victory is decidedly limited inasmuch as most of the populations and species at risk are located in tropical moist forests, where the cost of preserving habitat may be high, and where what happens is beyond the reach of U.S. policy. While the Endangered Species Act does have an international component that seeks to halt traffic in endangered specimens, it cannot address the problem of habitat modification except in the United States. (And, in any event, the 430 overseas species now on the endangered list seem puny compared with estimates of future extinctions.) Indeed, its value is largely symbolic. Having an effective endangered species policy of our own provides a moral basis for urging similar concerns upon others.

In situ/Ex situ

Measures to conserve the world's biological resources can be divided into two classes. In what are called in situ approaches, species are left where found in nature, preserved in more or less natural settings. Ex situ approaches, on the other hand, include the removal of species from their natural habitat, for preservation in permanent collections, such as in zoos and botanic gardens, and the preservation of seeds and other genetic material in a controlled environment. The Atlas lion, for example, is extinct in the wild but maintained in zoo collections. Perhaps the most important ex situ approaches involve the maintenance of plant and animal germplasm for agriculture (for example, seed collections), in which are kept wild or primitive varieties of crops and domestic animals.

Until recently, germplasm collection and maintenance has been rather haphazard and informal throughout the world. In the United States many private collections exist, assembled from all over the world by individual scientists and seed companies to meet research and commercial needs. In addition, the Agricultural Research Service of the U.S. Department of Agriculture operates the National Seed Storage Laboratory (NSSL), intended to provide backup storage for the private collections. Although this informal network of private collections has been instrumental in improving agricultural productivity, it has remained oriented toward the specific research needs of the collectors rather than preservation in its own right.

The apparent deficiencies of private germplasm collection led to the establishment in 1973 of the National Plant Germplasm System (NPGS). In part, this system is supposed to serve as a clearinghouse for users of germplasm by providing a centralized source of information on private germplasm collections, and to strengthen the ties between the NSSL and private collectors. NPGS also is establishing a network of germplasm banks, the first of which opened recently on the campus of Oregon State University. The United States also contributes—both directly and indirectly through the World Bank and United Nations—to the International Board of Plant Genetic Resources (IBPGR), the international coordinator of germplasm collection and storage. About forty germplasm banks around the world are now part of the IBPGR system, storing over one million varieties of crop plants.

The principal advantage of ex situ collections is cost. Plants that can be preserved from seeds are quite inexpensive to maintain. Clonal propagation of plants that cannot be preserved by seeds is more costly, but usually inexpensive compared with the opportunity costs of maintaining habitat. Ex situ collections also are invaluable because they allow the assembly of genetic material from many disparate locations at a place where research is going on. Thus, much field work can be avoided.

Unfortunately, ex situ preservation is feasible for only a small fraction of species. Most obviously, ex situ techniques cannot be used for species as yet undiscovered. For many known species, furthermore, long-term preservation ex situ is not yet guaranteed because their reproductive mechanisms are insufficiently understood. Moreover, even where feasible, ex situ preservation suffers from serious shortcomings. A germplasm repository ordinarily will contain only a small fraction of the genotypes of the species unless the number of individuals kept is very large. In addition, conservation of a species outside its natural environment very likely will interrupt the evolutionary process. Particularly important for agricultural purposes is the danger that the species preserved ex situ will not evolve along with its predators. Finally, while ex situ techniques may be the least expensive way to preserve an individual species, it is rarely the least expensive way to preserve an entire ecosystem, and indeed may not work at all for this purpose.

Preserving habitat

The above considerations suggest that no matter how successful and economically important ex situ preservation becomes, it can only be regarded as a supplement to, not a substitute for, habitat preservation as a means of preserving species. In other words, saving a substantial portion of the world's biological resources may well require setting aside extensive areas as nature preserves. Other questions then arise: How extensive must such areas be? Where should they be located? And who will pay the cost of maintaining them?

Probably the most urgent priority is the preservation of germplasm for agriculture, because it is on this resource that the world's future food supply largely depends. At present, only about 150 species are used worldwide in agriculture, with three species (wheat, rice, and maize) providing over half of human caloric intake. Each of these 150 species evolved in a relatively small geographic area, and a substantial amount of overlap in the areas of various species can be found in twelve regions, often called Vavilov Centers (figure 1) after the Russian biologist who first studied them, are said to be the origin of most of the genetic diversity of agriculturally important plants. Obviously, habitat preservation efforts should be concentrated in these regions, although determination of the precise areas that are the best candidates for preservation requires further study.

In the humid tropics, one suggested approach to preservation is found in the concept of "refugia." During the Ice Ages of the Pleistocene period, the tropics were much dryer than they are now, and tropical moist forests apparently survived only in small patches. Although the theory is not without controversy, many experts believe that, because they were safe harbors during the cold periods, these refugia still contain relatively more species and, in particular, more endemic species than other currently similar areas. If they can be identified, these refugia would appear to be ideal candidates for preservation.

Both kinds of areas—the refugia and the Vavilov Centers—are located primarily in developing countries where the need for preservation must compete against other land uses, especially food and fuelwood production. Until recently, the policies of Third World countries tended to promote habitat destruction. Brazil, for example, has made the opening of the Cazon region a matter of national pride. Consequently, land in the interior was made available to landless peasants much in the manner of the U.S. Homestead Act. Developers of Amazon lands also receive generous tax breaks and import duty rebates.

Nonetheless, developing countries are becoming increasingly concerned about preservation of natural habitats. The Brazilian government recently purchased a section of primary forest in the state of Bahia that is especially rich in endemic species. In addition, several new conservation areas have been created in Brazil, including one of 22,000 square kilometers. Most other developing countries are much more conservation-minded than before. A leading example is Indonesia, which has announced a plan to set aside 5 percent of the nation's land area—over 10 million hectares—in parks and nature reserves.

One reason for the interest of developing countries in conservation lies in the potential economic value of biological resources. Until recently, diosgenin, a drug essential to the manufacture of cortisone and some birth control pills, could be obtained only from a plant indigenous to Mexico. The Mexican government in the past few years has raised the price from $5 per pound to $69 per pound, the latter a price at which synthetic substitutes become economically attractive. Other countries, including Kenya and Ethiopia, have given an indication that they will charge for germplasm whatever the market will bear. However, the poverty endemic to these countries makes it difficult for them to promulgate policies whose benefits are both uncertain and deferred. As in the United States, moreover, the costs of preservation largely will be borne in the vicinity of the area to be preserved. The present effects of the preservation, in other words, may include considerable suffering for many people who already live in extreme poverty.

First World incentives

While the bulk of the world's germplasm resources are located in the Third World, the principal users of these resources, at least for now, are the developed countries. This gives the developed nations a strong interest in preservation, and justifies actions by the western nations to assist in the preservation of endangered species and their habitat. Such actions can take one of two forms. First, they can actively discourage the destruction of habitat or taking of species. For example, inasmuch as cattle production is one of the principal causes of habitat destruction in the Amazon, it has been proposed that beef imports from Brazil (or at least from the Amazon region) be banned.

The trouble with such punitive measures is that they may generate hostility, especially if the target country does not agree that the species is endangered. The contretemps between the United States and Australia over importation of kangaroo products provides an example. In addition, unilateral or even multilateral actions to discourage markets in endangered species will not be fully effective if other countries are willing to provide markets. Some Western European nations, for example, have refused to restrict trade in endangered species.

The second approach would be to make habitat destruction unnecessary by substituting for the products that would be produced thereby. The United States and other developed countries might, for example, provide aid to developing countries in return for actions by those countries to prevent further conversion of natural areas. In fact, "trades" of this sort already have been implemented through the World Bank, where loans to Third World countries often have required an environmental component in project development plans. But many observers feel that the financial assistance currently being extended to such countries is too small to make much difference in their preservation policies. Moreover, recent trends, in the United States at least, are toward reduced funding, especially of multilateral institutions such as the World Bank.

The economic and political difficulties of preventing massive extinctions in tropical rain forests perhaps will engender a sentiment in the United States that such extinctions, while unfortunate, are not our problem. But they are, quite apart from any ethical responsibility we may feel. After all, the economic potential of a species does not end at national frontiers. It is U.S. agriculture, industry, and science that stand to benefit greatly from the preservation of genetic information in other areas of the world especially rich in this information, and it is U.S. agriculture, industry, and science that will lose greatly if this information is destroyed.

Author Winston Harrington is a fellow in RFF's Quality of the Environment Division. This article is adapted from a chapter on endangered species by Harrington and Anthony C. Fisher in Current Issues in National Resource Policy, edited by Paul R. Portney, with the assistance of Ruth B. Haas, which is to be published by RFF in November.