Chapter 11: Preserving Biodiversity

A Forest Without Elephants: Can We Save One of Earth’s Iconic Species?

Story Abstract & Additional Information

This chapter explains how many species on Earth are in danger of becoming extinct predominantly due to human impact. Protection plans can focus on individual species or entire ecosystems; both methods have proven successful. A combination of national and international efforts is helping address biodiversity loss.

Here are some of the key points in the story for this chapter:

What are the major causes of species endangerment and extinction today?

  • In general, conservation biologists agree that biodiversity the world over faces five main threats—threats tied to an expanding human population and increasing levels of affluence: overexploitation, pollution, climate change, invasive species, and—the number-one cause—habitat destruction and fragmentation. To bring attention to those that are at risk for extinction, the International Union for Conservation of Nature (IUCN) has established the Red List of Threatened Species:
  • In recent decades, despite a rash of international attention to the problems of biodiversity loss, each of the five threats to biodiversity has gotten worse. Overfishing, for example, has claimed some 85% of oyster reefs and as much as 90% of the world’s populations of large predatory fish like tuna and cod. Read about new global efforts to provide legal protection against overfishing:

Due to overfishing of cod, the New England Fishery Management Council, has called for a 77% reduction in cod quotas for the Gulf of Maine:

How do single-species conservation programs compare to ecosystem-based approaches?

  • Early conservation programs often took the single-species approach: They singled out well-known animals—known as flagship species—like pandas and condors, and focused on the specific threats those individual species faced, using a variety of methods, including captive breeding programs to increase population sizes and reintroducing the species to the wild. As part of Species Survival Plans, administered by the Association of Zoos and Aquariums, conservation work goes on in zoos and aquariums as well as in the wild:
  • As long as the main problem facing a species is low population size, reintroduction campaigns can be very effective, but this is insufficient if other threats—such as a degraded habitat or heavy poaching pressure—still exist. For this reason, many conservationists now support an ecosystem approach. This means identifying entire ecosystems—often biodiversity hotspots—that are at risk, and taking steps to restore or rehabilitate them. Listen to conservation biologist Daniel Jansen—who has worked for nearly 40 years restoring the area in and around Guanacaste National Park in Costa Rica—talk about some of the biology of the rainforest:

What legal protections do endangered and threatened species have in the United States and internationally?

  • A variety of national laws and international treaties (conventions) offer protection for species both inside and outside “protected areas.” In the United States, there are laws that specifically protect particular groups (e.g., wild horses or eagles) or specific habitats (e.g., wetlands), but the two broadest laws, both passed in the 1970s, are the main federal statutes that protect species: the Marine Mammals Protection Act (1972) and the Endangered Species Act (1973). Read about species restoration success stories in the U.S. National Park system:
  • Internationally, there are many treaties, such as the Convention on International Trade in Endangered Species of Wild Fauna and Flora (1973) and the Convention on Biological Diversity (1992). Read about the International Day for Biological Diversity, held each year on May 22:

Additional information about other topics from this chapter:

Conservation Genetics

  • Conservation genetics is the scientific field that relies on species’ genetics to inform conservation efforts. Through DNA analysis, conservation biologists can determine the amount of genetic diversity within a population, or the kinship between separate groups or even whether a given population is part of an endangered species. Conservation biologists are using DNA analysis to address the issue of elephant poaching in Africa: Because elephant populations from different regions of Africa are genetically distinct, scientists can match the DNA from a confiscated tusk to the region in Africa where it originated, helping law enforcement officials track down poachers and identify regions of high poaching activity:

Ecotourism

  • Conservation of biodiversity does not have to depend solely on regulations, laws, and treaties. There are other effective approaches to protecting species and their ecosystems. Some of these are market driven, such as ecotourism: A community, region, or nation may find that tourists who come to see intact ecosystems bring in more money that would be gained by harvesting resources. Read about a type of ecotourism that is growing in popularity—“voluntourism”: