Environmental Ethics

Earliest human society consisted of hunter-gatherers in which members of a settlement ventured afield to collect plants and fruits, to fish, and to hunt meat-producing animals. In these societies, humans behaved as predators in a sustainable manner, meaning they hunted to sustain their village but they did not decimate wildlife populations.

Today Earth approaches 7 billion people, which is beyond its carrying capacity. Population densities in Africa, Asia, and South America have forced some people into a far more menacing predator role in which wildlife numbers and habitat disappear in the face of human activities. Environmental ethicists have confronted the underlying cause of this problem: poverty. The International Union for Conservation of Nature (IUCN) and the European Commission published this viewpoint in an undated briefing titled Biodiversity in Development: The Links between Biodiversity and Poverty: “Poor people themselves are often the cause of biodiversity degradation and loss, especially if lack of income alternatives drives them to over-exploit the resources.” This statement emphasizes the complex association between human poverty and biodiversity.

Environmental ethics involves the search for a solution for two opposing needs: human hunger and wildlife survival. Many African communities depend on their native wildlife for food (called bushmeat) and for income. On a small scale this practice was at one time sustainable, but an increased demand for food and space far exceeds the capacity of wildlife populations to keep up. Threats to the survival of African wildlife now include the following: people hunting for food, destruction of habitat for agriculture or urban development, disappearance of prey animals, retaliatory or preventive killings to protect villages from predator animals, and illegal wildlife smuggling and poaching for income. Some residents sell their native animals as sources for medical drugs, nonmedical cures and supplements, aphrodisiacs, religious and ornamental items, and exotic foods. Wildlife protections exist in many nations but, unfortunately, as governments strengthen the protections, black-market prices for animal products soar. As a result, the extinction of some animals hastens rather than slows.

These forms of legal and illegal hunting have been driven by hunger. Starvation is an immediate crisis for people in many regions of the world in addition to Africa, and things like bushmeat often provide a family with its only protein source. So a need to protect endangered wildlife faces another equally critical need: preventing human starvation.

Some corners of the world rich in biodiversity have revised their relationship with native endangered wildlife. For instance, hunters in Thailand and Costa Rica refrain from capturing rare birds, reptiles, amphibians, or fish because they can make more money keeping them alive (instrumental value) for ecotourism. These two countries now earn more from ecotourism than they would by destroying animal habitats.

Ethicists must also consider conflicts between biodiversity and cultural needs that may not have an obvious instrumental value. The black rhinoceros’s habitat in sub-Saharan Africa has stayed about the same size in the past 30 years, yet 90 percent of the animals have disappeared. Two related factors have contributed to this tragedy: a black market that deals in rhino horns and petroleum. In Yemen, young men earn daggers with elegantly carved handles made from rhino horn as a symbol of status and wealth. As oil-rich Yemen’s wealth has grown in the past few decades, the country has become the world’s largest importer of black rhino horn to make these ceremonial pieces. The Convention on International Trade in Endangered Species of Wild Flora and Fauna (CITES) has put a global ban on the import of black rhino horn, but as a result the black market for rhino horn has flourished. Armed guards now protect many rhinoceros herds against poaching, and conservationists have even resorted to tranquilizing the animals and cutting off their horns to dissuade poachers. The dehorned animals confront another problem: adults use their horns to establish herd hierarchies and to protect their young. As with most ethical dilemmas, more than one aspect exists to each problem.

In 2005 conservationist Adam Oswell said in a radio interview in Australia, “In countries where people don’t make a lot of money, they’re not concerned about killing animals; they just want to feed their family and make money.” The link between poverty and biodiversity cannot be explained any better.

Keystone Species

Keystone species, by their natural behavior, determine the condition of other species in an ecosystem. If keystone species decline or go extinct, an entire ecosystem may not survive. Wilson has suggested with other ecologists that past extinctions were very likely due to the decline of certain keystone species that, in turn, caused ecosystem imbalance. Ecosystem imbalance occurs when one or more components disappear, putting stress on the remaining members of the ecosystem.

Sea otters and bees are but two examples of the many keystone species found in ecosystems. Sea otters’ main food is sea urchins. By holding


Ecosystems depend on keystone species for a variety of services. The loss of keystone species accelerates the loss of biodiversity because many ecosystem members depend on the keystone for survival.

sea urchin populations in check, otters keep them from devouring kelp forests and seaweeds that are home to hundreds of types of fish, perhaps thousands of species overall. Bees benefit ecosystems by pollinating plants and trees, which provide protective cover for other plants and habitat for insects. The insects then serve as a food source for many bird species, upon which foxes feed, upon which raptors feed.

Foundation species play a slightly different role from keystones. They change habitat in a way that enhances it for other species. African elephants play the role of foundation species through their feeding activities in which they crack and uproot trees, which helps open up areas of land and aerates soil. This condition promotes the growth of grasses for grazing animals, and eventually small bushes and woodlands follow the grasslands. The new vegetation favors tree grazers, insects, birds, and the predators that hunt them. Elephant feeding behavior therefore benefits not only ecosystems but an entire community.

In predation, one organism hunts, kills, and eats another organism(s) for its nutrition. Predators are carnivores or omnivores, and their prey are usually omnivores and herbivores. Predators play a keystone role by regulating populations of prey animals and thereby maintaining balance
within food webs. Examples of predator keystone species are wolves, lions, alligators, white sharks, and owls.

Predators furthermore keep populations of prey in check in a nonrandom manner. In other words, they do not usually attack the first prey animal they find, but rather select their prey. Predators remove old, weak, and sick animals and, as a consequence, the remaining strong and healthy population passes on its genes to offspring. Healthy prey populations then support healthier and perhaps larger predator populations. For example, years marked by very large North American deer populations have resulted in above average mountain lion populations. The converse situation may also occur in which as a prey population declines, predators regulate their
numbers to avoid starvation.

Another set of relationships in biological communities comes not necessarily from feeding habits, but from other aspects of animal lifestyle. These relationships are called symbiosis, and biological communities contain three main types: mutualism, commensalism, and parasitism. In mutualism, two or more species benefit from each others’ activities. For example, the bacteria living in the gut of termites receive a safe, nutrient- rich habitat, while they provide a benefit to the termite by digestxvi


Predators play a crucial role in every ecosystem by helping to regulate prey populations, which helps control overgrazing of plant species. The four predators shown here serve in these roles in their distinct ecosystems: (a) red-tailed hawk in New Mexico (Lin Evans) (b) snapping turtle being caught for tagging and scientific study (Mark Corner and Diverse Mobile Outdoor Environment, University of Massachusetts) (c) African lion (Herb Coleman) (d) white shark (Alice Christie).

ing woody food. In commensalism, one species benefits and the other is neither helped not harmed. Redwood sorrel, a small herb that lives in the shade of redwood trees, has a commensal relationship with the redwoods. Shade from the tall trees gives the sorrel its preferred habitat but the redwood tree receives no known benefit. Finally, parasitism is a relationship in which one organism benefits and the other is harmed. As an example, Phytophthora fungus lives on oak and other trees as a parasite and the fungus eventually kills the tree.


Prey species that are not held in check by predation deplete their food and other resources, and this leads to stress, competition, disease, and starvation, which are all characteristics of ecosystem imbalance. These circumstances cause a prey population to crash, which then threatens the predator.

The following sidebar “Environmental Ethics” examines the relationships that exist when humans become part of an ecosystem.

Environmental Ethics

Environmental ethics focuses on a difficult question: Which is more important to planet Earth, providing for humans or protecting species other than humans? Some ethicists have tried to answer this question by putting a value on all the world’s species, which, of course, is difficult, by dividing the question into three different value systems:

• commodity value—Can an animal or plant be made into a drug, a product, or be sold?
• amenity value—Do species improve human life in a nonmaterial way, as Henry David Thoreau described? That is, Thoreau believed life improved simply by having the opportunity to observe other animals.
• moral value—Do species have value on their own and not related to any human needs?

The world contains thousands of species that humans know little about, and these creatures and plants seemingly have no value at all in the environment. More likely, science has not yet deciphered the roles these species play. How is one to put a value on the thousands of unknown species? Most important, is the value of an entire endangered species worth more or less than a person who is hungry, poor, or jobless?

The Endangered Species Act’s well-meaning attempt to halt the disappearance of animals and plants opened a Pandora’s box of ethical questions. This law and biodiversity in general are complex subjects, yet humans may be running short on time to solve many of the puzzles held
within ecosystems.