Biodiversity at RiskBiodiversity at Risk

Environmental ScienceEnvironmental Science

ExtinctionExtinctionThe extinction of many species in a small The extinction of many species in a small amount of time is called a amount of time is called a mass extinctionmass extinction..

The last mass extinction event occurred when The last mass extinction event occurred when the dinosaurs disappeared.the dinosaurs disappeared.

Scientists warn that we are in the middle of a Scientists warn that we are in the middle of a mass extinction event now.mass extinction event now.

The current mass extinction is different from The current mass extinction is different from previous ones because it is being caused by previous ones because it is being caused by humanshumans

Species Prone to ExtinctionSpecies Prone to ExtinctionAn An endangered speciesendangered species is a is a species that has been species that has been identified to be in danger of identified to be in danger of extinctionextinction

A A threatened speciesthreatened species is a is a species that is likely to become species that is likely to become endangered in the foreseeable endangered in the foreseeable future.future.

The major causes of extinction The major causes of extinction today are the destruction of today are the destruction of habitats, the introduction of habitats, the introduction of non-native species, pollution, non-native species, pollution, and the over-harvesting of and the over-harvesting of species.species.

Habitat Destruction and Habitat Destruction and FragmentationFragmentation

As human populations As human populations grow, we use more land grow, we use more land to build homes and to build homes and harvest resources. harvest resources.

In the process, we In the process, we destroy and fragment the destroy and fragment the habitats of other species.habitats of other species.

It is estimated that habitat It is estimated that habitat loss causes almost 75 loss causes almost 75 percent of the extinctions percent of the extinctions now occurring.now occurring.

Ex. Florida PantherEx. Florida Panther

Invasive SpeciesInvasive SpeciesAn An exotic speciesexotic species is a is a species that is not native to a species that is not native to a particular region.particular region.

Even familiar organisms such Even familiar organisms such as cats and rats are as cats and rats are considered to be exotic considered to be exotic species when they are brought species when they are brought to regions where they never to regions where they never lived before.lived before.

When exotic species threaten When exotic species threaten native species that have no native species that have no natural defenses against them, natural defenses against them, they are called they are called invasive invasive speciesspecies

Hunting, Harvesting, and PoachingHunting, Harvesting, and Poaching

Excessive hunting can Excessive hunting can also lead to extinctionalso lead to extinction– Ex. Passenger PigeonsEx. Passenger Pigeons

Thousands of rare Thousands of rare species worldwide are species worldwide are harvested and sold for harvested and sold for use as pets, houseplants, use as pets, houseplants, wood, food, or herbal wood, food, or herbal medicine.medicine.

PoachingPoaching is is the illegal is is the illegal harvesting of fish, game, harvesting of fish, game, or other species.or other species.

PollutionPollution

Pesticides, cleaning Pesticides, cleaning agents, drugs, and agents, drugs, and other chemicals used other chemicals used by humans are by humans are making their way into making their way into food webs around the food webs around the globe.globe.– Ex. Bald Eagles and Ex. Bald Eagles and

DDTDDT

Areas of Critical DiversityAreas of Critical Diversity

Some areas of the world have a greater Some areas of the world have a greater number of endemic species than othersnumber of endemic species than others

An An endemic speciesendemic species is a species that is is a species that is native to an area and is found only there.native to an area and is found only there.

Areas of high biodiversity include tropical Areas of high biodiversity include tropical rain forests, coral reefs, and tropical rain forests, coral reefs, and tropical islandsislands

Captive Breeding ProgramsCaptive Breeding ProgramsWhen a species is clearly When a species is clearly on the verge of extinction, on the verge of extinction, people can start a captive people can start a captive breeding programbreeding program

Species are bred in Species are bred in captivity, with the hopes captivity, with the hopes of reintroducing of reintroducing populations to their populations to their natural habitats.natural habitats.

Ex. California CondorEx. California Condor

Preserving Genetic MaterialPreserving Genetic MaterialOne way to save the One way to save the essence of a species is essence of a species is by preserving its genetic by preserving its genetic material.material.

Germ plasmGerm plasm is hereditary is hereditary material (chromosomes material (chromosomes and genes) that is usually and genes) that is usually contained in seeds, contained in seeds, sperm, eggs, or pure sperm, eggs, or pure DNA.DNA.

Many botanical gardens Many botanical gardens and zoos act as germ and zoos act as germ plasm banks.plasm banks.

Other Efforts to Preserve SpeciesOther Efforts to Preserve Species

Zoos, wildlife parks, aquariums, and botanical Zoos, wildlife parks, aquariums, and botanical gardens, are living museums of the world’s gardens, are living museums of the world’s biodiversity.biodiversity.

But, these kinds of facilities rarely have enough But, these kinds of facilities rarely have enough resources or knowledge to preserve more than a resources or knowledge to preserve more than a fraction of the world’s rare and threatened fraction of the world’s rare and threatened species.species.

Ultimately, saving a few individuals does little to Ultimately, saving a few individuals does little to preserve a species as captive species may not preserve a species as captive species may not reproduce or survive again in the wild.reproduce or survive again in the wild.

Preserving Habitats and Preserving Habitats and EcosystemsEcosystems

Priority is now given to protecting entire Priority is now given to protecting entire ecosystems rather than individual species.ecosystems rather than individual species.

By saving the ecosystem, most of the species By saving the ecosystem, most of the species in an ecosystem are saved instead of just the in an ecosystem are saved instead of just the endangered ones.endangered ones.

When possible large areas are preserved for When possible large areas are preserved for two reasons:two reasons:1.1. Small areas are in danger from natural disastersSmall areas are in danger from natural disasters2.2. Some animals need a large range to find foodSome animals need a large range to find food

Endangered Species Act of 1973Endangered Species Act of 1973

Under the first provision of the Endangered Under the first provision of the Endangered Species Act, the U.S. Fish and Wildlife Service Species Act, the U.S. Fish and Wildlife Service (USFWS) must compile a list of all endangered (USFWS) must compile a list of all endangered and threatened species in the United States. As and threatened species in the United States. As of 2002, 983 species of plants and animals were of 2002, 983 species of plants and animals were listed.listed.

The second main provision of the act protects The second main provision of the act protects listed species from human harm.listed species from human harm.

The third provision prevents the federal The third provision prevents the federal government from carrying out any project that government from carrying out any project that jeopardizes a listed species.jeopardizes a listed species.

CITESCITESConvention on International Trade in Convention on International Trade in Endangered Species (CITES) Endangered Species (CITES)

The CITES treaty was the first effective effort to The CITES treaty was the first effective effort to stop the slaughter of African elephants being stop the slaughter of African elephants being killed by poachers who would then sell the ivory killed by poachers who would then sell the ivory tusks.tusks.

In 1989, the members of CITES proposed a total In 1989, the members of CITES proposed a total worldwide ban on all sales, imports, and exports worldwide ban on all sales, imports, and exports of ivory, hoping to put a stop the problem.of ivory, hoping to put a stop the problem.

The Biodiversity TreatyThe Biodiversity Treaty

The The Biodiversity TreatyBiodiversity Treaty is an is an international agreement aimed at international agreement aimed at strengthening national control and strengthening national control and preservation of biological resources.preservation of biological resources.

The treaty’s goal is to preserve biodiversity The treaty’s goal is to preserve biodiversity and ensure the sustainable and fair use of and ensure the sustainable and fair use of genetic resources in all countries.genetic resources in all countries.

Private OrganizationsPrivate OrganizationsMany private organizations work to protect Many private organizations work to protect species worldwide, often more effectively than species worldwide, often more effectively than government agencies.government agencies.– World Wildlife FundWorld Wildlife Fund – sustainable use of resources – sustainable use of resources

and wildlife protectionand wildlife protection

– Nature ConservancyNature Conservancy – has purchased land to turn – has purchased land to turn into nature preserves in 29 countriesinto nature preserves in 29 countries

– Conservation InternationalConservation International – identifies biodiversity – identifies biodiversity hot spotshot spots

– Greenpeace InternationalGreenpeace International – organizes direct and – organizes direct and sometimes confrontational actionsometimes confrontational action

Balancing Human NeedsBalancing Human NeedsAttempts to protect species often come into Attempts to protect species often come into conflict with the interests of the people.conflict with the interests of the people.

Sometimes an endangered species represents a Sometimes an endangered species represents a source of food or income. source of food or income.

Many people don’t understand how important Many people don’t understand how important biodiversity is to stable ecosystems.biodiversity is to stable ecosystems.

Many conservationists feel than an important Many conservationists feel than an important part of protecting species is educating people on part of protecting species is educating people on the value of biodiversity.the value of biodiversity.