Chapter 18 Module 61

Negative trends identified by the Convention on Biological Diversity

-Habitat loss has been slowed in some regions of the world, but remains high in other regions -Many fish species continue to be overharvested -On average, species at risk of extinction have moved closer to extinction -There is high variation around the world in the preservation of ecosystem services -Natural habitats are becoming smaller and more fragmented

Marine Mammal Protection Act

A 1972 act to protect declining populations of marine mammals. Prohibits the killing of all marine mammals in the US and prohibits the import or export of any marine mammal body parts.

Metapopulations

A collection of smaller populations connected by occasional dispersal of individuals along habitat corridors. Each population fluctuates somewhat independently of the other populations and a population that declines or goes extinct can be rescued by dispersers from a neighboring population. So if we set aside multiple protected areas and connect them through habitat corridors a species is more likely to be protected from extinction by a decimating event.

Endangered Species Act of 1973

A law requiring the federal government to protect all species listed as endangered.

Endangered species

A species that is in danger of extinction within the foreseeable future throughout all or a significant portion of its range.

Threatened species

According to U.S. legislation, any species that is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range.

Benefits of Endangered Species Act

Although the process of getting a species listed as endangered can take several years, once listed many threatened and endangered species have experienced stable or increasing populations.

Convention on Biological Diversity

An international treaty to help protect biodiversity. The treaty has three objectives: conserve biodiversity, sustainably use biodiversity, and equally share the benefits that emerge from the commercial use of genetic resources such as pharmaceutical drugs.

Ecosystem approach to conserving biodiversity

Awareness of potential sixth mass extinction in which humans have played a major part has increased interest in the ecosystem approach. This approach recognizes the benefit of preserving entire regions of the world, such as biodiversity hotspots. Protecting ecosystems is one of the major motivators of creating national parks and marine reserves. The amount of protected land has increased dramatically since 1960.

Species that have been removed from the endangered species list due to sufficient increase in population

Bald eagle, peregrine falcon, American alligator, eastern pacific gray whale

Example of captive breeding

California Condor. In 1987, only 22 of these birds remained. Thanks to captive breeding and improvements in the Condor's habitat, the population in 2013 was up to 400. Programs like these are a major function of zoos and aquariums around the world

Bringing back endangered species

Habitat protection and reduced contaminants in the environment have allowed grizzly populations to increase to the point where they could be taken off the Endangered Species List. Important grizzly populations live in Yellowstone National Park and have been protected there since 1975

Edge habitat

Habitat that occurs where two different communities come together, typically forming an abrupt transition, such as were a grassy field meets a forest

What is NOT true of the Endangered Species Act?

It uses a different definition for threatened than the IUCN (International Union for Conservation of Nature)

Larger islands vs smaller islands

Larger islands have more species and support bigger populations and a wider variety of habitats. This means these species are less susceptible to extinctions. Whereas smaller islands cannot support many species or large populations, and are therefore more likely to see their species go extinct

According to the theory of island biogeography

Multiple small conservation areas will protect species better than one large area of the same size

Size, shape, and connectedness of protected areas

Must consider the size of protected areas and whether or not to protect one large area or a number of smaller ones, as well as how they are connected to other areas or whether or not they are isolated.

What is a trend identified by the Convention on Biological Diversity?

Natural habitats are becoming smaller and more fragmented

Biosphere reserves

Protected areas consisting of zones that vary in the amount of permissible human impact. Ideally have core areas that have minimal human impact and outer areas that have increasing levels of human impact. But in reality, they can take many forms. Generally consists of a Core zone for observation, Buffer zone for recreation, tourism and research, and Transition area for human settlements, logging, and farming.

Methods for helping threatened species populations rebound

Providing additional habitat, reducing harvest, reducing the presence of a contaminant that is impairing survival or reproduction

Two general approaches to conserving biodiversity

Single-species approach and ecosystem approach

Controversy behind Endangered Species Act

The act restricts human activities in regions where endangered species live. Construction projects can be altered or halted. Organizations whose activities are threatened by the Act try to pit the protection of species against the jobs of people in the region. They argue that the government cares more about animals than people's livelihoods. This is especially true in the Pacific Northwest where loggers want to cut down much of the old-growth forest that is home to the spotted owl. In this situation, a compromise allowed logging to continue on some old-growth forest while the rest became protected habitat.

Captive breeding

The practice of capturing members of threatened and endangered species so that their young can be bred and raised in controlled environments and subsequently reintroduced into the wild

Applying theory of island biogeography to other areas

This theory was first applied to islands in the ocean, but now has been applied to natural parks and other protected areas surrounded by unprotected areas. Using the theory in these cases gives us some idea of the best ways to design and manage protected areas. For example, when the protected areas are far apart, it is less likely that species can travel between them. So when we create smaller areas, they should be close enough for species to move among them easily

Conservation legislation usually focuses on...

a single species

Problems with protecting many small habitats include

increased dispersal between populations, and the need for corridors between some protected species

The Marine Mammal Protection Act prohibits

the killing of all marine mammals