Biodiversity Outline

I. Introduction a. Over the past two decades, strong scientific evidence has emerged showing that loss of the world’s biological diversity reduces the productivity and sustainability of natural ecosystems and decreases their ability to provide society with goods and services like food, wood, fodder, fertile soils, and protection from pests and disease. II. Body a. [Amphibians] No group of animals has a higher rate of endangerment than amphibians. Scientists estimate that a third or more of all the roughly 6,300 known species of amphibians are at risk of extinction i.

The current amphibian extinction rate may range from 25,039 to 45,474 times the background extinction rate ii. Frogs, toads, and salamanders are disappearing because of habitat loss, water and air pollution, climate change and disease. iii. Because of their sensitivity to environmental changes, vanishing amphibians should be viewed as the canary in the global coal mine, signaling subtle yet radical ecosystem changes that could ultimately claim many other species, including humans. b. [Birds] Birds occur in nearly every habitat on the planet and are often the most visible and familiar wildlife to people across the globe.

As such, they provide an important bellwether for tracking changes to the biosphere. Declining bird populations across most to all habitats confirm that profound changes are occurring on our planet in response to human activities. i. A 2009 report on the state of birds in the United States found that 251 (31 percent) of the 800 species in the country are of conservation concern. ii. Globally, BirdLife International estimates that 12 percent of known 9,865 bird species are now considered threatened, with 192 species, or 2 percent, facing an “extremely high risk” of extinction in the wild — two more species than in 2008. ii. Habitat loss and degradation have caused most of the bird declines, but the impacts of invasive species and capture by collectors play a big role, too. c. [Fish]Increasing demand for water, the damming of rivers throughout the world, the dumping and accumulation of various pollutants, and invasive species make aquatic ecosystems some of the most threatened on the planet; thus, it’s not surprising that there are many fish species that are endangered in both freshwater and marine habitats. i. The American Fisheries Society identified 700 species of freshwater or anadromous fish in

North America as being imperiled, amounting to 39 percent of all such fish on the continent ii. In North American marine waters, at least 82 fish species are imperiled. Across the globe, 1,851 species of fish — 21 percent of all fish species evaluated — were deemed at risk of extinction by the IUCN in 2010, including more than a third of sharks and rays. d. [Invertebrates (depth into coral reefs)] Invertebrates, from butterflies to mollusks to earthworms to corals, are vastly diverse — and though no one knows just how many invertebrate species exist, they’re estimated to account for about 97 percent of the total species of animals on Earth.

Of the 1. 3 million known invertebrate species, the IUCN has evaluated about 9,526 species, with about 30 percent of the species evaluated at risk of extinction. i. Freshwater invertebrates are severely threatened by water pollution, groundwater withdrawal, and water projects, while a large number of invertebrates of notable scientific significance have become either endangered or extinct due to deforestation, especially because of the rapid destruction of tropical rainforests. ii.

In the ocean, reef-building corals are declining at an alarming rate: 2008’s first-ever comprehensive global assessment of these animals revealed that a third of reef-building corals are threatened. III. Conclusion a. While much concern over extinction focuses on globally lost species, most of biodiversity’s benefits take place at a local level, and conserving local populations is the only way to ensure genetic diversity critical for a species’ long-term survival. Not everything is lucid when it comes to biodiversity loss, but what it is clear that many thousands of species are at risk of disappearing forever in the coming decades.