[w]idespread evidence shows that the modern rates of extinction in many plants and animals exceed background rates in the fossil record. In the present article, I investigate this issue with regard to North American freshwater fishes. From 1898 to 2006, 57 taxa became extinct, and three distinct populations were extirpated from the continent. Since 1989, the numbers of extinct North American fishes have increased by 25%. From the end of the nineteenth century to the present, modern extinctions varied by decade but significantly increased after 1950 (post-1950s mean = 7.5 extinct taxa per decade). In the twentieth century, freshwater fishes had the highest extinction rate worldwide among vertebrates. The modern extinction rate for North American freshwater fishes is conservatively estimated to be 877 times greater than the background extinction rate for freshwater fishes (one extinction every 3 million years). Reasonable estimates project that future increases in extinctions will range from 53 to 86 species by 2050.
Thursday, October 18, 2012
U.S. Geological Survey Article Advisory: Extinction Rates in North American Freshwater Fishes, 1900-2010
Yesterday, the U.S. Geological Survey (USGS) advised of the release of an article, titled Extinction Rates in North American freshwater fishes, 1900-2010, 62 Bioscience, no. 9, Sept. 2012, 798-808. The article, authored by Noel M. Burkhead available here, discusses according to the abstract, how