On the pattern of discovery of introduced species
- *Donald Bren School of Environmental Science and Management, 4410 Donald Bren Hall, University of California, Santa Barbara, CA 93106; and ‡Marine Policy Center, Woods Hole Oceanographic Institution, Mail Stop 41, Woods Hole, MA 02543
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Edited by Simon A. Levin, Princeton University, Princeton, NJ, and approved January 29, 2003 (received for review October 28, 2002)
Abstract
Introductions of nonindigenous species can have significant effects. It is commonly claimed that the rate of species introductions to the United States has increased over time. This claim is based in part on the increasing rate of discoveries of introduced species. This discovery rate is influenced by factors other than the introduction rate. These include the sampling rate and population growth in the introduced species. In this article, we show that the discovery rate can increase even when there is no increase in either the introduction rate or the sampling rate. This suggests that the basis for some claims regarding an increasing rate of introductions may be invalid.
Footnotes
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↵ † To whom correspondence should be addressed. E-mail: costello{at}bren.ucsb.edu.
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This paper was submitted directly (Track II) to the PNAS office.
- Copyright © 2003, The National Academy of Sciences
