the upper altamaha initiative:
fall 2007
altamaha spinymussel
Thomas Floyd, Steve Carpenedo, and Jaclin Durant
Abstract
The Altamaha River in the Coastal Plain of Georgia is home to numerous endemic mussel species. Since presence/absence surveys began in the late 1960's, several of these endemic mussels have experienced dramatic decreases in population. The Altamaha spinymussel, Elliptio spinosa , has possibly seen the most marked decrease in population and in 2002 the United States Fish and Wildlife Service (USFWS) elected to list this species as a candidate under the Endangered Species Act (16 U.S.C, 1531-1544). Past research showed that while the occupied range of the Altamaha spinymussel in the main stem of the Altamaha and Ocmulgee has remained stable, they are possibly extirpated from the Oconee and Ohoopee drainages. The remnant populations are ~60-75% less prevalent and as no juveniles were found in the most recent surveys, the continued viability of the population is in question. Based on this information, in 2006 the USFWS upgraded their candidacy status from 5 (non-imminent) to 2, imminent danger of extinction unless action is taken. To protect a species from extinction, the source of the threats must be known and how these threats impact the viability of a species. Little is known about the life history of the Altamaha spinymussel or the threats that may be the cause of the imminent extinction of this species. The USFWS speculates that poor water quality, either from sedimentation, organic pollutants, or heavy metals may be responsible for the decline in the population experienced. It is unknown which of these is the culprit and how, if at all, it is impacting the population as a whole and the physiology of individuals. Through a comprehensive literature review on the effects of environmental pollutants on Unionidae mussels, and a GIS analysis of available data on the source of environmental pollutants into these watersheds, we hope to increase our knowledge base of this species and its habitat and make steps forward in protecting the Altamaha Spinymussel.
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