http://biology.usgs.gov/s+t/noframe/f076.htm
This is the citation for the article with 2 diagrams I couldn't include in the above quote
fig 1
Fig. 2. The percentage of the U.S. mussel fauna classified by conservation status category: undetermined, endangered and presumed extinct, endangered, threatened, special concern, and stable. Fig. 2. The percentage of the U.S. mussel fauna classified by conservation status category: undetermined, endangered and presumed extinct, endangered, threatened, special concern, and stable.
