Distribution and Density of Three Uncommon or Imperiled Unionid Species in Northern New York

The New York Natural Heritage Program lists Eastern pearlshell Margaritifera margaritifera as imperiled, and Pocketbook Lampsilis ovata and Yellow lampmussel Lampsilis cariosa as uncommon in New York. The population and distribution of these mussels in the lower Salmon and Little Salmon rivers (Franklin County, NY) were estimated using double sampling at 10 transects from 2005 through 2012. Thirteen species of mussels were collected in the study area dominated by Eastern elliptio Elliptio complanata (89%). Pocketbook, Yellow lampmussel, and Eastern pearlshell each represented 1% or less of the living mussels collected in transects and the distribution of empty shells of Pocketbook was similar to those living; Yellow lampmussel empty shells were more abundant (49% of those collected) at the most upriver part of the Little Salmon River where no living Yellow lampmussel was collected. Eastern pearlshell was found only in 2012. Comparison of midden shells revealed a greater concentration of Pocketbook (90% of those collected in middens) at the lower part of the Salmon River that was not associated with a transect. This midden also produced 72% of Yellow lampmussel collected in all middens.