Status of freshwater unionid populations at Pictured Rocks National Lakeshore
Nichols SJ, Crawford E, Amberg J, Kennedy G, Black G, Allen J. 2002. Status of freshwater unionid populations at Pictured Rocks National Lakeshore. U.S. Geological Survey, Great Lakes Science Center. Ann Arbor
Stream and inland lake habitats of Pictured Rocks National Lakeshore, MI were surveyed by snorkelers and SCUBA divers for freshwater mussels. Qualitative surveys established mussel habitat depth preferences (above the thermocline) in lakes. Densities were estimated from random, quantitative surveys in various substrates using portable grids. Whole lake populations were calculated from these data and areas of appropriate habitat. Species identification was based on living animals and non-living shells. Seven species and 1 intergrade were identified: eastern elliptio (Elliptio complanata), spike (Elliptio dilatata), fatmucket (Lampsilis luteola and Lampsilis radiata), pink heelsplitter (Potamilus alatus), giant floater (Pyganadon grandis), lake floater (Pyganadon cataracta), and intergrades (Pyganadon grandis x cataracta). None is threatened or endangered, although the pink heelsplitter (Potamilus alatus) was unexpected and was found in only one lake. Growth rate (shell length) and age classes were estimated from collected specimens. Chlorinated hydrocarbons from soft tissue were measured for representatives of 5 species. Specific host fish of the larval (glochidia) form are discussed. Mussel distribution was geo-referenced from Grand Sable, Beaver, Little Beaver, Chapel, and Kingston Lakes. No mussels were observed in streams. Threats to mussel populations and management recommendations are discussed. Maps illustrate survey sites and distribution of mussels in the lakes. Presence of fingernail clams (Sphaerids) was noted in lakes and streams. No exotic bivalves were found. Freshwater sponges were also noted.
- Type
- Published Report
- Authors
- Nichols, S; Crawford, E; Amberg, J; Kennedy, G; Black, G; Allen, J
- Date of Issue
- 2002-05
- Publisher
- U.S. Geological Survey, Great Lakes Science Center
- Units
- PIRO
- Keywords
- Beaver Lake, Chapel Lake, eastern elliptio (Elliptio complanata), fatmucket (Lampsilis luteola), fatmucket (Lampsilis radiata), Freshwater Mussels, giant floater (Pyganadon grandis), Grand Sable Lake, Invertebrates (Invertebrata), Kingston Lake, lake floater (Pyganadon cataracta), Limnology, Little Beaver Lake, Natural Resources Management, pink heelsplitter (Potamilus alatus), Pollutants, Population, spike (Elliptio dilatata), Sponges (Porifera)