Distribution, Abundance, and Biomass of Freshwater Mussels (Bivalvia: Unionidae) in Lake St. Clair
نویسندگان
چکیده
A mussel population survey was conducted in Lake St. Clair with divers using SCUBA to sample at 29 stations throughout the lake. Mean abundance was 2 m~2 and mean biomass was 4.4 g dry wt m~2. Of the 18 species collected, Lampsilis radiata siliquoidea was by far the most abundant, accounting for 45% of all individuals. The age-frequency distribution ofL. r. siliquoidea was dominated by individuals between 9 and 12 years old. In contrast, the second most abundant species, Leptodea fragilis, showed yearly variation in recruitment with no apparent trends in year class strength. Annual production of L. r. siliquoidea was 0.20 g m~2 y~l and the turnover ratio was 0.13. The diversity and composition of mussels in Lake St. Clair appear little changed since the turn of the century, but there are indications that population numbers may be declining in the future. ADDITIONAL INDEX WORDS: Molluscs, clams, productivity.
منابع مشابه
Long-Term Decline in Freshwater Mussels (Bivalvia: Unionidae) of the Western Basin of Lake Erie
Long-term trends in the abundance of unionids in the western basin of Lake Erie were examined from data collected at 17 stations in 1961, 1972, and 1982. The mean number of unionids at these stations declined over this time period, decreasing from 10 m~2 in 1961, to 6 m~2 in 1972, down to 4 m~2 in 1982. This decline in abundance was reflected in the decrease in the number of stations where muss...
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