Service biologists sampling freshwater mussels on the Big River. A square frame is placed on the stream bottom at 150 random locations per site. Divers remove substrate by hand from inside the frame to a depth of 10 cm, place in attached bag, bring to the surface, and sort on a floating sieve to find mussels. They identify and measure the mussels, then return them to the stream. This sampling method estimates the density of mussels living on the stream bottom.
Photo by USFWS; Andy Roberts
December 3, 2013
Missouri Ecological Services and Fish and Wildlife Conservation offices are working together to study native freshwater mussel populations and how they might be affected by stream sediments contaminated with heavy metals from lead mining on the Big River in southeastern Missouri. In preparation for this task, we researched published literature and conducted interviews with preeminent mussel biologists to develop and implement the most statistically and scientifically defensible survey methodologies.
In the summer of 2013 we completed the first phase of the study, which is locating and delineating survey sites. To accomplish this task, we traveled over 68 miles of the river channel searching for suitable habitat and mussel beds. This represents the first time the river has been thoroughly explored to determine the full extent and distribution of suitable mussel habitat. In all, 76 sites were identified and evaluated as potential survey sites. Suitable habitat was found in 20 of these sites, and these areas were delineated for later sampling. Continue Reading the Field Notes Report »
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