Download Full Text (484 KB)


Benthic filter feeders are important organisms in estuaries due to their ability to remove algal and non-algal particulate matter from the water column. Microcystin (MC) is a cyanotoxin that is known to have adverse effects on diverse consumers, though its effects on benthic filter-feeders are not well-studied. In this study, we examine the effects of microcystin on the filtering activities of Rangia cuneata, a common and often dominant filter-feeder in tidal freshwaters. Clams and seston obtained from the James River were used along with commercially-available microcystin to measure clearance rates of Rangia across a gradient of dissolved microcystin concentrations. We also compared clearance rates of James River clams to natural food sources in the presence and absence of microcystin. Our results show that dissolved microcystin inhibited Rangia clearance rates. Even at the lowest concentration tested (0.40 μg MC L-1) clearance rates were significantly lower than controls. Dietary experiments showed that when elevated microcystin was present in the James (September), clearance rates were lower for clams fed James River seston relative to clams fed seston from another source. Our results suggest that the presence of microcystin may diminish ecosystem service provided by benthic filter feeders.

Publication Date


Subject Major(s)

Center for Environmental Studies, Department of Biology, Integrated Life Sciences Doctoral Program

Current Academic Year


Faculty Advisor/Mentor

Paul Bukaveckas


Virginia Commonwealth University. Undergraduate Research Opportunities Program

Is Part Of

VCU Undergraduate Research Posters


© The Author(s)

Effects of dissolved and dietary Microcystin on clearance rates of Wedge Clams (Rangia cuneata) in the tidal fresh James River