Boles, L. C., R. N. Lipcius, 1994.   Potential for Predator-Mediated Biological Control of the Zebra Mussel in the Hudson River Estuary.  School of Marine Science, Virginia Institute of Marine Science, The College of William and Mary.

Proceedings of The Fourth International Zebra Mussel Conference, Madison, Wisconsin, March 1994

Potential for Predator-Mediated Biological Control of the Zebra Mussel in the Hudson River Estuary

Abstract
Predation controls community structure in aquatic systems. The success of introduced species like the zebra mussel, Dreissena polymorpha, is due in part to ineffective predators in the newly colonized systems. We quantified distribution, abundance, and mortality rates of a D. polymorpha population in the middle portion of the Hudson River Estuary, New York. Rocks were collected along a depth gradient in the field, and were sampled for density and size structure of the resident mussels. Predator exclusion experiments with rocks harboring a known number of D. polymorpha were used to estimate natural mortality. In addition, we conducted manipulative field experiments to test the effectiveness of the blue crab, Callinectes sapidus, at consuming zebra mussels by presenting similar rocks to crabs in field enclosures. Field sampling in the months of June, July and August indicated a dense (~30,000 m^-2) population composed of a single cohort of 1+ year class mussels. Mussel density increased dramatically with depth less than two meters below the spring-low-tide mark. In cage experiments, C. sapidus caused mortality rates an order of magnitude higher than those measured for the local predator guild, which was primarily composed of finfish. Consumption of zebra mussels by pumpkinseed, Lepomis gibbosus, was observed in the field on several occasions. Although blue crabs have the potential to limit zebra mussel abundance, at the present this is unlikely in the Hudson River Estuary due to the low natural abundance of the predator within the system. However, high predation rates of D. polymorpha by C. sapidus in this estuarine habitat indicate that the blue crab is capable of regulating the zebra mussel in habitats where the blue crab is abundant.

Entire Paper
Keywords: Ecological_interactions, Population_dynamics, Predators, Zebra_mussel
Product Type: Publication, Proceedings
User Type: Resource_management