Significant fish predation on zebra mussels Dreissena polymorpha in Lake Champlain, U.S.A.

Abstract

The objectives of this study were to: (1) determine which fishes were consistently eating zebra mussels Dreissena polymorpha in Lake Champlain and document their feeding behaviour and (2) quantify the diet composition of the fish predators that were found to consume zebra mussels. From 2002 to 2005, freshwater drum Aplodinotus grunniens, pumpkinseed Lepomis gibbosus, yellow perch Perca flavescens and rock bass Ambloplites rupestris all consumed zebra mussels at varying frequencies and amounts. Aplodinotus grunniens and L. gibbosus chewed clumps of zebra mussels, expelling shells, whereas P. flavescens and A. rupestris swallowed small individuals whole. Lepomis gibbosus consumed zebra mussels at the highest frequency (65-89% of prey consumed) and zebra mussels comprised a large part of this fish's diet (up to 40% by dry mass). Zebra mussels were also an important component of the diet of A. grunniens (up to 59% of the diet by dry mass, 40-63% frequency of consumption). The percentage of the diet comprising zebra mussels in P. flavescens and A. rupestris varied significantly from year to year but never exceeded 10%. Because A. grunniens and L. gibbosus crushed zebra mussels, the nutritional return from consuming zebra mussels would be similar to other prey; for P. flavescens and A. rupestris zebra mussels were only partially digested and the nutritional return would probably be low. As predation on zebra mussels is widespread and significant, it is possible that fish predators could contribute to regulating the population of zebra mussels in Lake Champlain.

Zebra mussel (Dreissena polymorpha) affects the feeding ecology of early stage striped bass (Morone saxatilis) in the Hudson River estuary

“…In the Great Lakes, the appearance of zebra mussel depleted populations of the amphipod Diporeia, which forced Lake Whitefish and Alewives to shift their prey use; feeding success declined, as did growth rate and condition (Madenjian et al 2015;Pothoven et al 2001;Pothoven and Madenjian 2008). Some fishes incorporate zebra mussels into their diets (French and Bur 1996;Nack et al 2015;Pothoven et al 2001;Ruetz et al 2012;Watzin et al 2008), but we found no evidence of early stage Striped Bass feeding on zebra mussel veligers. Other molluscs occurred as rare prey in Striped Bass and other early-stage fishes in our samples; thus we regard as possible but unlikely that the absence of young bivalves in our samples might be attributable to preservation in formalin.…”

Predation and physical environment structure the density and population size structure of zebra mussels

“…The abundance of the exotic mussel, Musculista senhousia, in a southern California bay was largely constrained by a small number of native molluscivores (Reusch 1998). Fish predation is proposed to control zebra mussel populations in Lake Champlain, USA (Watzin et al 2008), in eastern North America (French 1993), and in coastal wetlands (Bowers and de Szalay 2007). Bioenergetic modelling suggested that fish predation might decelerate zebra mussel invasion success and spread in southern US waters where fish growth rate and metabolic demands are high (Eggleton et al 2004).…”

“…McMahon (1991) proposed fishes as the most active predators of settled zebra mussels, but only a handful of studies have indicated the potential of fish predation to control invasion success and density of exotic mussels (Eggleton et al 2004, Bartsch et al 2005, Watzin et al 2008. The relative importance of biotic interactions and the physical environment to successful invasion is poorly understood (Havel et al 2005).…”

A food web modeling analysis of a Midwestern, USA eutrophic lake dominated by non-native Common Carp and Zebra Mussels

“…Shunting energy away from the pelagic food web can reduce abundance and growth of sport fishes (Mayer et al, 2000;Miehls et al, 2009;Rutherford et al, 1999;Thayer et al, 1997). However, some fish species can prey directly on zebra mussels and invertebrates associated with zebra mussel colonies, potentially enhancing those populations and fisheries they support (Magoulick and Lewis, 2002;Watzin et al, 2008). …”