US EPA

7879132 

Journal Article 

Selective feeding and biodeposition by zebra mussels and their relation to changes in phytoplankton composition and seston load 

Baker, SM; Levinton, JS; Kurdziel, JP; Shumway, SE 

1998 

1 

Journal of Shellfish Research
ISSN: 0730-8000
EISSN: 1943-6319 

17 

4 

1207-1213 

WOS:000079628200037 

We examined the ability of zebra mussels (Dreissena polymorpha) to preferentially infest or reject various phytoplankton species and nonliving particles. Our objective was to determine if preferential ingestion by zebra mussels could explain the changes observed in the Hudson River since their invasion: (1) decline of cyanobacteria, Microcystis in particular, (2) rise to dominance by diatoms, and (3) very small change in total seston load. We found that zebra mussels are capable of efficiently sorting and rejecting particles. Not only were clearance rates higher when the cyanobacterium Microcystis was present in suspension, but Microcystis was preferentially ingested over almost all other particle types tested. Diatoms were generally rejected as diffuse pseudofeces which were easily resuspended, even in still water. The rejection of cattail (Typha) detritus by zebra mussels corresponds to the rejection by oysters (Crassostrea virginica) of cord grass (Spartina) detritus particles (Ward et al. 1998). Pseudofeces of clay or detritus particle types were also very diffuse. In a few cases, however, clay or detritus particles, rather than phytoplankton cells, were preferentially ingested by zebra mussels. The interaction of selective feeding by zebra mussels with resuspension of diffuse biodeposits by tidal mixing may explain the differential decline of phytoplankton groups and nonliving particles in the Hudson River. 

zebra mussels; particle selection; clearance rates