Volunteer Monitoring for Zebra Mussels
Ecosystem Impacts
•Filter feeders
–Reduce phytoplankton
–Suppress zooplankton
–Change fish community
First, zebra mussels are filter feeders. They filter suspended material out of the water column and transfer it to the benthos or bottom of water bodies. This can result in a decrease in the amount of chlorophyll, phytoplankton, and primary production in a water body.
Zebra mussels can also suppress zooplankton populations by filtering water. In areas of eastern Europe, the biomass of phytoplankton and zooplannkton decreased more than 10-fold following the introduction of zebra mussels (Karatayev et al. 1997).
In addition, the decline in zooplankton populations due to zebra mussel filtration can also affect fish community structure. In particular, reducing the amount of zooplankton available can affect the growth of fish that are planktivorous at some point in their development (MacIsaac 1996).
The aquatic food web can be like a house of cards, with a precarious balance from phytoplankton to zooplankton to planktivorous fish to piscivorous fish. If zebra mussels wipe out the lower trophic levels, the entire food web can collapse.