Why are zebra mussels a problem?Why are zebra mussels considered to be a problem? Here are some of the reasons.
Why are zebra mussels considered to be a problem?
•Ecological impacts: Zebra mussels have disrupted the traditional aquatic food chains of many inland lakes in the U.S.
Regardless of their size, inland lakes represent unique ecological systems. When zebra mussels enter into these fragile systems, their voracious filter feeding depletes the availability of microscopic organisms that play a critical part in each lake’s ecological food web.
As a result, valued sportfish are impacted. Zebra mussels consume considerable amounts of these beneficial microscopic organisms and this creates less food for larval and juvenile fish that support sport and commercial fisheries.
•Biological impacts: Zebra mussels are similar to other mussel species because they attach themselves to hard surfaces. However, unlike other species, zebra mussels will readily attach themselves to native mussels.
This behavior is known as “bio-fouling” and with the spread of zebra mussels, native mussel populations have been severely reduced.
Some native mussels are more tolerant than others, but even for these resistant species, becoming covered by zebra mussels makes them more vulnerable to environmental stressors, such as extreme water temperatures, lack of food, or parasites and disease.
As zebra mussels spread, biologists are concerned that populations of native mussels will decline, and perhaps some of the rarer species may be completely eliminated
•Human health impacts: As significant filter feeders, zebra mussels may increase human and wildlife exposure to organic pollutants (PCBs and PAHs).
Early research shows that zebra mussels can rapidly accumulate organic pollutants within their tissues to levels more than 300,000 times greater than concentrations in the environment.
They also deposit these pollutants in their pseudofeces. These contaminants can be passed up the food chain so that any fish or waterfowl consuming zebra mussels will also accumulate these organic pollutants. Likewise, human consumption of these same fish and waterfowl could result in further risk of exposure.
•Swimmers: Beaches are also affected by zebra mussels. The sharp-edged mussel shells along swimming beaches can be a hazard to unprotected feet.
Source: The Stop Aquatic Hitchhikers, part of a public awareness campaign sponsored by the U.S. Fish and Wildlife Service and the U.S. Coast Guard.