Water Quality
Changes in water quality, like increased transparency, can be quickly apparent following zebra mussel invasion (see the Increase in Water Clarity and Increase in Macrophyte Coverage and Biomass section). Other water quality impacts can be more difficult to detect, such as decreased dissolved oxygen (Effler and Siegfried 1994) and increases in concentrations of soluble phosphorus and inorganic nitrogen (Caraco et al. 1997, Effler et al. 1997). The impact of these less obvious water quality changes, however, can be significant. The respiration of zebra mussels on the rock bottom of a channel within the Seneca River, for example, degraded the oxygen resources of the river to the extent that violations of New York State water quality standards occurred.
Other Aquatic Organisms Fouled by Zebra Mussels
Besides unionids, a variety of other organisms have been reported with attached zebra mussels, but the effects of this fouling are not well understood. These include macrophytes, gastropods, crayfish, and trichopteran cases.
Zebra mussels attached to this crayfish.
Note the dense zebra mussel coating on the lower portion of Ceratophyllum, a submersed macrophyte.
Numerous other macrophyte species in inland lakes have been observed with dense layers of zebra mussels (Myriophyllum sp.).
Whether such thick mussel coatings impact photosynthesis and or other physiological functions is unknown.
Alteration of the Freshwater Ecosystem, An Overview
Increase in Water Clarity and Increase in Macrophyte Coverage and Biomass