Zebra Mussel

Originally from Eurasia, zebra mussels made their first appearance in North America in the Great Lakes in the early nineties. The mussels have since made their way to Texas, and over the years, this invasive species has proliferated in the state, killing off alarming numbers of native species and clogging pipes used for power plants, drinking water, manufacturing and boating.

Zebra mussels are small, fingernail-sized mussels native to the Caspian Sea region of Asia.
Considered one of most damaging of the invasive species introduced to this country, zebra mussels were transported to the Great Lakes in ballast water from a transoceanic vessel in the early nineties. The mussels have since spread rapidly to all of the Great Lakes and waterways in many states, as well as Ontario and Quebec, and to southeast and western portions of the United States including Texas.

One of the zebra mussel's most defining characteristics is its tendency to colonize hard substrates and surfaces (e.g., rocky bottoms and water intake structures) in high densities, with as many as tens of thousands living in a square yard.

Zebra mussels have had deleterious effects on local ecosystems. They reduce the amount of phytoplankton available for other organisms and increase water clarity, causing changes to the ecological structure of the lake community. In addition, zebra mussels accumulate contaminants within their tissues to levels greater than concentrations in the water column, increasing the exposure of wildlife to contaminants. Zebra mussel infestations also threaten native mussel populations by attaching to the native species and essentially smothering them.

Zebra mussels have caused a great deal of economic damage by clogging intake pipes of water treatment and power plants as well as boat engine cooling systems. Unfortunately, solutions to these problems are few and not highly effective, resulting in high costs for cleaning and control measures.