What's New House measure supports shippers on water dumping The Associated Press (5/24) A plan gaining support in Congress and backed by the cargo shipping industry would establish a nationwide policy for dumping ballast water into U.S. waterways that environmental groups say would open the door to more invasive species like zebra and quagga mussels.
Overview Zebra mussels (Dreissena polymorpha) 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. Since that time, they have 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.
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.
Glen Canyon National Recreation Area Expanded Zebra Mussel Action Plan (2007) National Park Service, U.S. Department of the Interior, Glen Canyon National Recreation Area, Arizona and Utah An Action Plan to prevent the spread of zebra mussels in Lake Powell and the upper Colorado River. The Zebra Mussel Prevention Program was further expanded in May 2008, at which time both Lake Powell and the upper Colorado River were believed to still be free of the mussels.
Quagga-Zebra Mussel Action Plan for Western U.S. Waters (2010) Western Regional Panel on Aquatic Nuisance Species This plan summarizes current dreissenid mussel management strategies of agencies across all levels of government, identifies priority actions, and makes recommendations on ways to coordinate activities.