Ecosystems

Sudden marsh dieback events are not uncommon and have occurred in coastal marshes from the Gulf of Mexico to Maine. Brown Marsh is a term given to the unusually rapid and extensive browning of Louisiana’s saltwater marsh grass Spartina alterniflora, commonly known as oyster grass or smooth cordgrass. One of the most severe events occurred in 2000, when over 100,000 hectares (ha) of salt marsh were...

Wetlands provide habitat for thousands of species of aquatic and terrestrial plants and animals. Wetlands are valuable for flood protection, water quality improvement, shoreline erosion control, natural products, recreation, and aesthetics. Wetlands are among the most productive habitats on earth providing shelter and nursery areas for commercially and recreationally important animals like fish...

Wetlands are transitional areas, sandwiched between permanently flooded deepwater environments and well-drained uplands, where the water table is usually at or near the surface or the land is covered by shallow water. They include mangroves, marshes (salt, brackish, intermediate, and fresh), swamps, forested wetlands, bogs, wet prairies, prairie potholes, and vernal pools. In general terms...

The USGS documents the zebra mussel's geographic distribution and studies its behavior and biology. The resulting information is critical in helping to develop strategies aimed at containing and controlling the mussel's spread. Meanwhile, catching and transporting zebra mussels for use as bait, food, and aquarium pets is highly discouraged. We also encourage good boat hygiene: Wash your boat off...

Zebra mussels are an invasive, fingernail-sized mollusk that is native to fresh waters in Eurasia. Their name comes from the dark, zig-zagged stripes on each shell. Zebra mussels probably arrived in the Great Lakes in the 1980s via ballast water that was discharged by large ships from Europe. They have spread rapidly throughout the Great Lakes region and into the large rivers of the eastern...

Two agencies within the Department of the Interior (DOI) are responsible for researching and regulating snakeheads: the U.S. Geological Survey (USGS) and the U.S. Fish and Wildlife Service (FWS) . As the research arm of the DOI, the USGS has conducted extensive, worldwide research on snakeheads that provides a basis for regulating the importation and interstate transport of those fish in the...

Snakeheads are freshwater fishes with little, if any, tolerance for saltwater. Within their native and introduced ranges, they live in small and large streams, canals, rivers, ponds, reservoirs, and lakes. Many species can tolerate a wide range of pH, and one species living in Malaysia and parts of Indonesia prefers highly acid waters (pH 2.8-3.8). The northern snakehead and several other species...

Snakeheads are air-breathing freshwater fishes that are not native to North America. In scientific terms, snakeheads are divided into two distinct genera: Channa (snakeheads of Asia, Malaysia, and Indonesia) Parachanna (African snakeheads) In the summer of 2002 and again in late spring 2004, Channa argus , the northern snakehead, generated national media attention when anglers caught this fish in...

During all of their life stages, snakehead fish compete with native species for food and habitat. A major concern is that snakeheads might out-compete (and eventually displace) important native or other established predatory fish that share the same habitat. As adults, snakeheads can be voracious predators. Should snakeheads become established in North American ecosystems, their predatory behavior...

If you capture a snakehead fish: Do not release the fish or throw it up on the bank (it could wriggle back into the water). Remember, this fish is an air breather and can live a long time out of water. Kill the fish by freezing it or putting it on ice for an extended length of time. Photograph the fish if you have access to a camera so the species of snakehead fish can be positively identified...

Dead snakehead fish--on ice or frozen--can be imported for food purposes to any state except those where importation or possession of dead snakeheads is illegal. Live snakeheads of one species that are being cultured in Hawaii (but not exported to the United States mainland) are available in one market in Honolulu. Hawaii regulations require that all fish must be killed and their gills removed...

Prior to being added to the list of injurious wildlife under the Lacey Act in 2002, which banned import and interstate transport without a permit from the U.S. Fish and Wildlife Service, snakeheads were sold in pet stores and in live food fish markets and some restaurants in several major U.S. cities, including Boston, New York, and St. Louis. Live specimens have been confiscated by authorities in...