Snakehead would dominate anything native to the United States put in with them. That is one of the biggest reasons they are illegal to own in I believe all 50 states now dead or alive. The Northern Snakehead is the largest threat to the United States waterways and has already been found in many states, the latest being Arkansas, that I know of.
The first discovery of Channa argus in the United States came October 22, 1997, while the California Department of Fish and Game were electro-shocking Silverwood Lake. This single specimen was, and still is, the only specimen that was ever found in this lake (Courtney et al 2004). The first established population discovered in the United States came about five years later in a two-acre pond known as Crofton Pond in Wheaton, Maryland (Courtney et al 2004). Between May and July of 2002, multiple specimens were captured in this pond, including over 100 juveniles proving that these fish had successfully established a population. It was later determined that two specimens were released in the pond by a local aquarium owner, because they were too large for his aquarium (Courtney et al 2004). These two fish became the downfall for this pond. When the department treated the lake with rotenone to eliminate the population, they gathered more than 1,200 Northern Snakeheads (Courtney et al 2004). These fish had not only successfully spawned, they had completely overtaken this pond. It was just a matter of time before they ate all the other species that were smaller than them.
Other discoveries in the United States have been Newton Pond in Sudbury, Massachusetts where only one fish was discovered (Courtney et al 2004). Two fish have been reported to have been caught by two fishermen in Lake Wylie in North Carolina, but North Carolina Wildlife Resources Commission never recovered any specimens through subsequent electro-shocking (Courtney et al 2004). Meadow Lake in Philadelphia produced three specimens in July 2004 (Orrell 2005). There was also one specimen recovered in Chicagos Burnham Harbor in Lake Michigan (Orrell 2005). There has been sufficient evidence found to prove that these fish have established a population in the Potomac River system. The last major discovery found in the United States came as recently as 2008. An Arkansas fish farmer that was raising Northern Snakeheads before it became illegal was said to have terminated all of his specimens, although it is unclear what the farmer meant with this statement (Stephens 2008). These fish showed up in the Big Piney Creek watershed, which is a tributarty to the Mississippi River. When the Arkansas Fish and Game Commission (AFGC) discovered an established population in 2008, in the Big Piney Creek watershed they decided their only chance for preventing this population to extend their range was to eradicate it (Stephens 2008). The 49,000 acres of land around the watershed of Big Piney Creek has 39 miles of creeks and 408 miles of ditches that connect to the Mississippi River (Bleed 2009). The reasons the AFGC gave for concluding to eradicate according to Stephens (2008) were:
They are aggressive top predators that eat most fish species, strong competitors with other predatory fish species, can tolerate Arkansas temperatures year round, can spawn up to five times per year, can severely effect food web of fisheries, the young receive care from both parents which improves survival rates, they thrive in delta environments with sluggish vegetative water with low oxygen levels, and can survive out of water.
The planned eradication effort used 24,000 pounds of the powdered and 3,000 gallons of liquid rotenone (Bleed 2009). Rotenone is a chemical substance derived from roots of tropical bean plants and it works by stopping the fish from using oxygen absorbed in the blood (Stephens 2008). This treatment would not only kill the snakeheads but it would also exterminate all species of fish, some amphibians, and aquatic invertebrates in the treated area. Rotenone does not affect terrestrial insects and will not kill wildlife that consumes water or dead fish treated with rotenone. It is not known what effects it will have on the plants and trees of the treated area (Stephens 2008). This eradication effort is predicted to cost $750,000. This does not include restoring populations of other fish species also killed in the eradication efforts (Bleed 2009).
These fish have the capability of eating prey up to thirty-three percent of their own body length. They can also survive out of water for a long while, depending upon the air temperature and moisture. These fish have been recorded surviving up to seven days out of water when the average air temperature was 7 degrees Celsius.
Just for a little back information...Above are bits and pieces of a reasearch paper I wrote on Northern Snakeheads. Here are some links:
[url=Http://sports.espn.go.com/outdoors/fishing/news/story?id=4012118]Dead Snakehead walking[/url]
Arkansas Outdoors News Letter The rest of my sources were scientific journals and published books.
