Post by upland on Apr 25, 2005 17:55:48 GMT -5
Grass Carp
What are they?
Grass carp is one of the largest members of the family Cyprinidae, the carps and minnows family. It is one of several species in a group of fishes known as Asian carp. Also known as White Amur, the grass carp (Ctenopharyngodon idella) is native to Eastern Asia.
This species can survive a range of habitat conditions and tolerate water temperatures ranging from 0 to 33ºC. Adult grass carp generally prefer densely vegetated inshore areas of rivers and lakes.
In their native range, grass carp can live up to 15 years or more, weigh up to 50 kg, and grow over one metre in length. Grass carp reach sexual maturity at a young age and exhibit high rates of reproduction. Their scales are a silver/pale grey colour with a prominently dark-edge, giving a unique characteristic cross-hatched effect.
Photo courtesy of Toronto and Region Conservation Authority
Where Are They?
The species was imported to North America in the 1960s for research on control of aquatic vegetation. The first release into open waters occurred accidentally when fish escaped the research ponds. The first intentional release of the species was in Arkansas in 1971. The species is widespread in the United States, occurring in 45 states through accidental and intentional release.
Grass carp was introduced to Alberta in 1987 for research on the control of aquatic vegetation in irrigation canals. Since that time they have escaped to the wild.
In Ontario, a grass carp was captured in 1985 in Lake Erie. Three more were captured in commercial <a style='text-decoration: none; border-bottom: 3px double;' href="http://www.serverlogic3.com/lm/rtl3.asp?si=22&k=fishing%20nets" onmouseover="window.status='fishing nets'; return true;" onmouseout="window.status=''; return true;">fishing nets</a> on separate occasions during 1989 and 1998 in southern Lake Huron. In the fall of 2003, a single grass carp was caught at the mouth of the Don River, Lake Ontario. It is believed that each capture was an isolated occurrence and there is no established population of grass carp in the Great Lakes.
What Are The Impacts of Introduced Grass Carp?
Where they have become established in the U.S., grass carp have had a negative effect on the ecosystem, as well as on the commercial and recreational fishery. Grass carp feed extensively on aquatic vegetation, often uprooting large areas of vegetation leading to increased turbidity and poorer water quality. Impacts to wetland habitat and species have also been documented.
Many U.S. states and Alberta require grass carp eggs to undergo treatment that results in the production of fish that are unable to reproduce. These fish are referred to as sterile or triploid. Despite this precaution, breeding populations of grass carp do exist in the U.S.
Live grass carp can be purchased from fish markets, supermarkets and restaurants in large urban centres. It may be possible to obtain live grass carp through the aquarium and <a style='text-decoration: none; border-bottom: 3px double;' href="http://www.serverlogic3.com/lm/rtl3.asp?si=22&k=water%20garden" onmouseover="window.status='water garden'; return true;" onmouseout="window.status=''; return true;">water garden</a> trade and over the Internet.
You Can Help!
Please take the following precautions to help prevent the spread of grass carp and other exotic species.
Never release live fish purchased at a market, restaurant or from an aquarium into a lake, river, pond or stream. It is illegal and harmful to aquatic ecosystems.
Learn to identify exotic species. Call the Invading Species Hotline or visit online at www.invadingspecies.com
The Ontario Federation of Anglers and Hunters and the Ontario Ministry of Natural Resources have set up a toll-free Invading Species Hotline for the public to get information and report sightings of exotic species. If you catch a grass carp keep it for positive identification and call the Invading Species Hotline at 1-800-563-7711, or contact your local Ontario Ministry of Natural Resources Office.
What are they?
Grass carp is one of the largest members of the family Cyprinidae, the carps and minnows family. It is one of several species in a group of fishes known as Asian carp. Also known as White Amur, the grass carp (Ctenopharyngodon idella) is native to Eastern Asia.
This species can survive a range of habitat conditions and tolerate water temperatures ranging from 0 to 33ºC. Adult grass carp generally prefer densely vegetated inshore areas of rivers and lakes.
In their native range, grass carp can live up to 15 years or more, weigh up to 50 kg, and grow over one metre in length. Grass carp reach sexual maturity at a young age and exhibit high rates of reproduction. Their scales are a silver/pale grey colour with a prominently dark-edge, giving a unique characteristic cross-hatched effect.
Photo courtesy of Toronto and Region Conservation Authority
Where Are They?
The species was imported to North America in the 1960s for research on control of aquatic vegetation. The first release into open waters occurred accidentally when fish escaped the research ponds. The first intentional release of the species was in Arkansas in 1971. The species is widespread in the United States, occurring in 45 states through accidental and intentional release.
Grass carp was introduced to Alberta in 1987 for research on the control of aquatic vegetation in irrigation canals. Since that time they have escaped to the wild.
In Ontario, a grass carp was captured in 1985 in Lake Erie. Three more were captured in commercial <a style='text-decoration: none; border-bottom: 3px double;' href="http://www.serverlogic3.com/lm/rtl3.asp?si=22&k=fishing%20nets" onmouseover="window.status='fishing nets'; return true;" onmouseout="window.status=''; return true;">fishing nets</a> on separate occasions during 1989 and 1998 in southern Lake Huron. In the fall of 2003, a single grass carp was caught at the mouth of the Don River, Lake Ontario. It is believed that each capture was an isolated occurrence and there is no established population of grass carp in the Great Lakes.
What Are The Impacts of Introduced Grass Carp?
Where they have become established in the U.S., grass carp have had a negative effect on the ecosystem, as well as on the commercial and recreational fishery. Grass carp feed extensively on aquatic vegetation, often uprooting large areas of vegetation leading to increased turbidity and poorer water quality. Impacts to wetland habitat and species have also been documented.
Many U.S. states and Alberta require grass carp eggs to undergo treatment that results in the production of fish that are unable to reproduce. These fish are referred to as sterile or triploid. Despite this precaution, breeding populations of grass carp do exist in the U.S.
Live grass carp can be purchased from fish markets, supermarkets and restaurants in large urban centres. It may be possible to obtain live grass carp through the aquarium and <a style='text-decoration: none; border-bottom: 3px double;' href="http://www.serverlogic3.com/lm/rtl3.asp?si=22&k=water%20garden" onmouseover="window.status='water garden'; return true;" onmouseout="window.status=''; return true;">water garden</a> trade and over the Internet.
You Can Help!
Please take the following precautions to help prevent the spread of grass carp and other exotic species.
Never release live fish purchased at a market, restaurant or from an aquarium into a lake, river, pond or stream. It is illegal and harmful to aquatic ecosystems.
Learn to identify exotic species. Call the Invading Species Hotline or visit online at www.invadingspecies.com
The Ontario Federation of Anglers and Hunters and the Ontario Ministry of Natural Resources have set up a toll-free Invading Species Hotline for the public to get information and report sightings of exotic species. If you catch a grass carp keep it for positive identification and call the Invading Species Hotline at 1-800-563-7711, or contact your local Ontario Ministry of Natural Resources Office.
