A fish so invasive the U.S. government will spend $60 million to stop it from entering the Great Lakes has been spotted in Toronto.
Two Asian Grass Carp were found in Tommy Thompson Park this week, the Toronto and Region Conservation Authority (TRCA) said in a statement on Wednesday.
The fish have big appetites and are sometimes used to control the growth of algae. However, sometimes they eat too much, destroying the existing ecosystem. The other concern is that no one knows where these two particular fish came from.
TRCA staff discovered the first carp on Monday while relocating fish from a pond. At the time, staff were working on the construction of a nine-hectare wetland.
The second fish was found during a deliberate search on Tuesday. All three levels of government, the TRCA, the Ontario Ministry of Natural Resources and Forestry, as well as Fisheries and Oceans Canada, were involved in Tuesday’s search.
Both fish were sent to a Fisheries and Oceans Canada laboratory in Burlington for further investigation. Staff are searching for more.
Unlike the common carp, which was introduced to Ontario in the 1800s, they are native to Eastern Asia. The fish were initially brought to Arkansas in 1970 but escaped into the Mississippi River in the early 1990s. Since then, they’ve had a negative effect on the environment as well as on commercial and recreational fishery. In some parts the upper Mississippi, the Asian Carp now accounts for more than 90 per cent of the weight of all fish.
It’s the first time a live Grass Carp has been seen in Toronto since 2003. At the time, 12 years ago, one was found by TRCA staff at the mouth of the Don River. That fish was sterile. The two fish found this week were healthy males. There is concern that if females are found, the fish breed quickly.
The TRCA says Tommy Thompson Park is one of the most significant restoration projects in its portfolio.
Note: The grass carp is not the kind of carp that jumps, as seen in the video below. It is still a threat to the ecosystem.