Researchers revealed that grass carp had invaded three of the Great Lakes, becoming a serious threat to other fish which feed on the same aquatic plants as they do. The new scientific analysis was released on January 27. Scientists are trying to keep this phenomenon under control, struggling to avoid harming other ecosystems. The grass carp represents one of the four Asian carp species which threatens to populate the largest area of the freshwater system in the world.
- Scientists have announced that the population of grass carp in the Great Lakes is continually rising.
- This species threatens the development of other fish and their habitats.
- Researchers discovered that some of the captured grass fish are fertile.
Silver and bighead carp will probably compete with other species of fish in the area which also feed on microscopic animals and plants. What is more, grass carp also feeds on aquatic vegetation which provides habitat for many species. Researchers argued that grass carp were found in Lakes Erie, Ontario, and Michigan, but they could not yet establish for how long there are populating the lakes and how numerous they are.
Marc Gaden, a spokesman for the Great Lakes Fishery Commission, stated that they have developed for the first time a binational study reviewed by some of the best practitioners in the field who share the same opinion when it comes to the risk imposed by these invasive carp and their effect on the Great Lakes’ habitats. Back in the 1960s, grass carp were brought to the US to control the overgrowth of grass in waters.
Like many other Asian carp, this species reached the Mississippi River and then they have migrated toward the Great Lakes. Gaden claims that researchers were already aware of the fact that this species was already populating these lakes but in small numbers. Now, the population of Asian carp has grown. Some of the fish may have reached Lake Michigan by using a Chicago-area waterway network before the installation of electric barriers bound to block the migration of fish.
Gaden also noted that until recently this species did not represent a threat, they did not receive a lot of attention. Unfortunately, now, their population is worryingly growing. The danger of a full-fledged invasion seems to be increasing. One of the most significant parts is that some of the captured ones were fertile. Some of them bred in hatcheries, being allowed to be sterilized before reaching to be released. Since 2012, 23 grass carp have been captured in Canada.
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