Somewhere, either on a social media site or on a nature/fishing-oriented television show, you may have seen a fairly large fish jumping out of the water and either landing in a boat or smacking someone in the boat, and you laughed because it did not happen to you!
Well, we may soon be laughing at our neighbors or ourselves, as these invasive fish are on the move, with a live one discovered just nine miles from Lake Michigan. This is especially true if the plan released in August by the Army Corps of Engineers does not work or is not approved.
The fish that is creating this turmoil is called the silver carp (Hypophthalmichthys molitrix), and it is one of several invasive fish species referred to as Asian carp. According to the Michigan Department of Natural Resources' Asian carp fact sheet, Asian carp are considered to be a “highly invasive species in the U.S. and are capable of impacting economic, ecological and human health,” and should be taken seriously.
Silver carp are described as a deep-bodied fish that is silvery in color when they are young, but changes to a greenish color with a silver belly when they are older. They have a large mouth, but do not have any teeth in the jaw.
Silver carp differ from our native carp because of the size and unusual position of their eyes. These fish are noted for leaping out of the water when startled, usually by a motor boat. They are native to eastern Asia. In the U.S., these fish will mature as early as 2 years old and can live up to 20 years. They can weigh between 40 and 60 pounds when mature, and can leap between 5 and 10 feet out of the water when scared.
According to the U.S Geologic Service’s nonindigenous aquatic species fact sheet, they were introduced into the U.S. in the 1970s to remove algae and other materials from catfish farm ponds, and were also stocked in several municipal sewage lagoons to clean up the waste water. It is believed that flooding may have released these fish into nearby rivers, where they became established. Early on, silver carp were also used as a fast-growing, inexpensive white fish for fresh food markets. By 1980, silver carp were in natural waters downstream from fish hatcheries and Arkansas fish farming facilities. Since then, they have been moving upstream toward the Great Lakes.
The reason for concern about this fish is its tremendous appetite and ability to strain water for small aquatic plants (algae) and small aquatic animals that are the base of the aquatic food chain and a food source that native fish and their young require to survive. In addition, their native habitat in Asia is similar to the Great Lakes, so they are expected to survive quite well should they reach the Great Lakes.
According to the National Wildlife Federation’s website, stopping Asian Carp from entering the Great Lakes, in particular Lake Michigan and Lake Erie, is critical. They are a threat to the Great Lakes' annual $7 billion sports fishing economy and the ecosystem of the Great Lakes. They deplete the aquatic food chain, allowing them to outcompete native fish species for food, resulting in the native fish becoming weak and possibly starving from lack of food. This potential scenario could result in the decline or elimination of native fish populations from the Great Lakes ecosystem.
As reported on the National Wildlife Federation blog on Sept. 13, the Army Corps of Engineers released a plan to keep Asian carp (including silver carp) from entering the Great Lakes. While the plan still needs approval, it consists of a series of electric barriers, water jets, noise cannons and a flushing lock at a critical choke point. This series of deterrents is being called a gauntlet, and is proposed to be located near Joliet, Illinois.
There are many organizations working to keep Asian carp from entering the Great Lakes, including those previously mentioned. More information can be found on the New York Invasive Species Information website at nyis.info.
Be aware that Asian carp have been added to the federal Lacey Act as an injurious species, and transportation and possession of Asian carp is banned. Let’s all stay aware of this potential problem and hope we will only see them on social media or television in the future, and not in the Great Lakes.