Carp

March 4, 2023

One of the apps on my phone is called Fishbrain.  This app tracks fishing reports from other users.  I have set the reports to only cover my area.  My thought is to see what, and how, and where fish are being caught, and then decide if this might be a good place for me to fish.  Fishbrain also notifies me when someone I follow has posted along with other articles that might be of my interest.  I received an email this morning from Fishbrain on invasive carp in North America.  The article especially dealt with Canada’s attempt to keep all four species of carp out of their waters.

When I looked online, I found carp (Cyprinidae family) are a large freshwater fish native to central Asia that have been introduced in other countries.  Carp are the most widely distributed freshwater fish in the world.  Carp are extensively farmed in Europe, Asia, and the Middle East, are a popular angling fish in Europe, but in North America, Canada and Australia, carp are considered invasive and a pest.  Asian carp were brought to the US in the 1960’s and 1970’s for use as biological control.  Bighead Carp (Hypophthalmichthys nobilis) and Silver Carp (Hypophthalmichthys molitrix) were used to control algae and Black Carp (Mylopharyngodon piceus) were used to control snails in aquaculture facilities in Arkansas.  Flooding allowed them to escape their controlled ponds and make their way into the Mississippi River Basin.  The spread of Grass Carp (Ctenopharyngodon idella) in the US is largely the result of stocking for aquatic vegetation control.  Grass Carp can either be fertile (called, “diploid”) or sterile (called, “triploid”).  Some states allow fertile Grass Carp to be stocked, some only allow triploid Grass Carp to be stocked, and some states do not allow them at all.  Bighead Carp primarily eat zooplankton, Silver Carp primarily eat phytoplankton, Black Carp primarily eat mollusks (snails, mussels), and Grass Carp primarily eat aquatic vegetation.  Fertile fish can spawn several times a year depending on the conditions, and large populations take food from native fish.

I previously mentioned how carp have overrun the Mississippi River and its tributaries, but the article said there are no established populations of carp in Canada.  There have been individual captures of carp in the Canadian waters of the Great Lakes.  Three single specimens of Bighead Carp have been collected in western Lake Erie between 2000 and 2003 and are believed to have been intentionally released.  There have been 29 captures of Grass Carp since 2012 in the waters or tributaries of lakes Huron, Ontario, and Erie, and 9 tested fertile.  It is likely that these fish were escapees from areas where populations were being used for aquatic plant control, or by live releases.  No Silver Carp or Black Carp have been found in the Great Lakes to date.  While Canada is concerned about all four species, Grass Carp are the most immediate risk as they appear to be naturally reproducing in two US tributaries of Lake Erie.  Grass Carp can weigh over 80 pounds (36 kg), reach lengths of over 5 feet (1.5 m), and can eat up to 40% of their body weight a day in aquatic vegetation.  Since they are not established in Canada, this presents a threat to wetlands already under stress.

THOUGHTS:  When I was a boy the town’s hardware store held a competition for the largest fish.  I was an avid fisher person and caught a carp which I brought in as an entry.  The 3 pound 6 ounce (1.5 kg) fish was the largest carp entered, and I won a rod and reel combo.  It was only years later that my father told me carp were not a category.  While carp are considered trash fish in the US due to their image and boniness, they are a staple in other parts of the world.  There are a few chefs who are trying to introduce carp to the American palate, but generally by another name and often ground into a patty.  This is a huge food supply that is unused because of perception.  We can reject other cultures or persons due to our own perception.  Act for all.  Change is coming and it starts with you.