Vampire fish makes a comeback in Great Lakes

 

Vampire fish makes a comeback in Great Lakes (msn.com)

Vampire fish makes a comeback in Great Lakes

 

National Post

Vampire fish makes a comeback in Great Lakes

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Sea lampreys use their sucker mouths and teeth to attach to fish and feed on their innards.© Provided by National Post

A parasitic ‘vampire’ that attaches to fish and drains it of its life has been making a comeback in the Great Lakes.

Sea lamprey populations are picking up in the Great Lakes, where it’s considered an apex predator, after a mitigation program lapsed during COVID.

The long, skinny fish, with a circular mouth lined with several rows of sharp teeth, have survived at least four mass extinction events and have looked largely the same for more than 340 million years.

 

 

“We’re very happy that they’re not cute like bunnies because it would be much harder to convince people that we need to rid the Great Lakes of them,” Greg McClinchey, the legislative affairs and policy director for the Great Lakes Fishery Commission (GLFC), told the WSJ . “They are unquestionably the stuff of nightmares.”

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Sea Lampreys are native to the Atlantic Ocean, where they’re food for birds, turtles and fish, and even insects, according to Yale Environment 360 . Their larvae, meanwhile, serve as spawning grounds for fish and help maintain water quality.

While sea lampreys in the Atlantic aren’t known to kill the fish they attach to due to co-evolution, each sea lamprey in the Great Lakes is capable of killing 18 kilograms of fish in about a year, according to Great Lakes Fishery Commission (GLFC), an organization created in partnership between the U.S. and Canada to control sea lampreys:

 

“Host fish in the Great Lakes are often unable to survive sea lamprey parasitism, either dying directly from an attack or from infections in the wound after an attack.”

The fish that survive often suffer from weight loss and a decline in health.

Sockeye salmon caught in an aboriginal commercial fishery on Kamloops Lake are showing extensive signs of lamprey bites.

Chestnut and silver lampreys are two of four native lamprey species in the Great Lakes that attach to a host fish to food. Unlike the sea lamprey, they rarely kill the fish they feed on, according to Michigan State University. Sea lampreys, on the other hand, go after, and take down, most species of large fish, such as trout, sturgeon, whitefish, pike, catfish and salmon.

The creatures were first seen in Lake Ontario nearly 200 years ago, after the construction of the Erie Canal linked the lake and the Atlantic Ocean. It is thought they entered the rest of the Great Lakes following improvements to the Welland Canal in 1919, which linked Lake Erie to Lake Ontario.

Due to the lack of natural predators and an abundance of host fish, the Great Lakes proved to be excellent breeding grounds for the sea lampreys. With each female able to produce 100,000 eggs, sea lamprey populations in the Great Lakes had dramatically increased by the 1940s.

Before the invasion, Canada and the U.S. harvested 15 million pounds of lake trout in the Upper Great Lakes. By the 1960s, only 300,000 pounds of lake trout were caught, about 2 per cent of the average. Survival rates of larger fish were especially poor.

The vampire like fish has been a problem in the great lakes ever since it arrived in the 1800’s.© Tyler Brownbridge

Mitigation efforts that began in the early 1950s, when sea lampreys were killing 100 million pounds of fish a year, used barriers around lamprey habitats to prevent spread. In 1958, GLFC started using special chemicals, called lampricides, to manage their numbers around tributaries where they laid their eggs. After decades of effort with the use of lampricide, traps and barriers, sea lamprey populations in the Great Lakes were reduced by around 90 per cent.

After years of success, travel restrictions imposed during Covid severely curtailed mitigation programs, the effects of which are now starting to be seen by both researchers and startled fishers . That’s because it takes two years for a juvenile sea lamprey to start preying on fish. And with the pandemic restrictions lasting from 2020 to 2021, their population is expected to rise further before the effects of recent intervention is seen.

Marc Gaden, deputy executive secretary of the Great Lakes Fishery Commission, told Fox News in an email that crews are “hitting the lamprey hard in 2022 and 2023” to control the lampreys.

“We did see a spike in numbers in 2022 and we expect to see the same in 2023 (the survivors of the curtailed 2021 season),” wrote Gaden. “We’re hoping the Covid spike was a blip.”