Control measures have proved themselves successful, as blood-sucking sea lamprey numbers are thankfully down around the Great Lakes, where their population has plagued the fish and dampened on the economy of fisheries since the 1930s. For once though, they reached an all time low.
- Lampreys migrated to the Great Lakes in 1939, and killed around 103 million pounds of fish
- Preventive measures started in 1954, and now have see to only 10 million pounds of fish loss to sea lamprey
- One lamprey can kill 40 pounds of fish per year, causing economic and ecological harm
- Their numbers have reached an all time low in Lake Huron and Lake Michigan
Measures have been taken by the Great Lakes Fishery Commission that cost $14 million for the United States and $7 million for Canada in order to trim down the numbers of sea lampreys skulking around the waters and preying on vulnerable fish. The problem started in 1939, when the invasive species made its way across the Atlantic Oceans and into the lakes.
The lamprey is a eel-like species, with a gruesome and horror-like series of razor sharp teeth that is nothing short of inducing nightmares. Their circular mouths latch onto the fish, find holes between the scales, and effectively start sucking out their bodily fluids.
They often feast on whitefish, trout, salmon, sturgeon, or even the smaller fish, such as walleye and perch.
They are highly damaging to the ecosystem of the Great Lakes, with just one single lamprey able to kill around 40 pounds of fish in its lifetime. Annually, 103 million pounds of fish feel prey to the parasitic creatures before the Great Lakes Fishery Commission started investing in preventive measures in 1954.
The problem has always been that the species does not have a natural predator, so it essentially has a free ride to latching onto the fish, with no one to disturb them while they feast and cause their population to plummet. According to biologist Barb Zielinski, the fish are already stressed out due to habitat loss, so the lampreys are only adding more salt to the wound.
However, reports have it that their numbers have reached a 30-year low in Lake Huron, a 20-year low in Lake Michigan, and their population is marginally less in other areas as well. In fact, they now annually kill only under 10 million pounds of fish, an incredible decline from the extensive damage they caused in the 1930s.
According to the organization’s spokesman, Marc Gaden, Lake Huron’s lamprey numbers have dropped by 85%, going from 440,000 to 69,000 due to the preventive measures, while their population dropped to 80,000 in Lake Superior, 27,000 in Lake Michigan, 24,000 in Lake Ontario, and 10,000 in Lake Erie. This is good news for both American and Canadian fisheries.
They used traps and a poison that essentially kills the lampreys in their larval stage in rivers, before they reach adulthood and migrate to lakes. While it’s impossible to eradicate all the parasitic creatures from the waters, the control measures will continue to bring the numbers even lower in order to not allow the creatures to rebound from the loss.
Any slip could bring them back to lurking around the waters and feasting on vulnerable fish.
Image source: bassfishing-gurus.com
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