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Lake Erie Charter Captain Dave Adams of D & D Charters answers questions and provides tips and insights into fishing the region.
If you would like to Ask the Captain a question, please click HERE.
October 22, 2004
The Lamprey: History, Status, and Outlook
Dear Capt. Dave,
Can you provide any information regarding the reports of steelhead that have been entering the tributaries with lamprey eels attached to them? Do you believe this is going to be a problem for the fish or the lake this year or the future?
Thanks,
Jim
Captain Dave's response:
Hello Jim,
It has always been my belief - and I have been quoted many times as saying - Mother Nature can repair anything man has destroyed and stabilize any imbalance in nature, which man has created. I was wrong.
If the sea lamprey were left unchecked, the "population will explode" Chuck Murray, Pennsylvania Fish & Boat Commission fisheries biologist said.
According to the International Association for Great Lakes Research sea lampreys (Petromyzon marinus) - commonly called the lamprey eel - are so destructive that under some conditions, only one of seven fish attacked will survive. For example, before sea lampreys entered Lake Erie in 1921 (by 1938, they were in all the Great Lakes), Canada and the United States annually harvested about 5 million pounds of lake trout in lakes Huron and Superior. By the early 1960s, however, the catch was only about 300,000 pounds. The fishery was devastated.
The sea lamprey does not need looks to kill
The lamprey is a parasite that indiscriminately kills. It will kill lake trout. Also, sea lampreys prey on salmon, steelhead, whitefish, chubs, burbot, walleye, catfish, and sturgeon. They latch onto a fish with their disc-shaped mouth. Then, they make holes in the sides of their victims and feed on the blood and body fluids. They stay attached for hours, days, or weeks. Small as well as large fish might immediately die from the attack or die later because of an infection from the large wound. Those that don`t die are left with a large scar.
The lamprey, which can survive in fresh or salt water, is native to the Atlantic Ocean. They are 12 to 20 inches long, with a fin from their midsection down and under the tail. They have dark brown to black backs and a light yellow to pale brown belly. Their mouth is circular with rows of teeth.
Unfortunately, the lamprey also is a proficient reproducer, with each female laying over 100,000 eggs.
Sea lamprey control status
Courtesy of Great Lakes Fishery Commission
Adult sea lampreys spawn in places such as Conneaut Creek. After spawning, they die. Their fertilized eggs hatch into small, wormlike larvae, which burrow into stream bottoms. The larvae then feed on debris and small plant life (algae) for an average of 3 to 6 years before they transform into the disgusting, parasitic adult. The adults migrate into the Great Lakes where they spend 12 to 20 months feeding on fish. The complete life cycle, from egg to adult, can take an average of 5 to 8 years to complete. During that life cycle, each sea lamprey can destroy an estimated 40 pounds of fish.
Elimination of this disgusting parasite has proved impossible. Fishery management agencies, however, have been successful in controlling them by concentrating on where they reproduce, In fact, several million dollars are spent each year on different methods of control.
A measurement goal in lamprey population control is wounds per 100 fish. These figures are mainly taken from deep-water assessments (netting) of lake trout; which, when over 25 inches are the preferred host of the sea lamprey. It is an excellent method of monitoring the lamprey population.
"The goal is five percent," Murray said. "We haven't received the 2004 survey results, yet, but wounding rates were up in 2003 to 10.4 wounds per 100 fish." This is a substantial increase, the Great Lakes Fishery Commission reported in their 2004 Coldwater Task Group Report, over 2002 when rates were below the target of 5 wounds per 100 fish. Still, wound rates in 2003 were lower than the years from 1997 through 2001.
Sea lamprey control status
Courtesy of Great Lakes Fishery Commission
The sea lamprey continues to reproduce in Crooked and Conneaut Creeks as well as other streams, Murray said. If population controls such as lampricide treatment, barriers, and lamprey traps are not used, we could see a repeat of the 60s`. "If they quit treating," Murray added, again, "the population will explode."
Stopping this parasite is done by four methods: lampricide treatment, sea lamprey barriers, sea lamprey traps, and the sterile-male-release-technique.
According to the Great Lakes Fishery Commission the chemical lampricide treatment (TFM) is the primary method to control sea lampreys. TFM kills sea lamprey larvae in streams with little or no impact on other fish and wildlife. TFM is not harmful to humans or other mammals at the concentration applied. It is registered as a lampricide with the U.S. Environmental Protection Agency and with Health Canada. The Conneaut, Cattarugus (scheduled for 2004), and Big Creeks and the Grand River have been treated with TFM.
Sea lamprey barriers, the Great Lakes Fishery Commission states on their web site, www.glfc.org, have been built to block the upstream migration of spawning sea lampreys; most barriers allow other fish to pass with minimal disruption. Barriers have reduced or eliminated lampricide treatment on many streams. Several barrier projects are proceeding on Lake Erie tributaries, including the proposed low-head barrier on Conneaut Creek. Newer barrier designs include velocity barriers that take advantage of the lamprey's poor swimming ability, electrical barriers that repel sea lampreys during the spawning run without risk to other fish or animals, and adjustable-crest barriers, which can be inflated during the spawning run and then deflated to allow other fish to pass during the rest of the year.
Sea lamprey traps are operated at various locations throughout the Great Lakes, often in association with barriers. Traps are designed to catch lampreys as they travel upstream to spawn. Male lampreys caught in the traps are used for the sterile-male-release-technique; most females are used for research.
The sterile-male-release-technique, their web site says, aims to reduce the success of sea lamprey spawning. Each year male sea lampreys are collected and sterilized. When they are released into streams the sterile males compete with fertile males for spawning females. Only spawning sea lampreys are used in the sterile-male-release-technique. Spawning sea lampreys (including the sterile males) are past their parasitic phase (that is, they no longer prey on Great Lakes fish) and die after the spawning run.
If you do catch a steelhead with a lamprey, don't lose your head (although this lamprey did)
They are ugly and slimy, but they won't hurt you.
Do I think the lamprey will be problem this year or in the future? No: because Mother Nature has a few friends working with her. The fisheries biologists and their agencies work in balance with Mother Nature and do an excellent job of controlling the sea lamprey population. My thanks go to these unsung heroes, who dedicate their lives to protecting our natural resources.
My new quote is: "Mother Nature can repair anything man has destroyed and stabilize any imbalance in nature, which man has created -- providing she first consults with the fisheries biologists."
Good Fishing,
Capt. Dave Adams
Dave Adams is an author and professional charter captain who operates D & D Charters on the Pennsylvania waters of Lake Erie.
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