Examining Canadian Food Production and Consumption
Stratford Chefs School immerses students in hands-on culinary training with Practical courses that build real-world culinary skills, but also teaches Theory courses such as Food History, Culinary Management, Communications, Nutrition, and more, exploring multiple aspects of cuisine that contribute to the development of skilled and well-rounded, thoughtful chefs.
The Level 2 Gastronomy course taught by Chef-Instructor Randi Rudner, for example, examines the critical issues facing our food systems, sustainability, and the roles food and cooking play in modern culture. When asked to reflect on the food world around them and investigate a current issue in Canadian food production of personal interest, a number of thought-provoking essays were submitted by our Level 2 Students. The impact (and control) of an invasive species on fish populations of the Great lakes was examined by Level 2 Student Jenny Duong. We are thrilled to share her essay with you, with her permission.
'The Invasion of Sea Lamprey and Their Successful Control', by Jenny Duong
A Personal Connection and a Change Of Heart
This report examines the success of ongoing efforts to control sea lamprey populations in the Great Lakes and their impact on fish populations, particularly in terms of Canadian food production and consumption. Having fished in Lake Erie as a child, and as a conscious cook and fish eater, I was fascinated to learn about the economic importance of the Great Lakes, the devastating effects of the invasive sea lamprey, and the successful collaborative efforts of both the United States and Canada to address the issue. At first, upon learning of the destruction of the lake trout population, the sea lamprey quickly became an object of disdain. However, as I delved deeper into the biology of the sea lamprey, a creature so ancient and resilient, adapting to survive in an environment far removed from its natural habitat, I began to appreciate its role in the ecosystem, despite the damage it causes.
First, Let Us Revel In The Great Lakes Fishery
The Great Lakes consist of five lakes: Lake Huron, Lake Ontario, Lake Michigan, Lake Erie, and Lake Superior. Together, they hold about one-fifth of the world’s fresh surface water and provide habitat for 177 species of fish, 139 of which are native. The region supports over 75,000 jobs and has an economy valued at more than $7 billion annually (Great Lakes Fishery Commission, 2025).
The lakes are a prized resource for commercial, recreational, and tribal fishing, attracting people from all over the world. Documents dating from the 17th century show European explorers watching the Indigenous catching many fish in the Great Lakes. Their passion for fishing turned into a commercial fishing boom, while the Indigenous people were subsistent on the fish with a barter and trade economy, and practiced a full cultural relationship with the fish (Haskin 2024).
The Great Lakes region is a unique source for sports fishing due to its massive, ocean-like space, the quality, and the variety of fish. In order to keep up with the demand of anglers, the Great Lakes are stocked from artificial propagation. In 2024, they were stocked with 3,620,957 fish consisting of 10 species across 243 stocking events, according to the Great Lakes Fish Stocking database (Great Lakes Fishery Commission 2025). As such, the health of the lakes has a profound impact on the economy, local communities, and the natural environment.
Decimating The Fish Population: The Ugly Fish Causing Ugly Problems
People saw the Great Lakes as a bountiful and abundant natural resource but in the last 200 years, exploding human populations, pollution, invasive species, and overfishing are among the major factors in the changes in the fish fauna (Haskin 2024).
The sea lamprey became an invasive species in the Great Lakes in the early 1800s, following the construction of shipping canals. Initially, they were confined to Lake Ontario because they couldn’t swim past Niagara Falls. However, after the Welland Canal was widened in the 1900s, they spread into Lake Erie, Lake Huron, Lake Michigan, and eventually Lake Superior, where their numbers peaked in 1938 (Great Lakes Fishing Podcast, 2025).
In Lake Erie, where fisheries were not yet well-developed, the problem went unnoticed; but when sea lampreys reached Lake Huron and Lake Michigan, they decimated the lake trout population, their favourite prey. From a population of five million lake trout in the 1940s, the numbers dwindled to near zero by the 1950s . It’s estimated that four out of every five lake trout were killed by sea lampreys (Great Lakes Fishing Podcast, 2025). Lake Superior, the last lake invaded, saw the first efforts at sea lamprey control. The decimation of the lake trout population, along with the collapse of the tourism economy dependent on fisheries, created an economic crisis for the surrounding communities.
The Sea Lamprey: An Ancient Invader
The sea lamprey, a creature dating back 340 million years, has survived more than four major extinction events (Great Lakes Fishing Podcast, 2025), making it one of the most adaptable organisms on the planet. Originally native to the Atlantic Ocean, sea lampreys coexist with larger fish such as tuna and sharks, where they act as parasites. While they would wound the fish, they rarely caused death. However, in the Great Lakes, where the fish species are much smaller, the sea lamprey has become a predator, severely affecting local fish populations.
A sea lamprey’s mouth is a sucker-like cup filled with 150 razor-sharp teeth (Great Lakes Fishing Podcast, 2025), which latch onto a fish. Its rasping tongue bores through the fish’s scales and flesh, feeding on its blood. The sea lamprey secretes an anticoagulant that keeps the fish from clotting, allowing it to feed for months if needed. While a fish may not die from the lamprey itself, the damage can lead to death through blood loss, infection, or predation. Around 1 in 7 fish attacked by a sea lamprey might survive, but the rest succumb to these fates (Great Lakes Fishing Podcast, 2025).
Pollution and Misunderstandings
Initially, people blamed factory pollution for the decline in fish populations, but Lake Erie, which had the highest pollution levels, showed the least damage to fish. It turned out that the pollution in Lake Erie was so severe that sea lampreys couldn’t spawn there, offering a misleading solution. In an attempt to improve water quality, legislation was passed to reduce pollution, which inadvertently created a more favourable spawning environment for the sea lamprey.
The Life Cycle Of The Sea Lamprey
It was important to learn of the life cycle of the sea lamprey in order to control them. First, the lamprey hatches from eggs as larvae, which are smaller than a pinky finger. These larvae swim downstream and bury themselves in the stream bed, where they filter-feed on phytoplankton for three to ten years. In this stage, they pose no threat. Once they metamorphose, they develop eyes and a sucker mouth and begin their parasitic phase. During this phase, they can consume up to 40 pounds of fish (Great Lakes Fishing Podcast, 2025). After maturing, the sea lampreys focus solely on spawning.
To find suitable spawning habitats, surviving larvae release pheromones that guide adult lampreys to areas where they create nests, latch onto rocks, and release their sperm onto eggs. After spawning, the adults die.
While sea lampreys prefer lake trout, they are not picky eaters. They will latch onto any fish they can, including sturgeon, perch, bass, or walleye. This predatory behaviour makes them especially destructive to the Great Lakes ecosystem. Fortunately, humans need not fear sea lampreys, as they only feed on cold-blooded creatures (Great Lakes Fishing Podcast, 2025). If a sea lamprey latches onto a human, it is likely just hitching a ride rather than seeking a meal.
Efforts To Control The Sea Lamprey
When the problem reached a peak, the coastal, tribal, and fishing communities talked to their electoral representatives. It was such a pervasive problem causing much disruption with the economy that both the American and Canadian government started working together on the issue. This problem spanned six states and two provinces, different tribal nations and different jurisdictions; they had to form an entity that worked across borders and thus the Great Lakes Fishery Commission was established in 1955.
The first control method used when the sea lamprey first invaded was to eat them. Unfortunately, it was not at all appetizing in taste, visually the meat was grey and the texture was mushy. No matter the cooking technique, it would not taste good. As well, they have a high concentration of heavy metals since they are drinking the bodily fluids of apex predators. However, in some parts of the world such as Portugal, they consider it quite a delicacy where they serve sea lamprey in a stew of their own blood. As well, the Queen of England served ceremonial sea lamprey pie and in fact in 2015, the Great Lakes Fishery Commission sent sea lamprey to the Queen for this dish.
One attempt of control was using traps to remove the sea lamprey, but it was hardly efficient enough to be classified as a control method. It is mostly used for assessment purposes by being placed near dams and to help determine the size of the sea lamprey population.
Barriers are a control method that block the sea lamprey from passing and also limit the area needed for sea lamprey control.
The most efficient and effective method, but most expensive, is using lampricide treatment. It is a selective toxicant that they use to target larval lamprey. First, they begin by deciding which areas have an abundance of sea lamprey larvae by sending out agents with ghostbuster-like backpacks that have electric paddles. These paddles tickle the sea lamprey out of the seabed and the number of larvae determines if it is a good candidate for the treatment. They apply the toxicant in 5 parts per million concentrations which is a very small amount. They use different forms such as spraying the concentration into the water as well as in blocks so it slowly dissipates in streams to ensure all larval lamprey are attacked. The lampricide is coloured yellow so you can easily see which areas have been treated. Fun fact: the lampricide was the 5209th chemical they tested that finally combatted the sea lamprey without harmful effects to other species (Great Lakes Fishing Podcast, 2025).
Another control method that is used and is heavily invested in as well, is using pheromones. Scientists have determined that sea lampreys have an “alarm cue” which is a repellent pheromone that is released by dead or dying sea lamprey to ward off living sea lamprey from an inhabitable area. These pheromones can be used to control the movement of sea lamprey into areas for lampricide treatment and also repel them from good spawning habitats.
Unfortunately, there are no established prey predator relationships that affect the sea lamprey population. If fish did prey on lamprey, it would be in the larval stage and because of the opportunistic chance.
The Sterilization Program
One new approach to sea lamprey control involves sterilizing male lampreys. Scientists capture males, sterilize them with DNA implants, and release them back into the wild. When these sterilized males mate with females, they produce no fertile offspring. Over time, this genetic method could potentially drive the sea lamprey population to extinction (Great Lakes Fishing Podcast, 2025).
What To Do If You Catch A Sea Lamprey
If you catch a sea lamprey, ensure it’s the right species, as there are four native lamprey species in the Great Lakes. The sea lamprey is significantly larger, typically ranging from one to two feet long. Once identified, cut off its head and chop it into several pieces. If the lamprey has attached itself to a fish, you can still eat the fish by removing the wound caused by the lamprey.
What Have We Learned
Even though the population of sea lamprey has decreased by 90%, the control must be ongoing especially since a single female will produce 100,000 eggs. A pair of sea lamprey can easily produce a population within the many spawning habitats of the Great Lakes. In the '90s, they experimented with sea lamprey control and they saw an uptick in lake trout wounding and a decline in the lake trout population. If the control is stopped, you won’t see the effects immediately, but maybe within three or four years (Great Lakes Fishing Podcast, 2025).
About Jenny Duong
Jenny Duong completed our 32 Week Apprenticeship Program earlier this month and will graduate in June as a member of our Class of 2025. Jenny's use of food as an outlet for creativity inspired her to pursue a career in the culinary arts. Her long-term goal is to be a small business owner, offering quality service that provides the individuals in the community something of value. On her application to the program, Jenny stressed her commitment to diversity and equity: "As a person of diversity, I aim to employ others from the BIPOC community, and showcase their strengths, talents, and the uniqueness of each individual's background."
Bibliography
Great Lakes Fishery Commission. 2025. "The Fishery." Great Lakes Fishery Commission. https://www.glfc.org/the-fishery.php.
Great Lakes Fishery Commission. 2025. "Stocking Events 2024." Great Lakes Fish Stocking Information System. Accessed February 10, 2025. https://fsis.glfc.org/stocking/events/2024/.
Great Lakes Fishing Podcast. 2025. “Sea Lampreys in the Great Lakes: Great Lakes Fishing Podcast Episode 103.” SoundCloud. Last modified February 17, 2025. https://soundcloud.com/greatlakesfishingpodcast/sea-lampreys-in-the-great-lakes-great-lakes-fishing-podcast-episode-103.
Haskin, Lindsey. 2024. The Fish Thief: A Great Lakes Mystery. United States: The Film Sales Company. Documentary film.
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