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Why Farming Fish in the Great Lakes Might Not Be Such a Bad Idea

Taste the rainbow trout.
(Photo: Nathan Rupert/Flickr)

(Photo: Nathan Rupert/Flickr)

Speckled fish are swimming around a 50-foot-square pen in Fraser Bay, Ontario, an inlet in the northeastern section of Lake Huron. It's one of 14 net pens on either side of the Cold Water Fisheries dock there, near lakeside cottages with mountainous backdrops. I'm talking about 5.5 million fish here. The company harvests 1.7 million pounds of rainbow trout, also known as steelhead, every year from each of its two farms off Ontario's shores. It's been in business for close to 30 years, and now it hopes to expand its business across the lake to the Michigan side.

The Canadian government first allowed fish farms in Lake Huron in 1988. This huge body of freshwater now has seven such facilities, and the government is reviewing proposals for five more (but recently it hasn't been approving commercial operations). As Cold Water Fisheries owner Robert Devine told Michigan Public Radio, he wishes to expand but is getting nowhere with the Canadian government. That's why, he says, he wants to head south to the United States—well, more like west to Escanaba Bay, Michigan, where the conditions are very similar to those he has had so much success with in Fraser Bay.

Cold Water Fisheries is one of two companies looking to raise fish in net pens off U.S. shores, part of an aquaculture industry that grows by up to 10 percent each year. One of the benefits to Michigan, says Dale Jordison, a production manager for the company, would be local, affordable fish. In Ontario, Cold Water Fisheries has an outlet in town where it sells its product at a fraction of the grocery store cost. Another benefit would be jobs and more money coming into the state. At one of its locations, Cold Water Fisheries employs 45 people, and Michigan estimates that two new facilities could gross the state $4.5 million.

The science shows that, at a certain level, net pen aquaculture can be done with minimal impact to the surrounding ecosystem.

Some lawmakers say it's a great idea and proposed a bill last December that would allow the industry to bring its net pens to Michigan's waters. Opposing legislators followed by introducing a bill outlawing such nets, saying the risks to the ecosystem are too great.

If Cold Water Fisheries and the other interested party, Aquaculture Research Corporation, get to set up shop in Michigan, they would deposit fish (the exact number is proprietary, Jordison says) in the spring and fall into each of their near-shore pens. There they would live until they grow to 2.5 to 3.5 pounds, eating, sleeping, and excreting waste until they are harvested. That fish poop contains phosphorus, a nutrient that in excessive amounts can bring harmful algal blooms to lake ecosystems. Under Ontario regulations, phosphorus levels cannot exceed 10 parts per billion within 100 feet of its cages, Jordison says.

To help figure out what impact the fish in those net pens might have, Michigan's departments of Agriculture and Rural Development, Environmental Quality, and Natural Resources set up an independent panel of scientists to look at the industry's environmental ripples. In their report, published last October, the authors discussed what more phosphorus could do, the potential for disease, and the effect escapees might have on the naturalized rainbow trout population ("naturalized" because the state stocks the lakes with this non-native species every year).

The panel recommended that if the industry moves forward, it should do so slowly, starting with just one or two sites. The science shows that, at a certain level, net pen aquaculture can be done with minimal impact to the surrounding ecosystem, says Jim Diana, director of the Michigan Sea Grant College Program and a member of the panel.

Jordison says that, in his experience in Fraser Bay, many of those environmental concerns haven't been an issue. Phosphorus is absorbed into the ecosystem by invertebrates, such as the benthic amphipod Diporeia, and fish like perch and suckers. In fact, a little more phosphorus might not be so bad in Lake Huron. Unlike in Lake Erie, where algal blooms have wreaked havoc in recent summers, phosphorus levels in Lake Huron are low due to a huge invasive mussel problem. The mollusks take the nutrient out of the water column and deposit it on the lake bed, where organisms like phytoplankton can't readily use it. As for disease, Jordison says Cold Water Fisheries hasn't had to use antibiotics on its fish for the last eight years. And escapees? Cold Water fish come from the same source as the lake's stocked rainbow trout, he says. The only difference is that the company's fish are sterile.

Jordison thinks a lot of the issues around fish farming are because it hasn't been around as long as pig farming and cattle farming (two industries that take up a lot of land and expel a ton of waste). "If science was the only thing that was used, there would be a lot more acceptance of [my] industry."

To show American officials how the business works, Cold Water Fisheries needs support from state agencies to start a pilot project off Michigan's shores. The agencies are expected to give policy recommendations to the Michigan government this year, and then the Great Lakes Fishery Commission will likely weigh in.

While the fish farmers wait for an answer, their operations, like their trout, will be confined to Canadian waters.


This story originally appeared on Earthwire as "Taste the Rainbow ... Trout?" and is re-published here under a Creative Commons license.