A large Fishing Tug tied up in Collingwood's harbour was loaded with a special cargo on Tuesday morning – more than 30,000 small lake trout were poured into large holding tanks on the deck.

The boat is a research vessel operated by Ontario’s Ministry of Natural Resources and Forestry. Arunas Liskaukaas is the managing biologist on board and says lake trout were once the top predatory fish in the upper Great Lakes until the 1930s when the eco system started to change.

“Populations lake trout collapsed just over a decade (ago), and it was a combination of habitat deterioration, over exploitation of the commercial fishing and the introduction of the sea lamprey and the sea lamprey was the death knell for the lake trout,” says Liskaukaas.

This load of lake trout was released in 30 meters of waters about five kilometers off the Craigleith shoreline. 

Restoring lake trout populations on the upper Great Lakes has been part of an international mission since Canada and the United States first agreed to take better care of Great Lakes eco system in the 1970s.

Georgian Bay is now the focus of stocking efforts for the ministry. This year 1.6 million lake trout will be released into bay near the shoals, where they traditionally spawn. Trout populations in in the main basin of Lake Huron and Lake Superior are already considered rehabilitated. 

While the Ministry of Natural Resources focuses its stocking efforts on lake trout, local sportsmen's clubs are also working to stock streams and rivers with other species of trout and salmon. Eggs are collected at fishways then grown in tanks to be released back into the wild for fisherman to catch.

Rick Baldry, president of the Georgian Triangle Anglers Association says the hatchery is a way to make up for what fishermen take away.

“We are raising fish for the sportsmen. Rainbow trout, speckled trout and brown trout, that we can put back in area streams so fishermen can get out there and enjoy it,” says Baldry.

Despite the fact that millions of fish are being poured into the lake and local streams, Liskaukaas says Georgian Bay can no longer support as many large predatory fish as it once did because  invasive species like zebra mussels, quagga mussels and the spiny water flea. He's hoping the rapid changes that have taken place in the lake over the past two decades will slowly stabilize.

“We will probably arrive at a new equilibrium and hopefully there will be opportunities for recreational fishers for Chinook salmon and an emerging lake trout population throughout Georgian Bay,” says Liskaukaas.

The lake trout that are being stocked are all coming from a hatchery operated by the ministry in Chatsworth.