Fish populations get a helping hand from Ontario hatcheries

By April Lawrence

SHARBOT LAKE – Ontario Ministry of Natural Resources fish culture stations work to keep

fish populations stable in the province’s lakes with a stocking program called Put, Grow, Take.

 

The put in the program’s name is for the hatcheries putting fish in the lakes. The

fish then have the opportunity to grow in the lake, and then are fished – taken – by

anglers.

 

Angela Tooley, a hatchery technician at the 0White Lake fish culture station – one of nine

hatcheries operated by the natural-resources ministry across Ontario – says lake

stocking can take some stress off of native fish species, and adds to the angler

experience. Some lakes, however, are stocked to rehabilitate the fish populations, by

bringing back a native species or helping the native species that is already there.

Tooley and her co-workers get a list every year of their target numbers for the fish

needed for the lakes. Fish eggs are then collected based on how many of each kind of

fish are needed.

 

“Egg collection for all the species is at a different time of the year, once a year for

each species,” said Tooley. “There are some wild egg collections, but most of the

trout eggs come from other hatcheries that have brood stocks” –

mature fish that the hatcheries have on hand specifically for egg collection.

 

Wild egg collection happens when the fish species is almost ready to spawn. Each

species spawns at different times in the year. For example, last year walleye at Hay

Bay, in Lennox and Addington County, were collected in the early spring when they

were starting to show up on the shoals, she said. Large trap nets are set to catch

the fish and bring them to shore to spawn. The fertilized eggs are taken back to the

hatchery.

 

There are currently eight species of fish at White Lake Fish Culture Station: splake, lake trout,

brook trout, rainbow trout, brown trout, walleye, whitefish and cisco.

 

Trout species are stocked throughout all of Eastern Ontario, including Lake Ontario.

Starting this fall cisco will also be stocked into Lake Ontario.

Lake Simcoe receives 140,000 whitefish which is part of a rehabilitation project.

Many of the lakes are stocked once a year or every other year.

 

Depending on the size of the fish the hatchery is working with, there can be up to a

million fish there at a time, she said.

 

“Density is a factor on how many fish can be held at the station.

The larger the fish, the fewer that can be held at the facility.”

It is possible for there to be over 1.5 million fish at the hatchery depending on the time of the year.

 

When the fish are ready for stocking in lakes, they are taken off their feed – in the

case of small fish, usually the day before stocking, though larger fish sometimes

have to be off feed for two or three days, explained Tooley. This is so their stomachs

are empty and they don’t throw up while being transported, something that would

have a negative effect on the water quality in the tank, she said. Oxygen levels and

water temperature in the tanks are also carefully monitored.

 

Stocking takes place in the spring and fall. In the fall, fish are transported in tanks on

the backs of trucks to the lakes they are being released in. In the spring, helicopters

flying low over the lakes are used. The tank on the helicopter contains six individual

smaller tanks, so six lakes can be stocked in one flight. When the pilot is close

enough to the water, the tank specified for that lake is opened and the fish are

released.

 

Correction: An earlier version of this story reported incorrectly that the White Lake fish culture station worked with the Ministry of Natural Resources. In fact, the station is part of the Ministry of Natural Resources. The story also reported incorrectly that all of the lake trout from the station are put into Lake Ontario. In fact, two strains of lake trout are stocked in Lake Ontario and a third strain is stocked in inland lakes.