The Importance of Fish Stocking Programs

February 1, 2009 by  

By Doug Leier

Perch are important to ND lakes for fishermen, especially in the winter

Perch are important to ND lakes for fishermen, especially in the winter

I  learn something new everyday, even if I don’t want to. It’s part of life.

Sometimes, I realize that what I thought was fact, is not. Other times, when I think I have something figured out, it turns out I’m way off base. As I said, that’s just the way life is. And the outdoors is no different.

As you head out fishing this spring, take a moment to revisit often discussed fisheries topics.

First of all, when assessing angling opportunities, it’s almost impossible to compare lake to lake. That applies to waters within North Dakota, or comparisons of North Dakota lakes to those of other states.

North Dakota lakes can be as different as winter weather from Bowman to Grand Forks. Sure, they’re in the same state, but Bowman is deep in the heart of North Dakota’s so-called banana belt, and Red River Valley winters are typically much colder and snowier by comparison. Trying to compare Minnesota natural lakes to a constructed reservoir in North Dakota, such as Pipestem in the east central part of the state, or Heart Butte in the southwest, just isn’t fair.

Why is it so important to understand the differences between lakes and reservoirs? Because it helps us better understand the North Dakota Game and Fish Department’s strategy for stocking fish into state waters.

Since North Dakota does not have comparable number of natural, deep, fishing waters as its neighbors to the east, game and fish biologists work hard to provide the best possible opportunities given the hand they were dealt. Stocking often plays a major role in developing those opportunities.

In natural lakes and rivers, certain species of fish have been present for ages. They have evolved so they can reproduce within the type of habitat the water provides, and have adapted to certain food sources. Reservoirs may provide livable water, but they may not have the type of spawning habitat that allows a particular fish species to reproduce. In those cases, stocking may be necessary to sustain a fishery in the long-term.

Reservoir water levels also change more dramatically than natural bodies of water. What might be good spawning habitat one year could be several feet from the water’s edge the following year. If water levels fall far enough, a reservoir may not be able to support fish life over the winter.

Another more common question is, why doesn’t the department stock walleyes more aggressively in the state’s lakes?

Greg Power, fisheries division chief for the game and fish department, meets the question head on:

North Dakota leads the nation every year in stocking numbers of walleye and perch

North Dakota leads the nation every year in stocking numbers of walleye and perch

“North Dakota, year in and year out, leads the nation in terms of walleye and northern pike stocking. For example, last year North Dakota fishing waters received almost 9 million fingerlings. In fact, there were likely fewer walleye fingerlings stocked in all of the upper Great Plains states combined, compared to North Dakota alone.”

It’s important to differentiate between the fingerlings to which Power refers, and “fry” that may be stocked in other states in high numbers. Fry are tiny fish only a few days out of the egg. Most walleye and northern pike stocked in North Dakota are 1-1.5 inches long and a couple of months old. Instead of being stocked in lakes a few days after they hatch, North Dakota fry are held in rearing ponds for several weeks so they can grow up a bit, giving them much better odds of long-term survival.

This is possible because of the cooperative effort between state and federal agencies. North Dakota is blessed with two federal hatcheries – Garrison Dam and Valley City national fish hatcheries – that are highly productive and staffed by a committed group of professionals, Power says.

But successful stocking is more than just having enough fish to dump into any particular body of water that citizens feel need a boost.

“Our stocking protocol begins with the respective district fisheries supervisor (we have six districts in North Dakota) make annual stocking recommendations to our production supervisor,” Power explained. “We are not (hatchery) production limited so our district fisheries supervisors can develop walleye stocking requests for each lake solely based on need and their respective biological understanding of a particular lake.”

And the biology of stocking does factor in. “The biologists’ stocking requests vary upon the species and lake to be stocked, existing fishery, environmental conditions, and other variables,” Power noted. “There may be times the district supervisors do not want to stock a particular lake due to strong year classes already present. In addition, we do have some natural reproduction of most species in North Dakota waters, thus we need to take this into account when making our recommendations.”

If the game and fish department does decide to stock a lake, Power says, the stocking policy is not restrictive and allows maximum stocking rates – the number of fish per acre – that are likely the highest in North America.

Stocking is just one of several factors that can influence a lake’s fish population. Habitat is the most important of these factors, Power said. “Stocking walleye into a lake is nothing more than a tool in our tool chest to effectively manage a fishery,” he added. “If environmental conditions are not supportive of a particular year class, we could stock hundreds of thousands of fingerlings and have the same eventual return as we would if we had not stocked any fish.

“We have been marking every walleye stocked in North Dakota the last six years. This effort has documented many cases where stocking helps tremendously. We have also documented cases where few if any stocked fish made a contribution.”

Our preliminary statewide stocking requests for 2006 includes more than 6 million fingerlings for more than 100 water bodies. Each body of water is unique, and understanding why fish flourish in one pond and not another is all part of the stocking process.

And all part of the process of learning something new every day.


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