Stocking Up on Fish

State DNR's stock fish from hatcheries to fulfill management objectives. Photo by author

One might assume fish are very poor parents. After all, state owned and operated fish hatcheries are a major part of the fish management programs for every DNR in the country. There aren’t any deer hatcheries or wild turkey farms. Most DNRs have given up on hatcheries to stock baby game birds, but they all have fish hatcheries. Are fish that bad at procreation they need professional help?

In general, the answer is no. Most fish are perfectly capable of producing plenty of offspring; in fact, give them a bit of a window and they will absolutely flood their environment with progeny. That’s why instances occur when lakes and ponds have overly abundant numbers of bluegills, catfish, carp – even bass and crappies in some cases.

However, not every body of water or river system is filled to capacity with fish. Not every lake or river has the kinds of fish people enjoy catching. Not all kinds of fish are even available in nature. Here’s where hatcheries can be important and worthwhile investments for fishing license holders.

Hatchery produced fish provide fishing opportunities for anglers that would not otherwise be available. Fish stocking 100 years ago was done with little knowledge of the habitat requirements for a given species and with little understanding of the complexities of lake and river ecosystems. Walleyes were stocked in Florida lakes, northern pike were stocked in places no pike would, could or should ever exist. Common carp were stocked in many locations and people fought to get them. How’d that turn out?

In the early 1950’s, fishery biologists began to study ecosystems to gain an understanding of how they operated in order to make informed decisions for future management. As more information was gathered, management recommendations resulted in a variety of stocking changes.

The species raised in hatcheries changed, the places where hatchery reared fish were planted were changed. Biologists figured out Florida would never be good for walleyes, carp were never good anywhere. In other instances changes were made in the size of fish stocked. Millions of tiny fry were once planted in waters with large populations of predatory fish, resulting in few returns to anglers. All they were doing was feeding the predator fish. More importantly, many stockings were stopped completely because it was learned natural reproduction could produce more than enough fish to support a fishery for wild fish.

Nowadays, fish stocking programs fall into three general categories: introductory stocking, put and take stocking and a hybrid between the two called put-grow-and take.

Waters selected for these programs are assessed by studying their habitat, water quality and fish population – both predator and forage fish. Introductory programs are the easiest but least used. This occurs when a new reservoir, lake or pond is created, when a massive fish die-off occurs or a lake is drained and refilled. Generally, in a newly made or recently renovated lake, hatchery fish are added once or twice and the fishery then maintains itself through natural reproduction.

In many Midwestern lakes and rivers, spawning habitat is lacking, but once baby fish are introduced, they thrive. Here, a put-grow-take stocking can work well. Walleyes, pike, stripers, muskies, even Great Lakes salmon are supported by stocking programs where routine, continuous stockings on various time tables are made instead of relying on naturally reproduced fish.

Most Midwestern states do have hatcheries devoted to a limited, truly put/take fishing. This is when a hatchery raises a fish from fry-size to catchable size in the hatchery, then stocks the big-enough-to-keep fish for anglers to catch. Rainbow and brown trout are the species most often used for put-take and most are stocked in just a few locations – special areas, such as the tailwaters below large reservoirs. The fish are stocked to be caught and probably won’t survive long in the wild.

Mike Schoonveld
Mike Schoonveld grew up hunting and fishing in rural Northwest Indiana. In 1986 he piggy-backed a career as an outdoor writer onto his already long tenure as a wildlife biologist with the Indiana DNR. Now retired from his DNR position, Schoonveld is a U.S. Coast Guard licensed boat captain, operates Brother Nature Charters on Lake Michigan and spends much of his time trailering his boat to fishing hotspots around Indiana and the Midwest. Mike can be reached through his website or visit Mike's Outdoor World Blog at


Please enter your comment!
Please enter your name here