When to Stock Fish

Fish are planted in Michigan's public waters by the Department of Natural Resources under the following conditions as outlined in Michigan's "DNR Fish Stocking Guidelines":

Where natural reproduction and survival are inadequate for maximum production of the species.
Where a growth potential is assured in the natural environment whereby more pounds of fish will be taken in the fishery than were originally stocked.
Where the fishery produced justifies the cost of the program.

Private Plants in Public Waters
Private plants of fish in public waters are authorized at times under DNR permits when it can be determined that no damage will be done in any way to the public interest in the existing fishery. When permitted, fish must be procured from a licensed Michigan game fish breeder.

Many proposals to plant fish in public waters are in conflict with what is in the long term the best public interest.

Stocking in Wild Trout Populations
Whenever hatchery-raised fish are stocked on top of self-sustaining wild populations of trout, the following problems should be considered:

Competition with Wild Stocks Wild Stocks would be expected to outperform hatchery stocks. Stocked fish could disappear in a short period of time.
Exceeding the Carrying Capacity If the carrying capacity of the stream is exceeded, success would not be expected. Both wild and stocked trout could be stressed resulting in widespread mortality. When the density of trout exceeds carrying capacity, the proportion of trout surviving to the next year tends to be lower.
Genetics Over time, salmonid stocks become adapted to local habitats. With this adaptation they become best suited to survive in their environment.

Fish reared in hatcheries become adapted to hatchery conditions. Numerous scientific studies have shown that when they are stocked into natural stream habitats they exhibit poorer survival than naturally reproduced fish. Offspring of hatchery reared fish are considered less genetically fit than progeny of wild salmonids. Stocking of large domesticated trout that can reproduce the same year as planted has a risk of "contaminating" the gene pool.

Blue Ribbon Trout Streams
Certain trout streams in Michigan, such as the Au Sable River, have earned the designation of "Blue Ribbon Trout Streams." This DNR Fisheries Division program is designed to identify and publicize Michigan's premiere trout streams and to provide direction for their management, protection, and enhancement.

A major criterion for designation and future management direction for these streams is having and maintaining strong stocks of wild resident trout that best suit the stream's character. These streams must have the basic natural ingredients to be self-sustaining. Stocking large hatchery trout in these streams has no proper function; such a practice would introduce an undesirable element of artificiality.

It would be far more advantageous to strive to improve trout habitats in streams like the Au Sable, especially those habitats desired by large trout.

Beyond this, we must remember that:

1. There is a limit to the size and number of trout that a stream can support. Expectations must be realistic.

2. If there are means to increase survival of resident wild trout, we must find and implement them.

RWOL

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