By the 1870s, fish populations in the Great Lakes and inland waters were disappearing because of habitat destruction, dam construction (blocking fish movement), overharvest and pollution.

Photo 1. Early logging practices (from 1860 to 1900) destroyed Michigan’s streams during the transport of logs to the sawmills.

Photo 2. During the late 1800s and early 1900s, there was little in the way of regulations on or the enforcement of regulations concerning the taking of fish and game. This lead to the loss of many fish and game species and the collapse of many populations.

Photo 3. The lack of regulations also caused the collapse of many Great Lakes fish populations. This is a picture of a commercial fishing boat from Lake Erie with a massive catch of lake herring in 1918. By 1926, lake herring stocks in Lake Erie completely collapsed.

Hatcheries were the only technique available to fisheries managers of that time to stem the loss of rapidly diminishing fish populations. Because of the lack of political will at that time, fisheries managers were unable to have any effect on the massive loss of aquatic habitat.

Fish stocking is still one of the principal tools used in fisheries management. Approximately 40% of all recreational fishing in Michigan depends on stocked fish, including 70% of the Great Lakes trout and salmon fishery. Developing and maintaining hatchery facilities that can readily produce the fish needed for fishery management is handled by the Michigan Department of Natural Resources’ Fisheries Division-Fish Production Section.

Fish Production Goal

The goal of Michigan's Fish Production program is to hatch, rear, and transport fish required for the management of both Great Lakes and inland fisheries.

Fish Production Components

In order to achieve this goal the following six functions work together.

• Hatchery Facilities: The Fisheries Division of the Michigan Department of Natural Resources operates six fish hatcheries with a production capability of nearly 750,000 pounds annually.
• Stock Acquisition: Selection of appropriate brood stock is the essential beginning of fish production. Genetically diverse wild or captive brood sources must be maintained for the species and strains (a subgroup of a species that is genetically different) of fish required for fishery management. Different fish species and strains perform differently depending upon the type of water stocked. Fishery managers strive to match species and strains of fish to the waters in which the fish will be stocked. Parent selection and spawning is shaped to avoid inbreeding, which is the result of a loss of genetic diversity, through the use of genetically appropriate breeding regimes.
• Fish Rearing: The varieties, sizes, and numbers of the species and strains of fish required for effective fishery management must be efficiently reared within the hatchery capacities. Careful control of fish inventories, feeding, and water supplies meet our fish managers requirements.
• Fish Health & Quality Assurance: It is critical that fish reared for stocking must be in good condition, kept free of debilitating and lethal diseases, and free of symptoms of chronic stress. Healthy fish are the key to successful fisheries management. Fish that are diseased or stressed will not survive in the wild and could spread diseases to naturally produced fish. When fish are concentrated into small volumes of water, special efforts are required to prevent debilitating stress or disease.
  Preventive measures, diagnosis, and treatment are important elements of fish health and quality assurance. Fish Health Specialists from Michigan State University School of Veterinary Medicine provide diagnostic services and annual fish health inspections to all six hatcheries as part of the effort to maintain healthy, high quality fish for stocking. Other cooperators in maintaining fish health and quality for the fish production program are the Great Lakes Fish Health Committee, the U.S. Fish and Wildlife Service Fish Health Centers and hatcheries, and the agencies of other states with which Fisheries Division exchanges fish and eggs.
• Fish Marking: Evaluation of both fisheries stocking decisions and fish production activities ultimately depends on results in the fisheries. Fish marking is a critical tool for distinguishing stocked fish from wild fish and for distinguishing among groups of stocked fish. Fish sampled during Fisheries Division surveys and those captured by anglers that are examined by Fisheries Division personnel are routinely examined for marks. This information is used to determine the effectiveness of our stocking decisions and program. Marking a fraction of stocked fish is a routine and key part of the fish production program.
• Fish Distribution: Hatchery fish must be stocked according to fishery management plans in the manner and at times which will produce optimal results. Most fish reared in Michigan's hatcheries are stocked in waters far from the hatchery. Stocking must be accomplished within tight time constraints and can be very stressful to fish. Computerized planning tools and specialized trucks are used to properly accomplish this task. Fish distribution to the stocking sites is a critical element of the fish production program.