In July 1937, the Conservation Commission instructed Fisheries Division to examine all of the trout water then in state ownership to see if a suitable location for a trout fisheries experiment station was available. The search ended in the fall of 1938 on the headwaters of Hunt Creek, about 10 miles south of Atlanta. The Hunt Creek Fisheries Research Station in Montmorency County was officially established in 1939. The research area encompasses nearly 3000 acres and includes several miles of the Hunt Creek mainstem, seven tributary streams and four lakes, all within a one-mile radius of the office.

Lakes such as East Fish Lake, pictured at left, are used to study the survival and growth of different genetic strains of trout stocked into Michigan trout waters. Research lakes have also been used to evaluate survival and growth of Arctic Grayling in Michigan.

In a sense, the research area is like a large outdoor laboratory. Experimental designs for on-site studies incorporate treatment-and-control methodologies, high replication, large sample sizes, and collection of data for long periods of time so that natural variation in fish populations can be distinguished from variation due to experimental factors. Present studies focus on streams and rivers, but researchers also investigate fisheries in lakes such as the sinkhole lakes in the Pigeon River State Forest. Researchers at the station also study river fish species and their habitat on many other rivers throughout Michigan. Research findings are published in research and technical reports and in peer-reviewed fisheries journals to assist fisheries managers and scientists in the management of fisheries and their habitats. Cooperative studies with universities such as MSU and UM allows researchers at the station to conduct detailed investigations that could not be accomplished with limited DNR staff.

A major objective of research at Hunt Creek is to find solutions to fisheries problems. Because the waters in the research area have been closed to fishing since 1965, and because land use activities are rigidly controlled, Hunt Creek is an ideal location for controlled studies of the effects of habitat changes on fish populations.

Research has shown that large woody material such as logs and trees are beneficial to fish populations. It provides resting areas where fish can escape fast water current. Management techniques such as the addition of large woody material to streams to provide refuge from predators can substantially increase trout survival and production in some rivers.

Removal of large woody material or brush from streams by landowners or others reduces habitat quality for fish and usually results in lower fish populations.

The effectiveness of management techniques for enhancing or restoring fish habitat in Michigan streams is usually measured by estimating fish populations because this is much cheaper than conducting on-site angler census. However, in streams open to fishing, the effectiveness of habitat improvement investments on fish populations are difficult to measure because anglers often fish harder in areas where habitat has been enhanced, harvesting most of the increased fish production. Average fish populations after the fishing season may appear unchanged even when angling success has been greatly enhanced. The Hunt Creek fishing closure eliminates this uncontrolled variable so that actual effects of habitat manipulations can be more accurately and economically measured by studying them under controlled, yet natural conditions.

Stocking

In the early days of fisheries management fish stocking was viewed as a panacea for virtually every fisheries problem. We now know that habitat protection and enhancement has far greater potential for improving fishing, particularly in streams. When stocking fish failed to provide the dramatic response that many expected, researchers began marking fish and measuring how many survived to be caught by anglers. During the 1940s and 1950s many studies examined the effectiveness of stocking different sizes and species of trout.

In general, 5% or fewer of these hatchery trout survived for one year. Moreover, anglers frequently caught less than 5% of the trout stocked in streams with resident wild populations. Anglers could catch higher percentages of stocked rainbow and brook trout since they are easier to catch, but a fishing license would only pay for a handful of fish in the creel when they were stocked on top of wild populations. Rainbow trout also tended to migrate far from stocked areas. Because of these findings, and similar findings throughout the U.S., MDNR now stocks trout in streams only when some factor such as poor reproductive success limits production of trout.

In contrast to the findings in healthy streams, trout stocked in lakes can give a very good return for a stocking investment. Trout in lakes grow faster, have fewer opportunities to emigrate, and generally suffer lower rates of natural mortality than trout in streams. We have conclusively demonstrated that in lakes with appropriate water quality (temperatures and dissolved oxygen) adequate food supplies, and sparse populations of predatory fish species such as northern pike, it is usually possible for anglers to harvest many more pounds of trout than are stocked because they survive and grow well in such habitats.

Regulations Research

Hunt Creek staff designed or conducted many research studies on effects of different angling regulations during the period from about 1950 to the turn of the century. Effects of different angling regulations–size limits, creel limits, no-kill regulations, and restrictions on legal tackle types– were studied extensively over the years in an array of Michigan Rivers, but most notably in branches of the Upper Au Sable River. Models developed from these studies are used to predict changes in trout populations that are expected to result from changes in regulations.

Genetics Studies

Many studies of the relative performance, i.e. survival and growth, of various genetic strains of trout have been conducted over the years in the Hunt Creek Research Area and Pigeon River Country State Forest lakes. Genetic strains of trout exhibiting superior survival and growth in the wild are a better investment since they can usually be reared at a similar cost in hatcheries. Several studies conducted in the 1970’s and 1980’s compared survival and growth of Canadian strains of brook trout (Assinica and Temiscamie) to the performance of domestic hatchery brook trout and hybrid crosses between these strains. The performance of both the pure Canadian strains and the hybrid crosses was superior to that of the domestic brook trout when they were stocked in lakes. As a result of these findings, most brook trout now stocked in lakes in Michigan are either purebred Assinica, or hybrid-crosses between Assinica and domestic brook trout. Since both domestic and hybrid strain brook trout cost about the same to rear in the hatchery, anglers are now able to catch more and bigger brook trout for the same dollar investment. The above picture is a Assinica-strain brook trout.

In the 1980’s and early 1990’s Hunt Creek staff studied the relative survival and growth of wild strains of brook and brown trout from streams that were subject to different levels of angler harvest over time. Study findings had several management implications. First, they indicated that high harvest rates may be reducing the genetic fitness of some fish stocks thereby resulting in poorer fishing quality. Findings also indicated that stocking hatchery trout on top of healthy wild populations has the potential to reduce the genetic fitness of the wild populations since some stocked trout survive to breed with the native stock. This research lead to the development of a new brown trout broodstock derived from wild parents. Recent research on the progeny from this “wild” strain of brown trout demonstrated that on average, they grew and survived better than the other genetic stocks of brown trout presently stocked into Michigan streams.

Habitat Protection and Enhancement Studies

From about 1970 through the 1990’s, studies within the Hunt Creek Research Area focused on measuring effects of environmental degradation on trout populations and the development of techniques to mitigate these effects. A long-term study conducted during the 1970’s and 1980’s conclusively showed that relatively small increases in sand erosion into streams severely degrades habitat quality and can reduce brook trout populations to less than half of their normal abundance level.

The red line in the graphic above shows that standing stocks of brook trout declined from an average of 112 kilograms per hectare to 45 kilograms per hectare when habitat in a “treatment” section of Hunt Creek was degraded by sand. Brook trout populations were restored after sediment traps were first constructed in 1982 to remove the excess sediment. The blue line shows population abundance in a control section of Hunt Creek that was not degraded by excess sediment.

This study, along with cooperative research conducted with the U.S. Forest Service, demonstrated that sand traps (large holes dug into river channels to trap excess sand sediments) were an effective tool for restoring or improving trout habitat in streams degraded by excess erosion. MDNR Fisheries Division, the U.S. Forest Service, and private groups now maintain hundreds of sand traps on streams throughout the state to restore and enhance fish habitat. This research has also heightened awareness of the need to better control erosion into streams from common sources such as roads and pipelines. Present studies of sediment effects in streams seek to determine the effectiveness of sediment basins in rivers that vary in their size and hydrology. The above picture is a sediment trap on the Sturgeon River (Otsego County).

Effects of summer withdrawals of water from trout streams were recently studied in the research area during the 1990’s. In this study, trout and insect populations in a stream section where summer stream flow was experimentally reduced were compared to those in sections having natural flow regimes. Another segment of this study involved testing and development of models that can be used to extrapolate results observed at Hunt Creek to other waters of the State.

More recently, Hunt Creek staff worked as part of a team to develop standardized methods for assessing the status and trends in fish populations and habitat throughout the state. Todd Wills, research biologist at Hunt Creek, has primary responsibility for coordinating this statewide program.

For a more complete description of this study and other current studies at the Hunt Creek Fisheries Research Station, click on the link to Current Studies.