Trout Respond to Habitat Restoration
Fall 1994
Fisheries biologists recently conducted a very revealing survey of trout numbers and distribution at an important demonstration area in Newaygo. Michigan Department of Natural Resources (MDNR) survey crews sampled the fish community at the Bigelow Creek Habitat Demonstration area, a cooperative project of the Michigan Wildlife Habitat Foundation (MWHF), the U.S. Forest Service, FishAmerica Foundation, Wildlife Forever (of Minnesota), and three chapters of Trout Unlimited. The project restored habitat through inexpensive construction of current deflector and fish covers in a 1/2-mile stretch of the Muskegon River tributary. It was designed to show what could be done to combat effects of excessive sand bedload without high costs.
The two-year effort utilized volunteers and laborers from the Muskegon County Corrections Facility and was not completed until last fall. But within just a few weeks after the more than 20 individual sites where structures were installed were treated, MWHF and the Forest Service biologists noted some dramatic physical improvements to the stream. Deep pools with swift current and rocky bottoms replaced stretches which were formerly only inches deep in summer and sand-covered bottoms.
"We aimed to create one deep pool and one gravel-bottomed riffle at the intervals equal to about 7-10 times the channel width," said Dr. Patrick Rusz, MWHF Wildlife Projects Manager who designed the project. "That translated to sets of structures spaced 70'-200' apart. We tried to put the bends back in stretches which had been straightened by erosion since the logging era, and narrow the channel to pre-logging widths. This allowed the water to flow faster, scour out sediments, expose long-buried rock bottom, and create swift pools. We then let the streamflow itself do most of the work. We didn't dig any sediment traps or carry out any other major construction in the stream."
The success of any fish and wildlife habitat demonstration "is in the pudding," that is, in the actual response of the species to be helped. So the project included "before-and-after" sampling of the Bigelow Creek's trout population. In 1990, prior to the project, Forest Service fisheries biologists sampled trout by electrofishing upstream from and in the demonstration area. They found 27 brown trout, of which five were larger than 12", per 1,000 linear feet of water in the upstream "control" area. The count in the demonstration area (pre-project) was 18 trout with four longer than 12" per 1,000 feet. The recent MDNR survey found 40 per 1,000 feet in the untreated upstream area with only one larger than 12" per pool classified as "good habitat." In contrast, the post-project demonstration stretch now held 110 brown trout per 1,000 feet with four to six fish larger than 12" under each structure!
The data are still being analyzed, and more fish sampling will be done in the next few years. The Forest Service is also in the process of carefully measuring the physical changes in the stream caused by the project. But the preliminary survey results and observations are very encouraging. "Survey crew members have been amazed at how the structures at Bigelow Creek attract and hold browns," Said Tom Walter, a Forest Service fisheries biologist who played a major role in supervising the restoration work. "They found 17 browns larger than 12" in one of the restored pools. That is really impressive."
"The survey numbers directly measure only a change in distribution of trout, not in production rates," said Rusz. "Only a long-term study can show the effect of any project on restored habitat on trout spawning and survival. But the dramatic use of the structures we installed have a definite benefit to the fisheries resource. And we have already shown that the techniques applied at Bigelow Creek are extremely inexpensive in comparison to other management strategies."
Fisheries biologists recently conducted a very revealing survey of trout numbers and distribution at an important demonstration area in Newaygo. Michigan Department of Natural Resources (MDNR) survey crews sampled the fish community at the Bigelow Creek Habitat Demonstration area, a cooperative project of the Michigan Wildlife Habitat Foundation (MWHF), the U.S. Forest Service, FishAmerica Foundation, Wildlife Forever (of Minnesota), and three chapters of Trout Unlimited. The project restored habitat through inexpensive construction of current deflector and fish covers in a 1/2-mile stretch of the Muskegon River tributary. It was designed to show what could be done to combat effects of excessive sand bedload without high costs.
The two-year effort utilized volunteers and laborers from the Muskegon County Corrections Facility and was not completed until last fall. But within just a few weeks after the more than 20 individual sites where structures were installed were treated, MWHF and the Forest Service biologists noted some dramatic physical improvements to the stream. Deep pools with swift current and rocky bottoms replaced stretches which were formerly only inches deep in summer and sand-covered bottoms.
"We aimed to create one deep pool and one gravel-bottomed riffle at the intervals equal to about 7-10 times the channel width," said Dr. Patrick Rusz, MWHF Wildlife Projects Manager who designed the project. "That translated to sets of structures spaced 70'-200' apart. We tried to put the bends back in stretches which had been straightened by erosion since the logging era, and narrow the channel to pre-logging widths. This allowed the water to flow faster, scour out sediments, expose long-buried rock bottom, and create swift pools. We then let the streamflow itself do most of the work. We didn't dig any sediment traps or carry out any other major construction in the stream."
The success of any fish and wildlife habitat demonstration "is in the pudding," that is, in the actual response of the species to be helped. So the project included "before-and-after" sampling of the Bigelow Creek's trout population. In 1990, prior to the project, Forest Service fisheries biologists sampled trout by electrofishing upstream from and in the demonstration area. They found 27 brown trout, of which five were larger than 12", per 1,000 linear feet of water in the upstream "control" area. The count in the demonstration area (pre-project) was 18 trout with four longer than 12" per 1,000 feet. The recent MDNR survey found 40 per 1,000 feet in the untreated upstream area with only one larger than 12" per pool classified as "good habitat." In contrast, the post-project demonstration stretch now held 110 brown trout per 1,000 feet with four to six fish larger than 12" under each structure!
The data are still being analyzed, and more fish sampling will be done in the next few years. The Forest Service is also in the process of carefully measuring the physical changes in the stream caused by the project. But the preliminary survey results and observations are very encouraging. "Survey crew members have been amazed at how the structures at Bigelow Creek attract and hold browns," Said Tom Walter, a Forest Service fisheries biologist who played a major role in supervising the restoration work. "They found 17 browns larger than 12" in one of the restored pools. That is really impressive."
"The survey numbers directly measure only a change in distribution of trout, not in production rates," said Rusz. "Only a long-term study can show the effect of any project on restored habitat on trout spawning and survival. But the dramatic use of the structures we installed have a definite benefit to the fisheries resource. And we have already shown that the techniques applied at Bigelow Creek are extremely inexpensive in comparison to other management strategies."