Brook Trout Tagging

By John Pepin – The Mining Journal Munising Bureau

MUNISING — A new phase of coaster brook trout research is set to begin at Pictured Rocks National Lakeshore this month, with the help of a grant of nearly $8,000 from Trout Unlimited.
“This Embrace-A-Stream grant is critical to advancing our understanding of coasters and their behavior,” said Doug Miller, secretary of Trout Unlimited’s local Fred Waara Chapter. “This information is essential to our efforts to restore Lake Superior’s world-famous coaster fishery.”

The $7,960 will be used to purchase special sonic tags to track coaster brook trout that have left the Hurricane River and are traveling in Lake Superior. The Hurricane River is one of three streams at Pictured Rocks where coaster rehabilitation efforts have been taking place over the past decade.

“A lot of fish go out of the streams at Pictured Rocks, but we don’t know what happens to them after that,” said Jill Leonard, a Northern Michigan University biology professor who has been heading up the coaster brook trout efforts at Pictured Rocks. “We’re hoping this is really going to help us understand how they are using that habitat in the big lake.”

Coasters, a larger-than-typical strain of native brook trout, are similar to the steelhead version of rainbow trout in that they migrate to Lake Superior and grow quite large before returning. The fish, which look identical to regular brook trout when young, get their name from the adult fish’s habit of living in the coastal waters of Lake Superior. Coasters commonly grow to 26 inches and larger, and are also thought to use tributary streams for laying eggs, feeding or cover.

Since the late 1990s, researchers have been working on coaster brook trout population studies along the shore of Lake Superior and within Sevenmile Creek and the Hurricane and Mosquito rivers. A total of 164,760 coaster brook trout have been stocked in those streams since 1997.

Leonard said each spring and fall there are times when about 10 percent of the overall population of brook trout in the streams leave for Lake Superior. This is typical of such fish considered “partial migrant” species. So far, no fish of the typically much larger coaster size are returning to the rivers at Pictured Rocks. Researchers aren’t sure whether enough time has passed for them to grow large enough. Or there could be other reasons, including the coasters not surviving to reach the larger size. If that is the case, biologists don’t know why.

The new study will use sonic tags, each costing $290, to tag between 15 and 25 coasters captured in the Hurricane River. Receivers on loan to the project from the U.S. Geological Survey will pick up readings from fish swimming by the sensors, which will be attached to about 20 buoys set about a mile offshore.

“The receiver will float underwater,” Leonard said. The tags will last for 90 days and will be used on fish as small as 5 inches, but preferably on larger fish between 10 and 14 inches. The buoys will record information throughout the summer.

The National Park Service and Michigan Department of Natural Resources are working with NMU on the project. Ken Snyder, Fred Waara TU Chapter president in Marquette, said his chapter will be providing volunteers and recruiting others to help in the labor-intensive coaster project at Pictured Rocks.

Previously, specialized electronic tags have been inserted into the abdomens of brook trout at Pictured Rocks. The coded tags are used with electronic monitoring equipment to log when individual fish leave or enter the stream. The tags are sometimes also inserted into the head of trout.
Automatic fish counting stations are installed near the mouths of the three streams and are continuously working to record data. The monitoring equipment is a cable strung across the river, with colored tape hanging from it.

The systems work throughout the winter months and track when juvenile coaster brook trout leave their home streams. So far, researchers have found that fish stocked into the streams behave much the same as the wild trout already in the rivers. Currently, there are special state size and season limitations in place for anglers on the coaster streams at Pictured Rocks, which will remain in place until at least April 2008.

Embrace-A-Stream is the flagship grant program for funding TU grassroots conservation efforts. Funding is provided primarily by TU members, with additional support this year provided by Costa del Mar, the National Oceanic and Atmospheric Administration, the FishAmerica Foundation and the Federal Sport Fish Restoration Fund.

“Trout Unlimited national has been very interested in the coaster brook trout program, not only up here, but elsewhere as well,” Snyder said.

This year, the Embrace-A-Stream program will provide more than $225,000 for 38 projects that address water and fish habitat quality, native fish restoration, instream flows and fish population research.

Since its inception in 1975, Embrace-A-Stream has funded more than 800 projects totaling about $3 million.