Montague man assists DNR fish research

Topics concerning muskellunge and fisheries research, diseases, stocking and management.
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Hamilton Reef
Posts: 1156
Joined: Thu Apr 28, 2005 9:43 am
Location: Montague, MI on White River

Montague man assists DNR fish research

Post by Hamilton Reef » Sat Sep 26, 2009 10:54 am

Montague man assists DNR fish research

http://www.whitelakebeacon.com/news.php?story_id=19788
09/21/09 Fran Schattenberg Contributing Writer

Marking fish is critical in maintaining healthy population

Labeling fish at fish hatcheries to study many aspects of their food supply, growth, behavior, and longevity has been an activity for over 20 years.
Simple external tags such as wires or ribbons have been replaced by optical marking recognitions, and now, technology has enabled internal markings such as the coded-wire tag (CWT) and oxytetracycline dye (OTC) vertebra dye markings. The mission is to aid in research to maintain a healthy fish population in the Great Lakes.

And, retired fisheries biologist Tom Hamilton of Montague is helping retrieve information from the marked fish.

Hatchery coded-wire tag marking (CWT) by the Michigan Department of Natural Resources Fisheries Division has been the responsibility of the Charlevoix Fisheries Research Station since 1990 where more than 15 million trout and salmon have been tagged, and more than 75,000 tags recovered.

The internal coded-wire tag/microchip (CWT) is a miniscule round wire, one millimeter long, inserted in the snout of a three-inch fingerling fish. The CWT fish have an external visual marking with a small adipose fin on the fish’s top side removed. The CWTs are read using a microscope by trained technicians.

A unique series of numbers on this tiny tag will give hatchery origin, stocking locations, and any special data such as diet experiments, genetic strains, or programs that the DNR or state universities are working with.

Where CWT are inserted by a machine, the OTC dye is introduced as part of the hatchery diet which will leave a dye mark on the vertebra. When vertebre samples are examined under an ultraviolet light a dye mark will reveal if the fish came from a hatchery and lack of any dye mark will be noted as natural reproduction from the rivers.

Neither the wire nor vertebra dye markings injure the fish or harm its natural movement. The concepts are a marvel of modern technology.

In mid-July there was an opportunity to provide the DNR with CWT and OTC data from our management zone because of the cooperation of the Muskegon Sportfishing Association’s Muskegon Shoot-out Tournament, and the Michigan Anglers Association that brought the fish to Fisherman’s Landing for research examination, then cleaning and ultimately donation to area food pantries.

The research examination was done by retired fishery biologist Tom Hamilton of Montague. Long associated with fish research and assisting the DNR when asked, Hamilton had access to several hundred tournament fish for the data collection.

“The Great Lakes are divided into management zones in cooperation with other states. The current severe budget crisis restricts biologists’ travel to collect data from our zone. After so much time and money has been spent on these programs, and with a limited window of opportunity to get fish samples, there was no way I could say ‘No’ to help the DNR in this grave time of need.”

Hamilton’s CWT protocol was to look for the missing adipose fin as an external indicator. If missing, he removed the snout by cutting through the head just behind the eyes, and the snout is frozen for later transmission to the Charlevoix Fisheries Research Station.

The OTC protocol was specific-fish based since there is no external indicator for the vertebrae dye. Hamilton removed the tail at the adipose fin of every 22-inch or smaller chinook salmon in the tournament catch. These frozen tail samples would be sent to the DNR District Office in Plainwell.

There was a third protocol that Randall Claramunt of the Charlevoix Fisheries Research Station requested. Hamilton could provide entire stomach samples to determine feeding habits. Hamilton did take stomach samples from lake trout, steelhead, brown trout and chinook.

This yearly procedure has provided a base for hatchery fish management in a two-billion-dollar-a-year fishing industry.

The analysis of the management zones’ frozen fish samples are analyzed during the winter months. The data then becomes part of the DNR decisions for the coming year.

This information is then made available to charter captains and the public in the Michigan Sea Grant series of workshops http://www.miseagrant.umich.edu/fisheries. For more information on the coded wire tag program as well as other current fishing information go to http://michigan.gov/dnr, then click fishing.

A major focus, of course, is hatchery fish survival during the fishing seasons and natural reproduction. Hamilton puts it squarely: “It is a fine balancing act to match stocked fish to available forage food which is shared with the naturally reproduced fish. The whole program is right there.”

Companion Article #2

DNR monitoring mission is an enormous task

http://www.whitelakebeacon.com/news.php?story_id=19787
09/21/09 Fran Schattenberg Contributing Writer

Even from an individual viewpoint looking out at Lake Michigan, the scope seems enormous.
But when you consider that Lake Michigan is one of the world’s largest fresh water lakes, the Department of Natural Resources’ monitoring mission assumes gigantic proportions.

Randy Claramunt of the Charlevoix Fisheries Research Station is part of the state’s on-going research program for the Great Lakes. He notes that several decades of research have provided a foundation for science based management, and new technology has given the system a boost.

Central to that has been the coded wire tag and OTC (internal chemical dye) advancements.

Claramunt says that what is sought is a balance between the predator (hatchery fish) and the prey by, ideally, ascertaining the ratio of hatchery predators vis-à-vis the prey, and how healthy are they in the wild.

A focus, of course, is on salmon which, Claramunt describes as “the eating machine of the Great Lakes. So when in the late 1980s the prey became scarce, the salmon died. This necessitated a change in the number of hatchery fish that were released in order to balance a healthy ratio.”

Since then the release numbers have varied over the years. Claramunt notes that “in 2006, Lake Michigan stocking rates were cut by 25% to help balance for a healthy ratio. By 2008 catch rates had declined but we wanted that because catch rates had been at a record high level. The salmon that are being caught this year are in better condition, and bigger.”

Other factors that are involved here are the interdependences of other Great Lakes. A part of Claramunt’s job is to be involved in that coordination, and in particular with Wisconsin, Indiana, Illinois, the Federal government, and the tribal governments, with their focus on lake trout and white fish.

Considering the over-all impact on a $2-billion-dollars-a-year industry, the DNR Fisheries Research, like every aspect of society, is faced with financial constraints. To that end, for Claramunt “volunteers are invaluable. If it were not for people like Tom Hamilton we would not have the necessary information. They are critical to our on-going research.”

Claramunt finds that he is part of a vast group of people who have a passion for this aquatic environment. It is a drive that enables them to do with what they have as best as they can.

With this in mind, the dedicated ones have to learn to live with such things as Great Lakes contamination from foreign shipping. The frustration is that there are solutions for contamination, if companies would do it.

And closer to home, there is a state-of-the-art hydro-acoustic/sonar technology that an cover l,000 kilometers in a surveillance path to survey the entire lower food-web from prey fish (alewives) to their food (mysis). This survey is a critical input to managing the predator-prey balance in Lake Michigan.

In a three-week-period and in cooperation with the United States Geological Survey, the entire of Lake Michigan could be surveyed. But, this year reductions in budgets will result in large areas of Lake Michigan not sampled primarily from a shortfall of less than $10,000 in fuel and operating costs.

Claramunt and the other researchers, including volunteers like Tom Hamilton, do as much as they can with what they have to help keep those “eating machines” alive so they can continue to keep exotic prey fish in balance and promote healthy Great Lakes fish communities for today and the future.

Larry Porter
Posts: 845
Joined: Mon May 02, 2005 9:40 am
Location: Hastings MI

Post by Larry Porter » Sat Sep 26, 2009 5:19 pm

Well done, HR! Stepping up to the plate for fish research!

Hamilton Reef
Posts: 1156
Joined: Thu Apr 28, 2005 9:43 am
Location: Montague, MI on White River

Post by Hamilton Reef » Sat Sep 26, 2009 9:42 pm

The point of the article was to get more anglers involved with helping the DNR fishery programs during difficult times. These obvious win/win partnerships keep the good fishing going. Of course the MMA organization already understands this and is a role model for other organizations to follow.

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