June 23, 1995
TO: Wisconsin Federation of Great Lakes Sport Fishing Clubs contacts, Wisconsin Commercial Fisheries contacts, Great Lakes Study Committee, Lake Michigan Commercial Fishing Board, other interested individuals
FROM: Bill Horns, Great Lakes Specialist
SUBJECT: Fisheries Issues Pertaining to Lake Michigan
This is to bring you up to date on several issues that may be of interest to you. I will be brief. If you have further questions about these issues, or about any others, please call me at 608.266.8782, or send me a note. Our fax number in the Bureau of Fisheries Management is 608.267.7857.
Sport fishing reports have been good, except for yellow perch outside of Green Bay. The coho fishery may be a little weak because lakewide stocking in the spring of 1994 was far below target levels, but many anglers are taking their daily bag limit of three cohos. On the commercial side, the lake whitefish population is in great shape, and, with the exception of yellow perch, other species are holding up.
As you are aware, the yellow perch population in Lake Michigan has declined, reflecting five years of poor reproduction. Some of you attended the meeting last December in Kenosha where the issue was discussed by a large group of sport and commercial fishers from all four states. Following that meeting the four fish chiefs met and agreed to a lakewide yellow perch protection strategy, of which our new rules are a part. We have cut the daily sport bag limit from 50 to 25 in Lake Michigan, closed fishing for yellow perch during June (1995), and reduced the commercial harvest by 65% in Lake Michigan. The yellow perch population in southern Green Bay, where we cut the allowable commercial harvest last year (1994), is in somewhat better shape than that in Lake Michigan.
If you would like a copy of the new Lake Michigan Integrated Fisheries Management Plan, let me know. Copies are also available from some the DNR offices on the lake.
Commercial lake whitefish quotas have been raised, reflecting a very strong lake whitefish population. The whitefish population is shared with Michigan. We hope to work with Michigan to develop better joint management of this shared population.
In recent years all Great Lakes states have coped with high mortality rates among newly-hatched salmon and trout produced from wild parents. The condition is referred to as Early Mortality Syndrome (EMS). We do not know the cause, although it is clearly not a bacteria or virus, and hatchery rearing practices are not the problem. Although the cause is unknown, fish health specialists in the Great Lakes states seem to have developed an effective treatment, thiamine. Eggs treated with thiamine have shown markedly better survival through the critical period immediately following hatching than untreated eggs.
Because we took extra eggs last fall and because treatments with thiamine have markedly reduced Early Mortality Syndrome, we are on track to meet or exceed stocking quotas for 1995-96. In fact, survival has been so good that it became necessary to cull 130,000 surplus cohos from the production system. The small surplus cohos were stocked out last week, divided equally between Lake Michigan District and Southeast District. With luck, it will not be necessary to extend the reduced coho bag limit beyond 1995. Unless we take action to extend the current rule, the coho bag limit will revert to five in 1996. Our experimental comparison of stocking yearling and fingerling cohos is going forward. Sport harvests and returns to brood rivers in 1996 will provide the first data to compare the two stocking strategies.
The ruffe is a small perch-like fish of no known sport or commercial value. Ruffe are native to parts of Europe and Asia. Ruffe were carried to Duluth/Superior Harbor in the mid 1980's in the ballast of an ocean-going vessel. As far as we know, they are still confined to the western end of Lake Superior, and are not yet in Lake Michigan. Their range is expanding to the east, and now reaches at least 60 miles into Michigan waters of Lake Superior. Although we do not know how ruffe will effect native fish, we would like to slow their spread to the east. Several steps have been taken. There has been some controversy about a proposal to apply chemical piscicides to Lake Superior tributary streams for the purpose of slowing the spread of ruffe. We see no solid reason for believing that that strategy would work, and we are concerned about the harm it would do to native fish in the target streams. We are currently working with others to study seasonal ruffe movements to see if they are vulnerable to chemical control during the early summer.
Michigan anglers are concerned about the open-lake harvest of steelhead produced naturally in their streams. They believe that the open-lake harvest is a threat to the continued health of naturally reproducing populations in Michigan tributaries. (We have no natural steelhead reproduction in our streams.) I do not know when or if this issue will get to the stage of rule making, but there is clearly a need for a lakewide discussion of management of this species. One of the ideas that has been floated is to mark all hatchery produced steelhead and then set high size limits or low bag limits for unmarked (that is, naturally reproduced) steelhead.
The round goby is expanding its range north from Illinois. Rule changes to outlaw possession or transport of goby and to restrict bait harvest from Michigan waters may be needed to minimize the risk of transportation of gobies into inland waters. We are also looking into restricting commercial bait harvest from tributary streams.
Under current rules commercial fishers cannot always assure that, upon their death or disability, the value of their license and quotas will be transferred to a designated beneficiary. We are looking into rule changes to remedy this situation in a way that does not imply a property right to wild fish.
Salmon stamp funds will be used for a new water line from Lake Superior to the Les Voigt State Fish Hatchery. This major project will greatly enhance our ability to produce salmon and trout efficiently at that facility.
1995 is the second year of experimental summer trawling for smelt in Lake Michigan. This study is funded by the trawlers, who are seeking to show that they can efficiently harvest smelt during summer without excessive harvests of alewives or other species. Under current rules commercial trawling in Lake Michigan is prohibited from April 20 through November 15.
This is the first of a series of informal memos to keep you informed about fisheries management on Lake Michigan. I hope you find it helpful. Please let me know if you have questions about any of these issues.