Lake Michigan perch make strong showing
Wednesday, October 5, 2005 11:40 AM EDT
By Paul Smith Correspondent
Milwaukee, Wis. After a decade of generally dismal news about the plight of Lake Michigan yellow perch, reports are emerging from biologists around the lake that may put smiles on anglers faces.
According to preliminary reports from the Wisconsin DNR, a record number of young-of-the-year perch were produced in 2005.
Were seeing more young fish this year than at any time in our records, said Brad Eggold, supervisor of the DNRs Southern Lake Michigan Work Unit. The fish still have to make it through winter, but were cautiously optimistic 2005 will produce a very solid year-class, or maybe even better.
Eggold cited data from the DNRs annual young-of-the-year perch assessment, conducted by beach seining and with gill nets at sites from Kenosha to Sheboygan. The tests were conducted from late August through the middle of September.
DNR crews this summer caught 39 young-of-the-year perch per 100 feet of net (expressed as the catch per effort, or CPE) in the beach-seining study, eclipsing the previous highs of 18.2 in 1989 and 3.0 in 1998. Most years in the last decade have been characterized by very poor perch recruitment, and tests have yielded only a handful of young-of-the-year perch, or worse. The CPE from 1995 to 2004 was 0.7, 0, 0.5, 3.0, 0, 0, 0, 1.3, 0.1, and 0.4, respectively.
The gill net study also yielded good numbers of young perch. The Sept. 15 set off Wind Point in Racine caught 555 young-of-the-year perch, a record for a gill net set in southeastern Wisconsin, according to Eggold.
These are quite promising findings, Eggold said. And fortunately, they are corroborated by other researchers.
The Lake Michigan perch population began a significant decline in the early 1990s. A report from a researcher at Michigan State University estimated perch have declined in the Wisconsin waters of Lake Michigan from 25 million in 1986 to 1 million in 2002. In the waters of Green Bay, the DNR estimates perch declined by 90 percent, but have shown an increase in the past four years.
To help protect the shrinking population in the general waters of Lake Michigan, the commercial fishery was closed in 1996, and stringent sport fishing regulations have been imposed. The daily bag limit is five fish per angler, and to help provide protection to adult fish before and during their typical spawning period, the sport fishing season for yellow perch on Lake Michigan is closed from May 1 through June 15.
Scientists have yet to provide a definitive explanation for the perch crash. Many of the same theories that have been discussed for the past 10 years are being considered today, including nutritional problems caused by lack of food, primarily because of the presence of zebra mussels, as well as the effects of weather and predation on young perch by alewives and other fish.
Most biologists believe no single factor is responsible for the decline and continue to study synergistic effects.
Wisconsin biologists have been tracking the last strong year-class of perch, the 1998 year-class, and monitoring its reproduction. A fair year-class was produced in 2002, fish which will be caught by anglers in increasing numbers in 2006.
The scene for a good 2005 year-class was framed by early reports that DNR divers found high numbers of egg masses on a traditional Lake Michigan spawning reef in spring. Divers reported 81, 76, and 18 egg masses on three dives in an area where they saw only one egg mass in 2004.
From what we saw, the big females from the 1998 year-class hit the spawning reefs early, and that has given the young fish more time to grow, Eggold said.
The young-of-the-year perch captured this fall range from 60 to 85 millimeters in length and were classified as large and robust by DNR biologists.
The 2005 data from the Lake Michigan waters of southeastern Wisconsin are part of a larger, brighter picture for perch emerging this year.
According to early verbal reports from Illinois and Indiana, biologists have encountered better numbers of young perch this summer than in recent years, Eggold said. Formal reports wont be available until later this year.
On Wisconsin waters of Green Bay, natural reproduction was at least fair in 2005 and enough to encourage fisheries managers who would like to proceed with plans to increase sport bag limits and commercial harvest quotas in 2006.
August trawling surveys in Green Bay captured 1,123 young-of-the year perch per hour, slightly higher than the catch rate of 730 per hour in 2002 and 612 per hour in 2004, according to DNR reports. The past four years have resulted in fair to excellent reproduction of perch in Green Bay, including the record-breaking yield of 2003, when trawling surveys hauled in an unprecedented 7,867 young fish per hour.
DNR officials are proposing to increase the daily sport bag limit for perch caught in Green Bay from 10 to 25, and commercial harvest from 20,000 to 60,000 pounds. Public hearings on the proposals for the waters of Green Bay will be held in October. If enacted, the changes would take effect in 2006.
No regulation changes are proposed for the general waters of Lake Michigan.
The next assessment of Lake Michigan perch will occur in December when the DNR begins the annual graded mesh assessment.
Until then, biologists will analyze data from the past year. The question will be asked: Why did a potentially very large year-class of perch emerge this year?
There will be a lot of number crunching and looking at things like weather, currents, food availability, Eggold said.
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