The Science


- Dr. Wilberg's Study finding that Critical female yellow perch were overfished. Mostly by commercial fishers. With a total population at highs, there still weren't enough females for both the sport and commercial fishers. In conclusion he finds that by 1994 there probably weren't enough large breeding females left to repopulate those waters off SE Wisconsin and bordering Illiniois waters. I believe Dr. Wilberg estimates that 37% mortality is the maximum.

- A 2005 report finds that Lake Michigan perch are faithful to certain reefs. That they just don’t really roam the lake. I find the study of perch reefs more analogous to salmon rivers, with perch on their reefs as susceptible to depletion by nets as salmon in their rivers. Certainly a call for protecting reefs from nets.

A 2006 study finds that Lake Michigan yellow perch eat invasives. Response of Yellow Perch Diet to a Changing Forage Base
in Southern Lake Michigan, 1984-2002. Holly A. Truemper, Thomas E. Lauer, Thomas S. McComish, and Rod A. Edgell

- An award winning 2008 study, finding that in the presence of commercial nets, the perch population becomes on average smaller and the population shifts to majority of males. It also appears to disagree with Mr. Horn’s (WNDR) 2001 paper finding that, lack of food, not overfishing was the cause of smaller perch. Please note that when perch nets were pulled from Lake Michigan the average perch size increased over 50%.

- WDNR's Graded Mesh surveys confirms that commercial perch fishing shifts the perch population to mostly males. Critical years circled, 1989- start of quota system; 1993- end of CanAm sting; 1996- last year of commercial perch fishing. % female numbers then start back up. Anyone know of a natural predator that targets mostly female perch. Humans do, because females grow larger, faster.

Is management and science harmed by commercial fishing? Commercial fishers return fewer perch tags then sportsmen except for one year. 1986, when a case of beer (P. 3) was given out for every tag returned to the WNDR with proper information. It would appear that a case of beer is worth more then helping the fishery? What of tags from illegally caught perch, like CanAm? What of all the lost information from incidental catch of game fish?