I debated adding my two cents to this entry, then decided to let the message of IDNR director Marc Miller on the July closure for perch fishing on Lake Michigan in Illinois waters stand in its entirity.
Here's Miller's response to my e-mail that I was doing a followup article on the July closure:
Dale, there is no change. I asked recently for an update to this question. Since we also receive questions on commercial harvest too, you will find this answered as well. Please don't be alarmed by this. If we see improvement in data, recreation will be first priority. Chris McCloud is out today, so I am forwarding the info. Here's what I received:The current sport regulations include a 15 fish daily bag limit with July closed to perch fishing. Children under 16 are exempt from the July closure but are subject to a 10 fish daily bag limit during July. There is currently no commercial quota for yellow perch. We recognize that these regulations can have a negative impact but we must balance these concerns with the most appropriate management actions for protecting the perch population from overharvest.blockquote>
A fish population can sustain itself under normal conditions if sufficient numbers of young fish enter the adult population to replace older individuals lost through natural and fishing mortality. Unfortunately, this has not been happening with Lake Michigan perch since the late-1980s. Invasive species and changes in the food web are the most likely culprits for poor recruitment and the subsequent decline in perch numbers, not the commercial or sport harvests. New year classes of sufficient abundance have been sporadic due to poor and unpredictable survival of newly hatched perch. This has resulted in the perch population's reproductive potential being supported by an occasional year class of sufficient abundance instead of three or four relatively strong year classes as we had in the past.
A stable perch population should consist of several relatively abundant year classes. Currently, we do not have this. We consider the perch population still vulnerable to overexploitation because female perch grow much faster than males and more quickly obtain the larger sizes that anglers prefer. These faster growth rates result in females generally comprising a major portion of the large or jumbo perch that anglers are currently harvesting or that would be caught in commercial gear. Also, female yellow perch generally have a shorter life span than males also because faster growing fish usually die sooner than slower growing fish and because they undergo greater stress during spawning.
The purpose of the July closure is to limit the total number of yellow perch that potentially could be harvested annually from Illinois waters. Illinois Natural History Survey creel data for the 2009 season reported a total harvest of 263,500 with July open to kids under 16, this is a 17% decline from 2008. From 1990-1994, an average of 44% (range: 31-59%) of the total annual Illinois sport harvest occurred during the month of July. If July had been open to all anglers in 2009 the perch harvest could have been approximately 470,000 perch (range 382,000 to 643,000), or an additional 207,000 perch.
The goal for the Department is to maintain the annual perch harvest at a level consistent with protecting the population. By limiting the total number of perch harvested annually we hope to insure that a sufficient number of females will be available to sustain the population over a longer time span. Higher harvests would not be a problem if abundant year classes were routinely appearing and entering the adult population and in greater numbers than is currently happening. Since we must proceed with caution until we obtain multiple year classes in the adult population. Perch year classes hatched in 2004, 2005, and 2006 were thought to have the potential to provide sufficient numbers to replace the adult perch currently sustaining the population, however, this has not occurred. Slow growth rates have delayed entry into the spawning stock and fishable population. Survival rates have been lower than expected, resulting in fewer individuals. We will continue to evaluate the status of the yellow perch population through our annual assessments as we have done in past years.
Preliminary information from the 2010 yellow perch spawning assessment completed June 2, 2010 by the Lake Michigan Program indicates that the population status has not changed and any increase in harvest is not recommended. Samples from this assessment will have to be analyzed and we expect to have is completed by late fall or early winter. This information, along with data about the success (or failure) of the 2010 yellow perch hatch (gathered over the summer), will be used as a basis to evaluate potential regulation changes.