Yellow perch populations in the Les Cheneaux Islands increased in size and number in 2005, owing to what biologists are calling a "phenomenal" year class in 2003 for perch, both here and around the Great Lakes.

Fisheries Biologist Dave Fielder of the Department of Natural Resources Alpena Research Station said so many young perch hatched in 2003 and survived that they have contributed to a growing perch population. Mr. Fielder said 2005 catch rates were the highest measured since 2000, when populations plummeted to the lowest numbers ever recorded.

In the Les Cheneaux Islands, at least, survival rates may be tied to federal double-crested cormorant control activities. United States Department of Agriculture Wildlife Services agents began lethal control by oiling eggs and shooting a select number of cormorants in 2004. Yellow perch and other fish species' survival rates have been on the rise since then, suggesting that fewer cormorants mean more fish. Since perch population increases have only been recorded for a few years, however, Mr. Fielder and other scientists are hesitant to call cormorant control the silver bullet that ensures a prolific future for perch. Speaking to a large group of sportsmen, anglers, and concerned public this spring in Cedarville, Mr. Fielder was still optimistic.

"This positions us very well to further test the effects of doublecrested cormorant control," Mr. Fielder said. "Now that we have some strong year classes in the system, we can measure how some of these effects are working."

He said the stronger numbers "are consistent with the kinds of results we were anticipating with cormorant control," just like the demise of the 1998 year class, which contributed to 2000's dismal population, "is consistent with the types of predation caused by cormorants."

At least three more years of data is needed before researchers know more. Other factors in the lakes might be helping perch populations as much as cormorant control. Alewives, an invasive forage fish, have nearly disappeared in Lake Huron since 2003, which is may have improved perch production in other areas of Lake Huron. Alewives eat and compete with newly hatched perch fry.

Mr. Fielder has been conducting netting surveys in the Les Cheneaux Islands twice each year for the past six years, and will continue the August and October surveys again this year. The data he collects is compared to creel surveys collected by DNR creel clerks Bill and Linda Schroeder during fishing seasons to provide a synopsis of fishing conditions in the area.

The DNR keeps track of all the species of fish collected in the nets, as well as other factors like fishing pressure and the survival rates of young fish from year to year.