Great Lakes Article:

States to slash salmon stocking in Lake Michigan
By Dan Egan
Milwaukee Journal Sentinel
Posted on Bradenton.com on November 15, 2005

MILWAUKEE - Lake Michigan's popular chinook salmon stocking program will be throttled back next year due to plummeting numbers of alewives - the Pacific salmon's favored food - and mounting evidence that large numbers of chinook are now reproducing naturally in lake tributaries.

The states of Wisconsin, Michigan, Indiana and Illinois will slash their combined planting program by 25 percent, from 4.3 million to about 3.3 million, the Wisconsin Department of Natural Resources announced Tuesday.

Reductions in annual plantings have in the past been greeted with suspicion by angler groups, but state fishery managers from around the region made a good case for the switch before those groups at a meeting held in Kenosha earlier this fall.

"I sensed there was strong support from angler groups to cut lake-wide stocking overall. I thought the message was well received," said DNR biologist Paul Peeters. "(But) I do think there was some angst among sporstsmen about where the cuts would be."

To hold up its end of the agreement, Wisconsin will drop its chinook plantings next spring by 21 percent, or about 300,000 fish.

Lake Michigan's salmon program started in the 1960s with the dual goal of controlling the invasive alewives and to give a boost to recreational fishing on the big lake.

The states' combined stocking programs peaked in the late '80s with about 8 million chinook planted annually, but those programs were dramatically reduced after massive salmon die-offs due to disease. Biologists say that disease was likely tied to malnutrition - the lake could not support the amount of chinook being planted.

Chinook plantings were reduced further in 1999 to just more than 4 million annually.

The problem is the lake's alewife population has continued to plummet. A study released this spring showed the lake's adult alewife population dropped by about 70 percent between the fall of 2003 and 2004, and today the lake's alewife population is perhaps 5 percent of what it was in the 1960s.

One theory behind the recent drop-off in alewives is the Atlantic natives can't handle the Great Lakes' temperature swings. Some scientists also think the decline may be at least partially tied to a drop in food for the alewives called diporeia. That shrimp-like creature has disappeared from vast expanses of the lake bottom since the arrival of the invasive zebra mussel.

Meanwhile, evidence suggests that as much as 50 percent of Lake Michigan's chinook population is now reproducing on its own - something never expected when the stocking program began.

Most, if not all, of that natural reproduction is occurring in the cold and relatively clean streams and rivers of Michigan.

"It's critical the states work together to manage the fishery, so I'm pleased we were able to reach agreement," Mike Staggs, Wisconsin DNR fisheries director, said in a news release. "Natural reproduction of chinook has improved tremendously in Michigan streams in recent years, and the result of this good news and other factors is that there are too many fish for the forage base to support. We think the lake-wide reduction will help sustain the fabulous fishing anglers have enjoyed in recent years."