Mild, dry winter means problems for walleye

  • Advertisement

HB Store


User avatar
Dewey
Moderator
Posts: 36727
Joined: Thu Mar 11, 2010 7:57 pm
Location: Wisconsin
Status: Offline

Mild, dry winter means problems for walleye

Unread postby Dewey » Wed Mar 14, 2012 4:52 am

Wisconsin residents used to the bitter cold and heavy snowfalls commonly associated with Midwest winters welcomed this season's mild temperatures and below-normal precipitation.

But this year's dry winter could have an adverse effect on the reproduction of a particular fish that swims in local waters.
Each spring, walleye — a fish that inhabits the waters of the northern United States and Canada — venture up the Wolf and upper Fox rivers to spawn in flooded marshes that depend on a constant water flow.
"That flow is really critical to make it a good functioning marsh," said Kendall Kamke, senior fisheries biologist for the state Department of Natural Resources.
Kamke said the marshes provide an "incubating environment" for the walleye eggs. The dark bottoms and shallow water allow the sun to heat up the eggs that lay on flooded vegetation. The marshy areas also provide protection for the young walleye — known as fry — from hungry predators.
But reaching that perfect water flow in the marsh depends on the amount of precipitation that falls and water runoff. And from the looks of it, Kamke isn't optimistic that enough excess water will provide good flow to the marshes this year.
According to the National Oceanic and Atmospheric Administration, Wisconsin's 2012 winter precipitation total — 3.73 inches — is the lowest since 2006. That also translates into low snowfall. For the Appleton area, snowfall totals were 2.1, 9.9 and 7.2 inches for December, January and February, respectively — way below the previous winter's numbers of 18, 14.2 and 24.1 inches, respectively.
Much of the flooding needed to create the marsh flows comes from snowmelt as well as frost that makes the water run off into the rivers instead of soak into the ground.
Despite the low snowfall, Kamke said an ideal marsh environment could still be created this year as long as that spring rain comes.
"If we get a really wet spring … then all this can change quickly," he said.
Tom Helman, a meteorologist for the National Weather Service in Green Bay, said forecast models currently show above-normal precipitation coming to this part of the state — a good sign for the Lake Winnebago System walleye.

Where that precipitation lands, however, is key. Kamke said the water must fall near the upriver marshes for the runoff to have an effect. Spawning is spread out along both the Wolf and upper Fox rivers, but some popular sites include areas to the north around Fremont and Shiocton, and to the south near Eureka and Berlin.

One dry spring, however, would not adversely affect the local walleye population, Kamke said.
"Generally, walleye populations only need to have a good solid year class about once every three years to maintain the same size and age structure," Kamke said. By "year class," Kamke means the fish that are produced during that spawning year.
Only multiple years of drought can have an overall effect on the walleye population and in turn affect fishing, he said.
This was precisely what happened in the latter half of the 1980s when the Lake Winnebago walleye numbers dropped off after consecutive years of low rainfall.
DNR sample counts of year class populations have been fairly strong for the past decade. In 2011, the DNR recorded its fifth-largest count since trawling assessments began in 1987, and 2008 was the second-largest year.
Spawning usually begins around April 10 on the Wolf River and about a week earlier on the upper Fox River.
But with higher temperatures descending on the state, Kamke thinks spawning could occur a week or more early this year.
"It just depends … how long that warm air sticks around with us," he said.



  • Advertisement

Return to “Game fish, pan fish, and general fishing talk”

Who is online

Users browsing this forum: No registered users and 21 guests