OSHKOSH - Changing food supplies affecting where lake sturgeon congregate and a subsequent increase in sturgeon harvest rates in the Lake Winnebago system are spurring proposals to change how the state preserves populations of this late-maturing, long-lived species while still allowing broad participation in a unique spearing season.
A trio of recommendations to continue achieving those goals are the topic of a public hearing Aug. 17 in Oshkosh. The hearing begins at 7 p.m. in Meeting Room A, Winnebago County Coughlin Building, 625 E. County Road Y.
The recommendations, developed over the past year by the Department of Natural Resources' Oshkosh area fisheries staff and the Winnebago Citizens Sturgeon Advisory Committee, are aimed at providing long-term management solutions to reduce the risk of overharvesting the world's largest remaining population of this vulnerable, gigantic fish, according to Ron Bruch, Department of Natural Resources senior sturgeon biologist and Oshkosh fisheries supervisor.
"We've done everything we can over the last 10 to 15 years to bring harvest of adult females down to an acceptable level while continuing to allow anyone who wants to participate to do so," says Ron Bruch, Department of Natural Resources senior sturgeon biologist. "Those actions have helped immensely, but we're not quite there yet."
Spearers in 2004 exceeded the safe harvest level for adult females by 61 percent, a particular concern because females are the cornerstone of the lake sturgeon population and don't start spawning until they are 20 to 25 years old, and then spawn only every three to five years.
The following recommendations have been developed with the advisory committee over the past year, Bruch says, to reduce the potential for excessive overharvest and increase spearing opportunities:
- Upriver Lakes permit drawing. This proposal would create a sturgeon spearing season on the Upriver Lakes (Lakes Butte des Mort, Winneconne or Poygan ) that would be held every year beginning in 2007 and would be open to a limited number of spearers selected through a random drawing of people requesting upriver permits. The total harvest proposed for this season would be capped at a fraction of the separate harvest limits DNR sets each year for adult females, juvenile females and males from the Lake Winnebago system, and the season could run 16 days if the triggers weren't reached. From 1971 to 2000 the DNR conducted two day Upriver Lakes season every five years that was is open to all permit holders; in 2005 a special regulation was adopted limiting the season to one day.
- "Fast start" season 100 percent closure trigger. Beginning in 2006, DNR could close the spearing season at the end of a spearing day should any one of the three harvest caps -- for juvenile females, adult females or males -- be reached or exceeded. This proposal is similar to the emergency rule in place for the 2005 spearing season.
- "Slow Finish" season 90 percent closures. Beginning in 2006, the trigger for closing the spearing season would be increased to 90 percent of the harvest cap. "Our experience has shown that in a majority of seasons, the 80 percent trigger could be increased to 90 percent without increasing the risk of overharvest to the sturgeon stock," he says. Under current rules, the season is closed 24 hours after the end of the spearing day when 80 percent of any one of the three harvest caps is reached or exceeded.
The recommendations would allow DNR to move quickly to protect the Lake Winnebago sturgeon in seasons where spearing conditions are ideal and harvest caps are reached quickly, while
extending the season and spearing opportunities when water clarity and other spearing conditions are unfavorable and the risk of excessive harvest is low, Bruch says.
In addition, having a lottery on the Upriver Lakes for a limited number of spearers allows that season to be offered more frequently than once every five years, as under current rules, and can help take some of the pressure off the Lake Winnebago fishery, he says.
"These recommendations will allow Wisconsin to preserve the Lake Winnebago system sturgeon population and maintain a biologically sound, economically significant open access fishery in spite of recent environmental changes," Bruch says.
The abundance of gizzard shad has increased in Lake Winnebago and provided an excellent additional food source for Winnebago sturgeon. As a result, the fish have been congregating in the winter in the southern tip of Lake Winnebago to feed on large schools of gizzard shad.
Coincidentally, winter water quality has improved significantly following the completion and implementation of the Winnebago Comprehensive Management Plan in the late 1980s, which in turn was the impetus for large-scale programs to control polluted runoff entering the Winnebago system. The improving water quality has boosted spearer success.
The overall result of these trends was illustrated perfectly in 2004, when spearers exceeded the harvest cap for adult females by 61 percent, or 259 fish, and fully 89 percent of all lake sturgeon harvested in that year were speared in the southern tip of the lake, Bruch says.
Concern over the prospects for a similar overharvest in 2005 spurred the Natural Resources Board to authorize DNR to close the 2005 season after one day if any one of the harvest caps was reached. But board members also ordered DNR to devise longer-term solutions.
The 2005 Lake Winnebago season ended up lasting longer - 12 days -- than expected, and the 2005 Upriver Lakes season had a lower total harvest than anticipated, because poorer water clarity and ice conditions tracing to warm weather, rain and runoff a week before season hampered spearing.
The proposed recommendations allow DNR to respond to different season conditions that will affect spearer success, Bruch says, "We're trying to work on both ends: protecting lake sturgeon if conditions are ripe for a high harvest and providing more spearing opportunities if the risk of overharvest is low."
FOR MORE INFORMATION CONTACT: Ron Bruch (920) 424-3052
Article Source:
http://justnorth.com/Articles/tabid/105/articleType/AuthorView/authorID/12/justnorth.aspx