Trout streams keeping their cool despite drought
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Joanna Griffin, DNR fisheries specialist, 608-264-8953; |
http://dnr.wi.gov/news/BreakingNews_Lookup.asp?id=2446
EAU CLAIRE, Wis. -- Although drought and high heat have caused fish kills in some marshes and shallow lakes in Wisconsin, the state’s trout streams remain in good condition, biologists said.
Many of these streams are continually refreshed by groundwater springs. The influx of cold water provides a buffer against hot, dry conditions at the surface.
“Streams in La Crosse, Monroe, Vernon and Crawford counties are still in good shape,” reports Department of Natural Resources area fisheries manager Jordan Weeks. “Waters levels are slightly below normal, but temperatures are good, fish populations are abundant and fishing has been excellent.”
No one can predict how long this will continue, as these creeks depend on underground aquifers. But for now, the streams have proven amazingly resilient.
Also, biologists point to the difference between short and long term consequences. Counties in the southwest have had plenty of rain in recent years, recharging groundwater resources, but are parched this year. Counties in the northwest have had rain this year (while still needing more) but are still reeling from the effects of a six-year drought.
“This area of the state is experiencing a longer term precipitation deficit that is lowering groundwater levels and causing greater impacts on trout streams than this summer's weather,” said biologist Jamison Wendel in Spooner.
Still, Wendel reports, the streams in northwest Wisconsin are in good shape.
In Langlade, Lincoln, Forest, Florence, Oneida and Vilas counties trout stream levels are at average or above average levels for mid-summer with excellent populations of stream trout.
“Warm spells can increase water temps to stressful conditions in some streams,” said biologist Dave Seibel, “but as long as cool nighttime temperatures return every few days, trout can find relief and handle the conditions just fine. Angler reports have been very good.”
Recent surveys show strong trout populations in Eau Claire and Chippewa counties as well, reports biologist Heath Benike, though he notes that cold-water fish like trout become a bit lethargic as water temperatures rise.
Further west in St. Croix, Pierce, Dunn and Pepin counties – where 3.6 inches of rain fell in the past week – the streams are in top condition. Both flow and fish populations are normal.
“We do not anticipate any drought related problems in this part of the state, now or in the near future,” said biologist Marty Engel at Baldwin.
In the central sands area, flows have dropped slightly at some locations, but temperatures and populations are holding steady.
“Stream crews are noticing some movement of trout up into the cooler, headwater portions of streams.” said biologist Dave Bartz of Waushara and Marquette counties.
Surveys show fewer trout in tributaries of Lake Michigan, indicating that lake-run trout below the first dam are dropping back into cooler, deeper water, said biologist Steve Hogler. In Sheboygan County, biologist Travis Motl said water levels are low but temperatures are normal and fish appear healthy. Cooler evenings and adequate groundwater are helping.
In Waukesha and Walworth counties, as in Waupaca and Shawano counties, fish are tending to concentrate near headwaters. Streams are lower than average but the fish look good. Streams are at normal levels and temperatures in Marinette and northern Oconto counties with strong trout reproduction and decent numbers of harvestable fish.
Mike Staggs, bureau of fisheries director, advised anyone with questions about a particular stream to contact their local fish manager. Patience is advised as crews are busy conducting surveys in the field. Contacts for local fisheries managers are available on the DNR website.
Staggs said it is unlikely any streams will be closed to fishing in Wisconsin even if the drought worsens. During the drought of the late 1980s, many streams were closed, but when the drought ended and biologists analyzed the effects, they concluded closing the streams was not helpful. In the highest quality streams, trout numbers either remained strong or rebounded quickly and marginal trout streams depend on stocking in any case.
The bottom line: if you like to fish for trout, go for it. When high temperatures are in the upper 80s and 90s, however, you might want to get out there at dawn. By noon, you’ll be melting in your waders.