 November/December 2000 | |||||||
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More Stories: Minnesota’s Sturgeon Resurgence Where have all the big pike gone? Where are Minnesota’s biggest bucks? Conservation plates net $2 million so far Slot limits measure up on Winnie Antlerless-only permits not a solution
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From the field
1. Stearns County “In this part of the state, it’s rare to find even a 5-acre tract of prairie, much less a 60-acre one like we have here,” says Mike Lee, a DNR plant ecologist. The site, which is bisected by a narrow meandering stream, also contains a wet meadow and a small seepage fen. More than 100 native plant species grow on the site, which also contains upland sandpipers and sandhill cranes.
Attending the dedication were Stearns County Board of Commissioners Chair Mark Sakry, County Commissioner Don Ote, DNR Scientific and Natural Area Program Coordinator Bob Djupstrom, neighboring landowners, and friends and family of Sarah Vest. Vest, who died of cancer in 1999, worked for the SNA Program for seven years. She had asked that memorials be given to the program. Approximately 75 friends and family members donated more than $16,000, which was used to help purchase the addition to the SNA. Also attending were the Johnson family, who formerly owned part of the SNA parcel, and Orano “Grindy” Grindahl, who traveled to the ceremony from his home in Oregon. Grindahl’s great- grandfather had first purchased the prairie parcel in 1868, and it stayed in the family for more than 130 years. “I can still remember back in 1945, when I was only 14 years of age, traveling to the acreage to help my dad do an annual burning of the prairie to promote a better yield of the next hay crop,” Grindahl said. “To this day, the land has never been tilled.” Grindahl said he and his wife agreed to sell the land to the DNR to be managed under the SNA Program because “that way, we knew it would ensure protection of [this area] under the law.”
Donna Dustin stares at about 50 quart-size jars lined up on a counter in the Detroit Lakes fisheries office and lets out a sigh. “Well, here goes,” says the DNR fisheries biologist as she opens a lid and spreads the gooey contents on a laboratory table. Then, holding a magnifying glass in one hand and a tweezers in the other, she picks through algae, seeds, sucker eggs, insects, and other detritus netted last spring from Ada Creek near Backus. “Here’s one,” she says after several minutes, holding up a mosquito-sized walleye fry. She sets it aside and continues her search for additional fry, and will continue, jar by jar, well into winter. Dustin’s tedious work is part of a several-year study to determine if improving walleye spawning habitat in streams is worth doing. Walleyes spawn in gravely substrate of streams flowing into lakes, but sand washing downstream often fills in the gravel. Since the late 1980s, the DNR has been adding rock and gravel to stream spawning sites. Though the habitat improvements are thought to boost spawning conditions, Dustin says fisheries managers have never known “how much they are increasing the number of fish coming off an area, and whether it is enough to justify the cost.” The study should help answer those questions. Step one was to survey the number of walleye fry produced in three known walleye spawning sites on each of two study streams--Ada as well as Pelican River in Detroit Lakes. In May of 1999 and 2000, biologists set drift nets downstream of spawning sites and captured whatever floated down. That’s what Dustin is looking through this fall and winter as she counts walleye fry. The next step was to improve the spawning habitat at the sites. Fisheries crews completed that work this past summer, using engineering formulas developed by DNR Ecological Resources staff in Fergus Falls. The crews added tons of rock and gravel and then steepened the stream gradient to increase water velocity so that sand can’t fill in the newly installed habitat. The final step will begin next spring after walleyes spawn, when Dustin and colleagues return to the sites with drift nets. By this time next fall, she will be facing another tableful of jars. But those ones, she hopes, will be filled with far more walleye fry than she found today. When Tom Heinrich finished his yearly fall gill-netting survey recently, he was struck by the total absence walleyes, sauger, and perch from this year’s hatch. The survey is designed to sample fish from a range of year classes, or generations of fish. By knowing the relative strength of year classes, biologists can roughly estimate the relative numbers and sizes of fish in the lake from year to year. Heinrich, DNR large-lake specialist for Lake of the Woods, says the 2000 year class bust was likely due to cold weather that hit the region in mid-May and continued well into June. “Walleyes spawned a bit earlier than usual this year due to an early spring,” he says. “Then we had that cold weather come through, and it probably killed a lot of the newly hatched fish.” The lack of a bumper 2000 year class will likely not affect the fishing on the big border lake, however. Heinrich says that Lake of the Woods has several strong year classes that will be providing anglers with plenty of fish. The fall survey indicated the presence of walleyes from 15 different year classes, indicating a healthy fishery and an abundance of large, old fish. The most abundant fish are those from a productive 1997 year class. Heinrich says those fish will be roughly 14 inches long next spring. “A lot of 1-pounders will be showing up on the end of many anglers’ lines,” he says. The MinnAqua Program broke new ground in reaching kids through two new partnerships this past summer. MinnAqua, the DNR’s aquatic education program, held three major events at the Fishing Hall of Fame in Walker. Up to 600 kids gathered with parents and other adults to review angling regulations and learn how to identify different species and fish safely. Then they headed to a nearby stocked pond, where every kid was able to catch a fish and turn theory into fact. “It’s so great when they catch a fish,” says Deb Runksmeier, who temporarily coordinated the northern Minnesota MinnAqua Program during the summer. “Then we can point all the things they just learned like where the fins are located, and coloration.” The other partnership was with the Minnesota Fishing Museum in Little Falls. MinnAqua has trained museum staff to run 3-hour education events in which kids learn about fish and lake ecology while playing games, doing puzzles, and play acting. Runksmeier said groups from Kinship Partners--similar to Big Brothers and Big Sisters--and the Girl Scouts came to the museum to participate in the education events. This winter the MinnAqua Program will be working with the museum and hall of fame staff to set up similar events for next summer. Do fluctuations in Rainy River water levels, caused by the hydropower dam at Fort Frances, Canada, harm habitat for fish and other aquatic life? That’s the puzzle that DNR Ecological Resources biologists are trying to solve with a study they began this year. Luther Aadland, a fisheries research scientist at Fergus Falls, reports that the study is focusing on a wide range of aquatic habitats, from deep pools to riffles, the shallow, gravel-lined areas of streams and rivers. “Riffles are the especially sensitive to water level fluctuations and that’s where most aquatic invertebrates live,” Aadland says. The project, done cooperatively with the Ontario Ministry of Natural Resources and the Rainy River First Nations Band of Ojibwe, examines the entire aquatic community, including invertebrates such as mayflies, small nongame fish such as darters, and game fish such as walleyes. Funding comes from the new Heritage Enhancement Account, established in May 2000 by the Minnesota Legislature to use state lottery dollars for habitat improvement projects. Particular attention is being paid to lake sturgeon, a huge and long-lived fish that has been making a slow recovery on the Rainy in recent decades. Sturgeon spawn in shallow rapids and riffles. Biologists and anglers are wondering if rapid declines in water levels in spring could kill sturgeon eggs or newly hatched fish. Since 1996 a Canadian company, Abitibi Consolidated, has operated the water-control structures at the Fort Frances hydropower dam that determine water levels downstream. DNR scientists are solving the water level puzzle by creating a computer model that determines water depth and speed associated with different habitat features, such as sunken logs, boulders, and deep pools. “Into that model, we integrate habitat suitability information, which is basically a database that shows what types of habitat different fish need at different stages of their life,” says Aadland. That habitat data has been collected on dozens of streams and rivers throughout Minnesota over the past decade by the Ecological Resources Division’s Stream Habitat Program. Aadland says DNR biologists have measured the habitat of more than 100,000 fish in roughly 4,000 areas. In addition to identifying, measuring, and aging the fish, they measured the water depth and velocity from each site, as well as substrate type and related cover. Biologists hope to have the study completed during the next two years so they can present the information to the International Joint Commission, a group that resolves border water issues. Over the next several months, 20 newly hired DNR wildlife technicians will be meeting with landowners in southwestern Minnesota to help them enroll land in the federal Conservation Reserve Enhancement Program (CREP). The technicians will work out of Soil and Water Conservation District (SWCD) offices within the Minnesota River watershed. Ken Varland, DNR southwest region wildlife supervisor, says the technicians were hired “to assist with one-on-one contacts needed to inform rural landowners about the benefits of CREP.” The new technicians join 14 existing SWCD staff, who have been swamped with requests for information about the permanent land retirement program. CREP links the federal Conservation Reserve Program with the state Reinvest in Minnesota Program. Widely supported by conservation and hunter groups, CREP has so far enrolled roughly 20,000 acres of erodible land. “Our goal with these new technicians is to enroll up to 100,000 acres,” says Varland. “That’s an additional 80,000 acres of land that will be permanently retired and will be able to produce wildlife as well as reduce soil erosion that degrades water quality.” It was just a few hours into the deer hunting season when Bob Tangen examined the first buck of the weekend at Mauer’s Tavern. Tangen, assistant manager at the nearby Whitewater Wildlife Management Area (WMA), spent the rest of the weekend estimating the age of roughly 90 bucks in the bucks-only Zone 3A hunt. Among the biggest buck he saw was a 220-pounder that had a 13-point rack. By examining the wear of the deer’s teeth, Tangen estimated it to be four-and-a-half years old. But he says that many large-racked deer he examined that weekend were far younger. “Hunters who brought in some really nice deer--some big 8- and 10-pointers--were really surprised when I told them the animal was just a year-and-a-half old,” Tangen says. He explains that southeastern Minnesota is so mild in the winter, and produces so much nutritious corn and acorns, that bucks can reach trophy size just by escaping hunters for one season. But with intense hunting pressure, rare is the buck that lives that long. “A two-and-a-half year old buck is an old buck down here,” Tangen says. By gathering information on the age of harvest deer, Tangen is helping DNR wildlife research scientists build an accurate population model of the Whitewater WMA deer herd. Because there’s no way to determine exactly the number of deer in the area and their ages, managers use the population model to determine, among other things, how much doe hunting to allow in order to keep the population at a reasonable level from year to year. | ||||||
