podcast , Mortality Rate of Tournament Caught Walleye

[lonehunter]

[url "http://www.michigan.gov/documents/dnr/DNR_8_25_206720_7.mp3"]http://www.michigan.gov/documents/dnr/DNR_8_25_206720_7.mp3[/url]

[url "http://www.michigan.gov/documents/dnr/DNR_8_25_206720_7.mp3"][#800080]Mortality Rate of Tournament Caught Walleye[/#800080][/url] [url "http://www.michigan.gov/podcast/1,2348,7-153-46403-174918-51887-,00.xml"][/url]

[lonehunter]

[font "arial, helvetica, sans-serif"][#00e010]Measuring Tournament Fishing's Impact on Our Walleye Populations[/#00e010][/font]
[font "arial, helvetica, sans-serif"][black]July 5
Big water, big fish, big prizes, big names and big business. Modern walleye fishing tournaments have become the NASCAR of the fishing world.
But do they also have a big impact on our walleye populations?
The "live-release" tournament format developed by organizers over the past several years requires contestants to use a properly aerated live well and make every effort to keep the walleyes alive for release after the weigh-in. A weight deduction is taken for any fish that is unable to swim upright in the official bump tank.
But do these efforts really work? How many of these fish really survive once released?
This is the topic of a multistate research project being conducted in cooperation with FLW Outdoors, one of the premier walleye tournament organizers in North America. The impact study is being conducted by graduate students at the University of Minnesota and the Michigan Department of Natural Resources is one of five state partners.
According to Dave Fielder, DNR fisheries research biologist at the Alpena Great Lakes Fisheries Research Station who is Michigan's liaison on the project, the researchers visited several FLW Outdoors walleye tournament sites in Michigan last year and have been going out again this year to gather more data.
"The researchers collect 'reference fish' in advance by electrofishing which temporarily stuns the fish allowing for their capture without the stress of hook and line techniques," Fielder said. "These fish are marked and then put in floating net pens right alongside some of the tournament-caught fish."
The primary goal of the impact study, he said, is to compare survival between the control fish and the caught fish after five days.
Fielder said other elements of the research project include a laboratory analysis to determine indicators of how successful the release of a fish will be, and a study designed to assess the attitudes of the greater angling community on its views of competitive fishing on public waters.
"The inclusion of the angler attitudes portion of the study is to provide a complete look at the issue of tournament impacts," Fielder said, "so it is not just limited to the biological implications if any."
In Michigan, the project researchers gathered data from four walleye tournaments, including one in the Michigan waters of Green Bay out of Menominee, one in the Bays de Noc out of Escanaba, one in the Detroit River out of Trenton, and the last one, which will be July 11-14 at the Bays de Noc out of Escanaba.
Similar tournaments have been monitored in other participating states including Minnesota, South Dakota, Wisconsin, Iowa and North Dakota. Funding for the study comes from the participating states and FLW Outdoors.
"The power of this study is the large sample size; that is the geographic coverage and large number of tournaments being monitored to determine the range of response," Fielder said.
As many as 24 walleye tournament events are expected to contribute data to the analysis.
Although not complete, Fielder said results thus far indicate that survival of released tournament fish depends on a variety of factors including how warm the water is and how rough the water was during the fishing day.
But other factors, he said, also may include the distance traveled to get back to the weigh-in and the conditions in the boat's live well.
"Some tournaments experienced a very high survival of the angler-caught fish while nearly all fish in other tournaments didn't survive," Fielder said. "In most tournaments, an intermediate loss of about 30% was common."
When the impact study is completed, each state will decide how best to apply the information to its own situation.
Lake Huron Basin Coordinator Tammy Newcomb, who along with Fielder initiated Michigan's participation in the project, said some states may opt to develop policies and regulations concerning live-release walleye tournaments and others may use the information to develop educational materials for tournament organizers and contestants.
"Here in Michigan, our current understanding is that most anglers don't have a big problem with tournament fishing if they can be assured the fish aren't being killed," Newcomb said.
However, some tournament sites, such as Saginaw Bay, which hosted a FLW Outdoors fishing event June 30 but was not part of the study, may continue to be held as catch-and-keep tournaments because the water in the bay is usually too warm and shallow for good live release, she said.
"In each case," Newcomb added, "the goal will be to find ways to accommodate competitive fishing opportunities and yet ensure protective measures for the fish population."
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[lonehunter]

[font "arial, helvetica, sans-serif"][#00e010]Walleye are year-round work for fisheries managers[/#00e010][/font]
[font "arial, helvetica, sans-serif"][black]December 9, 2004
As thousands of Michigan walleye anglers await the start of ice fishing season, Steve DeWitt is beginning work on a collection of walleye that would drop most fishermen’s jaws.
DeWitt is a Department of Natural Resources Fisheries Division technician at the Alpena research station. Over the coming winter, he’ll examine approximately 1,500 walleye that were caught, frozen, and shipped to his office by fellow DNR field workers throughout the state. His review will determine what percentage of the walleye living in certain Michigan waters were produced in Michigan fish hatcheries and how many were wild fish.
While the DNR’s six hatcheries are best known for salmon and trout production, but the leading species--by the numbers--planted by the DNR is walleye.
Michigan began its walleye program in the late 1970s, as the fish began gaining popularity among anglers. Today, walleye rank among Michigan’s top three angling opportunities, with bass and salmon.
"We produce approximately 5 to 10 million walleye fingerlings each year, on average," said DNR Hatcheries Manager Gary Whelan. "We also produce nearly 20-30 million fry, smaller fish that measure about one-third-inch.
"But what’s really amazing about Michigan’s walleye program is how little of it can be accomplished in the controlled conditions of the hatchery. All the fingerlings are produced in outdoor rearing ponds, and those ponds depend on weather conditions."
Sometime around early April each year, fisheries managers collect and fertilize eggs from spawning walleye in the Tittabawassee River in Midland, the Muskegon River in Muskegon, and Little Bay De Noc near Escanaba. One large adult female walleye produces approximately 100,000 to 300,000 eggs. Each female is fertilized with one male to maximize genetic diversity. The fish are collected by electro-fishing or in nets, handled carefully and released after the collection. The Lower Peninsula eggs are sent to the Wolf Lake Fish Hatchery near Kalamazoo, and Upper Peninsula eggs go to Thompson State Fish Hatchery. They incubate for 18-21 days before hatching.
Unlike salmon, walleye do not spend much time at the state hatcheries. Within the first five days of their lives, they are placed in a solution of tetracycline, which imprints a permanent chemical "mark" in their bones. The stain does not harm the fish, but is visible under a black light, which scientists use to identify them as hatchery fish. After the tetracycline bath, the walleye are transferred to one of nearly 50 outdoor ponds located throughout the state.
Many of the rearing ponds are owned by private groups, working in partnership with the DNR to promote walleye production in Michigan. In early spring prior to the arrival of the walleye hatchlings, specialists and cooperators are filling and fertilizing the ponds with either inorganic or organic fertilizers.
"Young walleye feed on zooplankton," said DNR Fisheries Biologist Jim Baker, a unit supervisor whose district includes southern Lake Huron. "To get zooplankton growing, we put soybean meal in the ponds several weeks before the fish arrive. The part of the equation we can’t control is air temperature and sunlight, which are critical to producing a good crop of zooplankton."
By the second week of June, fish in the Lower Peninsula ponds have been there for approximately 50 days, and are 1.5 inches on average. The same process takes until mid-July in the Upper Peninsula. A sample of the fish are tested to ensure they are healthy, and they are then ready to go to their permanent homes on rivers, inland lakes and the Great Lakes.
But how do DNR managers decide where to stock walleye?
"We base our stocking decisions on three goals," said Lake Huron Basin Coordinator Tammy Newcomb. "In some places, we stock walleye in an effort to restore lost populations or to rehabilitate degraded populations. In other places, we stock to provide an additional recreational opportunity. Sometimes, we use walleye to improve an existing fishery. Predation by walleye on stunted bluegill and perch populations can improve those fisheries."
On inland lakes in the west and southwest part of the state, DNR biologist Jay Wesley said he looks for at least 80 acres with a fair amount of sand, few weeds, and shoals with depths of 5-20 feet. Lakes with a good forage base of minnows or stunted panfish also are desirable.
"Turbid water, particularly in warmer river systems, seems to provide optimal habitat," Wesley said. "They don’t like muck bottom lakes, where you typically find largemouth bass, bluegill, crappie, and pike." He said the DNR typically will plant a lake three times, and perform follow-up net surveys to determine whether the species is successfully adapting. In most Michigan waters, it takes three to five growing seasons for inland lake walleyes to reach 15 inches, the minimum size to keep on inland waters.
Saginaw Bay is perhaps Michigan's best example of the DNR working to rehabilitate walleye through stocking. Walleye once were abundant in the bay, but pollution and over-fishing through the early 1900s, coupled with an influx of exotic species like alewives and rainbow smelt, caused walleye populations to crash by the late 1940s.
The first glimmer of hope came in the late 1970s with the emergence of the DNR walleye program and the implementation of the federal Clean Water Act, which provided large amounts of restored habitat for walleye and other coolwater species.
"I remember when those fish showed up to spawn for the first time in 1981," Baker said. "We’ve continued an extensive stocking program and fishery has grown and developed into a world-class fishery. Growth rates in Saginaw Bay are 135% of the state average, and the average walleye is 4-5 pounds."
[/black][/font] [font "arial, helvetica, sans-serif"][#00e010]New Walleye Tagging Project Begins in Lakes Erie and Huron[/#00e010][/font]
[font "arial, helvetica, sans-serif"]April 6, 2005
When the friendly DNR creel census clerk asks you about your angling success after a day’s fishing on Lake Erie or Lake Huron this summer, if your catch includes walleye, don’t be surprised if the clerk pulls out a small handheld device (that looks something like a TV remote) and passes it over the head of the fish.
The clerk will be looking for an internal passive integrated transponder (PIT) tag.
A PIT tag is a radio frequency microchip about the size of a grain of rice that transmits a unique ID code or number to a special detection wand. Unlike the external, metal tag that biologists attach to the walleye’s lower jaw, a PIT tag will not be noticeable to anglers. A syringe is used to place the PIT tag just under the skin in the head area.
Each year, thousands of walleye in Lake Erie and Lake Huron (Saginaw Bay) are tagged by the resource agencies who cooperatively manage these important fisheries.
According to Gary Towns, fisheries supervisor for the Michigan Department of Natural Resources’ Lake Erie management unit, walleyes are captured at spawning sites during March and April. Each fish is measured, sexed and visually assessed for reproductive status, and a scale sample is collected for aging, before the jaw tag is applied. The fish is immediately released.
The lake-wide tagging program for Lake Erie, begun in the early 1990s, helps fisheries managers in Michigan, Ohio, Pennsylvania, New York and Ontario set the annual total allowable catch for the walleye fishery, which is based, in part, on measuring harvest rates through the voluntary reporting of tags by recreational and commercial fishers.
"We depend on anglers to report the jaw tag capture back to us," Towns said. "The jaw tags are used to estimate the exploitation rate of the fishery which is the percentage of the adult walleye population harvested by anglers."
Biologists also use the tag return rate to estimate the natural mortality level for walleye, which is another important factor in assessing the sustainability of the fishery. Tag returns also provide information regarding walleye movement patterns in the lake.
"Unfortunately, there are some divantages to using the external jaw tags because they can fall off and anglers often fail to report them," Towns said.
So beginning in 2005, adult walleyes from several stocks in Lake Erie and Lake Huron are being tagged with a PIT tag.
The goal of the lake-wide research project is to implant PIT tags in approximately 14,000 walleyes (3,000 in Michigan) each year for three years; both tag types will be applied to 4,500 fish. The project is being funded by the Great Lakes Restoration Act Fund.
The annual walleye tagging for Saginaw Bay takes place on the Tittabawassee River said David Fielder, research biologist at the DNR’s Alpena Great Lakes Fisheries Research Station.
"A total 3,000 walleyes will be collected by electrofishing over a period of four or five days for jaw tagging by the DNR’s Southern Lake Huron Management Unit," Fielder said. "Then we’ll double tag 1,000 fish with both the jaw tag and the PIT tag."
Since the Saginaw Bay walleye tagging effort began in 1981, the DNR has tagged more than 80,000 walleyes.
"Walleyes also are tagged in Lake Erie and we often see some of them as far north as Saginaw Bay," Fielder said. "Our Saginaw Bay tag returns will show up as far north as Thunder Bay and as far south as Lake Erie. This research will help us learn more about the movement patterns of these fish in each lake."
For the Lake Erie part of the project, DNR biologists in southeast Michigan selected the Huron River because its spawning run of walleye is fairly easy to sample with an electrofishing boat. According to Mike Thomas, research biologist at the Lake St. Clair Fisheries Research Station, it will take about 10 days of shocking to reach the target number of 2,000 PIT-tagged fish.
"The size of the spawning run is small enough that we often recapture fish that we’ve tagged in previous years, but this provides more information about tag retention rates or patterns in tag loss," Thomas said.
Because the caught fish will be analyzed for tags by agency personnel rather than relying on anglers recognizing and reporting tags, Thomas said biologists hope to learn if enough harvested fish with the PIT tags can be checked to estimate exploitation.
"We also are very interested in looking at the comparison of tag retention between the standard jaw tags and the PIT tags," Thomas said.
In addition to the annual creel surveys, recreationally caught walleyes also will be scanned for tags at several fish cleaning facilities along Lake Erie, and commercially harvested fish in Ontario will be examined for PIT tags by port observers.
Results of this study will aid in decision analysis modeling, validate past tagging studies and improve understanding of mortality components for Lake Erie walleye.
"It is very important that anglers report the jaw tags if they get one on a walleye they’ve caught," Fielder said. "They can do this by writing to the address on the tag or going to the DNR Web site."
Anglers should report the tag number, date the fish was caught, location of the catch (both general and specific) and length of the fish. [url "http://www.michigandnr.com/TAGGEDFISH"][#000000]To report this information online, go to www.michigandnr.com/TAGGEDFISH[/#000000][/url].
[/font] [font "arial, helvetica, sans-serif"][#00e010]Recovery of Lake Erie Walleye a Success Story[/#00e010][/font]
[font "arial, helvetica, sans-serif"][black]June 8, 2006
Lake Erie is often the most maligned of the Great Lakes. Pollution problems have plagued the lake, which hosts several industrial centers on its shores. And the walleye fishery on the lake has gone bust and boom as well.
Walleye fishing on Lake Erie was booming in the late 1980s, but then began a bust period in the 1990s that extended into the early part of this decade. This prompted fishery managers from Michigan, Ohio, New York, Pennsylvania and Ontario to respond to the alarming decline in the abundance of walleye. The agencies ordered a reduced harvest in 2004 by over 30 percent in each jurisdiction.
Michigan is only responsible for 112 square miles of the 9,903 square miles of Lake Erie, but it is the western basin that Michigan is a part of that is considered the hot spot for walleye, along with the central basin.
Lake Erie and her fisheries have a long history of boom and bust. Industrialization of Lake Erie's shoreline in the early 20th century was clearly contaminating the waters. However, the declining environmental conditions didn't dissuade a growing commercial fishery for walleye into the 1950s. But by 1956, the increasing threat of over harvest and habitat destruction had reached its peak and in the early 1960s the bottom fell out of the commercial fishery. By 1970, fishery closures were common due to mercury contamination in walleye. The lake was considered dead by many who had relied on its abundance for years.
Several key events, though, were about to combine to help the lake recover. In 1975, the Lake Erie Committee (LEC), a bi-national committee of senior fisheries managers from each bordering state and Ontario, started working together to manage the lake's fisheries. Also, in the early 1970s, growing public awareness and concern in the United States for controlling water pollution would lead to the Clean Water Act of 1977. The Clean Water Act established basic structure for regulating the discharge of pollutants into the waters of the US, including the Great Lakes.
By the mid- to late-1970s, there were reports of not only cleaner water, but healthier fish. As the walleye population grew, so did the angler activity. By 1988, the sport catch was approaching the historical highs observed in the days of peak commercial fishing. Control of the fishing effort and harvest rates through the LEC wasn't working for a variety of social and political factors. Increased fishing efforts, sporadic hatching success, dwindling spawning stocks and newly discovered environmental and biological threats began to take their toll on the walleye population.
A walleye population that once was boasted at 70 million fish in the late 1980s was estimated to be only 16 million by 2000. In other words, where there used to be 7,000 fish per square mile, there were only 1,700.
As the final blow, in 2002, a complete year-class failure occurred during the hatching process. The failure ignited a debate between the bordering states and Ontario about whether or not harvest reductions were needed. Harvest reductions were agreed upon in 2003. In Michigan, the daily bag limit for walleye on Lake Erie was reduced from six to five fish, and the minimum size limit was increased from 13 inches to 15 inches. Also, the season was closed in April and May.
The 2003 year-class of walleye in Lake Erie hatched like gangbusters, mostly due to favorable weather conditions. Fishery managers called it the strongest hatch in 20 years. Survival of the new fish also was high due to the fact that there was a reduced population in the lake.
"The walleye spawning in 2003 was the best walleye year class in more than 20 years, and is primarily responsible for the improving strength of the walleye stocks in Lake Erie," said Kurt Newman, Lake Erie basin coordinator for the Michigan Department of Natural Resources. "The bulk of these fish have matured to a harvestable age this year, and walleye fishing in the Michigan waters of Lake Erie should be outstanding."
While the bag limit reduction of five fish and the minimum size limit remains at 15 inches, the April and May closure were lifted for the 2006 fishing season. Michigan anglers have enjoyed some outstanding spring fishing in Lake Erie waters, Newman said.
"Walleye populations can fluctuate wildly from year to year epending upon weather conditions and other variables. The LEC decided we could safely increase harvest levels in 2006 because of the spawning that occurred three seasons ago," Newman said. "Below average year classes in 2004 and 2005 will require continued monitoring to ensure the sustainability of this world class fishery beyond the time when the 2003 year class is no longer available. But, for the foreseeable future, walleye fishing is likely to stay quite good."
Whether trolling with worm harnesses or fishing with downriggers sporting night spoons, walleye anglers are enjoying a good year on Lake Erie this year.
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