PAGE 15 MAZINA’IGAN FALL 2017 • MILLE LACS LAKE • Survival of young walleye in Mille Lacs Lake GLIFWC biologist counts and measures young walleye in Mille Lacs Lake. (J. Curtis-Quick photo) (continued from page 1) Figure 1. Relative survival of age-0 walleye to their second fall (i.e., age-1) from 1999 to 2015 in Mille Lacs Lake. Age-0 and age-1 walleye were collected by electrofishing the shoreline in the fall (September or October) of each year. Relative survival was calculated by dividing the number of age-1 walleye per mile of shoreline by the number of age-0 walleye per mile of shoreline captured in the previous year. Relative survival value of one indicates that most of the age-0 fish reached age-1. Red circles indicate the lowest valley and peak in relative survival of age-0 walleye compared to previous years. High survival of age-0 walleye to age-1 occurs every 5 years. Figure 2. Relative abundance of age-1 walleye per mile of shoreline in Mille Lacs Lake from 1999 to 2016. Red circle indicates that abundance of age- 1 walleye from 2010 to 2016 was significantly lower than the previous years (1999-2009). Under the JASC, a team of biologists and technicians share responsibility for conducting walleye assessments on Ceded Territory lakes. Upper level fisheries managers review population data and establish safe harvest levels for state and tribal fishers. The event’s success at strengthening the work of the JASC drew the attention of officials in the US Department of the Interior, leading to the 2009 Partners in ConservationAward.RepresentativesfromBIA,GLIFWC,WisconsinDepartment ofNaturalResources,andUSFish&WildlifeServicesharedtheprestigiousaward for helping reduce social unrest related to treaty fishing and bolstering walleye stocks in the Wisconsin Ceded Territory. At the recent 25th Partners in Fishing celebration held at Lac du Flambeau June 7, Jackson singled out another group of collaborators that form an important link between fisheries managers and Ceded Territory communities. They also know where the fish hang out. “This event could not happen without the guides,” he said. “All 26 guides here today helped make this a success.” Teamwork and the football hook Beginning in 1999, Partners in Fishing planners enhanced the event with help from professional football players who came aboard to reinforce the power of teamwork—whether on a stadium field or in an agency office. Champions of Super Bowls I and II, Green Bay Packers legends Jerry Kramer and Fuzzy Thurston made a memorable visit to the 2004 Partners gathering at Lac Courte Oreilles. “One of the reasons my team, Fuzzy’s team, was an exceptional football team wasn’t really the people; we weren’t great athletes, but we were able to subjugate our needs, wishes, and wants for the benefit of the team. For benefit of every- one,” said Kramer, addressing the group near the Chippewa Flowage shoreline. “And the DNR and the Indian Nations are coming together, and you can have an incredibly powerful impact if you can become a team and do what is best for the area.” While the Partners roster includes 20 different Packers players—both active and retired—William Henderson and Gilbert Brown emerged as regulars, forming bonds with fisheries managers from all the agencies represented. The respective offense and defense standouts earned a championship in Super Bowl XXXI. For more on the work of the JASC and walleye population surveys in the WisconsinCededTerritoryseewww.glifwc.org/publications/pdf/Casting_Light.pdf Partners in Fishing (continued from page 2) 2008, and 2013, there was high relative survival of age-0 walleye to age-1, which suggests that a peak in survival may be occurring every five years (Figure 1). Similarly, low relative survival was observed every 3-4 years over this period. The most striking trends have occurred in the last few years. The charted valley in 2010, 2011, and 2012 was the lowest relative survival compared to valleys in previous years. Similarly, the peak in relative survival in 2013 was the lowest relative to peaks observed in previous years. This low rela- tive survival has translated to lower relative abundance of age-1 walleye in 2010 to 2016 compared to previous years (Figure 2). Collectively, this means both survival and abundance of young walleye has decreased in recent years, which can have negative consequences on the adult population of walleye in Mille Lacs Lake. Biological (e.g., predation) and environmental (e.g., water temperature and clarity) factors are both likely playing a role in the variability in survival and abundance of young walleye in Mille Lacs Lake. One or more of these factors changedrecently,resultinginlowerrelativeabundanceandsurvivalofyoungwall- eye. While the exact mechanism remains a mystery, we have identified a possible cyclical pattern in survival of age-0 walleye to age-1, with a peak occurring every five years. If this pattern repeats itself, we could potentially see another influx of young walleye sometime within the next 2-3 years. However,ifbiologicalandenvironmentalconditionscontinuetochange,then the influx of young walleye might be smaller relative to previous years. In either case, conservative management strategies should remain in place to encourage the establishment of another strong year class of walleye and improve the chances that adult walleye stocks will increase in Mille Lacs Lake. Please contact aaronshultz@glifwc.org for more information. Comments & questions about this article are welcome. Dr. Aaron Shultz, Dr. Adam Ray, Mark Luehring, Ben Michaels and Joe Dan Rose contributed to this article.