MAZINA’IGAN PAGE 22 SUMMER 2017 “We’ll be mapping the extent of EAB on Sugar Island reservation lands,” Martin said. “EAB can’t fly very far, so the best thing people can do is avoid moving firewood. That’s how new infestations typically start.” To date, Bay Mills’blackashforestpreserve nearBrimleyhasremainedfree of EAB. Sharing sap & knowhow TheBayMillsassessment crew didn’t collect a lot of sap fromSugarIsland—around23 gallons—buttheyknewsome- one who would make imme- diate use of it: Paula Carrick and her extended family at the main reservation. In her 38th sugarbushseason,Carricksaid the recent run was a poor one and her family welcomed the extra sap. “We thought it was a bad season,” Carrick said. “We put our taps out in March during a warm spell and there were a couple of really good days. Then it shut down for three weeks, ran a little bit more, but then that was about it.” Carrick and her sister Wanda help oversee a mainland sugar bush that draws multiple generations from three Bay Mills families. The sisters are noted for establishing the first national forest sugar bush under the 1998 Tribal/USDA Forest Service Memorandum of Understanding. From the nearby Hiawatha National Forest they produced two gallons of syrup and a handful of hard candies in 2000. Even with decades of knowledge and experience, the sisters remain intent on keeping their output at a modest level. “There’s no tubing, we’re not big and don’t want to get big,” Carrick said. “We just do it for the family and to pass the knowhow on to the younger ones.” True to her words, the family finished 2.5 gallons this past spring with sap from their sugarbush and the trees on Sugar Island. Bay Mills member Kimmarie Manabat skims out small particles from a boiling vat of maple sap. (P. Carrick photo) (Continued from page 6) water, this large, predatory zooplankton eatssmaller,nativezooplanktonthereby competingwithyoungfishforfood,and may be less edible for small fish due to its long abdominal spine.As these inva- sives have become established in Mille Lacs (Figure 2), native zooplankton abundance has declined. So that settles it right? The Mille Lacs walleye population has declined because the invaders redirected the energyinthefoodweb,andtogetthings back to the way they were, we just need to get rid of the invaders. Unfortunately, it’snotthatsimple.First,whileresearch- ers are evaluating population control methods, there have been no effective lake-wide control programs for zebra musselsorspinywaterfleas.Thismeans that for now, the invaders are here to stay.Secondly,whilethewalleyedecline coincided with the increase of these two invaders, a causative link is difficult to establish. Even though the zooplankton communityappearstohavebeenaffected by the invaders, walleye are surviving past the first summer of life when they dependonzooplanktonforfood.Survey catch rates of walleye in their first fall have not declined (2005-2008 catch rates averaged 86.2 per mile; while in 2009-2012 they averaged 103.9 per mile). Still, these fish are not surviving as well as they used to from ages 1-2. The 2005-2008 year-classes averaged 2.3 walleye per net lift at age 2 in fall assessment surveys, while the 2009- 2012year-classesaveraged0.41walleye per net lift. A study by a blue ribbon panel of fisheries experts suggested that predation on these young walleyeis higherthaninthepast.Hastheinvaders’ impact reduced the abundance of prey fish, causing large predator fish (e.g. adult walleye and northern pike) to eat more young walleye? Did the invaders reduce the total amount of walleye that can live in the lake? Researchers plan to explorethesequestionsinthenearfuture. For now, the zebra mussel and the spiny waterflea will continue to affect the Mille Lacs food chain. Low fishing mortality will help the walleye popula- tion increase from its lowest level, but biologists are unsure if good survival of young walleye will return. In the meantime, prevention is the best way to control the spread of aquatic invasive species.Closeattentiontoboats,trailers, and equipment when moving between waters is critical. While the best steps to prevent movement of each specific invasive are slightly different, washing, Chronicles of Mille Lacs (Continued from page 1) Figure 3. Simplified hypothetical food web before and after zebra mussels and spiny waterfleas were introduced to Mille Lacs Lake. Size of the box indicates changes in biomass for each trophic level (e.g., base of the food web, apex predators). Number of solid arrows indicate the relative amount of energy moving up the food web (less arrows equals less energy). Dashed arrow indicates that young fish may consume spiny waterflea, but may be more difficult due to abdominal spine, potentially resulting in consumption of fewer food items. • MILLE LACS/SUGARBUSH • Figure 1. Mean density of zebra mussels sampled at nine sites in Mille Lacs Lake from 2005 to 2015. Zebra mussels were first observed in very low densities (