• MERCURY • By Sara Moses, GLIFWC Environmental Biologist Updated mercury maps detail safe walleye consumption Additional Michigan 1842 inland lakes included There are a number of ways to reduce exposure to mercury while still harvesting and consuming ogaa. Sort and label the bags with the name of the lakes where the fish were harvested; and mark whether the fish were under 20 inches or over 20 inches. Follow the advice on the mercury maps for the maximum safe number of ogaa meals per month. (COR photo) Shockingly high levels of mercury found in Lake Superior lamprey It’slongbeenknownthatsealamprey(bimiizii)arebadnewsintheGichigami region. These creatures invaded our Great Lakes in the 1940s through man-made locks and canals.Adult lamprey attach to host fish, such as lake trout, by their ring of rasping teeth and feed off of blood and other bodily fluids. Dramatic decreases in lake trout, burbot, whitefish, and sucker populations coincided with increasing lamprey numbers, impacting commercial, subsistence, and recreational fisheries. Now we have one more reason to dislike theses slimy invaders—their mercury levels are sky high. GLIFWC researchers, in collaboration with scientists at the University of Wisconsin–Superior, recently looked at mercury levels in lamprey collected in Michigan and Wisconsin tributaries to Lake Superior. The results were shocking. Adult lamprey had mercury concentrations higher than any other fish from Lake Superior ever recorded. In fact, they were ten times higher than top predator fish, like lake trout. The good news is that the high mercury levels in lamprey do not pose a direct threat to the people around Lake Superior. Despite being considered a delicacy in Europe and by some tribes of the Pacific Northwest, lamprey are not typically consumed by humans in the Great Lakes region. But, there is a concern for wildlife whose tastes may not be so discerning. A number of birds and mammals, such as eagles, herons, ducks, seagulls, and otters, feed on adult lamprey. Not only adult lamprey have dangerously high levels of mercury in their tissues. The study found that lamprey eggs and larvae, about the size of a pencil, also have extraordinarily high mercury loads. These early life stages of lamprey are a potential food source for fish in the tributaries where they live. In addition to being a mercury source to the fish and wildlife that consume them, adult lamprey may be significant transporters of mercury within the Great Lakes ecosystem. Adults pick up the majority of the mercury in their bodies from the fish they feed upon in the lake. After one to two years in this parasitic phase, they return to the tributaries to spawn and die. Their decaying carcasses are then sources of mercury to these tributaries. With an estimated 80,000 spawning-phase lampreyreturningtoLakeSuperiortributarieseachyear,thisrepresentsasubstantial pulse of lake-derived mercury to the tributary streams and rivers. ControllinginvasivelampreyisimportanttoprotectingthefishesofGichigami. EveryspringGLIFWC’sGreatLakesSectionsetstrapsinLakeSuperiortributaries during the spawning run to estimate the number of adult lamprey, and to reduce their reproductive potential by removing a portion of the run. This work is done in cooperation with GLIFWC’s member tribes, the Great Lakes Fishery Commis- sion, and the U.S. Fish & Wildlife Service–Sea Lamprey Control program. For moreinformationvisithttps://data.glifwc.org/archive.bio/AdminReport17-07.pdf. By Sara Moses, GLIFWC Environmental Biologist The spring ogaa (walleye) season is right around the corner. Whether setting out upon the waters to harvest fish or simply enjoying the catch at the dinner table, GLIFWC’s mercury maps can help you make informed decisions about safe fish consumption. Byharvestingogaa,tribalmembersreaffirmtheiroff-reservationtreatyrights while providing their families and communities with a high quality food source. But, as with any fish, ogaa contain mercury, a contaminant that is released into the environment largely from the burning of coal and metallic mining and process- ing activities. Exposure to mercury above safe levels can cause negative health impacts, especially in fetuses and young children. You can reduce your mercury exposure by using the mercury maps to choose lakes with lower mercury levels for harvesting ogaawag, and by following recommended consumption advice for the lake where your fish were harvested. Under funding from the Great Lakes Restoration Initiative, GLIFWC updates the mercury maps every two years. The maps, most recently updated in January 2018, provide ogaa consumption advice for 348 individual lakes, including 16 new lakes with advice developed since the maps were last published in 2016. In particular, GLIFWC worked with the Lac Vieux Desert Band and the Keweenaw Bay Indian Community in recent years to significantly increase the number of lakes displayed on the maps within the Michigan 1842 Ceded Territory. Fish mercury levels change slowly over time, even as emissions of mercury in the region decrease. This, in combination with the rotating sampling scheme for lakes, means that we do not generally see dramatic changes in the advice provided by the maps from year to year. Walleye upgrades & declines for 2018 Since 2016, we changed our advice to less restrictive for three lakes and more restrictive for six lakes. A notable improvement is Bond Falls Flowage in Upper Michigan, which has changed from “Red” or “Do Not Eat” to a recommendation of up to one meal per month for the sensitive population (pregnant women, women of childbearing age, and children under 15 years of age). In Wisconsin, the safe number of ogaa meals from Star Lake (Vilas County) has increased from one to twopermonthforthesensitivepopulation.Themostpopularlakeaffectedbymore stringent consumption advice is Big St. Germaine Lake in Vilas County, where the safe number of ogaa meals for the general population (men 15 and older and women beyond childbearing age) dropped from eight to four per month. In an effort to inform and protect tribal members, GLIFWC began its mer- cury program in 1989. It has since measured mercury levels in more than 8,400 fish from Lake Superior and inland lakes across the Ceded Territories. Data from walleye sampling is used to produce GLIFWC’s mercury maps, which provide color-coded, lake-specific ogaa consumption advice. The maps indicate the safe number of ogaa meals that can be consumed per month from lakes where fish are typically harvested by GLIFWC’s member tribes. In addition, you can target smaller fish, which tend to be lower in mercury, or consume lower mercury spe- cies such as whitefish, bluegill, or perch. The updated Mercury Maps are now available on the GLIFWC website at http://glifwc.org/Mercury/index.html and will be made available at tribal registra- tion stations and at various tribal events this spring. While they may not gobble as much through the middle of daylight hours, birds are still receptive to calls and can be ambushed in meadows or other open areas that service as strutting grounds. Packedwithpureprotein,verylow infat,miziseisagreatchoiceforhealthy meals this spring, and freezes up nicely for a special occasion later in the year. See www.glifwc.org or visit your local GLIFWC registration station to pickupcarcasstags—whererequired— and more details on spring wild turkey hunting. Mizise registration Turkeys harvested off-reservation can be registered over the phone at GLIFWC’s toll free harvest registration line: 844-234-5439. To register your harvest, you will need your NAGFA ID number which can be found on your hunting license. Detailed instructions can be found on GLIFWC’s website: http://glifwc.org/Regulations (continued from page 3) Spring turkey hunt Native to theAtlantic Ocean, sea lampreys are parasitic fish with extraordinarily high amounts of mercury in its tissues. Lampreys have an eel-like body, with seven gill openings and a large round mouth with sharp, curved teeth. (CO Rasmussen photo) PAGE 5 MAZINA’IGAN SPRING 2018