Midwest Fish & Wildlife Conference 2019

AUTHORS: Jacob E. Bowman, Jill B.K. Leonard – Northern Michigan University.

ABSTRACT: Brook trout (Salvelinus fontinalis) express variability in movement strategies, including partial migration. Partial migration has gained attention because individuals that migrate can express polymorphism, growing larger than their stream counterparts. Partial migration and life history-related movement strategies may be related to individual variability in metabolic parameters; however, this has not been well documented in the field. We performed field metabolic rate determination on native brook trout in the Rock River in Alger County Michigan during spring and summer 2018, including both resting and active metrics. Brook trout were then tracked using PIT tags with stationary and backpack telemetry throughout the summer with a 46% recapture rate. Movement patterns were compared to metabolic rate rankings within fish. Each fish’s metabolic status was ranked relative to other individuals measured. The continuous field resting and field maximum measures were positively related (p<0.0001). The ranking sytem held this same correlation (p<0.0001). This relationship in metabolic parameters follows what is expected in individual variation of metabolism. Our work will allow us to understand at what level individual variation in metabolic phenotypes and associated movement phenotypes are related. This research will contribute to understanding the resiliency of valued life history strategies and morphotypes such as migration.

AUTHORS: Seth M. Bogue; Cassi Moody-Carpenter; Anabela Maia; Robert E. Colombo – Biological Sciences Department, Eastern Illinois University

ABSTRACT: The Sangamon River flows approximately 396 kilometers through central Illinois and is impounded in the city of Decatur for municipal use. The Sanitary District of Decatur (SDD) processes residential, medical, and industrial waste before releasing effluent into the river downstream of the dam. Discharge from the dam is significantly reduced during periods of low precipitation. As a result, the downstream stretch of the river is dominated by wastewater effluent. A high density of fish exhibiting elongated fins reside in this stretch of the river. To assess the relationship between effluent and fin elongation, Fathead minnows were exposed to wastewater effluent in microcosms at SDD and at a second wastewater treatment plant located in Charleston, Illinois. In addition, two control groups were exposed to dechlorinated tap water. Standard length, individual fin lengths, and weight was recorded for a total of 32 fish from each treatment during an 8-week time span. SDD treatment fish had significantly longer fins and exhibited better condition and faster growth in comparison to all other treatments. Our results are indicative of a causal relationship between SDD wastewater effluent and the fin elongation observed in fish of the Sangamon River. We hypothesize that fin elongation is the result of chronic exposure to contaminants and heavy metals present in the effluent.

AUTHORS: Michelle Carstensen, Erik C. Hildebrand, Dawn Plattner, Margaret Dexter – Minnesota Department of Natural Resources; Arno Wünschmann, Anibal Armien – University of Minnesota-Veterinary Diagnostic Laboratory

ABSTRACT: Minnesota’s moose (Alces alces) are dying at rates much higher than elsewhere in North America. Moose have been nearly extirpated from the northwestern part of the state and aerial surveys indicate the northeastern population has declined 55% over the past decade. In 2013, a new study began to determine cause-specific mortality of adult moose in northeastern Minnesota by using GPS-satellite collars to get rapid notification of mortality events and recover carcasses within 24 hours of death. A total of 173 moose were collared over 3 years with annual non-hunting mortality rates of 19%, 12%, 15%, 13% and 14% in 2013-2017, respectively, and an overall mean of 14.4%. In total, 57 moose have died from non-hunting sources of mortality and 3 moose were legally harvested. Response times from mortality notification to arrival at the carcass were within 24 hours for 65% of death events. Most causes of mortality were health-related (65%), which included parasites (30%; e.g., winter ticks, brainworm, and liver flukes), bacterial infections (20%), accidents (3%), calving (2%) and other undetermined health issues (10%).The remainder was wolf-related (30%), with predisposing health conditions identified in nearly half of these moose.  Legal harvest accounted for 5% of moose deaths. During the same time period, we also necropsied anecdotal moose deaths (n=91) across northern Minnesota, which included vehicle or train collisions, sick, and found dead animals. Parelaphostrongylus tenuis was confirmed in 42% of these cases, which is nearly twice the rate of detection of this parasite as in the collared moose studied during the same time period. 

AUTHORS: Hisham Abdelrahman, James Stoeckel – School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University; Jacob Westhoff, Missouri Department of Conservation

ABSTRACT: Previous researchers have shown that extraregional invasive crayfish possess certain life-history and ecological traits that facilitate their ability to successfully invade large areas in distant regions, whereas extralimital invaders tend to remain localized and occupy smaller ranges.  Physiological traits may provide additional explanatory power for realized and potential range of crayfish species. In this study, we tested for thermal performance differences related to respiratory physiology among multiple crayfish species with narrow to broad native and invasive ranges. We hypothesized that species with broad ranges would be thermal generalists relative to species confined to limited ranges. To test this hypothesis, we generated thermal performance curves of respiratory enzymes in the electron transport system (ETS) for 12 individuals from each of five species. Optimal thermal range was defined as the temperature range within which ETS enzyme activity was within 10% of the maximum observed value.  Contrary to our original hypothesis, optimal thermal range of respiratory enzymes was not correlated with geographic range, but was lowest in the most widespread species (Procambarus clarkii) which was also the only species with a strong propensity to burrow.  We also found that the two extraregional invaders (Faxonius virilis and P. clarkii) had significantly lower enzymatic activity levels at optimal temperatures than did the extralimital invader (F. neglectus) or the two native species with restricted ranges (F. eupunctus and F. marchandi).  Results thus far suggest that enzymatic thermal breadth may be more closely tied to habitat plasticity whereas enzyme activity level may be a more useful predictor of geographic range. Additional species are currently being analyzed to better assess the robustness of these conclusions.

AUTHORS: Chelsey L. Nieman, Suzanne M. Gray – The Ohio State University

ABSTRACT: Increasing anthropogenic turbidity changes underwater visual environments, leading to altered perception of visual cues. This alteration may have a variety of consequences, such as movement to other localities, a shift in diet or preferred prey, and reduced consumption of prey items. Lures are known to be perceived by fish as a potential prey item, therefore lure color/type can be utilized as a relative proxy for prey items that fish are capable of visually perceiving in turbid water. The objective of this study was to understand how shifts in visual environments may influence predatory success of Walleye (Sander vitreus) in Lake Erie using both local knowledge of altered fishing practices as well as lure success. Charter boat captains on Lake Erie are experienced in fishing in and around algal blooms and as such their knowledge and real-time lure success data allowed us to monitor color of lures that were successful in attracting Walleye under differing conditions. A survey of Lake Erie charter captains (N=37, 38% response rate) was used to determine how altered water quality (i.e. algal blooms) affected fishing practices and lure usage over the long term, with results indicating that lure color success changed in highly turbid water. Additionally, a mobile phone application, Walleye Tracker, was used by 19 charter captains over two years to gather real time data on lure successes. The use of photographs of lures and water conditions allowed for quantitative, in situ, analysis of lure successes in differing water clarity conditions. The results of this study indicate that increases in both sedimentary and algal turbidity that are altering the underwater visual environment are not only changing visual perceptions of Walleye, but also indicate that this is likely to have long-term consequences, not only for the ecosystem, but also for recreational anglers within these altered systems.