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: Tyler Grabowski, University of Illinois; David Wahl, Illinois Natural History Survey; Joe Parkos, Illinois Natural History Survey; Dalon White, University of Illinois; Anthony Porreca, Illinois Natural History Survey

ABSTRACT: Global climate change is expected to exert selective pressures on behavioral phenotypes within freshwater ecosystems through environmental changes associated with chronic warming of water temperatures. We compared the behavioral profiles of bluegill sunfish (Lepomis macrochirus) from three power-plant cooling reservoirs to the behavioral tendencies of bluegill from three ambient reservoirs to investigate whether long-term exposure to increased water temperatures influences the expression of behavioral phenotypes. Power-plant cooling reservoirs were considered as model systems for global warming due to their year-round elevated water temperatures (~5°C) when compared to ambient reservoirs. We quantified activity, boldness, and exploration through 30-minute assays in a common laboratory setting that tested the spatial usage and response of individual fish to a suite of situations involving novel items and a predator, largemouth bass (Micropterus salmoides). For each assay, multiple measurements were recorded for each behavior, leading to the development of a principal component score (PCA) for activity, boldness, and exploration for each individual. PCA scores for each behavior were compared between groups (heated or ambient) and then used to determine how well behaviors correlated to one another within groups. Distinct behaviors did not differ between bluegill from heated and ambient lakes. However, we found significant directional changes between groups for the correlations of activity and exploration as well as for boldness and exploration. These results suggests that chronic exposure to warming can influence the expression of behaviors, providing insight for how the behavioral composition of bluegill populations may be modified in chronically warmed systems.

AUTHORS: Tiffany Atkinson, Suzanne M. Gray – The Ohio State University

ABSTRACT: One of the most deleterious stressors on aquatic systems is elevated turbidity (i.e. concentration of suspended particulates in a body of water) resulting from human activities. In turbid waters, fish struggle to perceive visual cues, especially those associated with foraging (e.g. finding prey items) and reproduction (e.g. colorful nuptial displays). Thus, we expect foraging behaviors to be altered with some prey being less detectable under turbid conditions. In addition, in many fishes, females prefer males with more saturated red and yellow (carotenoid-based) nuptial coloration, as indicators of high male fitness. However, fish are unable to synthesize carotenoid-based pigments, thus they rely solely on their diet for these red and yellow nuptial displays. We evaluated the influence of turbidity on the diet and male coloration of an African cichlid (Pseudocrenilabrus multicolor victoriae) across a gradient of degraded water quality. Wild-caught, male P. multicolor from low turbidity sites, within an agricultural zone, displayed significantly more carotenoid-based coloration than males from high turbidity sites, with standard length as a significant covariate. However, we found that prey availability (based on point-in-time macroinvertebrate sampling) was similar across turbidity levels. Diet analyses will allow us to determine if turbidity caused a behavioral shift in foraging and will reveal if carotenoid uptake varies across sites. Our results can inform future land-use decisions to maintain viable African fisheries and conservation of aquatic biodiversity.

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: Jessica Ward, Gina Lamka, Autum Auxier, Hannah Mullinax – Ball State University

ABSTRACT: Cyanobacteria are prevalent blue-green algae in freshwater systems with adverse impacts on both human health and the environment. At least 8 classes of toxins produced by cyanobacteria have been identified with the potential to affect organismal physiology and function. Of these, ß-N-methylamino-l-alanine (BMAA) and its isomer 2,4-diaminobutyric acid (DABA) are potent neurotoxic metabolites of interest because they are a risk factor for neurodegenerative diseases in humans. However, sensorimotor integration is also critical to the successful survival and reproduction of resident aquatic organisms, and these neurodegenerative cyanotoxins have the potential to modify the expression of simple and complex behaviors within individuals and the outcomes of interactions between individuals in aquatic environments. One way that this can happen is through changes that compromise an organism’s ability to correctly perceive, process and respond to relevant biotic stimuli (e.g., predators, prey, or mates). In this study, we examined the effects of DABA on the foraging behavior of a larval fish (Promelas pimephales). We exposed larvae to a range of environmentally-relevant concentrations of DABA for 21 days. We then tested larvae in prey-capture assays to assess the effect of neural disruption on the outcomes of predator-prey interactions, and recorded individual prey strikes using a high-speed camera to assess changes in cognitive and motor aspects of hunting behavior. Compared with nonexposed fish, exposure to DABA was associated with reduced foraging success and an altered ability to recognize prey. These data improve our understanding of how aquatic contaminants affect stimulus-response pathways though their effects on brain function, and suggest that even subtle contaminant-induced shifts in perception, processing, or response can have marked effects on fitness.