Midwest Fish & Wildlife Conference 2016

AUTHORS: Jeffrey K Fryer, Columbia River Inter-Tribal Fish Commission

ABSTRACT: Low snowpack and hot weather resulted in Columbia River temperatures exceeding 22 degrees for three weeks just past the peak of the third largest Columbia Basin sockeye salmon run on record. For weeks, the region was treated to pictures and videos of dead and dying sockeye salmon and speculation high water temperatures killed 90% of the sockeye run. The actual story is not as dire with respect to the migration through the Columbia River in 2015, but the implications for the future may be of even greater concern. Sockeye counts at Columbia River dams result in an estimated 54% mortality rate for sockeye on their upstream migration. However, preliminary data from the two primary spawning areas in the Okanogan and Wenatchee basins suggests mortality to natal areas may have reached 90%, although that figure includes significant harvest. With a warming climate and a future forecast of lower snow packs, the conditions sockeye salmon faced in 2015 may become more frequent in the future.

AUTHORS: Jacob Schwoerer*, Missouri Cooperative Fish & Wildlife Research Unit; Craig Paukert,U.S. Geological Survey Missouri Cooperative Fish & Wildlife Research Unit; Hope Dodd, National Park Service Heartland I&M Network

ABSTRACT: Climate and land use change are major contributors to stream degradation, although the extent that these impacts have on various regions and stream systems likely differ. Determining a stream’s susceptibility to change from anthropogenic impacts is necessary to determine the stream communities most likely to experience a decrease in diversity, abundance, and function. Vulnerability assessments are tools used to depict a representative risk value for a faunal group, species, or habitat. To be effective, these vulnerability assessments link species specific life history traits to increased risk of extirpation or extinction so that an accurate portrayal of risk may provide managers with a starting point for conservation efforts. Our goal was to determine the vulnerability of fish and aquatic invertebrate communities to land use and climate change. Fish and invertebrate sampling was conducted from 1988 to 2013 at 88 sites throughout seven National Park Service units in the central United States. A trait-based approach was used for each faunal group (fish and invertebrates), and allowed us to determine overall community vulnerability, and factors driving a stream’s vulnerability (temperature, flow, habitat degradation, dispersal ability, or species persistence through time). Invertebrate communities at each of the parks were most vulnerable to an altered flow regime (mean among parks: 81% ± 6% of the community vulnerable) while the fish community was most vulnerable to in stream physical habitat alteration (mean among parks: 53% ± 15% of the community vulnerable). The most and least vulnerable park was consistent between fish and invertebrate assessments. Homestead National Monument, a small, fine substrate, low species-rich, prairie stream was found least vulnerable, and George Washington Carver National Monument, a medium sized, coarse substrate, low species-rich Ozark stream was found most vulnerable. Our results provide a framework that resource managers can use to determine aquatic biota vulnerability throughout Midwestern streams.

AUTHORS: Andrew K. Carlson*, Michigan State University, Center for Systems Integration and Sustainability, Department of Fisheries and Wildlife; William W. Taylor, Michigan State University, Center for Systems Integration and Sustainability, Department of Fisheries and Wildlife; Troy G. Zorn, Michigan Department of Natural Resources, Marquette Fisheries Research Station; Dana M. Infante, Center for Systems Integration and Sustainability, Department of Fisheries and Wildlife

ABSTRACT: The sustainability of freshwater fisheries is increasingly affected by modifications to terrestrial and aquatic environments that influence water quality, quantity, and ecosystem productivity. Drivers of ecological change include warming air temperatures, changes in precipitation patterns, instream habitat alteration, and invasive species. Amidst these alterations, there is a need for future management approaches that promote ecosystem resilience: the capacity of a system to absorb changes amidst disturbances without significant alterations to its structure or function. The state of Michigan, USA, contains highly valuable stream salmonid fisheries that are susceptible to impending ecological alterations driven by climate change. As such, there is need for a holistic, science-based fisheries management plan to enhance stream ecosystem resilience. The state of Michigan is responding to imminent ecological changes by designing a comprehensive management plan for stream brook trout Salvelinus fontinalis, brown trout Salmo trutta, and rainbow trout Oncorhynchus mykiss populations. To assist in developing such a plan, we used generalized and stream-specific regression models to forecast salmonid thermal habitat suitability in Michigan streams from 2006–2056 under different predicted climate change scenarios. Streams spanned a hydrological gradient from surface runoff to groundwater dominance and included all Michigan management zones (i.e., Upper Peninsula, northern Lower Peninsula, southern Lower Peninsula). Salmonid thermal habitat degradation, measured by the impact of temperature on growth (i.e., reduced or no growth) in July, was most common in surface runoff-dominated streams from 2012–2036, the period of greatest thermal warming. Thermal habitat degradation occurred least frequently in rainbow trout streams as adults and juveniles of this species have a wider temperature range (12.0–22.5°C) under which growth persists compared to brook charr (11.0–20.5°C) and brown trout (12.0–20.0°C). Throughout Michigan, maximum stream warming was predicted to be > 4°C in surface runoff-dominated systems, compared to < 2°C in groundwater-dominated systems, the latter of which typically had optimal growing conditions from 2006–2056 for all salmonid species investigated. Our results provide tools for scientists, managers, policy makers, and public stakeholders to better understand the causes of stream warming and consequences for valuable salmonid populations in Michigan. Fisheries professionals can use our findings to implement resilience-based management strategies and conserve productive salmonid fisheries amidst global change.

AUTHORS: Arthur R. Cooper*, Department of Fisheries and Wildlife, Michigan State University; Kevin E. Wehrly, Michigan Department of Natural Resources and University of Michigan; Ken Yi, Department of Fisheries and Wildlife, Michigan State University

ABSTRACT: Historic and contemporary human disturbances are a key driver of species loss and imperilment for many freshwater organisms, and coupled with climate change, increasing water demands, and continued landscape development, create an uncertain future for many species. In support of the State of Michigan’s 2015 Wildlife Action Plan, we assessed the vulnerability of fish species of greatest conservation need to current and future environmental threats. We first developed habitat suitability models for 27 stream fishes and 10 lake fishes (with an overlap of 6 species) with MaxEnt. Highly suitable habitats identified from these habitat suitability models were then used to examine vulnerability to habitat fragmentation and anthropogenic landscape disturbances, and future habitat suitability under climate change. Analysis of connectivity among highly suitable habitats indicates that large dams are playing a primary role in connectivity loss for the vast majority of both stream and lake fishes relative to small dams and waterfalls. On average, nearly 46% of highly suitable stream habitats and 57% of highly suitable lake habitats were considered moderately to severely disturbed. Comparison of current habitat suitability with habitat suitability projections under climate change show potential gains for warmwater and/or large river fishes due to increased water temperatures and stream flow, however these gains are subject to both biogeographic limitations and connectivity constraints imposed by barriers among current and future habitats. Conversely, stream fishes that are predominately coolwater and coldwater in thermal preference are projected to lose highly suitable habitats under climate change. Climate change projections for lake fishes were highly influenced by biogeography and connectivity, with all species projected to sustain losses in highly suitable habitat. Consideration of multiple threats to fish habitats, both contemporary and future, is needed to provide information vital to ongoing fish conservation efforts.

AUTHORS: Emily Dean*, Grand Valley State University; Mark Luttenton, Grand Valley State University

ABSTRACT: Native and introduced adfluvial fishes constitute a significant component of Great Lakes fisheries. Seasonal movement of adfluvial fish into coastal streams may deliver substantial amounts of energy that supplement coastal stream production. For example, Conte and Luttenton (unpublished data) noted that 40% of brown trout would consume large numbers of larval suckers when larval suckers were available in the drift while 60% continued consuming invertebrates (e.g., caddisflies). Using bomb calorimetry (cal/g dry weight), we determined the energy density of Chinook salmon muscle and eggs, larval white sucker, steelhead eggs and adult aquatic insects (i.e. caddisfly and mayfly). Energy density of Chinook salmon male muscle, female muscle and eggs yielded 5,062 cal/g, 4,759 cal/g, and 6,209 cal/g respectively. Steelhead eggs were similar to Chinook eggs generating 6,211 cal/g. Larval white sucker energy content (5,726 cal/g) was significantly lower than adult caddisflies (6,743 cal/g) which were energetically similar to salmon and steelhead eggs. Adult mayflies Hexagenia limbata yielded 5,122 cal/g. The high energy content and large runs of introduced adfluvial salmon, steelhead and native white suckers have the potential to seasonally supplement the energy content of coastal streams; this can provide a valuable food source to resident fish and stimulate secondary production.

AUTHORS: Jill Leonard, Northern Michigan University; Robert Cross, Northern Michigan University

ABSTRACT: Life-history variation in salmonid fishes related to movement behavior represents intraspecific biodiversity important for species resiliency and ecosystem functioning. We used RFID/PIT telemetry in two Lake Superior tributaries to assess movement behaviors expressed in brook trout Salvelinus fontinalis. Using a dataset of 650 fish tagged over four years, we detected 9-44% emigration from the streams, which likely represented the migratory (coaster) life history. Coasting behavior was not related to fish size or condition, but was predicted by a tagging location nearer to the mouth of the stream. Of the 506 fish (78%) that remained within the stream following tagging, the majority (55-60%) remained stationed close to their tagging site; however, the remainder exhibited other types of movement behavior ranging from unidirectional up- or downstream movements (20-40%) to nomadic roving (8-10%) within the study section. Mobile fish occurred throughout the streams, with a trend toward greater numbers of nomads tagged near the mouth; there was no relationship between size/condition and likelihood of mobile behavior. The proportions of fluvial movement behaviors were similar between streams and suggest more variability in movement behavior than is suggested by the migrant/resident dichotomy typically attributed to salmonids.

AUTHORS: Douglas J. Dieterman*, Minnesota Department of Natural Resources; John H. Hoxmeier, Minnesota Department of Natural Resources; Eric J. Krumm, Department of Biological Sciences, Minnesota State University-Mankato

ABSTRACT: The Clean Water Act (CWA) ensures protection of the chemical, physical, and biological integrity of the Nation’s surface waters to provide fishable and swimmable recreational opportunities. Many government agencies use fish-based indices of biotic integrity (IBI) to classify streams and rivers into those that represent excellent, good, fair, or poor biotic integrity. Ideally, sites with higher IBI scores and classified as excellent or good biotic integrity, should have more abundant and resilient sport fish populations that support more recreational opportunities than sites with low IBI scores. We compared relative abundance of all quality-sized and larger sport fishes, with emphasis on relative abundance of four size groups of smallmouth bass Micropterus dolomieu among biotic integrity classes to verify an association between biotic integrity and recreationally-relevant sport fisheries. We also compared smallmouth bass size structure, condition, growth and recruitment constancy. We found significant differences in relative abundance of sport fishes and smallmouth bass size structure among IBI classes. These patterns generally reflected a lack of recreationally-relevant populations at sites with poor biotic integrity. Among remaining IBI classes, bass condition, growth and recruitment constancy did not differ. However, considerable variation in these parameters was explained by the individual sites. This indicates that other unmeasured site-specific factors may be more important modifiers of bass populations than overall biotic integrity. Bass condition also differed between length groups with larger bass in poorer condition than smaller bass. These results confirm the appropriateness of implementing management activities to maintain and enhance biotic integrity in support of recreational fisheries management, and more broadly, reinforce the use of biotic integrity classes as an indicator of achieving, at least, the “fishable” goal specified in the CWA.