Vertical habitat use of adult Walleye conflicts with expectations from fishery-independent surveys

Ann Marie Gorman; Richard T. Kraus; Lee Gutowsky; Christopher Vandergoot; Yingming Zhao; Carey Knight; Matt Faust; Todd Hayden; Charles Krueger

doi:10.1002/tafs.10150

USGS · 70202670

Vertical habitat use of adult Walleye conflicts with expectations from fishery-independent surveys

Ann Marie Gorman·Richard T. Kraus·Lee Gutowsky·Christopher Vandergoot·Yingming Zhao·Carey Knight·Matt Faust·Todd Hayden·Charles Krueger

View original source ↗Export metadata ↓

Abstract

Stock assessments of Walleyes Sander vitreus in Lake Erie rely on a combination of suspended and bottom overnight gill‐net surveys to provide population and demographic information. However, the assumption that Walleyes undertake diel vertical migrations and become available to the suspended gill nets at night has never been validated. To understand how vertical habitat use affects the availability of Walleyes to fishery‐independent surveys, we compared individual behaviors observed by means of acoustic depth telemetry tags (20 individuals; 2013–2016) with catches in paired suspended and bottom gill‐net sets (273 paired sets; 2013–2016) used by management agencies. In contrast to our expectations and observations in other lakes, the mean depths for Walleyes most often occurred in the lower one‐half to one‐third of the water column, and at lake depths <25 m the fish tended to be close to the bottom. The relationship between fish and lake depth was dependent on year and season. At lake depths >15 m, Walleyes were found at shallower depths during stratified periods (i.e., summer) than during unstratified periods (autumn). They were also found at shallower depths in 2015 and 2016 than in 2013 and 2014. In paired autumn gill‐net surveys, (1) the overall proportion of Walleye catch was nearly equal in suspended and bottom gill nets and (2) the proportion of the catch in suspended gill nets declined with fish length. The pattern of decline was dependent on how deep the suspended net was fished and the year in which the data were collected. These results provide evidence that the suspended gill‐net surveys currently being used to assess Walleye demographics in Lake Erie are biased toward the capture small Walleyes, while bottom nets are biased toward the capture of large ones. Future telemetry investigations will be needed to understand whether these biases reflect differences in the depth of habitat between small and large Walleyes.

Explore related subjects

Transactions of the American Fisheries Society Article

Source-reported bounding extent: 41.27780646738183° to 43.068887774169625° latitude; -84.19921875° to -78.75° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Ann Marie Gorman, Richard T. Kraus, Lee Gutowsky, Christopher Vandergoot, Yingming Zhao, Carey Knight, Matt Faust, Todd Hayden, Charles Krueger. 2019-03-07. Vertical habitat use of adult Walleye conflicts with expectations from fishery-independent surveys. https://doi.org/10.1002/tafs.10150

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

The value of electronic tagging and tracking studies for understanding fish–hypoxia interactions

Objective Hypoxia (i.e., low dissolved oxygen availability) is a natural phenomenon but can also be induced by human activities (e.g., nutrient enrichment from runoff). Given that dissolved oxygen is essential for aquatic life, periods of hypoxia tend to have negative consequences (e.g., sublethal disturbances, mortality) for most fishes. Extensive laboratory research has documented hypoxia thresholds and physiological and behavioral outcomes for a variety of freshwater and marine fishes and there is also an extensive body of fieldwork assessing population-level responses (e.g., survival, distribution). Yet, studying how individual fish respond to hypoxia in the wild has proved challenging; electronic tagging and tracking tools (e.g., biotelemetry, biologging) have made it easier to study individual responses to hypoxia and complement other tools like hydroacoustics that tend to focus on population-level responses. Methods We review what has been learned from contemporary studies that employ electronic tagging and tracking tools to understand how fish respond to hypoxia in the wild. Topics explored include identifying and validating hypoxia thresholds, habitat compression, connectivity, mortality, physiological and bioenergetic consequences, and extreme weather conditions. We also consider what we have learned about evaluating various management plans for hypoxia and reflect on how electronic tags have also been used in aquaculture systems and in hybrid studies that combine laboratory and field research. We highlight fishes in Lake Erie as a research narrative to demonstrate how electronic tagging and tracking have markedly improved our understanding of a longstanding hypoxia issue. Results Our synthesis revealed that electronic tagging and tracking have provided critical information on how fish respond to hypoxia in the field, revealing complex trade-offs and compensatory mechanisms as well as cryptic hypoxia-induced mortality. Beyond just illuminating space use and mortality, tags equipped with various sensors are revealing how fish deal with hypoxia in real time in terms of physiology, bioenergetics, and behavior. Conclusions As electronic tagging and tracking methods experience further innovation and are increasingly applied to understand the effects of hypoxia on fish, we expect more unanticipated findings about the effects of hypoxia on fish in all aquatic ecosystems, which will strengthen our ability to manage and mitigate hypoxia. Combining tools and approaches (e.g., lab and field) is perhaps the best way to generate comprehensive understanding.

Transactions of the American Fisheries Society↗

USGS2026

Life history traits and population dynamics of Freshwater Drum across large river gradients

Objective Monitoring and assessment of nongame native fishes is limited, but conservation interest in these species is growing. Freshwater Drum Aplodinotus grunniens are a wide-ranging species that serve important functional roles and could serve as an indicator for similar but less common species. Our overall objectives were to quantify and compare population dynamic rates and life history of Freshwater Drum among study reaches in the upper Mississippi and Illinois rivers and relate these metrics to hypothesized environmental and anthropogenic factors. Methods We integrated recently collected age data with monitoring data to estimate age and size distributions, growth curves, maturation schedules, mortality rates, and young-to-adult ratios of Freshwater Drum in six study reaches spanning 1,500 km of river. Principal component analyses and linear regression were used to relate environmental and anthropogenic gradients (latitude, commercial harvest, hydrologic dynamics, primary productivity) to life history traits and population dynamic rates. Results We found latitudinal gradients in life history traits and population dynamic rates whereby Freshwater Drum in upstream, higher-latitude study reaches generally exhibited later maturity, slower growth, smaller maximum size, and lower mortality rates compared with those in lower-latitude study reaches. Further, young-to-adult ratios positively corresponded with chlorophyll- a concentration. No clear relationships were apparent between population dynamic rates and hydrologic variation or commercial harvest. Conclusions Latitude is an important structuring component of life history traits and population dynamics of Freshwater Drum in the upper Mississippi and Illinois rivers likely due to both temperature seasonality and disturbance regimes. The presence of demographic structure in a widespread, common species such as Freshwater Drum suggests similar patterns likely exist in other long-lived native fishes.

Illinois, Iowa, Minnesota, Missouri, Wisconsin↗

USGS2026

Evaluating reservoir passage and survival of juvenile Chinook Salmon to support reintroduction upstream of Shasta Dam, California

Objective Juvenile Chinook Salmon Oncorhynchus tshawytscha that are released upstream of Shasta Reservoir migrate more than 35 km to reach Shasta Dam, although survival through this system is poorly understood. We conducted a reservoir-scale acoustic telemetry study to quantify downstream movement and survival under seasonally variable environmental conditions to inform decisions about juvenile collection strategies for Chinook Salmon reintroduction above Shasta Dam. Methods A total of 656 hatchery-origin juvenile Chinook Salmon were acoustic-tagged, released near the mouth of the McCloud River, and monitored in Shasta Reservoir and the Sacramento River from September 2024 through March 2025 using an array of telemetry receivers. Results Most tagged fish failed to move downstream through the McCloud River Arm of Shasta Reservoir and arrive at Shasta Dam. Survival probabilities were estimated at 0.268 to the downstream end of the McCloud River Arm and 0.119 to Shasta Dam. For fish that did reach the dam, elapsed time from release to arrival was 66.4 d, and fish typically arrived and departed during daylight hours. Nine tagged juveniles were detected downstream of the dam, and three were later detected more than 500 km downstream. Conclusions The consistently low survival and restricted downstream movement provide important information indicating that downstream collection of juvenile Chinook Salmon should be focused in the lower McCloud River and the upper portion of the McCloud River Arm of Shasta Reservoir rather than at Shasta Dam.

California↗