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SFS Annual Meeting

Tuesday, June 4, 2024
10:30 - 12:00

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C02 Fish and Other Aquatic Vertebrates


6/04/2024  |   10:30 - 10:45   |  Freedom Ballroom F

ADDITIVE TOXICITY MODELING OF TRACE ELEMENTS IN FISH FROM AN INDUSTRIAL REGION Freshwater fisheries play a critical role in sustaining global food security, providing essential nutrients, proteins, fatty acids, and associated health benefits to consumers. Mining activities can introduce trace elements like arsenic (As) and selenium (Se) into freshwater environments, posing a potential risk to both recreational and subsistence fish harvesters. Monitoring programs that seek to assess these risks often use a “most restrictive contaminant” (MRC) approach, basing consumption advisories on a single contaminant of concern. However, these methods may underestimate risk, particularly in chemically complex mining regions where multiple contaminants may be present together at varying concentrations. To test this, we applied both the conventional approach and a more novel additive toxicity model (ATM) to assess potential consumption risks. We specifically studied 8 elements in freshwater fish muscle (n = 405), sampled from 17 Canadian lakes at varying distances from industrial mining impacts near Sudbury, Ontario. Consumption advisories from the ATM were typically more restrictive than those produced by the MRC approach, with the most pronounced differences seen in lakes with more direct mining impacts. The contribution of different elements to these estimates of chemical risk varied among lakes, with most lakes being dominated by either selenium or mercury, although arsenic and chromium contributed significantly in some lakes. Future analyses will include comparisons to more remote waterbodies, representing ecosystems contaminated through atmospheric deposition alone. This study contributes to the growing body of research on contamination of freshwater fish, offering insights that can inform more effective risk monitoring strategies.

Adam Lepage (Primary Presenter/Author), Laurentian University - Vale Living With Lakes Centre,;

Gretchen Lescord (Co-Presenter/Co-Author), University of Florida,;

Robert Paishegwon (Co-Presenter/Co-Author), Atikameksheng Anishnawbek First Nation,;

Lori Richer (Co-Presenter/Co-Author), Atikameksheng Anishnawbek First Nation,;

Curtis Assance (Co-Presenter/Co-Author), Atikameksheng Anishnawbek First Nation,;

Tom Johnston (Co-Presenter/Co-Author), Ministry of Natural Resources and Forestry,;

Dominic Ponton (Co-Presenter/Co-Author), Université de Montréal,;

Brian Branfireun (Co-Presenter/Co-Author), Western University,;

John Gunn (Co-Presenter/Co-Author), Laurentian University - Vale Living With Lakes Centre,;


6/04/2024  |   10:45 - 11:00   |  Freedom Ballroom F

SPECIES ATTRIBUTES CAN PREDICT TEMPORAL VARIATION IN DESCRIPTION OF FRESHWATER FISHES Rivers and lakes rank among the most diverse ecosystems on Earth, covering less than 1% of its surface yet representing more than 30% of global vertebrate richness. Among freshwater vertebrates, fishes are by far the most speciose, still being described at a rate of more than 200 species per year. Previous studies have examined attributes that act as predictors of temporal description patterns for other terrestrial vertebrates. The aim of this project is to unveil which species attributes have influenced the temporal description pattern of freshwater fish species, which still remain unclear. We have compiled attributes from various data sources (IUCN Red List and FishBase, among others) to obtain species characteristics and tested them as predictors of the description year of all freshwater fish using Generalized Least Squares (GLS) analysis. Our preliminary results for the order Salmoniformes suggest that species inhabiting smaller rivers at higher elevations are increasingly likely to be described in more recent years, as well as species with more congenerics at the time of description. Results for Cypriniformes described later in time show that they are significantly smaller in body size and range, as well as occupying fewer habitat types. We expect our findings to be able to guide future taxonomic efforts towards the areas of highest potential, which will aid in the protection of both newly discovered species and those that share their habitat.

Riley Saxton (Primary Presenter/Author), Cornell University,;

Peter McIntyre (Co-Presenter/Co-Author), Cornell University,;

Imanol Miqueleiz (Co-Presenter/Co-Author), Cornell University,;


6/04/2024  |   11:00 - 11:15   |  Freedom Ballroom F

Widespread density dependence in stream fishes The nature of population regulation is a central question in ecology. Streams are characterized by their hydrologic disturbance regimes and the role of density dependence versus disturbance as drivers of population fluctuations is debated. Negative density-dependent somatic growth is apparent in some stream fishes, and there is evidence that density-dependent processes regulate mortality, fecundity, and growth in a few highly studied taxa (i.e. salmonid species). However, the prevalence of density-dependent regulation at broad taxonomic and geographic scales is unknown. We examined a large database of stream fish abundance time series and used Bayesian model averaging to determine the strength of evidence in favor of density dependence in over 1,700 time series including 152 species on 5 continents. Our results suggest over 90% of fishes exhibit evidence of density dependence. Notably, strength of evidence varies significantly by family with, for example, the cyprinids (carps) and leucisids (minnows) exhibit wide variation from weak to strong, while ictalurids (catfishes) and percids (perches) exhibit strong evidence with low variance among populations. We also examined how evidence for the presence and strength of density dependence varies across life history traits. Overall, our results challenge the long-standing idea that stochastic rather than deterministic processes play a larger role in structuring stream fish populations. Our modeling approach also provides the ability to predict the strength of density dependence of both existing and repatriated populations which could inform management of stream fishes.

Elizabeth Duskey (Primary Presenter/Author), Oklahoma State University,;

Lindsey Bruckerhoff (Co-Presenter/Co-Author), Ohio State University,;

Casey Pennock (Co-Presenter/Co-Author), The Ohio State University,;


6/04/2024  |   11:15 - 11:30   |  Freedom Ballroom F

Effects of Morphology on Darter Swimming Ability The swimming abilities of most fish species are unknown. Darters (subfamily Etheostomatinae) are particularly understudied, and knowledge of their swimming abilities is valuable for multiple reasons. With around 250 described species, darters represent considerable North American freshwater fish diversity. Many darter species are benthic specialists with restricted movement and are particularly susceptible to habitat fragmentation. To help fill this knowledge gap, our goal was to model swimming speeds across a diversity of darter species. Specifically, we measured the critical swimming speeds (Ucrit) of nine darter species, used geometric morphometrics to create principal component (PC) variables for body shape, and conducted stepwise multiple regression to identify variables affection Ucrit. Our final model for predicting Ucrit retained only PC1 and PC3 as significant predictors (RSE = 37.2, df = 90, Adj. R2 = 0.166, p-value = 0.0003). Along the PC1 axis, faster individuals had a shorter anterior portion of the body with a more downturned head, a longer middle and posterior part of the body, pectoral fin insertions located higher up on the body, and caudal fin insertions that are closer together in relation to slower individuals. Along the PC3 axis, faster individuals had a more contracted dorsal surface, a more elongated ventral surface, more widely separated pectoral fin insertions, and a more anterior lower pectoral fin insertion in relation to slower individuals. Neither standard length nor species identity were significant predictors of Ucrit. Our results will be useful to basic and applied ecologists interested in fish swimming abilities and movement.

Ridge Sliger (Primary Presenter/Author), Clemson University,;

Brandon Peoples (Co-Presenter/Co-Author), Clemson University,;


6/04/2024  |   11:30 - 11:45   |  Freedom Ballroom F

Cascading effects of woody encroachment on prairie stream fishes The conversion of grasslands to woodlands is a global threat to the natural functioning of prairie ecosystems, with important consequences for their hydrology. Specifically, woody encroachment has been linked to water loss and changes in infiltration rates that in turn have reduced stream flow and increased stream drying. Long-term data on prairie stream hydrology, habitat characteristics, and fish community structure were used to evaluated how changes in hydrology have affected the resilience of fishes. Seven sites in two headwater stream networks were sampled seasonally for 17 to 22 years. This time period encompassed two extreme droughts that caused extensive drying in both networks. We quantified the resilience common fish species, measured as the time to recover to pre-disturbance densities following these drying events. Of the two sites with the most notable woody encroachment, the fish community at one site failed to recover following a drought in 2006 at the community at another site failed to recover following a drought in 2018. In contrast, the fish communities at sites with more stable native grassland cover and hydrology were more resilient to disturbance, rebounding to pre-drought densities within a year. Our results provide evidence that water loss and increased frequency of stream drying associated with woody encroachment in prairie ecosystems will decrease the resilience of headwater stream fish communities.

Keith Gido (Primary Presenter/Author), Kansas State University,;

Matthew Bogaard (Co-Presenter/Co-Author), Washington Department of Fish and Wildlife,;

Sophia Bonjour (Co-Presenter/Co-Author), U.S. Geological Survey, Columbia Environmental Research Center,;

Lindsey Bruckerhoff (Co-Presenter/Co-Author), Ohio State University,;

John Cleveland (Co-Presenter/Co-Author), Kansas State University,;

Keith Epping (Co-Presenter/Co-Author), Kansas State University,;

Crosby Hedden (Co-Presenter/Co-Author), Arizona Department of Game and Fish,;

Skyler Hedden (Co-Presenter/Co-Author), Arizona Department of Game and Fish,;

Garrett Hopper (Co-Presenter/Co-Author), Louisiana State University,;

Kade Jackson (Co-Presenter/Co-Author), Kansas State University ,;

Elle Krellwitz (Co-Presenter/Co-Author), Kansas State University,;

Erika Martin (Co-Presenter/Co-Author), Emporia State University,;

Casey Pennock (Co-Presenter/Co-Author), The Ohio State University,;

Peter Pfaff (Co-Presenter/Co-Author), St Mary's University,;

Elizabeth Renner (Co-Presenter/Co-Author), South Dakota Department of Game and Fish,;

Keith Gido (Co-Presenter/Co-Author), Kansas State University,;

James Whitney (Co-Presenter/Co-Author), Pittsburg State University,;