Category Archives: Conservation of Freshwater Fishes

Freshwater fishes are among the most imperiled groups globally with rates of decline comparable to declines in tropical rainforest species. Research in the PoeschLab focuses on developing a better understanding of the mechanisms for the decline of freshwater organisms. This research has four main themes, including: 1) threats to freshwater species at risk, 2) stream augmentation and hydrologic alteration, 3) climate change impacts to freshwater fishes, and 4) the spread and impact of invasive species. To achieve our research goals we utilize a variety of expertise in the PoeschLab and the University of Alberta. This includes expertise in: movement ecology and telemetry, assessing foodwebs using stable isotope analysis, population genetics and environmental DNA (eDNA) and morphology and swim performance.

Neufeld, K.R. (2016) Improving our ability to assess the impacts of hydrologic alteration on stream fishes: An interdisciplinary approach to assess the Threatened Western Silvery Minnow Hybognathus argyritis in Canada

Thesis title: Improving our ability to assess the impacts of hydrologic alteration on stream fishes: An interdisciplinary approach to assess the Threatened Western Silvery Minnow Hybognathus argyritis in Canada

Author: Kenton Neufeld

Abstract

Human induced hydrologic alteration is ubiquitous in North American riverscapes. These alterations have been shown to impact fishes by modifying habitats, influencing movement patterns and driving changes in community structure. Understanding these impacts is an essential first step for the conservation of fish in these systems. We use Western Silvery Minnow Hybognathus argyritis and the Milk River of southern Alberta as a model system to develop and apply an interdisciplinary approach to assess the impacts of hydrologic alteration on capture efficiency and habitat suitability of stream fishes. The capture efficiency of sampling gear is a key component of many fish research programs, and understanding the link between hydrology and capture efficiency is critical to accurately assessing the impacts of hydrologic alterations on fish. We measured seine net capture efficiency in the Milk River, and investigated the effects of flow, species, and habitat variables on capture efficiency using mixed effects models. Flow state was an important driver of capture efficiency, which increased ~5 % during augmented flow compared to natural flow. Habitat suitability assessments are commonly used to determine the impacts of hydrologic alteration on fishes, but often rely on poorly understood relationships between fish and their habitat. We used the swimming performance of Western Silvery Minnow to measure the cost of movement between habitat patches in the Milk River and incorporated this cost into a graph theoretic metric of habitat suitability (Equivalent Connected Area). Compared to augmented flow, the proportion of suitable area was ~ 475 % higher during natural flow, the mean cost of movement between habitat patches was ~ 13 % higher and Equivalent Connected Area increased ~ 0.119 (95% C.I. 0.109-0.130). By including flow as a variable in modelling capture efficiency and swimming performance as a mechanism defining habitat suitability, we show the utility and benefits of taking an interdisciplinary approach to assessing the impacts of hydrologic alteration on stream fishes.

Veillard, M. (2016) Investigating fine-scale movement patterns and comparative swimming performance of the newly identified and threatened Rocky Mountain Sculpin (Cottus sp.) across its Canadian distribution

Thesis Title: Investigating fine-scale movement patterns and comparative swimming performance of the newly identified and threatened Rocky Mountain Sculpin (Cottus sp.) across its Canadian distribution

Author: Marie Veillard

Abstract

Cumulative anthropogenic impacts to the riverscape, including hydrologic alteration, have contributed to an escalated number of freshwater fish species at risk in North America. Species dispersal is an important mechanism underlying many ecological processes. Understanding the scale at which species carry out their life history can inform both conservation actions and recovery potential. Our study used the recently-identified Rocky Mountain Sculpin (Cottus sp.), a species federally listed as threatened, to investigate the (1) fine-scale movement potential and (2) comparative swimming ability of adults throughout their restricted Canadian distribution. Rocky Mountain Sculpin are a small-bodied, cryptic benthic species that utilizes interstitial spaces for shelter. To assess the fine-scale movement potential of Rocky Mountain Sculpin, I conducted a mark-recapture study on Lee Creek, Alberta using Passive Integrated Transponder (PIT) and Visible Implant Elastomer (VIE) tags. I assessed the abiotic and biotic factors influencing movement using Boosted Regression Tree models. In this study I found that 89% of sculpins moved less than 30 meters, while a few individuals moved up to 240 meters. Biotic factors indicated sculpins moved from high to low abundances of fish due to intra- and inter- specific competition from congeners and benthic competitors. The most important abiotic factor contributing to movement was abundance of cobble substrate at destination transects. Interestingly, there was a strong interaction between biotic and abiotic components indicating the importance of focusing restoration efforts on both biotic and abiotic factors. To address the second objective, comparative fish swimming performance and recovery potential was assessed in a laboratory on individuals sourced from drastically different hydrologic regimes in Alberta and British Columbia, including the flow augmented, North Milk River. Permutational ANOVAs were used to compare swimming performance between rivers using two aspects of swimming ability: (1) slip velocity, the point at which fish slipped and transitioned into swimming and 2) failure velocity, the point at which fish could no longer hold position against the flow without resting. While we expected swimming ability to be correlated with natal hydrologic regimes, our study found there were no differences in failure or slip velocity between rivers. However, resting oxygen uptake prior to swim tests was significantly higher for fish from the augmented, North Milk River, indicating there may be a physiological response to flow augmentation. Over repeated exercise, fish failure velocity decreased from 7.45 ± 3.10 body lengths per second (BL s-1) in the first test to 6.18 ± 2.56 BL s-1 by the third test suggesting the use of anaerobic metabolism to power swimming performance of this small-bodied species. Linear mixed-effects models developed using body characteristics showed caudal morphology to influence both failure and slip velocities, while body height was negatively correlated to slip velocity, demonstrating morphological selection for benthic living. Taken together, these studies suggest that while large-scale flow augmentation may come at an energetic cost to sculpins, fine-scale developments may be equally as detrimental to this dispersal-limited species. Conservation for this species may then require both fine-scale and regional management.

Thayer, D. (2016) Identifying seasonal Lake Sturgeon (Acipenser fulvescens) movement patterns and habitat selection in the South Saskatchewan River Basin

Thesis Title: Identifying seasonal Lake Sturgeon (Acipenser fulvescens) movement patterns and habitat selection in the South Saskatchewan River Basin

Author: Donnette Thayer

Abstract

Lake Sturgeon (Acipenser fulvescens Rafinesque 1817) have experienced population declines throughout their range. In Alberta, low density age-class distributions, irregular recruitment, critically low spawning potential ratios and other factors led to a 2007 designation of “Threatened” for this species under the Provincial Wildlife Act. As a protected species, efforts to develop a comprehensive recovery strategy require an understanding of species’ biology, behavior, and critical habitat requirements. My objectives were to a) identify movement behaviors and habitat changes before and after an extreme flood event, and b) ascertain overwintering movement behaviors and habitat selection of South Saskatchewan River Basin Lake Sturgeon. Multiple-receiver acoustic telemetry was used to obtain triangulated, fine-scale movement patterns at the confluence of the Bow and Oldman rivers, a potential critical spawning habitat site, before, during and after an extreme flood, and at a study site on the South Saskatchewan River known to be critical overwintering habitat, before, during, and after the ice-on period. Substrate analysis was performed pre- and post-flood for Grand Forks, and substrate, bottom velocity, and depth analyses were performed for the South Saskatchewan River overwintering study site. In the extreme flood event study, movement behaviors were captured by receivers positioned to triangulate movements and provide positions at a fine scale. Receivers had been deployed to assess spawning behavior when the 2013 Alberta ‘Flood of Floods’ occurred, providing an opportunity to document fine-scale Lake Sturgeon movement behaviors before, during and after an extreme disturbance event. Lake Sturgeon showed a tendency to avoid high water velocity areas. Increases in flow rate showed a significant negative relationship to mean positional distance from shore. Substrate assessment prior to and following the flood showed a significant change in substrate composition. Mean gravel- and larger-substrate area increased, providing evidence that high flow rates in 2013 and 2014 exposed larger particle fluvial substrate. Complexity as measured by patch density increased, indicating a measureable overall increase in heterogeneity. Lake Sturgeon benefitted from improved spawning habitat following the extreme flood by gaining larger, cleaner substrate with more complexity. Although extreme flood events may be costly to human life and infrastructure, they may be ecologically beneficial to some freshwater organisms, particularly plesiomorphic, long-lived species such as Lake Sturgeon whose survival has depended upon a capability to adapt to erratic and occasionally extreme peak flow events. In the overwintering study, fine-scale movements by adult and juvenile Lake Sturgeon were tracked for a previously identified overwintering habitat in the South Saskatchewan River using acoustic telemetry from late October 2013 through April 2014 for a 1.5 kilometer reach of the South Saskatchewan River identified in a previous study as overwintering habitat. Period-segmented movement rates, depth selection, aggregation behavior and preferential overwintering habitat selection by adult and juvenile Lake Sturgeon were evaluated for 23-26 individuals (20-23 adults and 3 juveniles, depending on residency during period assessed – individuals not present during all segments were excluded) detected within the study area. Environmental parameters included depth, depth standard deviation (rugosity), bottom velocity, bottom velocity standard deviation, and substrate type (silt, sand, and gravel or larger substrate). Boosted regression tree (BRT) analyses were performed to identify habitat selection for Lake Sturgeon for period-aggregated core (50th percentile) and range (95th percentile) positions. Movement rates paralleled temperature variation, becoming highly restricted during periods of deepest cold. Increased aggregation was also noted for these periods. The deepest habitat positions occurred during ice formation and breakup. Depth and bottom velocity were the most important variables used to identify sturgeon habitat for all periods assessed. Since Lake Sturgeon display site fidelity and aggregation behaviors independent of resource availability, winter habitat may limit the population. While spawning habitat is crucial to ensuring successful recruitment, data suggests that a substantial portion of the population spends the greater part of the year in overwintering locations, making this habitat potentially more critical to the survival of the population as a whole than any other habitat. If winter habitat is degraded or otherwise compromised, it could hinder species recovery, and should be considered critical habitat, receiving appropriate protection. This was the first study to use fine-scale acoustic telemetry analysis of movement behavior and habitat selection for a Lake Sturgeon population occupying fluvial winter habitat.

Poesch, M.S., Chavarie, L., Chu, C., Pandit, S.N.*, and W. Tonn. (2016) Climate change impacts on freshwater fishes: A Canadian perspective. Fisheries 41(7): 385-391.

Abstract:

Current and projected patterns of global climate change are a major concern to freshwater fisheries in Canada. The magnitude of the impacts of climate change vary among species and ecoregions. The latest climate change scenario projections for Canada suggest that by 2050 temperatures will increase between about 4.9°C ± 1.7°C (average mean ± standard deviation) and 6.6°C ± 2.3°C under the Representative Concentration Pathways (RCPs) 2.6 and 8.5 emission scenarios, respectively. These changes will have an important influence on the physiology, distribution, and survival of freshwater fishes, as well as other ecological processes in direct, indirect, and complex ways. Here we provide a perspective from the Canadian Aquatic Resources Section on the impacts of climate change to freshwater fishes. Given the geographic size and diversity of landscapes within Canada, we have divided our perspective into three regions: eastern, western, and northern Canada. We outline the impacts of climate change to these regions and outline challenges for fisheries managers. Because climate change does not operate in isolation of other environmental threats, nor does it impact species in isolation, we suggest improved inter jurisdictional integration and the use of an adaptive and ecosystem-based approach to management of these threats.

Citation: Poesch, M.S., Chavarie, L., Chu, C., Pandit, S.N.*, and W. Tonn. (2016) Climate change impacts on freshwater fishes: A Canadian perspective. Fisheries 41(7): 385-391.

List of species that have potential to extend their range and/or abundance northward into the Arctic, with some biological characteristics related to expansion of their existing ranges.

Also Read:

Theis, S.*  Castellanos D.A., Hamann A. and M.S. Poesch. (2022) Exploring the potential role of habitat banks in preserving freshwater biodiversity and imperiled species in the United States. Biological Conservation 273: 109700.

*Lab members: Shubha Pandit, Mark Poesch. Check out opportunities in the lab!

Neufeld, K.*, Watkinson, D., and Poesch, M.S. (2016) The effect of hydrologic alteration on capture efficiency of freshwater fishes in a highly modified Prairie stream: Implications for bio-monitoring programs. River Research and Applications 32: 975-983.

Citation: Neufeld, K.*, Watkinson, D., and Poesch, M.S. (2016) The effect of hydrologic alteration on capture efficiency of freshwater fishes in a highly modified Prairie stream: Implications for bio-monitoring programs. River Research and Applications 32: 975-983.

Abstract

Hydrology is a defining feature of aquatic ecosystems. Changes in stream hydrology, due to climate change, water use and impoundment, have been shown to negatively affect fish populations. Assessing changes in hydrology and its effect on fish populations and communities remains an important consideration for aquatic monitoring programmes across the globe. In this study, we used the Milk River in southern Alberta as a model system to understand how hydrologic alteration may also affect capture probabilities of fishes and impact instream monitoring programmes. The Milk River receives the majority of its April to October flow via an inter-basin transfer from the St. Mary River, drastically altering the hydrologic regime and instream habitats for fishes during this augmentation period. We estimated species-specific seine net capture probabilities of fishes in the Milk River during augmentation and natural flow periods using depletion surveys in both open and enclosed sites. Using habitat data collected during the seine surveys, linear mixed-effects models were created with capture efficiency as the dependent variable. Models were compared using corrected Akaike’s information criterion, and the relative contributions of the different variables to the top models were examined. We found that species and flow characteristics, such as water velocity and the state of augmentation, played a prominent role in many of the top models explaining variation in capture efficiency. These results demonstrate that changes to stream hydrology clearly have the potential to impact gear efficiency and individual species assessments. Stream monitoring programmes, which aim to determine long-term trends in aquatic ecosystem health, need to be mindful that any change to stream hydrology—from climate change, fragmentation or stream alteration—can alter capture efficiency of the sampling gear and inadvertently alter species-specific trends.

*Lab members: Kenton Neufeld, Mark Poesch. Check out opportunities in the lab!

Seine net capture probability for Flathead Chub, Longnose Dace, Sucker species, and Western Silvery Minnow in the Milk River in southern Alberta during augmented and natural flow conditions, and from open and closed surveys. 

 

Alberta Conservation Association funds alpine fisheries research

The Alberta Conservation Association provided a grant to help research the impact of stocking of non-native trout on alpine ecosystems. This project is being led by MSc student Allison Banting with the help of Dr. Mark Taylor and Rolf Vinebrooke. Thanks ACA for your continued support of the PoeschLab.

Maitland, B. (2015) Stream Crossings in the Western Boreal Forest: Assessing Impacts and Prioritizing Restoration for Native Freshwater Fishes

Thesis Title: Stream Crossings in the Western Boreal Forest: Assessing Impacts and Prioritizing Restoration for Native Freshwater Fishes

Author: Bryan M. Maitland

Abstract

Growing anthropogenic development in response to rising demands for natural resources is a major concern for freshwater fish, particularly in resource rich regions such as Canada’s boreal forest. Expanding networks of industrial resource roads has led to the installation of hundreds of thousands of stream-crossing structures that are becoming increasingly common anthropogenic features on North American riverscapes. These structures can reduce available fish habitat, deteriorate instream habitat, and disrupt ecological connectivity by acting as barriers to fish and aquatic organism movement. My objectives were (i) to determine the extent to which commonly installed stream crossings affect stream fish communities in a boreal forest watershed, and (ii) to assess the application of operational research tools that utilize an optimization framework for mitigating the effects of fragmentation on native freshwater fish and informing restoration planning in the boreal forest. I used mixed-effects modeling and multivariate analyses to determine the effects of stream crossings from 33 culverted, bridged, and reference streams in an industrializing region of the boreal forest in west-central Alberta. Instream habitat characteristics such as mean depth, percent fines, and turbidity showed significant between- as well as within-stream differences among stream crossings. I found that the majority of fish species exhibited significantly lower densities (n·m -2) in upstream habitats as compared to downstream habitats, including a significant reduction in Slimy Sculpin densities in streams with culverts compared to reference streams. Multivariate tests showed that fish assemblages differ as a function of stream type and location. The prioritization method utilized in this study suggests that large gains in potential connectivity could be realized with a moderate investment (~$200K to $500K). I found that the operational research tool can be used to develop cost-benefit curves from the study watersheds, which can be used to minimize overall restoration costs to achieve particular management objectives in watersheds of interest, as well as provide defendable evidence for budget planning to regulators and decision-makers. Additionally, varying model parameters that account for species-specific differences in habitat use (e.g. dispersal distance) affected prioritization solutions, and should be considered in future prioritization analyses. In addition to effecting fish passage and stream connectivity, my results suggest that culverts may also be altering fish habitat, further contributing to large-scale changes in stream fish communities in the boreal forest. Further, my research highlights the efficacy of a novel, easy to use optimization-based barrier prioritization toolset that has minimal data requirements, is applicable to both stream-resident and long-range migratory species, and significantly reduces the mathematical and technical expertise needed to perform relatively complex optimization analyses.

Neufeld, K.*, Blair, S., and Poesch, M.S. (2015) Retention and stress effects of visible implant tags when marking Western Silvery Minnow Hybognathus argyritis and its application to other cyprinids (family Cyprinidae). North American Journal of Fisheries Management 35: 1070-1076.

Abstract:

Visible implant tags are commonly used in fisheries research to mark individuals or batches of fish as part of movement and mark–recapture studies. To be effective, these tags generally need to have high retention rates and little impact on the behavior or physiology of the marked individuals. We tested the retention rates of both visible implant elastomer (VIE) and visible implant alphanumeric (VIA) tags in 80–139-mm Western Silvery Minnow Hybognathus argyritis over a 104-d period. We also measured plasma cortisol and lactate to determine the impact of tagging on stress levels. We found that VIE tags had 100% retention and did not cause a significant increase in plasma cortisol levels, though plasma lactate levels were elevated in VIE treatment groups. Overall, VIE tags were found to be suitable for marking Western Silvery Minnow and similar species. Visible implant alphanumeric tags had 36% retention over 104 d and did not cause significant increases in plasma cortisol, though plasma lactate was elevated in the treatment group with both VIE and VIA tags. Given the high retention rates and low stress effects, VIE tags appear to be more beneficial for use with Western Silvery Minnow and similar-sized cyprinids.

Citation: Neufeld, K.*, Blair, S., and Poesch, M.S. 2015. Retention and stress effects of visible implant tags when marking Western Silvery Minnow Hybognathus argyritis and its application to other cyprinids (family Cyprinidae). North American Journal of Fisheries Management 35: 1070-1076.

Average Western Silvery Minnow (a) plasma cortisol and (b) plasma lactate concentrations for the various tagging treatments (VIE – Visual Implant Elastomer, VIA – Visual Implant Alpha, VIE+VIE – both) for days 1, 54 and 103/104. Error bars represent SD.

Also Read:

Fischer, S.M.*, Ramaza, P., Simmons, S., Poesch, M.S. and M.A. Lewis. (2023) Boosting propagule transport models with individual-specific data from mobile apps. Journal of Applied Ecology 60(5): 934-949.

*Lab members: Kenton Neufeld, Mark Poesch. Check out opportunities in the lab!