Thayer, D.*, Ruppert, J.L.W., Watkinson, D., Clayton, T. and M.S. Poesch. (2017) Identifying temporal bottlenecks for the conservation of large-bodied fishes: Lake Sturgeon (Acipenser fluvescens) show highly restricted movement and habitat-use overwinter. Global Ecology and Conservation 10: 194-205.

Abstract:

The relationship between species’ size and home range size has been well studied. In practice, home range may provide a good surrogate of broad spatial coverage needed for species conservation, however, many species can show restricted movement during critical life stages, such as breeding and over-wintering. This suggests the existence of either a behavioral or habitat mediated ‘temporal bottleneck,’ where restricted or sedentary movement can make populations more susceptible to harm during specific life stages. Here, we study over-winter movement and habitat use of Lake Sturgeon (Acipenser fulvescens), the largest freshwater fish in North America. We monitored over-winter movement of 86 fish using a hydro-acoustic receiver array in the South Saskatchewan River, Canada. Overall, 20 fish remained within our study system throughout the winter. Lake Sturgeon showed strong aggregation and sedentary movement over-winter, demonstrating a temporal bottleneck. Movement was highly restricted during ice-on periods (ranging from 0.9 km/day in November and April to 0.2 km/day in mid-November to mid-March), with Lake Sturgeon seeking deeper, slower pools. We also show that Lake Sturgeon have strong aggregation behavior, where distance to conspecifics decreased (from 575 to 313 m) in preparation for and during ice-on periods. Although the Lake Sturgeon we studied had access to 1100 kilometers of unfragmented riverine habitat, we show that during the over-winter period Lake Sturgeon utilized a single, deep pool (<0.1% of available habitat). The temporal discrepancy between mobile and sedentary behaviors in Lake Sturgeon suggest adaptive management is needed with more localized focus during periods of temporal bottlenecks, even for large-bodied species.

Citation: Thayer, D.*, Ruppert, J.L.W., Watkinson, D., Clayton, T. and M.S. Poesch. (2017) Identifying temporal bottlenecks for the conservation of large-bodied fishes: Lake Sturgeon (Acipenser fluvescens) show highly restricted movement and habitat-use overwinter. Global Ecology and Conservation 10: 194-205.

Monthly core (C) and range (R) extent kernel density maps for: A) November, B) December, C) January, D) February, E) March, and F) April. Black lines are core range (50% percentile), broken lines range (90th percentile) extent.

Also Read:

Miller, M., Stevens, C. and M. S. Poesch. (In Press). Effectiveness of Spawning Substrate Enhancement for Adfluvial Fish in a Regulated Sub-Arctic River. River Research and Applications.

*Lab members: Donnette Thayer, Jonathan Ruppert, 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.

Poesch, M.S. and D.A. Jackson (2012) Impact of species-specific dispersal and regional stochasticity on estimates of population viability in stream metapopulations. Landscape Ecology 27: 405-416.

Abstract:

Species dispersal is a central component of metapopulation models. Spatially realistic metapopulation models, such as stochastic patch-occupancy models (SPOMs), quantify species dispersal using estimates of colonization potential based on inter-patch distance (distance decay model). In this study we compare the parameterization of SPOMs with dispersal and patch dynamics quantified directly from empirical data. For this purpose we monitored two metapopulations of an endangered minnow, redside dace (Clinostomus elongatus), using mark-recapture techniques across 43 patches, re-sampled across a 1 year period. More than 2,000 fish were marked with visible implant elastomer tags coded for patch location and dispersal and patch dynamics were monitored. We found that species-specific dispersal and distance decay models provided qualitatively similar rankings of viable patches; however, there were differences of several orders of magnitude in the estimated intrinsic mean times to extinction, from 24 and 148 years to 362 and >100,000 years, depending on the population. We also found that the rate of regional stochasicity had a dramatic impact for the estimate of species viability, and in one case altered the trajectory of our metapopulation from viable to non-viable. The divergent estimates in time to extinction times were likely due to a combination species-specific behavior, the dendritic nature of stream metapopulations, and the rate of regional stochasticity. We demonstrate the importance of developing comparative analyses using species- and patch-specific data when determining quantitative estimates for mean time to extinction, which in the case of redside dace, were highly sensitive to different estimates of dispersal.

Citation: Poesch, M.S. & Jackson, D.A. 2012. Impact of species-specific dispersal and regional stochasticity on estimates of population viability in stream metapopulations. Landscape Ecology 27: 405-416.

Also Read:

Neufeld, K.*, Watkinson, D., Tierney, K. and M.S. Poesch. (2018) Incorporating connectivity in measures of habitat suitability to assess impacts of hydrologic alteration to stream fish. Diversity and Distributions 24: 593-604.

Schwalb, A.J., Cottenie, K., Poesch, M.S., and J. Ackerman (2011) Dispersal limitation in unionid mussels and implications for their recovery. Freshwater Biology 56: 1509-1518.

Abstract:

Freshwater unionid mussels are a highly imperilled group. Their dispersal abilities depend on the availability and the movement of host fish on which their parasitic mussel larvae develop. We examined the relationship between the dispersal abilities of unionid mussels and their conservation status on a regional (SW Ontario) scale and their distribution and abundance on a catchment scale (Sydenham River, SW Ontario) by determining host specificity and estimating the dispersal abilities of mussels on fish from a review of the literature. On the regional scale, we found that mussels with the most precarious conservation status relied on host fish with short movement distances, whereas vulnerable and more secure mussel species had host fish with 2–3 orders of magnitude larger movement distances. We were not able to detect a clear pattern on the catchment scale. Our results suggest that limited dispersal by host fish affects the abundance and distribution of unionid mussels and ultimately their conservation status on a regional scale. Information on dispersal limitations because of differences in host fish communities should be included in conservation and management decisions to ensure connectivity and maintain functioning mussel metacommunities.

Citation: Schwalb, A.J., Cottenie, K., Poesch, M.S., and Ackerman, J. 2011. Dispersal limitation in unionid mussels and implications for their recovery. Freshwater Biology 56: 1509-1518.

Also Read:

Maitland, B.M.*, Anderson, A. and Poesch, M.S. (2016) Prioritising culvert removals to restore habitat for at-risk salmonids in the Boreal forest. Fisheries Management and Ecology 23: 489-502.

Schwalb, A.J., Poesch, M.S., and J. Ackerman (2011) Movement of logperch—the obligate host ﬁsh for endangered snuffbox mussels: implications for mussel dispersal. Aquatic Sciences 73: 223-231.

Abstract:

Unionid mussels are highly imperiled and the survival of their local populations is linked to the availability and dispersal potential of their host fish. We examined the displacement distance of logperch (Percina caprodes), which are obligate host fish for endangered snuffbox mussels (Epioblasma triquetra), to determine the dispersal potential by fish. Logperch in the Sydenham River, Ontario, Canada, were electrofished and marked with visible implant elastomer on five sampling dates during the gravid period of E. triquetra. The majority of all recaptures (82%) of P. caprodes occurred within 30 m of their original capture location, with a mean displacement distance of 13 ± 3 m (mean ± standard error, n = 28). These results were consistent with a review of movement studies of small benthic host fish (i.e., darters and sculpins), which revealed average fish displacement distances of 37 ± 19 m (n = 14 species; range: 4–275 m). However, significantly greater movement distances were also found and the maximum displacement distance increased significantly with the spatial extent of the study and with the duration of the study. These results indicate that many P. caprodes remain in a small area, which could restrict the dispersal and (re)colonization potential of E. triquetra. Further studies are needed to determine the dispersal potential of mussels via host fish, which may be important for maintaining the connectivity among unionid populations.

Citation: Schwalb, A.J., Poesch, M.S., and Ackerman, J. 2011. Movement of logperch—the obligate host ﬁsh for endangered snuffbox mussels: implications for mussel dispersal. Aquatic Sciences 73: 223-231.

Also Read:

Veillard, M.F.*, Ruppert, J.L.W.*, Tierney, K., Watkinson, D., and M.S. Poesch. (2017) Comparative swimming and station-holding ability of the threatened Rocky Mountain Sculpin (Cottus sp.) from four hydrologically distinct rivers. Conservation Physiology 5: 1-12.