McPherson, M.*, Lewis, J.B., Cott, P.B., Baker, L.F., Mochnacz, N.J. Swanson, H.K., and S. Poesch. (2023) Habitat use by fluvial Arctic Grayling (Thymallus arcticus) across life stages in northern mountain streams. Environmental Biology of Fishes.

Citation: McPherson, M.*, Lewis, J.B., Cott, P.B., Baker, L.F., Mochnacz, N.J. Swanson, H.K., and S. Poesch. (2023) Habitat use by fluvial Arctic Grayling (Thymallus arcticus) across life stages in northern mountain streams. Environmental Biology of Fishes.

Abstract

Northern aquatic ecosystems face increasing pressures from climate change and natural resource development.  The Arctic Grayling (Thymallus arcticus) is a widely distributed, northern freshwater fish which can be vulnerable to such pressures. There remains a paucity of information on life stage requirements through most of the species’ range to reliably map and manage habitat to protect populations into the future. We sought to characterize fluvial Arctic Grayling distribution among mountain streams and determine habitat characteristics that habitat use across life stages. Sampling was conducted at 183 sites across the Little Nahanni River watershed to collect information on fish distribution and reach-scale habitat parameters. Arctic Grayling were collected for biological analyses of age, size, weight, and reproductive development. Based on age and size-classes there were four distinct post-emergence life stages: YOY, juvenile, sub-adult and adult. YOY Arctic Grayling were found exclusively in low elevation (<1000 m) streams, flat-water habitat dominated by silty-sand substrate with average water temperatures >10oC. Similarly, juvenile Arctic Grayling occupied low elevation, warm water stream habitat, but associated strongly with run habitats. Sub-adult Arctic Grayling, the most widely distributed life-stage, were found associated with riffle, pool, and cascade-boulder habitats. Adults occupied high elevation (>1200 m) habitats that were cold (mean stream temperature = 7oC), and had higher proportions of pool and boulder habitat. The dynamic nature of Arctic Grayling habitat use in mountain streams highlights the need to consider habitat complexes at the watershed scale when defining species life stage requirements, managing habitats, monitoring populations, and assessing potential impacts.

Keywords: Climate Change; Water Stress; Biodiversity; Preservation.

*Lab members: Morag McPherson and Mark Poesch. Check out opportunities in the lab!

Theis, S.*, Ruppert, J. L. W. and M. S. Poesch. (2023) Coarse woody habitat use by local fish species and structural integrity of enhancements over time in a shallow northern boreal lake assessed in a Bayesian modeling approach. Ecological Solutions and Evidence.

Citation: Theis, S., Ruppert, J. L. W. and M. S. Poesch. (2023) Coarse woody habitat use by local fish species and structural integrity of enhancements over time in a shallow northern boreal lake assessed in a Bayesian modeling approach. Ecological Solutions and Evidence.

Abstract

  1. The introduction of coarse woody habitat has been a widely adopted management practice for restoring and enhancing freshwater aquatic ecosystems. Although responses of aquatic fish and invertebrate communities have largely been documented for lotic systems, benefits for lentic ecosystems have been mostly unevaluated.
  2. We tested the responses of fish populations to coarse woody habitat structures through a Bayesian modeling approach in a northern boreal lake in Alberta, Canada by enhancing a stretch of littoral zone with low structural complexity through introduction of coarse wood bundles and whole tree structures. The study site was split into three treatments, a Spaced treatment (structures 30 m apart), a Clustered treatment (structures 15 m apart), and an unaltered area (Control).
  3. Catch per unit effort and Catch per unit area data were collected over 2 years and posterior model predictions showed an increase in habitat use of the enhanced areas by spottail shiner – Notropis hudsonius; northern pike – Esox lucius; white sucker – Catostomus commersonii; brook stickleback – Culaea inconstans. No probable effect on overall fish condition, measured in Relative Weight, was linked to the enhancements.
  4. Across the two-year study, wood bundles degraded faster compared to the whole tree drops, coinciding with leveling off catch per unit effort and catch per unit area predictions near wood bundles, although catch predictions increased near the whole tree structures. Structural degradation set in as early as 1 week post construction for wood bundles and was mostly related to anchoring aspects.
  5. Results from our study provide evidence for the benefits provided by coarse woody habitat within northern boreal lake systems.  They furthermore highlight the short-lived nature of wood bundles built with biodegradable substances.  Methodologically our results offer evidence on the feasibility and utility of predictive modeling frameworks in addressing pseudoreplication and providing informative value for ecological studies.

Keywords: Fish Abundance, Northern Boreal Ecoregion, Habitat Enhancement, Restoration, Lake Ecosystems, Bayesian

*Lab members: Sebastian Theis, Jonathan Ruppert and Mark Poesch. Check out opportunities in the lab!

Theis, S.*  Castellanos D.A., Hamann A. and M.S. Poesch. (2023) Small-bodied fish species from western United States will be under severe water stress by 2040. Conservation Science and Practice: e12856.

Citation: Theis S., Castellanos-Acuna D., Hamman A. and M. S. Poesch. (2023) Small-bodied fish species from western United States will be under severe water stress by 2040. Conservation Science and Practice: e12856.

Abstract

Human need to appropriate freshwater in combination with climate change has intensified the rapid decline in freshwater biodiversity. Based onUsing census data, threat assessments, life history traits, as well as projections for anticipated water stress, we carried out a risk assessment for 216 currently imperiled freshwater species in the United States. , the The results suggest that Southwestern, and the Rocky Mountains, regions willwere predicted to experience the highest increase in future water stress for 2040 in 41 minor watersheds. Resident-small species in the Southwest, found in single locations (21.6%) or on local level highly localized (62.2%), were listed as endangered (n = 37) and are predicted to experience severe water stress increases by Endangered species in the Rocky Mountains (n = 9), were found on a single basins or local level had localized distributions (33.3%), and had exhibiting predominantly potamodromous  behaviour (66.7%). Furthermore, many endangered species in key regions lack life-history data (41%). Our results highlight predict patterns of imperilment associated with life history traits and distributions, but that were unrelated to overall fish biodiversity or biodiversity hotspots. that assessing species using The research therefore highlights that biodiversity as an indicators may not be useful to prioritize conservation efforts for identifying future impacts to imperiled species, since many regions undergoing high water stress did not coincide with biodiversity hotspots.

Keywords: Climate Change; Water Stress; Biodiversity; Preservation.

*Lab members: Sebastian Theis and Mark Poesch. Check out opportunities in the lab!

Fischer, S.M.*, Ramaza, P., Simmons, S., Poesch, M.S. and M.A. Lewis. (2022) Boosting propagule transport models with individual-specific data from mobile apps. Journal of Applied Ecology.

Citation: Fischer, S.M., Ramaza, P., Simmons, S., Poesch, M.S. and M.A. Lewis. (2022) Boosting propagule transport models with individual-specific data from mobile apps. Journal of Applied Ecology

Abstract

Management of invasive species and pathogens requires information about the traffic of potential vectors. Such information is often taken from vector traffic models fitted to survey data. Here, user-specific data collected via mobile apps offer new opportunities to obtain more accurate estimates and to analyze how vectors’ individual preferences affect propagule flows. However, data voluntarily reported via apps may lack some trip records, adding a significant layer of uncertainty. We show how the benefits of app-based data can be exploited despite this drawback.
Based on data collected via an angler app, we built a stochastic model for angler traffic in the Canadian province Alberta. There, anglers facilitate the spread of whirling disease, a parasite-induced fish disease. The model is temporally and spatially explicit and accounts for individual preferences and repeating behaviour of anglers, helping to address the problem of missing trip records. We obtained estimates of angler traffic between all subbasins in Alberta. The model’s accuracy exceeds that of direct empirical estimates even when fewer data were used to fit the model. The results indicate that anglers’ local preferences and their tendency to revisit previous destinations reduce the number of long inter-waterbody trips potentially dispersing whirling disease. According to our model, anglers revisit their previous destination in 64% of their trips, making these trips irrelevant for the spread of whirling disease. Furthermore, 54% of fishing trips end in individual-specific spatially contained areas with mean radius of 54.7km. Finally, although the fraction of trips that anglers report was unknown, we were able to estimate the total yearly number of fishing trips in Alberta, matching an independent empirical estimate.

*Lab members: Samuel Fischer. Check out opportunities in the lab!

Van Mierlo V. A.*, Green S. J., Emmerton C. A., Nasr M., Buendia C., Wyatt F. and M. S. Poesch. (2022). Occupancy of invasive Northern Crayfish (Faxonius virilis) in northern systems is driven primarily by tributary water temperature. Freshwater Science 41(4).

Citation: Van Mierlo V.A., Green S.J., Emmerton C.A., Nasr M., Buendia C., Wyatt F. and M.S. Poesch. (2022). Occupancy of invasive Northern Crayfish (Faxonius virilis) in northern systems is driven primarily by tributary water temperature. Freshwater Science 41(4).

Invasive species are the 2nd-greatest threat to global freshwater biodiversity. Crayfish are especially robust invaders due to their omnivorous nature and ability to compete both directly (resource procurement) and indirectly (habitat occupation and modification) with native species. The Northern Crayfish (Faxonius virilis Hagen, 1870) was introduced to the North Saskatchewan River basin (Alberta, western Canada) and has persisted there since the early 1990s. Faxonius virilis’ impacts on native fish assemblages in the North Saskatchewan River have yet to be assessed, even though the watershed is ecologically, economically, and culturally valuable and home to multiple sensitive and at-risk fish species. We aimed to identify the instream environmental characteristics associated with F. virilis occupancy in the North Saskatchewan River basin and to determine which currently unoccupied tributaries are most vulnerable to F. virilis invasion. We used occupancy modeling to meet these objectives. We deployed 24-h baited crayfish traps and measured water temperature, turbidity, flow velocity, and physical complexity at 37 sites along the Alberta portion of the North Saskatchewan River basin. We detected F. virilis at 13/37 sites with no occurrences detected in the upper basin. Occupancy model selection and averaging revealed that water temperature alone was associated with occupancy of F. virilis in the North Saskatchewan River basin. Streams with mean summer water temperatures >∼19.7 C  were ≥50% more likely to be occupied by F. virilis than cooler streams and are at highest risk of invasion. Further, we found that streams with mean summer water temperatures <∼15.7 C had a <25% chance of becoming occupied by F. virilis than warmer streams. Coldwater streams may thus have some natural protection against F. virilis invasion. The results from this study provide practical guidelines for watershed management of invasive F. virilis populations in western Canadian river basins. Managing F. virilis is particularly important and time sensitive because F. virilis’ range will likely expand when water temperatures in the basin rise because of climate change

*Lab members: Victoria Van Mierlo. Check out opportunities in the lab!

Pentyliuk, N., Schmidt, B., Poesch, M.S. and S. Green. (2022) Recreational angler reporting as a tool for tracking the distribution of invasive Prussian Carp (Carassius gibelio). Conservation Science and Practice.

Citation: Pentyliuk, N., Schmidt, B., Poesch, M.S. and S. Green. (2022) Recreational angler reporting as a tool for tracking the distribution of invasive Prussian Carp (Carassius gibelio). Conservation Science and Practice.

Abstract

The recent invasion of Carassius gibelio (commonly known as Prussian carp or Gibel carp) in freshwater environments in central Canada threatens native North American aquatic species and ecosystems. Accurate distribution information is essential for targeting control efforts but is challenging given the resources necessary to continually sample the species’ potential distribution. We investigated the extent to which reports by recreational anglers—key resource users— could be used in a citizen science program to generate species distribution information, and factors affecting the accuracy of reporting for C. gibelio. Comparing the location of angler reports to the known distribution of C. gibelio generated by professional biological sampling across the region revealed that anglers can be a powerful resource for tracking an invasive species’ distribution; 88% of the C. gibelio angler reports aligned with invaded watersheds (HUC-8 [hydrological unit code 8], the second finest watershed unit) identified by professional biological sampling. For every report of C. gibelio received in a HUC- 8 area, the probability that area was invaded increased by more than 10 times (odds ratio= 10.26, ±95% CI: 4.4-29.7). Anglers’ fish identification abilities were also positively related to likelihood of reporting Carassius spp. (odds ratio= 2.52, ±95% CI:1.51-4.45). Anglers that fished more frequently were also more likely to have reported C. gibelio in an area accurately (odds ratio= 1.00, ±95% CI: 0.99-1.01), although the mechanism behind this relationship is unclear. Our results suggest programs that engage recreational anglers in reporting could provide a cost-effective alternative or complimentary tool for traditional Aquatic Invasive Species (AIS) population tracking.

Check out opportunities in the lab!

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.

Citation: 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: 10970.

Abstract

Habitat banking, a conservation approach to offset habitat loss, has been widely accepted and implemented in the United States, especially for the protection of freshwater ecosystems. The potential adequacy of the habitat banking approach has, however, not yet been formally quantified in the context of its underlying framework and policies. Using a gap analysis approach, we test the current adequacy and future potential of habitat banking for 2313 approved and 552 pending banks in the United States. In the analysis, we consider water stress due to projected climate change, freshwater diversity, imperiled species, and human population growth, among other factors. The results show that the highest conservation urgency was assigned to states in the Southwest with high levels of species imperilment and large increases in anticipated water stress. The banking network covers most of the freshwater biodiversity hotspots in the East and Southeast. Land ownership is a potential driver for the low bank density in western states, with large proportions of land being owned and managed through federal agencies and only 58 banks situated on federal land. While the banking network in the United States is one of the most developed on a global level, gaps and priority areas can be clearly identified to strengthen the current network and its role in preserving freshwater habitat and diversity.

Keywords: Offsetting; Conservation policy; Biodiversity market; Preservation.

*Lab members: Sebastian Theis and Mark Poesch. Check out opportunities in the lab!

Theis, S.*  Koops, M. and M.S. Poesch. (2022) A meta-analysis on the effectiveness of offsetting strategies for harm to freshwater fishes. Environmental Management 70(5): 793-807.

Citation: Theis, S.  Koops, M. and M.S. Poesch. (2022) A meta-analysis on the effectiveness of offsetting strategies for harm to freshwater fishes. Environmental Management 70(5): 793-807.

Abstract

Offsetting aims to compensate for negative impacts due to authorized anthropogenic impacts. While anchored into legislation through extensive frameworks across many countries, residual or chronic impacts can occur after offset establishment for example because of the ephemeral timescale of some projects. Advice and best practice on how to approach these impacts is rare. To address this, we reviewed 30 projects based on a systematic review and meta-analysis in freshwater ecosystems dealing with residual or long-term negative impacts to provide application advice for the three main identified approaches of: habitat creation, habitat restoration and biological and chemical manipulation. Project information was obtained from scientific databases and grey literature through Boolean search terms and web-scraping. Habitat creation projects, mainly targeting salmonids, had a pooled effect size of 0.8 and offsetting ratios of 1:5 with high biomass increases of over 1.4x compared to pre-establishment, associated with them. Habitat restoration projects targeted a wide range of species and communities with a pooled effect size of 0.66, offset ratios ranging from 1:1.2 to 1:4.6, and biomass increases generally > 1x compared to pre-restoration. Biological manipulation had the lowest effect size (0.51) with stocking efforts being highly variable both in terms of biomass benefits and project outcomes pointing towards stocking being mostly applicable in cases of direct fish harm not related to environmental degradation or habitat loss. Many projects targeted salmonid species and application for a wider range of species needs to be further assessed. We conclude that 1) all three assessed approaches have a potential application use for offsetting Residual or Chronic Harm with approach specific caveats. 2) time to record first benefits required one to two years with time lags needing to be accounted for in the implementation and monitoring process, 3) monitoring timeframes of more than four years and conducting pre-assessments increased projects success significantly.

Keywords: Offsetting; Conservation policy; Biodiversity market; Preservation.

*Lab members: Sebastian Theis and Mark Poesch. Check out opportunities in the lab!

Theis S.*, and M.S. Poesch (2022) Assessing conservation and mitigation banking practices and associated gains and losses in the United States. Sustainability 14: 6652..

Citation: Theis, S.  and M.S. Poesch. (2022) Assessing conservation and mitigation banking practices and associated gains and losses in the United States. Sustainability 14: 6652.

Abstract

Conservation and mitigation banks allow proponents to buy credits to offset negative residual impacts of development projects with the goal of No net loss (NNL) in ecosystem function and habitat area. However, little is known about the extend to which bank transactions achieve NNL. We synthesized and reviewed 12756 transactions in the United States as to meeting area and ecological equivalence (n = 4331) between approved negative impact and offset. While most transactions provided an offset equal or greater in area than the impacted area, approximately one quarter of transactions, especially targeting wetlands, did not meet ecological equivalence between impact and offset. Missing ecological equivalence was often due to the significantly increasing use of preservation, enhancement, and rehabilitation over creating new ecosystems through establishment and re-establishment. Stream transactions seldom added new ecosystem area through creation but mainly used rehabilitation to add offset benefits, in many cases leading to net loss of area. Our results suggest that best practice guidance on habitat creation as well as incentivization of habitat creation must increase in the future to avoid net loss trough bank transactions and meet the ever-accelerating global changes in land-use and the increase pressure of climate change.

Keywords: Offsetting; Conservation policy; Biodiversity market; Preservation.

*Lab members: Sebastian Theis and Mark Poesch. Check out opportunities in the lab!

Dutra, M.C.F., Pereyra, P.E.R., Hallwass, G., Poesch, M.S. and R.A.M. Silvano. (2023). Fishers’ knowledge on trophic ecology and of the tropical ‘super fish’ Plagioscion squamosissimus in two Brazilian Amazonian rivers. Neotropical Ichthyology.

Citation: Dutra, M.C.F., Pereyra, P.E.R., Hallwass, G., Poesch, M.S. and R.A.M. Silvano. (2023). Fishers’ knowledge on trophic ecology and of the tropical ‘super fish’ Plagioscion squamosissimus in two Brazilian Amazonian rivers. Neotropical Ichthyology.

Abstract

Fishers’ local ecological knowledge (LEK) can provide new data on fish trophic ecology. The pescada (Plagioscion squamosissimus) is among the most caught fishes in small-scale fisheries in the Brazilian Amazon. Our main goal was to evaluate the abundance, size, relevance to small-scale fisheries and trophic ecology (diet and feeding interactions) of P. squamosissimus in the Tapajós and Tocantins rivers, in the Brazilian Amazon, utilizing  data from fishers’ LEK and fish sampling. We hypothesized a higher abundance, size and more prey and predators cited by fishers of P. squamosissimus in the more pristine Tapajós River. We interviewed 61 and 33 fishers and sampled fish in nine and five sites in the Tapajós and Tocantins Rivers, respectively, in 2018. The comparison between fishers’ citations and fish sampled indicated a higher relevance of P. squamosissimus to fishers in the Tapajós River, where this fish had an average larger size and where the interviewed fishers mentioned more food items of P. squamosissimus. These results show that P. squamosissimus is a generalist fish, that is resilient to fishing and environmental pressures, as well as being important to fisheries and food security, and that LEK can provide useful insights to fisheries managers.

Keywords: Offsetting; Conservation policy; Biodiversity market; Preservation.

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