Edgar, M. (2022) The introduction of Cipangopaludina chinensis and tropic effects of sympatric freshwater fish invaders in southern Alberta reservoirs.

Thesis Title: The introduction of Cipangopaludina chinensis and tropic effects of sympatric freshwater fish invaders in southern Alberta reservoirs.

Author: Megan Edgar

Abstract

At present, one of the most pervasive risks to freshwater ecosystems are invasive species. Invasive species are among the leading antagonists to global biodiversity, since they can out-compete or predate on native species which leads to changes of the structure of food webs and alteration of ecosystem function. As biogeographic boundaries are broken down by human-related means of spread, more are we seeing novel occurrences between non-native species and the ecosystems they are introduced to. As invasive species continue to radiate from their original regions, it is critical to understand how these species will impact their new ecosystems. As of 2019, non-native Chinese Mystery Snail (Cipangopaludina chinensis (Gray, 1834)) has persisted in McGregor Lake Reservoir, Alberta, Canada. Additionally, Northern Crayfish (Faxonius virilis) a non-native species which has expanded their range into lakes and rivers in Alberta, exists in sympatry with Chinese Mystery Snail in McGregor Lake Reservoir.

I aimed to advise management programs related to both Chinese Mystery Snail and Northern Crayfish in Alberta lakes and reservoir systems, and provide important information regarding the trophic interactions and outcomes to native recreational fish species (Northern Pike (Esox lucius), Walleye (Sander vitreus), and Lake Whitefish (Coregonus clupeaformis)).

In this thesis, I provide a comprehensive literature review regarding Chinese Mystery Snail in Canada, along with pertinent information regarding their impacts, life history characteristics, morphological characteristics, and range within invaded and native ranges. The initial finding of Chinese Mystery Snail is officially documented in Alberta, along with biological information that may aid management efforts. DNA barcoding is used to confirm the species identification and the barcode is added to GenBank. We analyze growth rate and fecundity, and assessed the presence of digenean trematode cercariae in snails in McGregor Lake Reservoir. After a 24-hour experimental period, we confirmed that Chinese Mystery Snail specimens are not infected by digenean trematodes. We also determine that shell growth quickly outpaces shell width, and that upon emergence Chinese Mystery Snail is larger than many of the native snail species in Albertan waterbodies. We also determine that Chinese Mystery Snail in Alberta produce a lower average number of juveniles compared to populations elsewhere. We also suggest that Chinese Mystery Snail meet four of the five stages of species invasion: arrival, establishment, growth, and reproduction, however there is no evidence of dispersal to adjacent waterbodies.

With the use of stable isotope analysis and gut content analysis, I address the trophic consequences that may arise with the addition of Northern Crayfish and Chinese Mystery Snail into aquatic ecosystems in southern Alberta, as well as their impacts to Northern Pike, Walleye and Lake Whitefish. I sampled five reservoirs in Alberta (St. Mary’s Reservoir, Forty-Mile Reservoir, Sherburne Lake Reservoir, Travers Lake Reservoir, and McGregor Lake Reservoir), collecting macrophytes, benthic macroinvertebrates, small-bodied fish species, as well as invasives and large recreational fish species. I hypothesized that the presence of only one aquatic invader would create bottom-up effects on the food-web, and that an additional invasive species would amplify these effects, creating shifts in fish trophic positions by moving basal energy away from higher trophic levels through the consumption of algae and macrophytes, or by providing a new prey resource. I also hypothesized that Chinese Mystery Snail and Northern Crayfish would have overlapping niches, through competition for resources or predation. Briefly, I determined that fish are becoming more piscivorous compared to reference lakes where there are no invasive species present, community trophic positions are higher in reservoirs where only Northern Crayfish are present as an invasive, and that carbon ranges are narrower in systems with only Northern Crayfish and wider when both invasives are in sympatry. A few reasons that these effects may be occurring to fish include an “adaptive lag” period, or lack of macrophytes in invaded waterbodies due to the invasives present. I also discovered that trophic niche ellipses of Chinese Mystery Snail and Northern Crayfish are overlapping, pointing to competitive exclusion.

The results from this thesis address my overall goals to investigate the introduction of Chinese Mystery Snail and the potential impacts of interactions between Chinese Mystery Snail and Northern Crayfish on native recreational fish species in reservoirs in southern Alberta. The findings gained throughout this thesis are useful for the management of both invasive species and will hopefully provide a catalyst for other researchers and resource managers.

 

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 4(2): e12200.

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.

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 4(2): e12200.

Also Read:

Theis, S.*, Ruppert, J.*, Shirton, J.* and M.S. Poesch (2022) Measuring beta diversity components and beneficial effects of coarse woody habitat introduction on invertebrate and macrophyte communities in a shallow northern boreal lake: implications for offsetting. Aquatic Ecology 56: 793-814.

*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.

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.

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.

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: Sebastian Theis and Mark Poesch. 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.

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.

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.

Also Read:

Theis, S.* and M. S. Poesch. (In Press).  Mitigation bank applications for freshwater systems: Control mechanisms, project complexity, and caveats PLOS One.

 

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

Three new articles on habitat banking and offsetting accepted! Check them out!

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

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.

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

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.

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.

Also Read:

Theis S.*, and M.S. Poesch (2022) Current capacity, bottlenecks, and future projections for offsetting habitat loss using mitigation and conservation banking in the United States. Journal for Nature Conservation 67:126159.

*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.

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.

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.

Also Read:

Ruppert, J.L.W.*, Hogg, J., and M.S. Poesch. (2018) Community assembly and the sustainability of habitat offsetting targets in the first compensation lake in the oil sands region in Alberta, Canada. Biological Conservation 219: 138-146.

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