Category Archives: Restoration and Reclamation

Once species or their habitat have declined, restoration and reclamation is needed. One important component of restoration and reclamation is developing habitat offsets. Many countries have adopted habitat offsetting policies (e.g., Canada, United States, Europe, Australia, New Zealand, and United Kingdom), where the ideal goal is ecological equivalency, such that offsets are done in a manner which replaces habitats “like-for-like” in areas in close proximity to where those habitats were displaced. When ecological equivalency cannot be achieved with habitat offsets, such as when the extent, duration and intensity of the impacts are sufficiently broad in spatio-temporal scale (e.g. surface mining, Sun et al. 2017), offsetting currencies and flexibility may be needed. Research topics, includes: assessing the efficacy of fish stocking for restoration, developing methods to for offsetting fisheries productivity, advancing expertise and methodologies in hydroacoustics.

Van Mierlo, V. (2021) Occupancy and Impacts of the Northern Crayfish (Faxonius virilis) in Tributaries of the North Saskatchewan River Basin.

Thesis Title: Occupancy and Impacts of the Northern Crayfish (Faxonius virilis) in Tributaries of the North Saskatchewan River Basin

Author: Victoria van Mierlo

Abstract

Invasive species are the second greatest threat to biodiversity globally. 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. In the North Saskatchewan River (NSR) basin, the Northern Crayfish (Faxonius virilis) was introduced and has persisted since the early 1990s. Despite the North Saskatchewan River being an ecologically, economically, and culturally valuable watershed, the crayfish’s impacts on Alberta’s native fish communities have yet to be assessed.

We aimed to determine the in-stream environmental characteristics most associated with the crayfish’s occupancy in the North Saskatchewan River and determined which currently unoccupied tributaries are most prone to future invasion. We deployed 24-hour baited crayfish traps and collected environmental measurements (water temperature (°C), turbidity (NTU), flow velocity (ms-1), and physical complexity) at 37 tributary reaches along the Alberta portion of the North Saskatchewan River basin. Northern Crayfish were detected at 13 of 37 tributary reaches, with no occurrences detected west of Edmonton. Occupancy model selection and averaging revealed that water temperature alone drove occupancy of Northern Crayfish in tributaries of the North Saskatchewan River and that streams with mean summer water temperatures greater than 18.7 °C are 50% or more likely to be occupied by Northern Crayfish and thus, are at highest risk for subsequent invasion. Further, we found that streams with mean summer water temperatures below 15 °C were less than 25% likely to be or become occupied by Northern Crayfish. Cold water streams may have some natural protection against subsequent Northern Crayfish invasion.

We sampled ten North Saskatchewan River basin tributaries for F. virilis and six native common-generalist fish species and used stable isotope analysis to investigate if there is sharing of and/or exploitative competition for nutritional resources between F. virilis and native fish species. We also investigated if F. virilis sympatry was related to differences in fish isotopic characteristics and/or reduced condition of native fishes. Moderate overlap (13.8-40.2%) of F. virilis and native fishes’ fundamental isotopic niches indicated that F. virilis have the potential to consume the same resources as native fishes. However, overall segregation of realized isotopic niches indicated a lack of resource sharing between F. virilis and native fishes in NSR tributaries. Similarity between the Bayesian estimated realized standard ellipse areas (SEAB), carbon ranges, and body condition of F. virilis allopatric and sympatric native fish populations indicated that F. virilis sympatry did not have negative trophic effects on the native fish species in this study. Our results suggest that F. virilis may be utilizing dietary plasticity to exploit a slightly different trophic niche than native fishes and in doing so, avoid exploitative competition for nutritional resources. Dietary plasticity could facilitate the establishment and invasion of F. virilis populations in currently unoccupied tributaries of the North Saskatchewan River basin in the future.

The results from this thesis provide practical guidelines for watershed management of invasive Northern Crayfish populations in the North Saskatchewan River and Alberta. Our findings also highlight the importance for watershed managers to continue to prevent further spread of F. virilis in the North Saskatchewan River basin to prevent potential negative impacts on native fish while further research is conducted.

Hamilton, K. (2020) Streamflow is changing in rivers across Alberta: assessing regional variation in changing hydrologic indices.

Thesis Title: Streamflow is changing in rivers across Alberta: assessing regional variation in changing hydrologic indices.

Author: Kyle Hamilton

Abstract

The flow regime is a crucial factor in the well-being of aquatic and riparian ecosystems. Many components of those ecosystems, ranging for nutrient transport to morphology, are impacted by various hydrologic parameters. The parameters help define and quantify five important hydrologic regime characteristics: magnitude, duration, timing, frequency, and rate of change. Our study utilized the Indicators of Hydrologic Alteration (IHA) indices to (1) determine how various ecologically relevant components of streamflow are changing across Alberta’s various biomes; and (2) examine the similarities and differences between streamflow trends and climate trends. The overarching goal of these objectives is to create a foundation upon which water management practices can be created or modified.

Region-specific water management is required to balance the residential, commercial, and industrial water needs of a particular region with ecological concerns and conservation initiatives. Understanding the trends in hydrologic parameters is an important step in recognizing the vulnerabilities of each region. Streamflow at Water Survey of Canada stations was assessed for linear trends using a Mann-Kendall Trend Analysis. Our approach of assessing overall trends on a regional basis was validated when looking at trends in magnitude. The average daily flow rate for spring and summer months was found to be decreasing in the boreal region but increasing in the grassland region. Other hydrologic indices were found to exhibit significant trends on a province-wide level. Annual minimum and maximum flow conditions over a variety of durations were observed to be merging across the province. Similarly, the rate of change of streamflow between consecutive days is decreasing across Alberta.

To determine whether these results were the function of climate oscillation patterns, a composite analysis was performed to determine the effect of the El Niño–Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) on hydrologic indices. Only 8% of parameters were found to be significantly influenced by PDO patterns and 4% influenced by ENSO patterns.

McPherson, M. (2020) Habitat use by fluvial Arctic Grayling (Thymallus arcticus) across life stages in northern mountain streams.

Thesis Title: Habitat use by fluvial Arctic Grayling (Thymallus arcticus) across life stages in northern mountain streams.

Author: Morag McPherson 

Abstract

Northern aquatic ecosystems face increasing pressures from climate change and natural resource development, raising conservation concerns for species in these understudied regions.  The Arctic Grayling (Thymallus arcticus) is a widely distributed, but sensitive, northern freshwater fish that is a good indicator of general aquatic health. In the Northwest Territories (NWT), there has been little focus on studying riverine Arctic Grayling populations or their use of stream habitats within mountain river watersheds. The purpose of my research is to characterize fluvial Arctic Grayling distribution among mountain streams in the NWT, and to determine habitat characteristics and ecological factors that influence Arctic Grayling habitat use across life stages. Sampling sites (n=183) were selected in four sub-basins within the Little Nahanni River watershed in the southwest NWT. In the summer of 2015, each site (100 meters in length) was electrofished and stream habitat parameters were measured. Arctic Grayling were collected for biological analyses of age, size, weight, and reproductive development. Results showed shifts in Arctic Grayling development by size and age class that corresponded with shifts in distribution observed across the study streams. From these findings, four distinct post-emergence life stages for Arctic Grayling were identified: young-of-year (YOY), juvenile, sub-adult and adult. Step-wise logistic regression was used to explore the relationship between the occurrence of Arctic Grayling life stages and stream habitat characteristics. Multivariate regression tree (MRT) analysis was used to identify environmental thresholds and habitat-based life stage segregation, and redundancy analysis (RDA) was used to determine potential life stage-specific habitat correlations. Differences emerged in how Arctic Grayling life stages use habitat across a range of available stream conditions. YOY Arctic Grayling were found exclusively in low elevation, low gradient 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, as well as showing movement towards cooler water temperatures and more riffle dominated habitats. Sub-adult Arctic Grayling used the widest range of habitats across the study area, being found at a range of elevations and water temperatures, demonstrating the ability of this life stage to use a diversity of available habitats. Sub-adults showed a relationship to in-stream riffle, pool, and cascade-boulder habitats. Adults had a strong correlation to elevation and water temperature, using habitats with high elevation (>1200 m) and low temperature (7oC), and increased proportions of pool and boulder habitat. The four sub-watersheds studied provided distinct stream habitats and Arctic Grayling life stages separated across the habitat types, advancing our understanding of the life cycle habitat requirements for fluvial populations in mountain systems. It provides insight on the important and potential limiting factors, such as availability of warm water habitats, to population success in cold regions. 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 into the future. Improved understanding of the distribution, habitat requirements and ecology of different life history types and life stages of Arctic Grayling is crucial for the effective management and monitoring of this species in northern environments

Donadt, C. (2019) Trace element concentrations in riverine fish: relationships with body size, food web dynamics and trace element concentrations in surface water.

Thesis Title: Trace element concentrations in riverine fish: relationships with body size, food web dynamics and trace element concentrations in surface water.

Author: Caitlyn R. Donadt

Abstract

Freshwater fish are an important resource and form an essential component of freshwater ecosystems. However, stressors such as water pollution are negatively impacting freshwater biodiversity. Trace elements can be environmental pollutants and have the potential to negatively impact the health of fish, humans and wildlife.  My research builds upon results from a previous study in the Red Deer River watershed, which found trace elements in surface water at concentrations which pose a risk to humans and wildlife.  I examine trace element concentrations in fish from the Red Deer River watershed to determine: 1) the concentrations of trace elements in fish tissue and potential risk of these concentrations to humans and wildlife, 2) whether patterns in fish trace element concentrations reflect those in the surface water and 3) if biological characteristics influence trace element concentrations in fish.

To reach these objectives, I examined trace element concentrations in fish muscle tissue from streams and the river mainstem within the Red Deer River watershed. I compared patterns of trace element concentrations in fish to those in the surface water, which vary across four tributary streams, or upstream to downstream in the river mainstem. In both lotic environments, I included physical characteristics (age, body size) as well as food web tracers (stable isotope signatures d15N and d13C) together with trace element analysis. My results show most trace elements were at low concentrations in fish muscle tissue or not detected. However, mercury in many fish exceeded concentration criteria for human consumers, piscivorous wildlife and fish health. Patterns in fish trace elements did not reflect spatial patterns in surface water trace element concentrations and were often species-specific. Correlations between trace element concentrations and fish biological factors varied depending on the fish species and element considered, but the strongest relationships were with mercury. Mercury was often associated with trophic position and body size, but this relationship was stronger in the mainstem community compared to stream fish. This research indicates that trace element accumulation in fish, particularly mercury, is not limited to areas of high environmental concentrations within this watershed.

CBC interviews Dr. Poesch about new article on offsetting in freshwater ecosystems (CBC News; CBC Radio)

A recent review article on compliance and ecosystem function (Theis et al. 2019) in freshwater offsets was highlighted on CBC News and CBC radio in Edmonton and Calgary

Press Play to hear the interview on Edmonton AM or click this link to get redirected to CBC Edmonton AM Radio’s webpage.

Press Play to hear the interview on Calgary’s EyeOpener or click this link to get redirected to CBC EyeOpener Radio’s webpage.

Nelson-Chorney, H. (2019) Paleolimnological reconstruction of  Westslope Cutthroat Trout (Oncorhynchus clarki lewisi)  in alpine lakes using a next-generation sequencing platform.

Thesis Title: Paleolimnological Reconstruction of  Westslope Cutthroat Trout (Oncorhynchus clarki lewisi)  in Alpine Lakes using a Next-Generation Sequencing Platform (link; co-supervisors: R. Vinebrooke, M. Taylor)

Author: Hedin Nelson-Chorney

Abstract

Understanding historical species distributions is vital to the conservation and restoration of native species, yet such information is often qualitative.  Here, we show that the paleolimnological history of threatened freshwater fishes can be reconstructed using species diagnostic markers amplified from environmental DNA deposited in lake sediments (lake sediment DNA).  This method was validated through the detection of lake sediment DNA from non-native trout (Yellowstone cutthroat trout; Oncorhynchus clarkii bouvieri), which corroborated historical records of human-mediated introductions.  Moreover, we discovered native trout (westslope cutthroat trout; Oncorhynchus clarkii lewisi) lake sediment DNA that predated human-mediated introductions of freshwater fishes in a watershed with high topographical relief.  This unexpected result revealed that the population was of native origin and requires immediate conservation protection.  Our findings demonstrate that lake sediment DNA can be used to determine the colonization history of freshwater fishes and the structure of ecosystems, aiding in the identification of native ranges, novel native diversity, and introductions of non-native species.

Banting, A. L. K. (2018) Impacts of a novel predator on aquatic invertebrates in fishless lakes: Implications for conservation translocation

Thesis Title: Impacts of a novel predator on aquatic invertebrates in fishless lakes: Implications for conservation translocation

Author: Allison L.K. Banting

Abstract

Fishless mountain lakes hold important ecological and conservation value. As such,  managers are establishing conservation goals (e.g., non-native fish removal) to restore the  naturalness to many of these lakes. Simultaneously, managers who are recovering native (coldwater) fish populations threatened by climate change (e.g., Westslope Cutthroat Trout,  Oncorhynchus clarki lewisi and Bull Trout, Salvelinus confluentus) are exploring conservation  strategies involving the intentional translocation of native fish species to more suitable areas. These areas include unoccupied, or naturally fishless, stream and lake habitat within their native  range or favorable habitats outside their native range. This action presents a potential threat for  fishless mountain lakes as conservation managers view these as recovery habitat for imperiled native fish species. The purpose of my study was to inform native fish recovery efforts by  assessing the potential consequences of translocating native fishes to naturally fishless lakes, thus  outside their historic distribution. Forty alpine and sub-alpine lakes in Banff National Park, Alberta and Kootenay National Park, British Columbia were sampled and divided into three lake  types, including 13 naturally fishless lakes, 13 native fish-bearing or native fish-stocked lakes,  and 14 non-native fish-stocked lakes historically unoccupied by fish. Littoral invertebrate community composition, density and diversity were examined among lake types to 1) quantify  the impacts of introducing non-native fishes into historically fishless lakes, and 2) quantify the  differences between native fish lakes and naturally fishless lakes. These comparisons provided context for the scale of impact between two predators of different geographic origins (native vs. non-native) introduced to fishless lakes. The variation in environmental gradients amoung lake types was controlled for, suggesting fish presence strongly influenced changes to invertebrate community density and composition. Native and non-native fishes have the capacity to similarly alter littoral invertebrate community composition of fishless lakes, yet non-native fishes appear to have the greatest impact on littoral invertebrate density. Although impacts vary between native and non-native predators, the introduction of any novel fish predator to a fishless lake will result in a negative impact to key littoral macroinvertebrates, such as Gammaridae, Ephemoptera and Plecoptera, and a positive impact to burrowing taxa, such as Oligochaeta, Nemata and Chironomidae. While the introduction of non-native fishes has been repeatedly shown to affect invertebrate communities, the translocation of native fishes similarly has the potential to alter the ecology of a naturally fishless lake. With considerations for possible aquatic-terrestrial cross boundary effects, this study suggests that conservation ecologists consider the entire ecosystem when building resilience for climate change.

Docherty, C. (2017) Establishment, spread and impact of Prussian Carp (Carassius gibelio), a new invasive species in Western North America.

Thesis Title: Establishment, spread and impact of Prussian Carp (Carassius gibelio), a new invasive species in Western North America.

Author: Cassandra Docherty

Abstract

Freshwater ecosystems are some of the most imperilled on the planet. Invasive species pose the second largest threat to freshwater organisms after habitat degradation. Aquatic introductions have led to extinctions, competition for resources, hybridization, the introduction of foreign pathogens and the alteration of ecosystem structure and function. One of the most recent invaders in western North America is Prussian Carp (Carassius gibelio). The first record of this species in North America was in 2000, in Alberta, Canada, yet little is known about its invasion, current distribution or effects on stream communities. In Eurasia, Prussian Carp have been assessed as one of the most harmful invasive fish species because of its ability to reproduce asexually, high environmental tolerances and preference for human modified habitats. The arrival of Prussian Carp in western North America poses concerns for many native freshwater species. Therefore, the objectives of this study were to assess the severity of Prussian Carp’s invasion in western North America by 1) mapping Prussian Carp distribution and rate of spread since its initial arrival; 2) analysing the impact of Prussian Carp on native fish species; and 3) identifying environmental parameters that predict Prussian Carp presence. Using kernel density functions, we found that the range of Prussian Carp increased in Alberta, Canada from approximately 500 km² since its arrival (estimated as 2000) to over 20,000 km² in 2014. The rate of spread is increasing at an exponential rate over five year increments (e.g. 1.6, 2.1, and 2.3 times), suggesting rapid expansion since first detection. Our results did not indicate that Prussian Carp have a negative effect on native fish species, which is likely due to its recent expansion into these areas and an already depauperate species community. The most important habitat variables that best predicted the presence of Prussian Carp were: dense aquatic vegetation, high conductivity, pH, high dissolved oxygen and low flow rates indicating preference for relatively slow, eutrophic streams. Successful management of this species in western North America will require the integration of all levels of government between neighbouring provincial and national borders, as well as the public. Prussian Carp are a highly mobile species and given the connection to other watersheds in Canada and proximity to the Missouri/Mississippi drainages in the United States, agencies throughout North America should be aware of this invasive species and the potential impacts on native biota

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!

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.

Abstract:

Stream crossing structures are an increasingly prevalent anthropogenic feature on North American riverscapes, particularly in watersheds affected by industrial resource development in sensitive boreal environments. If improperly managed, stream crossings have the potential to alter fish habitat and impede fish movement. This study assessed instream habitat characteristics and fish communities from 33 culverted, bridged and reference streams in an industrialising region of the boreal forest in west-central Alberta. Mixed-effects modelling and multivariate analysis were used to determine impacts of stream crossings at three scales: whole-stream scale, within-stream scale and the interaction of scales. Instream habitat characteristics such as mean depth, water velocity, percent fines, turbidity, water temperature and dissolved oxygen showed significant between-stream as well as within-stream differences among stream crossings. 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 culverted streams. Multivariate tests corroborated these results, showing that fish assemblages differ as a function of stream type. This study suggests industrial stream crossings influence abiotic habitat characteristics in freshwater ecosystems, restrict biotic connectivity and impact fish community structure at the whole-stream and within-stream scales. Alterations to stream ecosystems associated with stream crossings may be driving large-scale changes in stream fish communities in the boreal forest. With expanded development expected in much of North America’s boreal region, mitigation measures which limit impacts from stream crossings are needed to ensure proper ecosystem function in freshwater systems.

Citation: 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.

Site Locations of Assessed Stream Crossings, including (a) Simoneete, (b) Latronell and (c) Deep Valley watersheds in Alberta Canada.

Prioritization given: net habitat gain (a,d), number of barriers removed (c,f) and the mean cost per barrier (c,f) across Deep Valley and Latronell subwatersheds.

Also Read:

Medinski, N.A.*, Maitland, B.M.*, Jardine, T.D., Drake, D.A.R. and M.S. Poesch (2022) A catastrophic coal mine spill in the Athabasca River watershed induces isotopic niche shifts in stream biota including an endangered rainbow trout ecotype. Canadian Journal for Fisheries and Aquatic Sciences 79(8): 1321-1334.

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