Master of Science in Ecological Restoration Applied Research Projects | BCIT Institutional Repository

Master of Science in Ecological Restoration Applied Research Projects

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The impact of roadway mortality on a long-lived freshwater turtle, Chrysemys picta bellii
Road mortality poses a significant threat to freshwater turtles globally, including the western painted turtle (Chrysemys picta bellii). Even low levels of road mortality can severely impact the long-term survival of these long-lived reptiles. While mitigation infrastructure is employed to reduce mortality, its effectiveness may vary depending on the location and species involved. Population viability analysis can be a valuable alternative for wildlife managers to assess the viability of the populations they monitor and the potential impact of management decisions, but are most useful when data from target populations is available. This research project aimed to evaluate the long-term persistence of a rural western painted turtle population experiencing road mortality. The study first investigated the effectiveness of a turtle tunnel and drift fencing in reducing road mortality. Parameters derived from the population were then used to model the long-term viability of the turtle population in the program Vortex under various scenarios of ongoing road mortality. This study analyses three years of mark-recapture, ratio telemetry tracking, and road mortality surveys done by contractors and summer hires of the Ministry of Water, Land, and Resource Stewardship at Baynes Lake, BC. The turtle population was estimated to be 1,451 (SD= 75) individuals, with a female-biased sex ratio (1.5 females: 1 male). Only a quarter of sexually mature females were found to be gravid in a given year, with gravid females laying only one clutch. Subadult and adult survivorship were calculated using the same dataset employed for the population estimate, resulting in a survivorship rate of 96.4% (SD = 1.3%) per year. Radio telemetry was used to assess the number of road crossings made in a given year. Gravid females were found to make a higher average number of road crossings (1.6 road crossings per season) than males (0.1 road crossings per season) or non-gravid females (0.7 road crossings per season). In 2021, an under-road turtle tunnel was installed in Baynes Lake, followed by the installation of drift fencing in the spring of 2023. Over time and after the implementation of drift fencing, more turtles were observed encountering the installed turtle tunnel. However, evidence regarding the complete traversal of the turtle tunnel was not conclusive. Before the installation of the turtle tunnel, casual community-led surveys in 2021 estimated a mortality rate of 1% of the population. Mortality rates, calculated over the duration of the survey periods, decreased after the installation of the turtle tunnel (0.1 mortalities per day in 2022) and further decreased after drift fencing was installed (0.03 mortalities per day). The long-term viability of the Baynes Lake population was modeled in Vortex, with additive road mortality modeled as a percentage loss of the population. The road mortality rate of 1% additive mortality, seen before road mortality reduction strategies, resulted in a 60% decrease of the initial population after 100 years. This indicates that even low levels of additive adult road mortality can lead to declines in the Baynes Lake western painted turtle population. Sensitivity testing of the model indicates that the Baynes Lake population is highly sensitive to changes in adult/subadult and juvenile mortality. Pre-mitigation mortality levels had the potential to dramatically impact the population of Baynes Lake. It is crucial to acknowledge and address what may appear to be relatively low levels of roadway mortality in rural areas, as even these seemingly modest rates can have a significant impact on western painted turtle populations., Western painted turtle, Chrysemys picta bellii, roadway mortality, population viability modeling, population estimate, scavenge rate
The impacts of exotic Typha on benthic invertebrate communities in the South Arm of the Fraser River Estuary
In recent decades, the exotic cattail Typha angustifolia and its hybrid Typha x glauca have invaded the Fraser River estuary. The impacts from this invasion on benthic macroinvertebrate communities, however, are yet to be studied. Macroinvertebrates play important roles in food chains, trophic dynamics, and nutrient cycling and are potentially at risk from this invasion. In this study, I compared the benthic invertebrate communities between exotic cattail stands and native vegetation stands at 25 paired sites. Sediment cores were analyzed for invertebrate abundance, biomass, and Shannon Wiener diversity index, and it was found that biomass and abundance were lower in exotic cattail when compared to native vegetation, however, there was no difference in diversity. Given the proximity to side channels, tidal inundation time would be a logical explanation for the differences in the benthic communities; however, it was not found to be a significant predictor. Given the invasive nature of exotic cattail and the correlations that were found, cattail should be removed in restoration projects where possible., Fraser River, Typha x glauca, Estuary, Invasive species, Typha angustifolia
Investigating biotic interactions as limiting factors of burrowing owl (Athene cunicularia) population recovery in British Columbia
Burrowing owls (Athene cunicularia) were considered extirpated from British Columbia by 1980 and still require active management to sustain a breeding population. My research objective was to investigate if predator-prey interactions limit the survival and reproductive output of burrowing owls in British Columbia. Wildlife camera photographs and direct observations were used to assess survival, prey return rate and availability, and predator occurrence rate at six different conservation-breeding release sites across two regions and three reproductive-output levels. Ten out of the twelve nests studied successfully produced at least one juvenile owl that is presumed to have survived to the end of the 2023 breeding season. Results indicate that there may be regional differences in reproductive output and prey availability but not predator occurrence. Neither prey availability nor predator occurrence were significantly correlated with burrowing owl reproductive output, although some prey metrics were trending towards significance. However, competition over food resources with other species may be more detrimental to burrowing owls than previously thought, particularly over vertebrate prey items. Relationships between burrowing owls and the other species they interact with in British Columbia are complex; predator-prey dynamics alone do not account for the variability of burrowing owl success rates across the region. Active management such as supplemental feeding and anti-competitor deterrents at the entrances to burrows may be necessary to support this endangered species until it has reached more sustainable population numbers., burrowing owl, endangered species, wildlife management, predator-prey, trail cameras
Investigating bull kelp decline in Saturna Island Interim Sanctuary Zone
Kelp is an ecologically, economically, and culturally important species that is facing global declines. This pilot project investigated if declines in Bull Kelp in the Saturna Island Interim Sanctuary Zone could be attributed to increased herbivory by sea urchins, and/or thermal stress caused by increased ocean temperatures. In areas where sea urchins were excluded, bull kelp was more abundant and in areas where sea urchins were not excluded, heavy grazing was observed. Throughout the summer 2023 study period, sea surface temperature did not exceed bull kelp’s adult or gametophyte thermal tolerance. Restoration of this site should include methods to reduce sea urchin herbivory, while carefully considering cultural and ecological implications., macroalgae, sea urchin, bull kelp, kelp restoration, herbivore exclusion
A meta-analysis of North Shore streams: maximizing the effect of installed rain gardens through strategic placement
A meta-analysis using pre-existing data was done for streams in the North Shore of Vancouver, British Columbia. Parameters considered were chemical concentrations from stormwater input including: heavy metals concentrations (Copper (Cu), Zinc (Zn), Cadmium (Cd), Lead (Pb)) and nutrient concentrations (Nitrate (N03-) and Orthophosphate (P04 3-))_ Chronic toxicity guideline exceedance based on the British Columbia Approved Water Quality Guidelines was found in all 94% of stream systems for Cu and 44% of stream systems for Zn. Heavy metal concentrations were found to be positively correlated with percent impervious surface cover in the watershed, with the strength of the correlation being metal-dependent. Three sites within the study had the highest levels of both Cu and Zn. These watersheds (Upper Keith Creek, Maplewood Creek, and Mackay Creek) were prioritized for rain garden installation. Rain garden building specifications to remediate for Zn and Cu were recommended and included addition of mulch layer, minimum depth of topsoil (30 cm), and vegetating with plants with high potential for biofiltration and/or phytoremediation., Impervious surface cover, Stormwater, Rain garden, Green infrastructure, Heavy metal analysis
A mitigation plan for salmonid spawning habitat in the Lower Seymour River, North Vancouver
Salmonids are a very important species to British Columbia and the Pacific Northwest. They are an icon of British Columbia’s heritage and they hold many ecological, economical, recreational, and cultural values. Unfortunately, Pacific salmonid populations have been declining over the last century due many reasons including degradation of freshwater habitat used for spawning and rearing. This degradation is largely due to expanding urbanization and the installation of dams for flood control, hydropower and water supply. The Seymour River is a mountainous river located in North Vancouver. Over the past century, this river has been subjected to many anthropogenic activities that have cumulatively altered the natural flow and sediment regime. The Seymour Falls Dam, located in the middle of the watershed, intercepts gravel transport from the upper watershed into the lower reaches. This combined with the intense channelization within the lower 4 km of the river, which has created conditions incapable of gravel deposition and retention, has led the lower reaches to become gravel deficient. This gravel deficiency has caused the degradation of traditional spawning grounds of chum (Oncorhynchus keta), and pink salmon (Oncorhynchus gorbuscha). This study aims to: 1) determine if there is a gravel deficiency for chum and pink salmon spawning in the lower 1.5 km reaches and, 2) provide recommended mitigative treatments of gravel addition to increase suitable spawning area, and therefore increase salmon productivity of the Seymour River. A site assessment was conducted on the lower 1.5 km of the Seymour River and included sampling of the five key parameters that define spawning habitat (i.e., water depth, velocity, dissolved oxygen, water temperature and substrate). A particular focus was given on analysing the substrate as it was expected to be deficient for spawning due to the predetermined conditions in the watershed such as the dam and the channelization. Results of the site assessment confirmed that substrate is the limiting factor for chum and pink salmon spawning in this area as the bed surface is composed of large cobbles and boulders too large for these specific species to move to dig a redd. Therefore, a xi mitigation plan of gravel addition is proposed to increase spawning habitat and conserve these salmon runs. Two gravel placement sites were selected between Mt. Seymour Parkway and Dollarton Bridge. A gravel mobility analysis determined that suitable-sized gravel will not be deposited or retained naturally on the channel bed due to the slope and water depth at high flood events. Therefore, gravel catchment structures are proposed to dissipate energy, thereby promoting deposition and reducing scouring. Each site contains a different design tailored to the specific characteristics of that reach. To retain gravel, spurs composed of the surface cobbles and boulders are proposed along with imbedded gravel pads composing of suitably sized gravel brought in from a local source. In total these two sites could provide about 1,925 m2 of additional spawning habitat which could support 209-836 pairs of chum or 3,208 pairs of pink salmon. Through long-term monitoring, this project in the Seymour River could provide strategies of gravel placement in large, urbanized, gravel-deficient rivers, in which current research is limited. Many rivers in North Vancouver (i.e., Capilano River, Lynn Creek, McKay Creek and Mosquito Creek) may be experiencing a gravel deficit similar to the Seymour River, and the strategies outlined in this project could be adapted to the specific conditions of those rivers. The cumulative effect of adding spawning gravel in each river within the Burrard Inlet, as well as elsewhere in the Pacific Northwest, could reduce stress in their freshwater phase and aid in rebuilding salmon populations from their precipitous decline in which they are on currently on track for. The strategies provided will also become important as more rivers become sediment deprived due to the construction of hydropower dams in response to a change from fossil fuels to renewable energies as climate change continues. The need for more innovative habitat mitigation strategies will be necessary to keep salmon from becoming a relic of the past.
Modelling potential impacts of sea level rise on Siwash Island
Siwash Island is a tidal marsh situated at the southern end of the Widgeon Marsh Regional Park Reserve, Coquitlam, British Columbia (BC). The numerical model MarshMorpho2D was used to depict the evolution of marsh under various scenarios of sea level rise (SLR), suspended sediment concentration (SSC), and tidal range (TR) over the next 80 years. Changes in SLR and TR substantially impact the island’s morphology. Higher TR and SLR cause higher inundation and erosion rate, resulting in loss of vegetation, elevation, and habitat across the island. The model projection indicates that Siwash Island is likely to submerge within the next 80 years. The MarshMorpho2D model provides insights for policymakers and conservationists to develop adaptive strategies to mitigate the effect of SLR on coastal ecosystems., tidal marsh, numerical model, MarshMorpho2D, sea level rise, tidal range, suspended sediment concentration
Nanaimo River estuary restoration: an assessment of berm removal on benthic macroinvertebrates in tidal channels
Macroinvertebrates in two berm-impacted tidal channels (Site A and Site B) were compared to a natural channel (Site C) to determine short-term response to berm removal restoration using a BACI study design. Multivariate analysis indicates that the benthic community composition shifted from before berm removal to after berm removal conditions but not in a predictable organized way. Total abundance was highest at Site A in both conditions (before and after berm-removal). Invertebrate diversity was similar and low among sites. Biomass was highest at Site C. Organic matter percentage was highest at Site C in both conditions and it appeared to increase in Site A and Site B after berm removal. Silt & Clay (>0.0063mm) were statistically different in Site C compared to Site A and Site B although very fine sand was the highest in percentage among sites and in both conditions. Berms affect channel and benthic invertebrate dynamics; time and more research are needed to fully restore the Nanaimo estuary., © Okezioghene Akporuno, 2020. All rights reserved. No part of this work covered by the copyright heron may be reproduced or used in any form or by any means – graphics, electronic, or mechanical including photocopying, taping, or information storage and retrieval systems – without written permission of the author., Estuary restoration, Tidal channel, Benthic macroinvertebrate, Sediment, Detritus, Berm
Novel ecosystems: necessity, revolution, or laziness?
The earth’s environment, climate, and natural systems are constantly changing, having little resemblance of ecosystems past. These new systems functioning in balance are termed “novel ecosystems” and have arisen as the new normal posing an important question in the restoration field as to how these systems should be approached. To address the state of novel ecosystems in the academic literature, I devised a matrix to assess variables of description regarding novel ecosystems and how they are expressed in the literature. Results showed a predominance of self-assembled systems with a disposition towards invasive species as a primary threat. Chemical, physical, and landscape data was severely lacking and most metrics for success were ecological. Data from the literature show a lack of research on designed novel ecosystems but shows promise for success given several examples. More research on novel ecosystems in restoration must be undertaken to fill gaps in aggregate data., © Michael Paleologou, 2020. All rights reserved. No part of this work covered by the copyright heron may be reproduced or used in any form or by any means – graphics, electronic, or mechanical including photocopying, taping, or information storage and retrieval systems – without written permission of the author., Ecological Restoration, Novel Ecosystems, Literature Review
Phytoremediation of contaminated soils
Phytoremediation poses an ecologically friendly and cost-effective alternative to other remediation methods such as chemical or thermal treatment. However, in contaminated sites such as retired oil wells and brine spills, it is common to have a co-contamination of salt and polyaromatic hydrocarbons (PAHs). The co-contamination of salt and PAHs may decrease the rate and effectiveness of bioremediation. Here we investigated the effect soil salinity has on the rate of phytoremediation, plant survivability and biomass. A 90-day greenhouse study was performed, growing alfalfa (Medicago sativa L.) in soils treated with varying salt (NaCl) concentrations in the presence of pyrene and benzo[a]pyrene. No significant differences were observed in the presence or absence of PAHs. Salt treatments has significant affects on plant biomass, nodulation, and successful germination., Bioremediation, Polyaromatic hydrocarbons, Alfalfa, Salt, Phytoremediation
A prey-based approach to restoration
Forestry in British Columbia’s old-growth forests has reduced critical foraging and breeding habitat for the coastal northern goshawk (Accipiter gentilis laingi) and restricted population growth. Now at-risk, efforts to recover this subspecies have focused on establishing suitable habitat and a well-distributed population within the province. However, regional diets and associated dynamics are also critical to goshawk recovery and remain poorly understood. Including a synchronous predator-prey recovery approach to current plans can bridge these knowledge gaps. A new model and methods were developed to translate prey biological requirements into structural surrogate features that could be parameterized and ranked within GIS software. Applying these ranks to known goshawk territories in the South Coast allowed for the visualization and quantification of areas with subpar predicted prey abundances. This provided insight on links between prey and forest structure and can be used to direct future restoration and research decisions for coastal goshawk prey-based recovery.
Re-establishing the historic fire regime to restore the Chittenden Meadow, Skagit Valley Provincial Park, British Columbia, Canada
Prescribed burning is being used by BC Parks as a restoration tool to maintain the ecologically unique Chittenden Meadow in Skagit Valley Provincial Park. Forest encroachment of conifers in the meadow, due to the absence of fire, has been an ongoing issue since the 1970s. BC Parks in partnership with the BC Wildfire Branch conducted prescribed burns in April 2003 and April 2021 to reduce forest encroachment into the meadow. In 2017, BCIT students re-established a series of plots to compare vegetation community changes with the 2003-2004 prescribed burn data. This data was compared to our 2021 findings. Continued long-term monitoring of the meadow will help to enhance our understanding of vegetation community changes following prescribed fires and will build upon a decade of existing data. The historical extent of the meadow remains unclear; therefore, we conducted a broad fire history study across ~275-ha of forest surrounding the Chittenden Meadow to better understand the area's past fire frequency and severity., prescribed burning, forest encroachment, vegetation community change, fire history study
Restoration options for Nicomekl River anadromous salmonids – Elgin Road Bridge Sea Dam
The Nicomekl River flows through historic Katzie First Nation territory in Surrey, British Columbia. The river provides salmon the linkage between their upland spawning and rearing grounds and the Pacific Ocean where they mature. Anthropogenic development has reduced habitat connectivity along the river, denuded the banks of vegetation, removed instream complexity, constrained the channel, regulated flow, and altered the water chemistry. A tidally controlled 7-gate sea dam is the source of the critical connectivity bottleneck on the river. It impairs free longitudinal migrations of adult and juvenile salmonids and increases adult and juvenile predation. Through literature review and site assessment, this study suggests a suite of restoration treatments to restore connectivity and site-based habitat attributes to the Nicomekl River. The study then considers management options in light of climate change, sea level rise, and how to generate public involvement to support the proposed treatments. The study concludes that urban stream restoration faces challenges as it must find a balance between the environmental and social needs of the Nicomekl River beyond simply repairing ecosystem damage and degradation., riparian restoration, salmonids, migration bottlenecks: connectivity
Restoration planning for urban salmonid habitat
Restoration of salmonid habitat has been completed in many urban areas; however, the success of these projects may be limited without consideration of water quality. Urban watersheds are affected by stormwater runoff which transfers toxic substances such as heavy metals, hydrocarbons, and fine particles from impervious surfaces into streams. Previous research has documented impacts of stormwater causing premature death in spawning coho (Oncorhynchus kisutch), and related extent of impervious surfaces to impacts on benthic invertebrates. This research aims to expand our knowledge on the effects of stormwater runoff on water quality and benthic invertebrate communities, and make recommendations for restoration of Mosquito Creek, in North Vancouver, British Columbia. Stream water quality was monitored, site habitats were assessed, and impervious surfaces were mapped. Benthic invertebrate samples were collected and analyzed for abundance, diversity, and pollution tolerance, comparing upstream and downstream of a stormwater inflow and two sites on a reference stream. Average water quality measurements showed minor impacts related to elevated temperatures. However, benthic invertebrate metrics revealed chronic water quality issues, reflecting cumulative impacts. Pollution tolerance index and abundance were reduced at the downstream Mosquito Creek site suggesting impacts from the stormwater inflow, while the Ephemoptera, Plecoptera, Trichoptera (EPT) to total ratio and overall stream health (Streamkeepers Site Assessment Rating) were significantly lower at Mosquito Creek overall suggesting watershed impacts from impervious surfaces and point-source pollution events. Restoration recommendations including a rain garden are discussed to improve water quality for salmonids., Restoration, Urban streams, Salmonids, Benthic invertebrates, Water quality, Stormwater
Restoring hydro-impacted wetlands for secretive marsh birds
Secretive marsh birds can be difficult to detect and are dependent on wetlands, leaving them vulnerable to wetland loss or alteration. This study examines the influence of management-altered hydrological regimes on five secretive marsh bird species in the West Kootenay and Columbia Wetlands in British Columbia, Canada. Focal species occupied wetlands with less frequently altered hydrological regimes more often and in greater numbers. Occupancy models suggested that woody vegetation, tall vegetation, and open water are important drivers of occupancy for these species. Wetlands most frequently experiencing heavily altered hydrological regimes had more open water and less tall vegetation, both of which were negatively associated with wetland occupancy. Water management operations may be promoting altered vegetation communities within these wetlands, in turn promoting lower occupancy of secretive marsh bird species. Restoration recommendations include: prioritizing lower elevation wetlands, limiting woody vegetation encroachment, and experimentally restoring the hydrological regime of affected wetlands., © Ashleigh M. Westphal 2019. All rights reserved. No part of this work covered by the copyright heron may be reproduced or used in any form or by any means – graphics, electronic, or mechanical including photocopying, taping, or information storage and retrieval systems – without written permission of the author., secretive marsh bird, Kootenays, British Columbia, hydro, water management, wetlands
The scale of ecological restoration: restoring steelhead habitat in the Oktwanch Watershed, Vancouver Island, B.C.
Forestry practices are thought to be the major cause of degraded salmonid habitat and declining steelhead populations in the Oktwanch River on Vancouver Island. Large woody debris installations and channel modifications were completed in Reach 1 of the Oktwanch River and adjacent side channels in 2001 to provide spawning and rearing habitat for multiple salmonid species and prevent further degradation, but were ultimately unsuccessful. This study investigated if watershed-scale restoration, rather than reach-scale, is necessary to restore this habitat for steelhead in the Oktwanch River indefinitely. This was achieved through an assessment of fish habitat in Reach 1 of the Oktwanch River and adjacent side channels and spatial analysis of the Oktwanch watershed using Landsat historical aerial imagery and i-Tree Canopy. The findings from this study suggest watershed-scale changes to forestry practices are required to restore steelhead populations in the Oktwanch River., forestry practices, watershed-scale restoration, reach-scale, woody debris installations, channel modifications

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