A full composition study of some key Fraser River foreshore marshes, Boundary Bay, Brunswick Point, Westham Island, Lulu Island, and Sea Island, had not been done in several decades, during which a large-scale marsh recession event occurred at two of the marshes. The vegetation composition is measured in this study with relation to soil water, soil pore water salinity, and elevation. The results in this study show a shift in the vegetation composition in some areas of the Lulu Island marsh, with the other marshes remaining relatively similar to historical data. The plant species’ tolerance to soil water, soil salinity, and elevation vary in each marsh, illustrating the need for individualized restoration plans for each marsh. Conserving and restoring these marshes is critical in light of the many changes in the Fraser River delta, including sea level rise, increased geese populations, altered sediment regimes, and urbanization., Fraser River, brackish marsh, salt marsh, vegetation composition, salinity, elevation
This study investigates the outcomes of restoration efforts completed on retired agricultural land in Southwest Ontario. Sites acquired by the Nature Conservancy of Canada were planted to kickstart succession to native deciduous forests, but the results of the plantings are mixed. Analysis of soil conditions indicated that low levels of soil organic carbon were correlated to low water content and high density unfavourable for plant growth. Analysis of remotely sensed imagery was done to assess and compare vegetation cover to reference conditions at Walpole Island First Nation. Analysis revealed that successful restoration was dependent on multiple soil characteristics, but conditions correlated to higher total organic carbon favoured greater vegetation cover. Remote sensing data revealed that succession towards tree canopy development was accelerated compared to passive restoration, and a shaded understory was established approximately 8-12 years following restoration. Future work can expand on succession and the effects of other restoration treatments., Soil, Reforestation, NDVI, Agriculture, Restoration, Secondary succession
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
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
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
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.
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
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.
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 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
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
In agricultural landscapes, hedgerows provide critical habitat for songbirds. Himalayan Blackberry (Rubus armeniacus; HBB) is a widespread invasive species in the Pacific Northwest that has been linked to lower breeding songbird diversity. My study explored two possible explanatory mechanisms: educed structural complexity and lower arthropod abundance as a food source. I conducted avian point counts in 51 hedgerow segments at two locations in the Lower Mainland of British Columbia. In these segments, I quantified vegetation structure using a Foliage Height Diversity (FHD) metric derived from LiDAR data. I sampled arthropod abundance on the foliage of woody understory vegetation. I used multiple regression to identify best fit generalized linear models. Songbird diversity decreased with HBB % cover and increased with FHD. However, arthropod abundance was unrelated to bird metrics, and similar between HBB and other native shrubs. This suggests that hedgerows should be managed to control HBB and maximize vegetation structure., songbird diversity, agricultural landscapes, Himalayan Blackberry, hedgerows, arthropods, LiDAR
Old field is a unnatural habitat that usually occurs as a result of agricultural land abandonment and is the product of early-stage natural succession on a previously managed field. In an agricultural setting with monoculture crops, old fields provide more vegetative complexity through ground cover diversity and shrubs and hedgerows. In Delta, British Columbia, several old-field sites are managed for wildlife and provide nesting habitat for songbirds over the summer, as well as foraging habitat for overwintering raptors during fall and winter months. I surveyed two old-field sites near Boundary Bay, and two field sites at the Vancouver Landfill to compare the influence of old-field vegetation on different bird communities and improve understanding on species using the landfill. I conducted fixed-radius point counts for songbirds, and standing counts for raptors. Comparing replicate field types (n=2) I found that overall diversity of songbirds was higher in old field, and also associated with structural features like shrubs and trees, while abundances of Savannah Sparrows (Passerculus sandwichensis) decreased with proximity to shrubs and trees. My results support the conclusion that installing structural vegetation features at the landfill would maximize breeding songbird diversity. I also found the landfill to support higher diversity of wintering raptor species, but old field supported consistently higher abundances. This suggests that the landfill is currently functioning as lower quality wintering habitat, and that different management techniques should be considered.