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
Coastal wetlands are an important ecosystem in the Great Lakes basin, providing spawning grounds and warm-water refuge for numerous fish and benthic invertebrate species during cold water upwelling events. Urbanization along the northwestern shore of Lake Ontario has led to a depletion of coastal wetlands, replacing them with artificial embayments. Three artificial embayments, the Credit River estuary, and one coastal marsh in Mississauga, ON were studied to determine if the artificial embayments function as warm-water refuge during upwelling events. Temperature loggers were placed in each study site and temperature was recorded every 15 minutes from July to October 2017. Upwelling events were isolated from the data, and frequency, magnitude, and duration of upwelling was determined. Most study sites had a frequency of 4 upwelling events throughout the study period. The average duration of upwellings varied from 30 to 70 hours, and the average temperature change ranged from -7.1ᵒC to -11.9ᵒC. All of the study sites seemed to buffer upwellings by reducing the magnitude of temperature change and increasing the duration of upwelling events to varying degrees. These results will inform the creation of future wetlands, restoration of existing embayments, and conservation of Great Lakes coastal wetlands., ecological restoration, coastal embayments, coastal marsh, upwelling, warm-water refuge, Lake Ontario
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
Burns Bog is a raised ombrotrophic bog in Delta, British Columbia and faced with myriad disturbances. This study is focused on the impact and restoration of peat extraction by the Atkins-Durbrow Hydropeat method. Depth to water table, relative abundance and distribution of vegetation, and the degree of peat decomposition at consistent-depth intervals were investigated to elucidate the status of passive and active ecological restoration in three fields previously harvested for peat approximately one decade apart and compared to a fourth unharvested field. Summary statistics, Redundancy Analysis, and regression were used to compare restoration status and trends in hydrology, vegetation composition, and peat accumulation. A lag period between cessation of harvest and implementation of restoration, coupled with rapid anthropogenic climate change, serve as impediments to restoration here. Intervention in the form of improved rainfall retention, assisted recolonization, and the introduction of nurse species are recommended to improve bog function and resiliency., Atkins-Durbrow Hydropeat method, Ditch blocking, Ecological restoration, Peat extraction, Raised ombrotrophic bog, Burns Bog
The MacKay Creek Estuary, is a severely altered estuarine ecosystem located within an active international port in Vancouver, British Columbia. Several elevated salt marsh terraces were constructed as part of a larger restoration project within the MacKay Creek Estuary. Site visits conducted in 2018 revealed 75% of the terrace surface area failed to establish salt marsh vegetation. Significant difference in soil pore-water salinity, oxidation reduction (redox) potential and tidal elevation were found between vegetated and unvegetated portions of the terraces. Additionally, exclusion from Canada Geese (Branta canadensis) herbivory increased total percent cover and colonization of the adjacent unvegetated area. The combination of soil parameters and herbivory, as well as potential interactions between factors may be responsible for the lack of vegetation progression within the constructed salt marsh terraces at MacKay Creek Estuary., restoration, salt marsh, redox potential, pore-water salinity, MacKay Creek, Fraser River, estuary, Canada geese
The purpose of this project is to develop an ecological restoration plan for degraded habitats on mid-channel islands in the lower Fraser River. The study focuses on Herrling, Carey, and Strawberry islands, large mid-channel islands located in the gravel reach between Mission and Hope, British Columbia. These islands are known to be critical off-channel rearing habitat for many fish species including the threatened White Sturgeon (Acipenser transmontanus) and interior and lower Fraser watershed Chinook Salmon (Oncorhynchus tshawytscha) populations. These islands are also home to many riparian plant and animal species. The flood-pulse concept (FPC) states that seasonal fluctuations in water levels for streams such as the Fraser River contribute substantially to the ecological function of the floodplain ecosystem where this phenomenon occurs. This often results in improved growth and survival rates for fish species that rely on a laterally-moving littoral zone of inundation. This phenomenon is thought by many to be the key to a properly functioning ecosystem in the lower Fraser River. Using a Digital Elevation Model (DEM) for the Fraser River between Hope and Mission, British Columbia, freshet flows (high water elevations) are presented to define the spatial extent of over-bank watering of Strawberry, Carey and Herrling islands. This over-bank watering provides lateral connectivity to floodplain islands. Based on extensive sampling in other studies, this lateral movement results in the creation of high-quality juvenile fish rearing habitat. A restoration plan is presented for those areas of Strawberry, Carey and Herrling islands degraded by recent land clearing for agriculture where they overlap sections defined as fish habitat from the spatial analysis., gravel reach, mid-channel islands, floodplain fish habitat, flood pulse concept, juvenile Chinook Salmon, lower Fraser River, White Sturgeon
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