Our work in the Fraser River estuary is focused on understanding juvenile salmon presence, timing and distribution. Our research will inform decisions on how to maintain the estuary’s ecological resilience to support the broader food web of species. Our work includes a five year restoration initiative to restore lost connectivity across of the delta of Sturgeon and Roberts Bank.
Fraser River Estuary Connectivity Project
The Lower Fraser and estuary is a highly modified environment with more than 70% of tidal marsh habitats that juvenile salmon rely on lost or locked away behind manmade structures. In most places these are dykes and armouring, but on the delta it includes the jetties, causeways and training walls that were built to control the arms of the river and aid navigation.
Today, the estuary is very fragmented by these structures that alter the flow of water, sediment and nutrients to Sturgeon and Roberts Banks, and restrict the passage of juvenile salmon that want to move onto the shallow tidal salt marshes of the delta to feed and grow.
Our plan over the next five years is to create openings in several of these man-made barriers that are preventing the movement of juvenile salmon into the estuary habitats they once occupied. The project includes the baseline research on juvenile salmon, including their presence and distribution in different habitats, their size and growth over the spring and how long they stay in the estuary.
The research aslo includes collecting the baseline information on conditions as they are now and the movement of salmon prior to creating the openings, so that we can evaluate the success of the openings once they are created.
Fraser Estuary juvenile salmon research project
As part of our efforts to understand, mitigate, and reduce habitat impacts from industrial proposals, Raincoast is working with its partners- particularly UVic’s Baum Lab– to characterize the use of the estuary by different species of juvenile wild salmon at different times and places.
Since 2016, we’ve been monitoring juvenile salmon across the Fraser River delta as we survey out-migrating juvenile salmon arriving from upper parts of the Fraser watershed. We monitor more than 20 sites in marsh, eelgrass and sandflat habitats across Roberts and Sturgeon Banks. Our research is advancing the understanding of juvenile salmon use (or not) in different habitats in the estuary including the populations origin, the size and growth rate of Chinook fry and smolts, the arrival and residency time and migration patterns.
In 2016 and 2017 we caught more than 55,000 fish from 40+ different species, including almost 9000 juvenile salmon. We collected just under 800 tissue samples from juvenile Chinook for genetic stock identification (GSI) which allows us to determine population specific trends. Raincoast will be publishing this research in peer reviewed journals in the near future.
Prioritizing threat management strategies to ensure long-term resilience of at-risk species in the Fraser River estuary
With partners at UBC (Martin Conservation Decisions Lab) and UVic (Baum Lab), we are undertaking a threat management assessment of more than 100 at-risk species in the Fraser River estuary to determine the management actions required to abate key threats and ensure the long-term resilience of these plants and animals.
The approach uses state-of-the-art techniques in conservation decision science to identify the most effective and least costly management actions to meet our goals. The project is being lead Dr. Tara Martin at University of British Columbia and Dr. Julia Baum and Dr. Laura Kehoe from the University of Victoria, in partnership with Raincoast, the Pacific Salmon Foundation, Fisheries and Oceans Canada and Environment and Climate Change Canada.
The project will produce a conservation prospectus that identifies priority actions needed to ensure the resilience of the Fraser River Estuary’s natural assets (plants, animals and habitat) into the future. In this highly contested estuary, with diverse public and private interests and multiple threats, demonstrating the return-on-investment of managing for its natural assets is essential. Through a rich set of collaborators and their networks, pathways for implementing these priority management actions will be developed.