Coastal Habitat Squeeze

Coastal habitat squeeze is another major challenge. The Fraser River Delta, the largest estuary along the Pacific Coast of North America, is a critical crossroads along the Pacific Flyway where multiple paths of migratory birds converge. The Fraser River foreshore and selected provincial and federally owned lands were designated as a Hemisphere Reserve in the Western Hemisphere Shorebird Reserve Network in 2004. Protected Wildlife Management Areas, including Boundary Bay, Roberts Bank and the South Arm Marshes, provide resting areas for over 5 million migratory birds each year. The complex food chains found on the foreshore extend from tiny microorganisms to large mammals. The invertebrates, plants and small fish in the estuary provide a nursery for millions of out-migrating juvenile salmon. Moreover, the salt marshes and wetlands are key habitats for sturgeon and herring. 

Unfortunately, with most of the current coastline fixed behind hard infrastructures (dikes and seawalls), these habitats (including salt marshes, mudflats and coastal wetlands) are not able to migrate with rising sea levels. If nothing is done, these critical habitats might disappear in certain locations along the coast by the end of the century. Coastal erosion due to a lack of sediment has further exacerbated this problem. Over the course of the twentieth century, dredging (for navigation) and the construction of a number of jetties and breakwaters have significantly altered sedimentation patterns. During the same period, upwards of 70% of the wetland areas have been replaced by agricultural, industrial, and urban development (Schaefer, 2004). This has substantially impacted connectivity and spawning grounds for salmon, sturgeon, and other fish species.