Long-Term Marine Monitoring: Port Metro Vancouver “Deltaport” Habitat Compensation

To limit the ecological impacts of the Deltaport Third Berth terminal expansion project, Port Metro Vancouver developed a Habitat Compensation Plan that stipulated the construction of compensatory habitats to accommodate nearby fish and eelgrass communities.

Located within the Fraser River estuary on the Strait of Georgia, British Columbia, the Roberts Bank Port Facility is one of the busiest import/export ports in North America. Situated at the end of a long causeway, this international shipping hub consists of two terminals: the Westshore coal terminal, and the Deltaport container terminal. In January 2010, the Deltaport terminal added a third berth to accommodate increased loading and storage requirements.

To limit the ecological impacts of the Deltaport Third Berth terminal expansion project, Port Metro Vancouver developed a Habitat Compensation Plan that stipulated the construction of compensatory habitats to accommodate the surrounding fish and eelgrass communities.

To verify the establishment and biological effectiveness of these new habitats, Archipelago, in conjunction with GL Williams and Associates Ltd., designed and implemented a long term marine habitat compensation monitoring program. This program encompassed three components:

• Introduction of intertidal and backshore habitats along the eastern side of the terminal approach causeway
• Restoration of the Tsawwassen salt marsh, including log removal and tidal channel revitalization
• Stabilization of a large sandbar associated with the tidal channels in the inter-causeway area of Roberts Bank

Starting in 2007, Archipelago implemented a program of pre–construction monitoring within each of the compensation habitats (ranging from mudflat and salt marsh to stable rock surfaces and vegetated backshore environments). After the project completion, a program of post-construction monitoring continued until 2015.

This long-term monitoring process examined several key elements through a range of methods:

• Shoreline changes (monitored by intertidal biophysical surveys, sediment sampling, elevation profiling, and photo documentation)
• Benthic infauna and epifauna community composition and diversity (monitored by core grab sampling and intertidal biophysical surveys)
• Macroalgae, eelgrass, and marsh vegetation cover and distribution (monitored by intertidal biophysical surveys and photo documentation)
• Nearshore fish community composition and diversity (monitored by beach seine and forage fish spawning surveys)
• Physical water quality (monitored by water sampling)

 

Throughout the program, Archipelago conducted habitat trend analyses between years to determine whether the created features were remaining stable, and whether vegetation and fauna were establishing within the new habitats.

By monitoring over an extended period, researchers could accurately gauge the effectiveness of the constructed habitats, identify important stressors and processes, and determine long–term trends that would not have been apparent from shorter term studies.

Nearly a decade after project completion, Archipelago’s long–term monitoring efforts have helped engineers understand the most effective design structures over time for this type of environment.