Port to plant eelgrass off Tsawwassen ferry terminal
Initiative aimed at offsetting damage caused by increased shipping in region
The Port of Vancouver is proposing to plant vast gardens of eelgrass on the ocean floor this year to benefit marine life ranging from fish to crabs near the Tsawwassen ferry terminal.
The project would create a total of four hectares of eelgrass habitat on the southeast side of the terminal at two ocean-bottom sites that were formerly dredged.
Documents posted on the province’s Environmental Assessment Office website show that a perim- eter berm would be created with rip-rap rock extending up to three metres above the existing sea floor to protect the eelgrass.
The eelgrass would be planted on new fill material and would be obtained from nearby donor beds at a rate of not more than two shoots per square metre. Scuba divers would handle the plantings.
Eelgrass beds are part of a series of initiatives by the port to offset environmental damage caused by several large-scale projects that would significantly increase shipping’s impact in the region.
In Richmond, north of Steveston’s south arm jetty, the port proposes to convert a sand flat at the mouth of the Fraser River into 43 hectares of intertidal marshland for a variety of wildlife, including juvenile salmon and birds.
Industrial projects in the port include planned expansion of the container terminal at Roberts Bank in South Delta and a seven-fold increase in oil tankers associated with Kinder Morgan’s pipeline expansion at Westridge Terminal in Burnaby.
Cynthia Durance is a marine consultant who specializes in transplanting eelgrass and is currently working on a project in Nanaimo to mitigate the impact of a sewage pipe. She developed a method specific to B.C. coastal waters that involves attaching a steel washer as an anchor to each eelgrass shoot being transplanted.
“We plant them in patches of 10,” she said in an interview. “Just like you wouldn’t leave one tree in the forest. It protects them and buffers the wave energy.” She has done more than 100 eelgrass transplants since 1996.
B.C. Transmission Corp. funded a similar eelgrass habitat compensation project near Tsawwassen ferry terminal in 2008.
Eelgrass beds provide not just habitat for marine species but filters water, traps and binds sediments, baffles wave energy, removes contamination, produces oxygen, and sequesters carbon, the port says in the documents. Among the species expected to benefit are juvenile salmon, herring, Dungeness crab, Brant geese, bivalves, shrimp, and sea stars.
The project is expected to begin in late summer or early fall and last four to five months.
A 2005 report on eelgrass restoration in B.C. for the Habitat Conservation Trust Fund noted that eelgrass beds serve as transportation corridors for wildlife. “They have been described as ‘salmon highways,’ providing respite from strong ocean currents and unrelenting predators, and as nutrient-rich nurseries for young marine organisms,” the report found.