Friday, August 23, 2019
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Waves of life invigorate Vancouver’s shoreline

Long before it became the ‘condo city,’ the prized waterfront real estate of Vancouver was home to towering kelp forests,…


Vancouver Convention Centre juts out over the water
The Vancouver Convention Centre seen at low tide with the top bench of the habitat skirt visible (Photo by Lindsay Sample)

Long before it became the ‘condo city,’ the prized waterfront real estate of Vancouver was home to towering kelp forests, roaming herds of sea urchins and beaches blanketed with shellfish. The creatures that depend on those staples as food — like salmon, sea otters, seals and even whales — were abundant in Vancouver’s waters.

Many species have since left Burrard Inlet and False Creek, but it was not the crippling housing prices that forced them out. Constructing a world-class waterfront requires destroying shoreline to build popular features like seawalls, marinas and commercial ports. As the skyline continues to expand, fewer and fewer refuges remain for marine life to call home.

Can’t handle the stress

Eighty per cent of Vancouver’s natural coast has been converted into man-made shoreline over the last century. Jamie Slogan, a marine ecologist who has worked all over the world and is now based in Vancouver, says many marine species “just can’t handle the stress we put on them” by abruptly altering their natural environments.

Slogan is the lead researcher on a groundbreaking project at the Vancouver Convention Center (VCC). The project is renewing habitat for nearly 100 species displaced by shoreline change in Burrard Inlet. It has transformed an industrially polluted section of coast into a thriving marine ecosystem and offers hope for the future of biodiversity on Vancouver’s shores.

“The new convention centre extends about 50 metres on to the ocean,” Slogan explains. “They’re required by law, by the Department of Fisheries and Oceans, to compensate for habitat damaged by the construction. The amount of new habitat had to equal the habitat that was lost.”

Waterfront developments, like the VCC, require destroying gradually sloping shorelines in favour of vertical walls that prevent buildings from falling into the sea. Seaweed and shellfish vital to ecosystems have difficulty attaching to smooth vertical walls.

Shellfish on the shore
A century ago, entire beaches, like this boulder on the North Shore of Burrard Inlet, were covered in mats of shellfish (Photo by Lucas Powers)

There is a struggle between what architects and biologists want on shorelines, says Cristina Bump, a Boston-based architect who is re-thinking urban waterfronts to promote biodiversity on seawalls.

“There’s obviously a stark contrast between something that is not touched by man. It’s wild, there’s nooks and crannies, there’s lots of different tide level depths, and then we come in and we make these vertical seawalls, and we basically make everything sleek,” says Bump.

“Things like that don’t provide anything for marine wildlife to grow on,” and she hopes to change that.

 

World’s first habitat skirt

Compensation efforts to make up for a loss of a gradual slope usually means dumping large rock piles, meant to act as shallow reefs, on to the ocean floor adjacent to the shore. But the new VCC juts out over water that is too deep for this conventional method to work, so the developers needed an innovative solution to meet the DFO’s standards.

Slogan’s employer, an environmental engineering firm called EBA Tetra Tech, got the contract.

“We came up with the idea of suspending an artificial habitat structure right off the building in the tidal range, rather than building it up from the seafloor,” says Rick Hoos, a senior marine biologist at EBA who oversaw the project.

“All the other potential options were just not feasible, outrageously expensive or both.”

The design they created is called a ‘habitat skirt.’ It’s the first of its kind anywhere in the world.

The structure mimics the rocky shorelines common to British Columbia, extending for 477 metres around the convention centre’s waterfront façade. It provides familiar habitat for species that live in the intertidal zone.

Creatures moved in to the area quickly. Now, after three years, the skirt supports more species than a natural site just downshore, according to Slogan.

He recently submitted his research to the DFO for approval. He insists the most vital function of the skirt is that it fills gaps in the natural shoreline. Migrating salmon need consistency in the coastline to successfully make it to the open ocean.

“A primary objective was to create an artificial shoreline for juvenile salmonids to follow because they like to follow shorelines on their journey out of the rivers,” he explains.

“If you go down there right now, you’ll see thousands of juvenile salmon swimming past on their way out to the ocean.”

Tidal pools are essential for the coastal ecosystem
Natural rocky shorelines, like this outcrop near Third Beach in Vancouver’s Stanley Park, allow for tidal pools to form at low tide (Photo by Lucas Powers)

A  habitat skirt is not the only way to bring back marine life to urban shores. Researchers on Vancouver’s North Shore and as far away as Sydney and Seattle have shown that minor modifications to existing seawalls can have major impacts on coastal biodiversity.

Listen: Marine biologist Scott Christie on West Vancouver’s shoreline rehabilitation efforts (1:12)

[audio:https://thethunderbird.ca/files/2012/03/LL-Feature-Audio-Slideshow-Scott-Christie.mp3|titles=Marine biologist Scott Christie on shoreline preservation efforts in West Vancouver]

Biologists believe this should be the norm, but they also know that legislation has helped to make it a reality.

 

Possible legislation change creates a doubtful future

The VCC habitat restoration project is a result of the Fisheries Act. It dates back to the repatriation of the constitution in 1982. The Fisheries Act gives the federal government the power necessary to ensure the conservation of Canada’s aquatic resources.

Under Section 35, whenever structures that may harm fish habitat are built on water — like the VCC — the developer must compensate with an equal amount of new artificial habitat. The compensation must be reviewed and accepted by the DFO.

“It’s a strong piece of legislation,” says Mark Hume, a national columnist for the Globe and Mail who focuses on issues in B.C. “Probably the most powerful piece of environmental protection legislation in the country.”

Critics of the Fisheries Act have argued that it is too powerful, placing unnecessary delays on waterfront projects and protecting habitat even where there are no fish.

In mid-March a document leaked from Fisheries Minister Keith Ashfield’s office that suggests major changes intended to restrict the act’s power could be coming. Ashfield hopes to amend the act to limit its protection to “economically valuable” fish species.

“The amendments are intended to make it more reasonable,” says Hoos. “Depending on how it is interpreted by the DFO, it can be almost impossible to meet the requirements.”

The proposed changes have caused an outcry.

“Groups nation-wide representing tens of thousands of Canadians are on record urging the federal government to re-think its plan to eliminate longstanding environmental protections,” says Jessica Clogg, executive director of West Coast Environmental Law.

“If these changes go ahead as proposed, it will make it ineffective. It just won’t have any impact,” says Hume. “Why would a developer spend more money than they have to?”

Slogan points out that the habitat skirt project may never have happened if it wasn’t required by law.

“It cost around $1 million to do, and that’s a lot. But it was worth it because of the things we have managed to do in terms of species,” he says.


If you build it, they will come

  • The habitat skirt unexpectedly became a nursery for thousands of Dungeness crabs attracted to food sources, like seaweeds, that have colonized the skirt.
  • Ling cod and rock fish, predatory fish species with very limited habitat in Burrard Inlet, have returned.
  • Dense forests of bull kelp have become established all around the skirt.
  • Sea urchins have taken to feeding on the algae on the lower benches. “The increase in predators is a strong indicator that the habitat skirt is effectively functioning in the manger of a typical intertidal habitat,” writes Slogan in his 2012 report on the project.

Comments


  • Great story! Nature is priceless. Loss of habitat is the number one killer of living organisms on the planet.

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