This is a little
bit of public innovation that surely applies to many other coastal sites were
industry and simple dumping has been ruinous.
What this tells us is that artificial eel grass works just fine and we
need to take advantage of that fact to produce habitat improvement.
For the past
fifty years, the waterfront around Vancouver has been steadily reshaped and
environmental restoration is high on the list.
At least now, we generally no longer used wood pilings treated with
creosote which only lasted twenty years anyway.
As you can imagine though, their replacement is generational because we
are usually replacing the whole related infrastructure at the same time.
This shows us
that even these tidal washes can be beautifully restored. When I came to Vancouver False Creek was an
industrial slough including a coopery right out of the eighteenth century. That is all gone now and restoring the herring will feed the fishery
out in the open harbor itself which is a powerful indicator of environmental
success.
Group hatches
plan to bring herring back to False Creek
Return of small fish would encourage return of
predators such as whales, dolphins
BY MATTHEW ROBINSON, VANCOUVER SUN OCTOBER 7,
2013
Jonn Matsen of the Squamish Streamkeepers’ Society
shows the plastic that could become a surface for herring spawn at Fisherman’s
Wharf. Eggs laid on creosote pilings die off.
Before bridges stretched across False Creek and
marinas dotted its waters, the Vancouver inlet was a rich spawning ground for
herring, which drew predatory dolphins and whales into surrounding waters.
But according to Jonn Matsen, co-chair of the
Squamish Streamkeepers’ Society, when False Creek was dredged and
creosote-soaked pilings were driven into the seabed, its herring-friendly
habitat faded and the fish and their predators all but vanished.
Now Matsen and the streamkeepers plan to reverse
some of the damage with an unexpected product that can turn docks themselves
into herring spawning grounds — plastic.
“Herring see a nice clean surface and they spawn on
it,” he explained. In particular, they are attracted to wooden pilings which
are often coated in creosote, a preservative that is toxic to fish eggs.
“What we’ve tried is wrapping the pilings with a
friendlier material,” he said.
The idea came about after the streamkeepers found
evidence in 2006 that herring had been attempting to spawn in the Squamish
Estuary about 50 km north of Vancouver. It’s a habitat which — like False Creek
— was once a significant spawning ground. The group soon discovered that
herring were attempting to spawn under docks in areas that had lost eelgrass
due to dredging or development. But their eggs were dying. The group
experimented by wrapping black plastic and landscape fabric around pilings to
block the creosote. It worked. The herring liked the texture of the surface and
eggs were surviving, so they wrapped more pilings — nearly 200 in all.
“Lo and behold, they came back and spawned
dramatically,” he said.
Over the course of a few years, other species
returned to the area as well, according to Matsen. He attributed the recent
return of Pacific white-sided dolphins and humpback whales to Howe Sound to a
resurgence in herring.
“There’s enough life back in Howe Sound that it’s
attracting the bigger predators,” he said.
“We think we can do the same thing in False Creek.”
Matsen said the downtown inlet remains a suitable
spot for herring for the same reason that it is an ideal location for boats —
it is protected from waves and heavy wind. But like other sheltered bays on the
heavily developed east side of Georgia Strait, False Creek needs some
modification to support herring again.
The society plans to install plastic wrappings on as
many as 20 pilings at Fisherman’s Wharf — by Granville Island — before herring
enter the area to spawn in February and March. It also intends to set up at
Burrard Civic Marina converted gill nets that mimic eelgrass and float with the
tide, a second method the group has tried.
“We’ve always experimented,” said Matsen. “We might
go in and do a couple of different things and then see how they react that
year.”
Matsen said the streamkeepers have relied on a
steady flow of $5,000 annual donations from Telus to keep their herring restoration
work going, including its recent test runs in False Creek.
Last winter the society installed small patches of
their latest iteration of plastic wrap in the inlet. When they returned to
check on them, they were laden with eggs.
Matsen predicts the smaller February spawn will be
successful, but cautioned that the fate of the larger March spawn could be
dependent on weather conditions. At low tide, eggs attached to the pilings are
exposed to air and if it’s too warm, they can fail. It is one reason for
testing both the piling and net systems at the inlet.
“It will be a little trial and error and hopefully
one year we’ll get the herring run back,” said Matsen.
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