VANCOUVER - Silvery hordes of Pacific herring, one of the key indicator species for the health of intertidal habitats, have begun spawning again along the once-toxic shoreline of south-east False Creek.
John Harper, marine scientists who is assessing the shoreline modification program constructed in front of the athlete's village site, found the evidence at low tide last Monday.
"We stumbled across it about 3 p.m.," he said. "There is an incredible herring spawn on this shoreline. It was every place. It seemed to coincide with their (city of Vancouver) habitat restoration and shoreline rehabilitation.
"My guess is that there was a kilometre of spawn," said the scientist.
"This is a really good news story. What an incredible event."
Harper said that when he examined federal department of fisheries and oceans records available online, he could find no official record of similar spawns, at least not in the modern era.
Although there was once an extensive herring fishery in the waters immediately around Vancouver supplying smoked kippers, over the past century, False Creek's shoreline was extensively modified with landfill and industrial development which left toxic contaminants in soil and sediments.
The herring departed, so evidence that they are returning to a site of artificially-restored habitat is a major environmental success story.
Pacific herring deposit their jelly-like spawn in shallow water and it often sticks to seaweed and kelp fronds. That's precisely where Harper found it, clinging to seaweed which had grown on the rocks and gravel of an artificial island built under the federal governmentıs ³no net loss² policy for development which interfered with habitat.
"This habitat was all created as part of the shoreline restoration and waterfront walk development," Harper said. "Part of the development was creation of a habitat island." The small island, roughly the size of four tennis courts, was constructed as compensation for changes to the foreshore made during the cityıs remediation program for the terrestrial landscape said Robin Petri, a city engineer and manager of the project. She said development began in 2005. Part of the rehabilitation work involved changes to a shoreline that had already been ³totally modified² by historic development.
So the city built a long narrow tidal island at the end of a constructed wetland that treats storm runoff from the adjacent remediated lands. It becomes an island only at the highest of high tide. Apparently, it established a stretch of viable new habitat for marine life.
Harper says he was checking out the island when he spotted what looked like herring spawn on the first little spur of exposed beach that he saw.
"None of this shoreline existed a couple of years ago," he said. "The seaweed got onto the rocks and established itself and then the herrring came to spawn on it. A kilometre of spawn is pretty good.² Herring comprise one of the most important food fishes, both for humans and for many animal species including salmon, sea lions, seals, porpoises, eagles, gulls, mergansers, cormorants and other diving birds.
During the annual March spawning along the east coast of Vancouver Island, almost 100,000 marine birds were counted in less than one kilometre of coastline by one wildlife biologist.
Herring roe on kelp fronds was and remains a traditional delicacy for first nations along the coast and there is a commercial fishery for Pacific herring roe, which is a high-priced commodity in Japan where it is typically
used in making sushi or as an appetizer and is also eaten as roe-on-kelp.
shume@islandnet.com
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Topic: herring fishing question (Read 9251 times)