Jane Emerick
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Members of the Squamish Streamkeepers believe they've solved the mystery surrounding the depletion of the herring population in the Mamquam Blind Channel and are now working towards a solution to the problem.
Dr. Jonn Matsen is the coordinator of the group developed in 2000 for the promotion and preservation of Squamish's streams. He said through his recent research on the channel, the group believes a tar-like substance called creosote, found on the pilings making up the Squamish Terminal dock, is poisoning herring eggs and killing them.
"The herring love to spawn on the pilings because they are protected from the wind [and] predators, as well as having a moderated temperature," he said. "We didn't know that they were spawning there and they probably have been there for thirty years and nobody checked."
He said the discovery the herring were spawning in great numbers on the pilings was met with another discovery; that herring who spawned there, didn't survive.
The creosote on the pilings is put on the wood to protect it from deterioration and marine life.
Matsen said during the 1960s herring was plentiful in the channel, but something occurred in the 1970s that caused the population of the fish to decline.
"People used to pick them up by the bucket full and not even make a dent," he said.
According to Matsen, research at the time showed the fish were dieing from eating the sawdust from the sawmill. However, four decades later another theory is being developed.
In February Dr. Matsen and Streamkeeper Cal Hartnel went down to the Blind Channel to put cedar bows in the water to try and simulate kelp and encourage herring spawning. When they went back in March they discovered that along with the bows the herring had spawned farther out in the estuary in great numbers.
"We found 250 metres of eggs along the east side of the training dike (windsurfing dike) and across the channel. On the west of Squamish Terminals we found 50 metres of eggs. And on the east side of the Squamish Terminal we found 100 metres of eggs on both the north and south sides where there is heavier kelp. There was also spawning on the Nexen lands on the kelp in an area protected from the wind by the old railway car loading dock."
However Matsen said when he and Hartnel returned a few weeks later they discovered the eggs laid on the kelp had hatched and swam away and the eggs that were on the pilings were dead.
"There was 10 feet of eggs on each pilling and hundreds of pillings, so there were more dead eggs then there were herring that swam away."
Matsen said the fact the dock was built around 1973, the time the herring numbers began declining, combined with the number of dead eggs found on the pillings, was evidence the creosote was causing the decline of the herring populations.He said the fish are naturally drawn to the pillings because of its sheltering benefits.
"Eggs need protection from the south wind, so wherever they have protection they spawn."
According to Matsen now that they have a theory on what is killing the eggs, the next step will be to find away for the herring have a "perfect" spot to spawn, and not poison their eggs at the same time.
"I think we have identified the missing piece of the puzzle," said Matsen. "The population will really shoot up if we can create a situation where the eggs on the pilings are surviving."
They thought of several options including blocking the herring from going in the pilings but decided the best solution would be to see if there was some kind of coating or wrap that would protect the eggs from the substance.
"Newer docks are made of steel, but it would take millions to rebuild the dock with steel and on the other hand only thousands to re-coat the docks," said Matsen, adding the group had received full support from the Squamish Terminals as well as the company that makes creosote.
"They are working with us to fix it."
Matsen said all marine life in the area would benefit from the return of herring to the area.
"Herring are the main eaters of plankton," he said. "If we could help their numbers it would increase the numbers of their predators too, such as seals and otters and even gray whales."
