tincan
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http://www.vancouversun.com/news/Po...+Creek+herring+population/10240095/story.html
Pollution thwarts efforts to restore False Creek herring population
Study finds recreational vessels larger polluters than oil tankers and cargo ships
Read more: http://www.vancouversun.com/news/Po...+population/10240095/story.html#ixzz3EuHjN5td
This year, for the first time in decades, millions of herring spawned in False Creek.
An estimated 10 to 20 million herring — a foundation food for salmon and whales — survived as eggs on a synthetic stand-in for natural eelgrass habitat that Jonn Matsen and the Squamish Streamkeepers developed and wrapped around creosote-soaked pilings in Vancouver’s waters.
But an equal number of eggs died before they could hatch, apparently poisoned by the same type of persistent pollutants that a new study out of the University of Calgary found to be a larger threat to the Pacific coast than oil tankers and cargo ships.
According to the study, oil seeping out of recreational boats, fishing vessels, and commercial cruise ships, as well as fuel leaks associated with private marinas, account for more pollution along the B.C. coast than oil discharged from tankers and transport ships.
Stefania Bertazzon, the lead author of the study and an associate professor of geography at the University of Calgary, used a novel method to measure oily substances spilled along the B.C. coast and then determine their likely source.
She and the other researchers relied on observational data gathered from 2008 to 2010 by remote sensors attached to aircraft flown by the National Aerial Surveillance Program, which monitors pollution along the coast.
But that data was only a starting point.
“The aircraft are only detecting the spills in a certain space. Then we come into the game and we tested the association between the oil spills and the marine traffic at each location,” she said.
The team then divided the coastal waters into 25-square-kilometre cells and figured out what type of vessels used that space.
“For each of these cells, we knew how many hours were spent there by each type of vessel,” she said.
The method has its drawbacks, Bertazzon noted. Speed of travel, for example, could reduce the apparent impact of some types of vessels in certain waters.
“We are also aware that the big tankers and cargo ships are more regulated. They have to undergo several inspections and they are aware of the overhead surveillance, so they know how to behave,” she said. “There may be a lot of reasons why some types of vessels get caught more.”
Bertazzon said it was clear from the data that more spills happen close to the shore, and many unintentional spills occur in the vicinity of marinas where boats are docking and refuelling.
“I think people could be more careful,” she said.
Pollutants from marinas and recreational boaters are a major hurdle for Matsen and the Streamkeepers in their bid to revive False Creek as a herring spawning ground.
When Douglas Swanston, a Streamkeepers diver and marine biologist, tested the herring eggs earlier this year, he found half had died, something Matsen and others attributed to the eggs’ exposure to surface-level oil, fuel and creosote that had leached from dock piles.
“All these marinas have a little oil slick on the surface that goes up and down with the tide, so the upper half of the eggs pretty much got killed off,” said Matsen.
There are consequences further up the food chain for large predators like salmon, and in turn, recreational and commercial fishers.
“Everybody wants a nice, protected place to put their boats so they can go catch fish somewhere else,” he said. “They don’t realize they just damaged another big chunk of the environment. Pretty soon you have to go way, way (out) to catch fish.”
The Streamkeepers have also been working to restore the herring population under the Squamish Terminals dock, where freighters are closely monitored.
Matsen said nearly 100 per cent of the herring eggs in those waters successfully hatch out.
Bertazzon said the study — titled Geospatial analysis of oil discharges observed by the National Aerial Surveillance Program in the Canadian Pacific Ocean — appears to be the only attempt to associate oil spills and maritime pursuits.
mrobinson@vancouversun.com
Read more: http://www.vancouversun.com/news/Po...+population/10240095/story.html#ixzz3EuHd0Gt0
Pollution thwarts efforts to restore False Creek herring population
Study finds recreational vessels larger polluters than oil tankers and cargo ships
Read more: http://www.vancouversun.com/news/Po...+population/10240095/story.html#ixzz3EuHjN5td
This year, for the first time in decades, millions of herring spawned in False Creek.
An estimated 10 to 20 million herring — a foundation food for salmon and whales — survived as eggs on a synthetic stand-in for natural eelgrass habitat that Jonn Matsen and the Squamish Streamkeepers developed and wrapped around creosote-soaked pilings in Vancouver’s waters.
But an equal number of eggs died before they could hatch, apparently poisoned by the same type of persistent pollutants that a new study out of the University of Calgary found to be a larger threat to the Pacific coast than oil tankers and cargo ships.
According to the study, oil seeping out of recreational boats, fishing vessels, and commercial cruise ships, as well as fuel leaks associated with private marinas, account for more pollution along the B.C. coast than oil discharged from tankers and transport ships.
Stefania Bertazzon, the lead author of the study and an associate professor of geography at the University of Calgary, used a novel method to measure oily substances spilled along the B.C. coast and then determine their likely source.
She and the other researchers relied on observational data gathered from 2008 to 2010 by remote sensors attached to aircraft flown by the National Aerial Surveillance Program, which monitors pollution along the coast.
But that data was only a starting point.
“The aircraft are only detecting the spills in a certain space. Then we come into the game and we tested the association between the oil spills and the marine traffic at each location,” she said.
The team then divided the coastal waters into 25-square-kilometre cells and figured out what type of vessels used that space.
“For each of these cells, we knew how many hours were spent there by each type of vessel,” she said.
The method has its drawbacks, Bertazzon noted. Speed of travel, for example, could reduce the apparent impact of some types of vessels in certain waters.
“We are also aware that the big tankers and cargo ships are more regulated. They have to undergo several inspections and they are aware of the overhead surveillance, so they know how to behave,” she said. “There may be a lot of reasons why some types of vessels get caught more.”
Bertazzon said it was clear from the data that more spills happen close to the shore, and many unintentional spills occur in the vicinity of marinas where boats are docking and refuelling.
“I think people could be more careful,” she said.
Pollutants from marinas and recreational boaters are a major hurdle for Matsen and the Streamkeepers in their bid to revive False Creek as a herring spawning ground.
When Douglas Swanston, a Streamkeepers diver and marine biologist, tested the herring eggs earlier this year, he found half had died, something Matsen and others attributed to the eggs’ exposure to surface-level oil, fuel and creosote that had leached from dock piles.
“All these marinas have a little oil slick on the surface that goes up and down with the tide, so the upper half of the eggs pretty much got killed off,” said Matsen.
There are consequences further up the food chain for large predators like salmon, and in turn, recreational and commercial fishers.
“Everybody wants a nice, protected place to put their boats so they can go catch fish somewhere else,” he said. “They don’t realize they just damaged another big chunk of the environment. Pretty soon you have to go way, way (out) to catch fish.”
The Streamkeepers have also been working to restore the herring population under the Squamish Terminals dock, where freighters are closely monitored.
Matsen said nearly 100 per cent of the herring eggs in those waters successfully hatch out.
Bertazzon said the study — titled Geospatial analysis of oil discharges observed by the National Aerial Surveillance Program in the Canadian Pacific Ocean — appears to be the only attempt to associate oil spills and maritime pursuits.
mrobinson@vancouversun.com
Read more: http://www.vancouversun.com/news/Po...+population/10240095/story.html#ixzz3EuHd0Gt0
