Disease
killing Pacific herring threatens salmon, scientist warns
Independent
fisheries scientist Alexandra Morton is raising concerns about a
disease she says is spreading through Pacific herring causing fish to
hemorrhage.
13
August, 2013
Ms.
Morton has called on the federal Department of Fisheries and Oceans
to investigate, saying it could cause large-scale herring kills and
infect wild salmon, which feed heavily on herring.
“I’ve
been seeing herring with bleeding fins,” Ms. Morton said Monday.
“Two days ago I did a beach seine on Malcolm Island [near Port
McNeill on northern Vancouver Island] and I got approximately 100 of
these little herring and they were not only bleeding from their fins,
but their bellies, their chins, their eyeballs. These are very, very
strong disease symptoms.”
Ms.
Morton, a researcher and environmental advocate who campaigns against
fish farms, said she caught some herring with similar symptoms in
beach seine nets in 2011, but was unable to get DFO to investigate.
The
problem seems much worse this time, she said, with all of the herring
she caught in the recent netting showing disease signs.
“It
was 100 per cent … I couldn’t find any that weren’t bleeding to
some degree. And they were schooling with young sockeye,” said Ms.
Morton, who suspects the disease is viral hemorrhagic septicemia
virus.
Dr.
Gary Marty, fish pathologist with the animal health centre for the
B.C. Ministry of Environment, said VHSV and a second disease, viral
erythrocytic necrosis, or VEN, are the two most likely suspects.
But
he said both diseases have been on the West Coast for a long time and
it is too soon to ring any alarm bells.
He
said Ms. Morton could be seeing a common, localized outbreak that
might just fade away.
“You’d
have to have more information or more fish dying” before concluding
there is a serious disease outbreak, Dr. Marty said.
“There
has been … research that shows it probably remains in the [herring]
population all the time, but at a very low level. So in that sense it
would be similar to influenza in people or just a cold virus in
people,” he said. “It will affect the population in late winter
and early spring and then as the fish get more food available in the
summer their condition improves and the virus goes away.”
Dr.
Marty said limited outbreaks of the two diseases are not necessarily
a bad thing.
“In
some respect for the population it’s actually good to have small
outbreaks, often because even though it may kill a few individual
fish, the survivors are then immune from the disease and actually the
population can be stronger as a result,” he said.
Dr.
Marty said he was aware of Ms. Morton’s catch of apparently
diseased herring, but hadn’t been officially notified by DFO of the
incident and had not begun any research himself.
DFO
officials weren’t available for comment Monday.
Lorena
Hamer, a spokesperson for the Herring Conservation and Research
Society, a non-profit founded by the herring fishing industry, said
the symptoms described by Ms. Morton sound like VHSV but scientific
confirmation is needed.
“I
do hope that DFO is following up on this – it would be good to get
confirmation of the disease, and more information on the extent of
the infection,” Ms. Hamer said in an e-mail.
She
noted that a paper published in a recent issue of the international
journal Veterinary Microbiology indicates that VHSV is a disease that
can spread between species.
The
paper, by researchers from Canada’s Pacific Biological Station, in
Nanaimo, and the U.S. Western Fisheries Research Center in Washington
State, states that farmed Atlantic salmon can develop VHS and
transmit it to Pacific herring.
“Viral
hemorrhagic septicemia is considered a serious disease of wild
Pacific herring, causing large scale fish kills,” states the paper.
Sun
News,
Aug 12, 2013: [Morton] dragged up several hundred of the fish this
past weekend and found the apparent infection had spread – instead
of their usual silver colour the fish had eyes, tails, underbellies,
gills and faces plastered
with the sickly red colour.
“I have never
seen fish that looked this bad,”
[...] In June, the affected fish were only found in eastern Johnstone
Strait, but have since spread to Alert Bay and Sointula, she said.
Canada.com,
Aug 16, 2013: Morton [...] pulled up a net of about 100 herring near
Sointula and found they were all bleeding. “It was
pretty shocking to
see,” said Morton [...] Herring
school with small sockeye
salmon and
are also eaten by chinook and coho.
‘Response’
from Canadian Government
Vancouver
24 hrs,
Aug 11, 2013: [Morton] says Fisheries and Oceans Canada [FOC]
isignoring
the problem.
[...] According to emails from FOC, the federal authority had asked
the marine biologist to send in 20 to 30 herring in September
2011,
saying that would be “more than sufficient for the lab to look for
clinical signs of disease and provide sufficient diagnostics.” She
did, and hasn’t
heard back since.
[...] FOC
officials did not respond to a request for comment by
the 24 hours presstime.
Canada.com,
Aug 16, 2013: Fisheries and Oceans Canada is trying to
confirm reports from an independent biologist that herring around
northern Vancouver Island have a disease that is causing bleeding
from their gills, bellies and eyeballs. [...] Arlene Tompkins of
DFO’s [Department of Fisheries and Oceans'] salmon assessment
section said staff in the Port Hardy area have
not found bleeding herring.
“We
are trying to retrieve samples,
but [Monday] we were not
successful because of heavy fog,”
she said. “We
haven’t had any other reports of fish kills or die-offs [see
salmon report below].”
Tompkins has seen photographs provided by Morton […]
Dr.
Gary Marty, British Columbia Ministry of Environment:
In some respect for the population it’s
actually good to have small outbreaks,
often because even though it may kill a few individual fish, the
survivors are then immune from the disease and actually the
population can be stronger as a result.
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