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Something to keep an eye on,

as well as this story, http://www.alaskadispatch.com/article/20140214/tiny-fish-could-be-blame-crashing-alaska-sea-life-populations
Tiny fish could be to blame for crashing Alaska sea life populations, February 14, 2014

The itty-bitty sand lance could be the culprit behind drops in the populations of Western Alaska’s Steller sea lions, sea otters and northern fur seals, and maybe offer a clue about king salmon declines.
A scientist who has spent much of his career studying paralytic shellfish poisoning has an all-encompassing theory about what may have killed gobs of threatened and endangered marine mammal predators in Alaska, not to mention the vaunted king salmon that appears to be on the decline in some of the state’s waterways.

Message: 2
Date: Tue, 18 Feb 2014 15:45:14 +0000

SARCOCYSTIS, PINNIPEDS – CANADA (02): (NOVA SCOTIA) COMMENT
***********************************************************
A ProMED-mail post
http://www.promedmail.org
ProMED-mail is a program of the
International Society for Infectious Diseases
http://www.isid.org

Date: Mon 17 Feb 2014
Source: Lena Measures [edited]

Re ProMED-mail Sarcocystis, pinnipeds – Canada: (NS) gray seal
20140217.2281787
———————————————————————-
Regarding the ProMED posting on sarcocystis and toxoplasma — this
report is very confusing. As the moderator indicates how climate
change can be linked to these findings is speculative. Gray seals
breed on ice in the Gulf of St Lawrence or islands such as Hay Island
off Cape Breton, Nova Scotia. During winter, coyotes, feral dogs, or
other terrestrial and avian carnivores will feed on seal placentas or
dead or live seal pups during the breeding season (December to
February). These predators may cross to Hay Island on ice, for
example, bringing infective stages of _Sarcocystis_ which may account
for infections in gray seals. This seems plausible given that the new
species is, according to the report, related to _S. canis_ from dogs.
However, the report appears to suggest that gray seals acquire
_Sarcocystis_ via contact with ringed seals when gray seals enter
formerly ice-covered Arctic waters where ringed seals live. In fact
ringed seals are known to move southwards along the Labrador coast,
occasionally reaching the Gulf of St Lawrence where gray seals occur.
Given these possible hypotheses above, it is not necessary to invoke
climate change.

As for _Toxoplasma gondii_ in Arctic beluga, this parasite has been
reported in St Lawrence Estuary beluga as well as in pinnipeds (based
on serological data) on the east coast of Canada. It is unknown how
transmission to marine mammals occurs — it may be via _T. gondii_
from domestic cats (coastal runoff or contaminated sewage) or there
may be a unique marine strain with unknown life cycle. Few Inuit own
domestic cats but infected Canadian lynx may be found in northern
boreal forests. Migratory geese may also transport _T. gondii_ above
the treeline to Arctic waters. In short, infections of _T. gondii_ in
Arctic wildlife including marine mammals and in Inuit populations
subsisting on country foods (wild game, often eaten raw), are not
fully understood in terms of transmission.


Dr Lena Measures
Sante mammifere marin/Marine mammal health
Peches et Oceans/Fisheries and Oceans Canada
Institut Maurice-Lamontagne/Maurice Lamontagne Institute
850, route de la mer, Mont-Joli, Qc,
Canada G5H 3Z4

[Many thanks to Dr Measures for shedding light on some aspects of
Arctic animal ecology that are relevant for parasites such as _T.
gondii_ and _Sarcocystis_.

Indeed, climate change has been invoked irresponsibly and blamed for
the emergence and re-emergence of a number of diseases. I concur with
Dr Measures’ words of caution. I did not intend to loosely implicate
climate change in these findings, but rather I wanted to make the
point that, should climate change be contributing to the transmission
of pathogens in the Arctic, producing scientific evidence of such
cause-effect relationships would be extremely challenging. Thus, most
suggestions about the involvement of climate change can only be
speculative.

But the absence of evidence is not proof of absence. If Arctic
ecosystems are suffering drastic changes, a cascade of interacting
effects impacting the dynamics of health of wildlife and the ecology
of parasites is to be expected. While the explanations offered by Dr
Measures are entirely plausible, they would not explain an emergence
or resurgence of parasites, should the latter be occurring. Climate
change should not be sloppily invoked, but neither loosely ruled out.
– Mod.PMB

A HealthMap/ProMED-mail map can be accessed at:
<http://healthmap.org/r/alyp&gt;.]

[See Also:
Sarcocystis, pinnipeds – Canada: (NS) gray seal 20140217.2281787]
………………………………………….pmb/mj/mpp

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