Re: [vernalpool] cause of spotted salamander mass mortality?

Chytrid infections do not seem to be an issue for our local Ambystoma.
I've tested about 120 adult spotteds for the fungus with only a couple of
low level positives. Katy Richards-Hrdlicka of Yale tested some of those
and has looked at many other New England Ambystoma with similar results.
As a group, Ambystomids seem very resistant to the infection, which
seemingly kills very few amphibians of any species in New England currently.

Spotted salamander embryos are quite tolerant of moderate levels of
chloride in water (up to about 1,000 micro-siemens - I did a study of
embryo mortality among quite a few egg masses in about 25 Westford, MA
vernal pools over a couple of years). Adults are likely a good deal more
tolerant than embryos. If it was some sort of salt, it would have needed
to be in very high concentrations. Also, if the salt was on the road, the
salamanders would likely have sensed it and avoided it.

If it was a toxin, I'd suspect something that is pretty acutely toxic (some
"icide").

Another less nefarious possibility though, which I mentioned before in
another incident this year, is that I and others have seen spotted
salamanders killed by sudden snaps of freezing weather when they have
migrated to a pool and find themselves wandering around a frozen over pool
with no access to water and plummeting temperatures.
Cheers
Bryan

On Fri, May 4, 2012 at 2:38 PM, matt burne <mattburne@gmail.com> wrote:

> **
>
>
> I'd doubt it, if they're massed together. An 'icide, be it herb or pest,
> or a salt treatment that exposes migrating animals to a lethal substance at
> a specific crossing site seems the most logical, without knowing specifics.
>
> Matt
>
>
> On Fri, May 4, 2012 at 2:26 PM, Twining, Jonathan E <
> jonathan.twining@enc.edu> wrote:
>
> > Is there any reason to suspect another cause, such as a chytrid fungus or
> > an amphibian virus? What about noxious algae in the pool?
> >
> >
> > Aloha and Malama ka 'aina,
> >
> > Jonathan E. Twining, Assistant Professor of Biology
> > Eastern Nazarene College
> > ________________________________
> > From: vernalpool@yahoogroups.com [vernalpool@yahoogroups.com] On Behalf
> > Of Brett Amy Thelen [thelen@harriscenter.org]
> > Sent: Friday, May 04, 2012 1:28 PM
> > To: vernalpool@yahoogroups.com
> > Subject: [vernalpool] cause of spotted salamander mass mortality?
> >
> >
> >
> > Hello Vernal Pool listservers --
> >
> > I just received the following email from a knowledgeable vernal pool
> > enthusiast in my area:
> >
> > I received some troubling news yesterday. Spoke with a friend who lives
> on
> > a dirt road in our town. Her neighbor who lives near a wetlands right on
> > the road found about 30 dead spotted salamanders by the side of the
> > wetlands. I haven't spoken to the neighbor yet, but these weren't run
> over.
> > Something else killed them, and she hypothesized that it was the calcium
> > chloride that the town has put down on the road to keep the dust down.
> Not
> > something that is usually done this time of year--more likely in the
> > summer.
> > I will try to get more information and hopefully, she took some pictures,
> > but it's a sad thing and if the calcium chloride is the culprit, I will
> > talk
> > with the road agent and see if they can avoid further treatments by
> > wetlands
> > in town.
> >
> > Does anyone have any thoughts (or can you point me in the direction of
> any
> > papers) on the potential cause of this mortality? Have you heard anything
> > about the impacts of calcium chloride on adult Ambystomids? I found one
> > literature review of road impacts on reptiles & amphibians (Jochimsen et
> > al.
> > 2004), which included a brief reference to unpublished data about
> mortality
> > of hundreds of blue-spotted salamanders along forest roads in Minnesota;
> > those salamander deaths were attributed to desiccation from calcium
> > chloride. Still, I'd be interested to read more, if any of you know about
> > research related to this, or have alternate theories.
> >
> > Thanks for any leads!
> >
> > Best,
> > Brett
> >
> > -----
> >
> > Brett Amy Thelen, M.S.
> > Program Director, Ashuelot Valley Environmental Observatory
> > Harris Center for Conservation Education
> > (603) 358-2065
> > thelen@harriscenter.org<mailto:thelen%40harriscenter.org>
> > www.aveo.org
> >
> > mailing address
> > 83 King's Highway
> > Hancock, NH 03449
> >
> > physical address
> > Carroll House, Room 303
> > Keene State College
> > Keene, NH 03435
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
> > ------------------------------------
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
>
> [Non-text portions of this message have been removed]
>
>
>


[Non-text portions of this message have been removed]



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