Kevin,
Well, species ranges do shift continually anyway. To establish a trend would
require gathering data on many species over a period of time. Existing
documentation can be included in such analyses as long as allowances are
made for differences in collecting methods, time spent collecting,
expertise, and taxonomic knowledge (for example, an early collector might
not be aware of subtle differences between dimilar species and lump them
together). Also, to be fair, one should be alert to the possibility that
some species' ranges might be shrinking southward.
In studies of a region covering a period of several years, it's a good idea
to include information on some of the major environmental upsets. Some of
them would be brief and violent, such as major hurricanes and oil spills.
Others would be slow but even more pervasive, such as shifts in agriculture,
fishing, offshore mining, and industry. Examples: Farming leads to more
rapid erosion than leaving the land forested, and some of the eroded soil
ends up in bays and the sea, enriching or smothering the seafloor. Offshore
mining for sand and gravel can eliminate local biologic communities and
alter the bottom so that other communities replace them. Dragnets can remove
scallops and other surface-dwelling organisms; fishing can remove predators,
with effects that can be difficult to predict or even document properly.
Sewage and industrial pollution have such familiar effects that I don't
think I need to hammer them in. New England has undergone so many such
effects over the past five centuries that it would be challenging (but not
impossible) to sort them out. On the plus side, New England has a good
record built up over many years by amateur and professional collectors -- a
historical record that is at best sketchy for most areas, e.g., the Alabama
coast before Doug Shelton's studies.
Any savvy collector can gather information today that will be invaluable
tomorrow to document environmental changes. And with digital photography, a
collector need not even remove shells from the environment, though physical
collecting is still best for accurate work, and especially to document
species that look much alike. I invite curators to comment on this,
particularly on their needs and interests.
Cheers,
Andy
Andrew K. Rindsberg
Geological Survey of Alabama
-----Original Message-----
From: Conchologists List [mailto:[log in to unmask]] On Behalf Of
Kevin Czaja
Sent: Monday, July 25, 2005 3:01 PM
To: [log in to unmask]
Subject: Re: Donax fossor in Rhode Island
Andrew,
can't say I've seen a large list of other species heading further
North, but I've only been collecting with intensity in the last five years.
The only other species that I've found perhaps creeping North is Solen
viridis. The Northern range limit based upon the literature is Rhode Island
(and I did find some really nice examples in Newport this past month).
However, over the last couple of years I've also found the species in
Hyannis, MA (lower Cape Cod). So that might be further evidence of a
warming trend. I know the effects of true global warming could be very bad
as I understand it, but I sure wouldn't mind more of those pretty Southern
species moving up to my neck of the woods! -K
On Mon, 25 Jul 2005 09:15:00 -0500, Andy Rindsberg
<[log in to unmask]> wrote:
>Kevin,
>
>Could be important, and it would be good for other New England
>collectors
to
>keep their eyes open. This is what a northward biogeographic shift due
>to global warming would look like, though of course that is not the
>only possible explanation. Are other species extending their ranges in
>tandem,
or
>is this the only one?
>
>Andrew K. Rindsberg
>Geological Survey of Alabama
>
>-----Original Message-----
>From: Conchologists List [mailto:[log in to unmask]] On Behalf Of
>Kevin Czaja
>Sent: Friday, July 22, 2005 6:38 PM
>To: [log in to unmask]
>Subject: Donax fossor in Rhode Island
>
>
>I recently found multiple specimens of Donax fossor on Easton Beach in
>Newport, Rhode Island. Is this find unique regarding the northern
>extent
of
>the species range? As I understood it, Long Island, NY was supposed to
>be the northern limit. I thought it even exceptional when I found the
species
>as far east as South Hampton, NY a few summers ago. Has anyone else
>found the species in Rhode Island? -Kevin Czaja Very much enjoying the
>Florida type weather in Boston, MA!
>
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