Date:         Fri, 30 Dec 2005 19:17:15 -0500
Reply-To:     Conchologists List <CONCH-L@LISTSERV.UGA.EDU>
Sender:       Conchologists List <CONCH-L@LISTSERV.UGA.EDU>
From:         "Harry G. Lee" <shells@HGLEE.COM>
Subject:      Re: "rare" and valuable shells and  heedless destruction.
Content-Type: multipart/alternative;


Dear Guido et al.,

In contrast to of aquatic mollusks, of which many dozens have become
extinct through the environmental deterioration wrought by man, marine
mollusks are quite resilient as Guido indicates. While I don't wish to
detract from this biological fitness of these sea-dwelling species, I am
compelled to comment on the sentence following Guido's pronouncement: "At
present, we know of NOT A SINGLE MARINE SPECIES extinct by humans," with
which I agree. He went on to write: "At one moment there was discussion
about a northern American limpet, but it was found again recently," and
that statement warrants clarification.

We began the discussion of the Bowl Limpet (Turgeon Quinn, et al., 1999),
Lottia alveus alveus (Conrad, 1831) in this forum over seven years ago.
This species-level taxon lived a monotonous but prosperous life attached to
the marine Eelgrass, Zostera marina (Linnaeus), in extensive beds along the
northeast coast of North America from Long Island to Labrador - that is
until 1930, when a plague of slime mold infestation catastrophically
reduced the plant populations, leaving the survivors only in brackish
backwaters where the parasite (and regrettably the Bowl Limpet, its
obligate epibiont) could not survive.  No specimen of Lottia alveus alveus
has been collected since 1929, when it was known to be abundant.

To my knowledge, its taxonomy has not been questioned since Carlton,
Carlton, Dudley, Lindberg, and Vermeij (1991) distinguished it from
northwest American [Lottia alveus parallela (Dall, 1914)] and northeast
Asian [L. alveus angusta (Moskalev, 1967)] populations. I haven't heard of
any rediscovery of Lottia alveus alveus (Conrad, 1831), but (1) I may have
missed something or (2) the  northern Pacific subspecies might be
(incorrectly) considered as evidence, one way or another, against the
extinction of the Bowl Limpet.

A all-too-infrequent contributor to this form, Kevin Cummings, wrote us in
1999 [slightly edited]: "As the topic of rarity was discussed recently I
thought that this article [Roberts and Hawkins, 1999] might be of interest
to some in the group.  The authors make the case that marine species could
be at a far greater risk of extinction than previously assumed. The only
documented extinct marine species cited was the eelgrass limpet, Lottia
alveus alveus, but they cite others on the verge."

Lets hope that our species, by heeding the admonition of the Robertses and
Hawkinses of the world doesn't ever refute Guido's pronouncement.

Harry

Carlton, J., 1993.  Neoextinctions of Marine Invertebrates. American
Zoology, 33, 499-509.
Carlton, D., J. Carlton, E. Dudley, D. Lindberg, and G. Vermeij, 1991.  The
first historical extinction of a marine invertebrate in an ocean basin: The
demise of the Eelgrass Limpet, Lottia alveus. Biological Bulletin 180: 72-80.
Gould, S. J., 1991.  On the loss of a limpet. Natural History [vol. and
no.?]: 22-27. June.
Roberts, C. M., and J. P. Hawkins, 1999.  Extinction risk in the sea.
Trends in Ecology and Evolution  14(6):241-246.

Turgeon, D. D., J. F. Quinn, Jr., A. E. Bogan, E. V. Coan, F. G. Hochberg,
W. G. Lyons, P. M. Mikkelsen, R. J. Neves, C. F. E. Roper, G. Rosenberg, B.
Roth, A. Scheltema, F. G. Thompson, M. Vecchione, and J. D. Williams,
1998.  Common and scientific names of aquatic invertebrates from the United
States and Canada: mollusks, 2nd edition. American Fisheries Society,
Special Publication 26, Bethesda, Maryland. ix + pp. 1-509 + 16 pls.
(unpaginated).


At 02:12 PM 12/30/2005, Guido wrote:
I cannot agree on that. I think not even 5 % of the coasts of Australia
have been properly explored for shells. There are so few people diving
professionally and the costs in getting these shells are so high that these
rather explain the price than the rarity. I agree that some populations can
be truly devastated in small corners...    and I also agree that quality is
so important that a shell with growth line, sand grains etc.. is worthless.
Especially in the thersites they are good for the garbage.  We make a point
on Guphil I by not collecting damaged shells, unless the crew wants to eat
them.

At present, we know of NOT A SINGLE MARINE SPECIES extinct by humans.  At
one moment there was discussion about a northern American limpet, but it
was found again recently.

Instead of pointing the finger to collectors one should think about the
truly destroying things, such as building a town along the coast.

Guido
Harry G. Lee, M.D.
Suite 500
1801 Barrs Street
Jacksonville, FL 32204 USA
voice (904) 384 6419
fax (904) 388 1827
email: shells@hglee.com
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