Trish,

Because of the Gulf Stream, there are many shells in the Ft Lauderdale area
that might seem to be more southern species. Not only do the veligers have a
chance to travel on the 4-knot current of the Gulf Stream to northern
locations (even in some cases to the Carolinas and Bermuda) but the Stream
is warm water, making living conditions possible for tropical species. There
are documented cases of sea turtles riding the Gulf Stream to Nova Scotia.

Also, my experience years ago at beaches on the east coast of Florida tell
me that very few shells actually wash up normally on these beaches. The
water depth drops very fast over there, reaching 100 feet within a mile or
two of shore; here in Sarasota we have to travel some 40 miles out to reach
that depth. Plus, there are rock reefs close to shore which trap shells and
make them available to hermit crabs (crabs keep the shells in the water).
Thus, wave action won't bring many shells ashore.

I really think the shells you find on the east coast of Florida are mostly
dredged shells, and the sand came from nearby.

Peggy

> Dear Listers,
> I have been "listening" for awhile now but have not yet entered any
> discussions.  However, yesterday I noticed the posting regarding the unknown
> Conus at John Lloyd State Park in Dania, Florida and decided to share my
> thoughts and observations, since I had just spent the morning collecting
> beached shells at this same location.  I also collected some young Conus
> which I have not been able to get the time to identify, but I will be looking
> at them soon and will take some digital photos in the next day or so.
> However, I am very interested in the situation at this location, because I am
> unfamiliar with the recent  history of the area.  I did spend a lot of time
> trying to figure out the source of the shells on this beach and had finally
> concluded that a major source is the apparently dredged sand that has been
> put there to renourish the beach, because there is definitely erosion
> occurring there now - there is a pronounced scarp that ranges in height from
> about 3 feet to over 6 feet, and the high tide on November 17 & 18 was
> eroding the base. The heavy rains on November 17 washed and exposed a number
> of molluscs at the edge of this scarp, and subsequently I found a great
> number of extremely fresh looking olives, cones, scallops, etc that had been
> preserved under a few feet of sand.  My impression was that this sand may
> have come from a location farther than just offshore in the Fort Lauderdale
> area - probably from further south.  My questions regarding this are: does
> anyone know when this beach was renourished, and where the sand has come
> from?  Are these cities getting any of it from the Bahamas? Is there any
> official source of this type of information?
> I do a lot of beach collecting, and although I maintain a skeptical mind with
> regard to dead shells, I still feel the information gathered from observing
> the occurrence of particular species at specific localities at different
> times of year,  and under different conditions can be quite informative.  But
> beach renourishment obviously causes a problem with this sort of data.
> Trish Hartmann
> [log in to unmask]
> Tampa, Florida
>

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                                  Peggy Williams
                                   Shell Elegant
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                                Tallevast FL 34270
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