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Collecting American Seashells SI
It is most surprising how many treasures within arm's reach are lost to
the uninitiated. A waterlogged board if kicked aside may be found to con-
tain three or four kinds of interesting wood-boring clams; a rock unturned
at the end of the beach may still shelter a pair of cowries or a nest of orangetentacled
Lima Clams; or the seafan momentarily admired and cast aside may
be the holdfast for a colony of rare, purple Simnia snails. All mollusks have
their particular ecological niches or favorite haunts, whether a very limited
type of locality or more extensive areas such as mud flats, rocky shores or
the open ocean. To be forearmed with a knowledge of where our species
live will often bring rich rewards from salt marshes, eel-grass flats, mangrove
trees, the backs of other marine creatures, the underside of boats or even the
stomachs of fish. The tracks made by gastropods on sand or mud bottoms
are characteristic for many species and can aid in hunting down live speci-
mens. So, too, holes of certain shapes and sizes in the sand flat are a betrayal
of the clam occupant deep below. At times it is worthwhile to know when
and where gregarious mollusks gather to breed. Their appearance is often
clocked not only by the seasons but often bv tidal conditions and the time
of day. Most intertidal species reveal themselves more frequently about half
an hour after the tide has begun to rise. A great number of species are more
active a few hours after dark, while others are content to wait until early
morning before starting on their foraging missions.
Attention to tides, seasonal moods of the ocean and the effects of winds
and currents is put to good use by the expert collectors. September seems to
be the most favorable time, for instance, to gather shells on the Carolina
strands. During late April and early May there is more likelihood of the
Purple Sea Snail, JajJtbma, being washed ashore on the east coast of Florida.
After winter gales, some New England beaches may be strewn with millions
of large Surf Clams, Spisida.
Low tide is obviously the best time to collect, and most collectors make
long-range plans to catch the spring tides. Local newspapers publish the
times of low and high tides, but many serious collectors prefer to use the
Coast and Geodetic Survey Tide Tables to plan well in advance for the lowest
tide of the month. Tide Tables for the Pacific and Atlantic coasts may be
obtained for a fraction of a dollar from the U.S. Department of Commerce,
Washington 25, D.C.
As you may well know, the rise and fall of tides are caused by the at-
traction of the moon, and to a lesser extent by the sun. Choose the time
of the new and full moon for collecting, for that is when the sun and moon
are uniting their forces to give the lowest or spring tides. Low tide lasts
for about fifteen minutes, but profitable collecting may be done one hour be-
fore or after. It is sometimes useful to know that the tides are about fifty
minutes later the following day. Be aware of the dangers of rising tides,