Dear Doug and others,
 
The principles of collecting ethics remain the same in all cases; practice
depends on circumstances. The various "Sheller's Creeds" are very good
statements of principles, which boil down to this or live shells:
 
Above all, take only what the earth can replace. If the earth can support
it, take what you need, but only what you need and can care for. And
remember that others have needs, too.
 
"What you need" depends on whether you plan to display, sell, study, eat,
or make craftwork from the mollusks. "Circumstances" include how many
people want to share a given site, whether the site is under stress, etc.
 
Dead shells and fossils are special cases. It is unwise to collect ALL the
dead shells at a site, because dead shells are habitats for living
creatures. For instance, fish use them for nesting eggs. But usually more
dead shells can be collected from a given site than live shells without
changing the environment much. Where a species is very variable, it is
reasonable to collect more specimens for study, as Doug Shelton pointed
out.
 
Fossils are not alive and are not renewable resources, so collecting them
can actually "rescue" them for science, but restraint is best here too. If
you take every shell at a site, it may ruin someone else's field trip the
next week. There is no point in filling shoeboxes and basements with
fossils simply because they are there, and taking fossils out of the rock
destroys much of the information about them, just as removing a pot from a
grave can destroy its significance as a grave gift. I wonder sometimes at
the need some people feel to fill mason jars with shark teeth or blastoids,
mixing specimens willy-nilly from different locations, just to have them.
Must be instinctive; we all descend from hunter-gatherers, after all.
 
Paleontologists sometimes calculate the minimum volume of shelly sediment
that should be collected in order to have a statistically significant
number of specimens to count. For shell-packed sand, this might amount to a
few liters (quarts) of sediment with thousands of small shells in all
states of preservation. If the study focuses on measurements of one species
instead of the whole fauna, then 300 is the minimum number needed for
accurate statistics, and 1000 is better. This number is determined by
mathematical considerations, not by anything in malacology. It is the same
number for any group of objects to be measured if you want to achieve a
reasonably narrow "standard deviation" or "smear" of numbers. Groups of
objects collected for statistical purposes are kept together as vouchers,
not broken up for trade afterward. (In statistical studies of live
creatures, the animals are usually measured while alive and returned to the
environment.)
 
Three hundred is NOT a suggested number for most collectors, ONLY for those
who have a specific, statistical, malacological question to answer AND
PUBLISH for the good of everyone, or for those whose job is to maintain
large public reference collections that anyone can study and publish from,
such as the Florida Museum of Natural History. And even these museums
generally want such large collections only for their core region of study,
not the world. So this message is not an excuse to collect 300 of a species
just to fill a mason jar.
 
Marlo and Jenny, I appreciate your "hands off" viewpoint toward live
shells. I rarely collect live mollusks myself; I have no good reason to.
But I spent yesterday showing fossils, hands on, to children at an open
house for a nature center, and I can tell you that the closer they get to
the specimen, the more their eyes light up.
 
Andrew K. Rindsberg
Geological Survey of Alabama