Here in Ecuador, a vigorous Spondylus fishery has sprung up
during the past 8-10 years; mostly Spondylus calcifer but also S.
princeps.  Unfortunately, most of the harvesting occurs within a
national park.  A number of conservation groups and (at last) the
government have become concerned about the unregulated harvest
and an investigation of the situation has been proposed.  Because
these species often grow in distorted shapes and are usually
heavily encrusted with other organisms, marking and measuring
them present some difficulties.  Does anyone know of a good
methodology for 1) permanently marking living Spondylus and 2)
measuring live Spondylus in situ with sufficient accuracy and
precision to calculate growth rates?  It seems that one might be
able to insert some soft material between the valves and induce the
animal to "bite down", leaving an impression of the valves.  Has
anyone ever tried such a technique on Spondylus or any other
species?

kate