BNT Feature Presenters: Melanie Devore and Deborah Freile

Thanks to Melanie for providing this summary of their research and
presentation!

The Bahamas National Conchservation Campaign http://www.bnt.bs/conchservation
has recruited the Bahamian public to join agencies, private entities and researchers
to protect The Bahamas’ favorite beautiful, tasty, mollusk the queen conch.  It is not
surprising that there are dozens of research papers on queen conch.  However, we
know very little about the general ecology and population structure of other large,
showy gastropods valued in the curio trade. Unlike conchs, helmets and triton are
predatory and their populations may not rebound once they collapse. Likewise, we
know very little regarding the impact of bulk collecting of targeted species used in
shell crafts.  During our presentation at the BNT Conference we will be discussing
the nature of commercial shell collecting and showing how some data can be obtained
using online catalogues from large, curio companies.  The conservation outlook for the
large, predatory gastropods so far is bleak.  The greatest hope for maintaining
populations of these iconic Bahamian mollusks rests in the waters of the Bahamas
MPAs.

 Abstract after the jump.

Curios and handicrafts comprised of marine products are commonly sold to tourists throughout the Caribbean. Though the majority of material comes from the Pacific; Trinidad and Tobago (4%) and Haiti (2%), as well as other countries in the Caribbean are also sources (Tissot et al., 2010). Currently we know very little regarding the biology, distribution and population sizes of many marine mollusks commonly targeted by curio collectors. But estimates put the trade of invertebrates at 2500 metric tons (Tissot et al., 2010) or 9-10 million animals mostly mollusks, shrimp and anemones (Wabnitz et al., 2003). The lack of information and published studies makes assessing the impact of shell collecting difficult. Recently we began to survey the sources of curios sold in the Bahamas, the U.S and from inventories of wholesale companies supplying shells to souvenir shops and hobby supply stores. In general, most shops in both the Bahamas and US are obtaining their shell inventory from wholesalers who operate large scale collecting operations in the Philippines and Indonesia. Most shells of Caribbean origin sold by wholesalers are harvested “slit” conchs. Large, decorative shells, including King Helmet (Cassis tuberosa), Queen Helmet (Cassis madagascariensis), and Trumpet Triton (Charonia variegata) shells, are currently largely obtained from Haiti. Wholesale suppliers often list “Bahamian Sea Fans” and “Bahamian Starfish” as part of their inventories. On smaller retail scales, opportunistic shell stalls are a source of marine curios on docks and public beaches. Besides conchs, helmet shells, starfish and True Tulip (Fasciolaria tulipa) shells are offered for sale. Other smaller shells for sale have included West Indian Top-Shells (Cittarium pica). Some of these shells appear to have been obtained alive while others were crabbed or collected from beach drift. Some mollusks, displayed in stores where lobster is available for purchase, appear to have been obtained from traps as by catch either alive or as crabbed specimens. In 1993-94 survey of by catch from lobster traps in Florida (Matthews et al., 2005), urchins and hermit crabs were common and Green Sea Urchin (Lytechinus variegatus) was often retained for sale in the curio trade. In the Bahamas, the lack of research on the impact of shell collection makes it difficult to determine best management practices. Collection of live animals has the potential to damage near shore habitats as rocks and corals on the reef flat may be overturned to obtain the live mollusks. Shell material washed on beaches contributes to sediments and also provides housing for hermit crabs. Current data we have for San Salvador Island indicates a decline in population numbers of King Helmet and Trumpet Triton over the past 15 years. Only one living Trumpet Triton has been encountered over the last five years. Since large shells are not commonly sold to tourists on the island, this decline could be linked with another factor other than collecting. The threat for large, carnivorous mollusks, with small population numbers, is a concern that needs to be addressed.

 

By | 2014-08-15T22:19:31-05:00 March 2nd, 2014|Categories: Conch, Invertebrates, Overfishing|0 Comments

About the Author:

Craig Layman
My lab’s interdisciplinary pursuits provide for a multi-faceted understanding of environmental change in the coastal realm. We are ecologists, asking questions that span population, community, ecosystem and evolutionary sub-disciplines. We often use a food web based perspective, exploring top-down (e.g., predation) and bottom-up (e.g., nutrient excretion) mechanisms by which animals affect ecosystem processes. All of our efforts are framed within a broader outreach framework, directly integrating science and education, using approaches such as this website.

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