Queen Conch in dramatic decline

The Queen Conch (Strombus gigas) is a large marine snail native to the Caribbean basin. Its range in the US encompasses the Florida Keys as well as the southeastern shore of the Florida peninsula.

This long-lived species matures late in life, making it vulnerable to fishing pressure. Queen conch is slow-moving and easy to pick up by hand, or with the simplest of fishing gear (known as poke poles).

They are especially vulnerable to fishing during the spawning season, when they gather in large numbers.

Demand for its delicious meat and beautiful shell have contributed to chronic over fishing and placed it under enormous stress throughout the Caribbean. The following is provided by the National Trust and Monterey Bay Aquarium Seafood Watch.

From birth, the Queen Conch creates a hard shell to protect its soft body by excreting calcium carbonate – a compound present in many animals such as the skeletons of coral polyps as well as our own bones and teeth. The mantle, a layer of skin surrounding the foot and lining the shell wall, discharges the calcium carbonate as a liquid which then hardens to form the shell. Conchs grow their shells in a clockwise spiral until a lip begins to form.

As the conch matures, it grows a fragile, flared lip that forms the base of the shell. This helps to prevent the conch from being overturned by wave action during rough weather.

Once the lip forms, the shell ceases most of its growth in length and begins to gradually thicken as the conch ages. The development of the lip means that the conch is now, basically, fully grown, however it is not yet sexually mature. Sexual maturity comes at about four to five years of age. At this point, it will have reached a length of approximately eight inches.

Breeding and spawning activity is most prevalent during the warmest months with some activity occurring year-round in warmer climes.

The introduction of scuba gear and freezer technology in the 1970s changed conch from a local specialty to an internationally-traded commodity, and since the 1970s, conch populations have been in recognized decline throughout the animal’s range.

Pollution and loss of nearshore habitat are preventing recovery in some areas, but there is also disturbing evidence that this species requires a certain density of adults to stimulate spawning behavior; where populations are too sparse, the adults no longer breed.

The drastic decline in conch populations across the Caribbean due to over-fishing, led to it being placed on the Convention on International Trade in Endangered Species’ (CITES) Appendix II in 1992. This means that member nations are obliged to have a fisheries management plan in place in order to export Queen Conchs.

Nevertheless, conch populations remain in an extremely fragile condition. One estimate suggests that out of 400,000 offspring, less than one conch will survive into adulthood. This alarming statistic, coupled with other environmental and human pressures, signals a worrying time for the Queen Conch.

The Cayman Islands’ Department of Environment conducts an annual conch survey to monitor the success of marine parks and replenishment zones in stabilising existing populations. In addition, they continue to recommend a reduction in legal catch limits to supplement their efforts and help protect the Queen Conch for future generations.

Cayman Sea Sense is dedicated to helping consumers make informed and environmentally positive seafood choices. For more information on this and other seafood options please visit www.nationaltrust.org.ky/seasense.html or contact [email protected].

FYI

For information on farmed conch please visit www.caicosconchfarm.com.

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