 QUEEN CONCH ( STROMBUS GIGAS) IN THE EXUMA CAYS, BAHAMAS by Ned Smith, Ph.D., and Patrick Pitts Division of Marine Science, HARBOR BRANCH OCEANOGRAPHIC INSTITUTION |
Using
surface drifters, oceanographers were able to determine that Exuma Sound
water moves an average of about 6 km (3.75 miles) onto the bank during
the flood tide, or at least as far as the large nursery areas. Further,
an analysis of water temperature data confirmed that conch nurseries in
this part of the Exuma Cays receive a regular flushing of oceanic water
from Exuma Sound. Those habitats which at first appeared suitable for
conch, but which were devoid of the animals, were rarely flushed.
It is unclear at this time how the oceanic water influences the conch or its habitat. The conch could be responding to a direct effect of the sound water, such as temperature. More likely, they are responding to indirect effects that the water mass may be having on habitat features such as food production or sediment distribution. Unfortunately, the queen conch is only one of the world's many commercially important fisheries species whose numbers are on the decline. As these species become threatened, it becomes increasingly important to understand the processes governing their larval transport, recruitment and distribution. 
Working together, scientists from various disciplines can add to our knowledge of these processes in general, and provide useful information needed to make sound management decisions regarding important fisheries resources. (Left) The authors, physical oceanographers Patrick Pitts and Ned Smith, preparing to collect drifter or drogue data. |
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