National Shark Research Consortium
Florida Program for Shark Research - Florida Museum of Natural History
Featured Projects
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NSRC Featured Project:
Southern Belize Barrier Reef Shark Survey
Nurse shark (Ginglymostoma cirratum)
© Christina Conrath
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FPSR biologists recently participated in a survey of the elasmobranch resources
found in the waters adjacent to the Southern Belize Barrier Reef. This work was
done in collaboration with researchers from the Wildlife Conservation Society (WCS)
and was part of a larger assessment of Belize's shark and ray populations being
conducted by that agency. Unfortunately there is a very little historical data
available on the abundance of these resources but information from interviews with
fishermen and resource managers indicates that Belize shark populations have declined,
possibly severely. In order to assess these resources a 12 day survey was conducted
between May 20th and June 2nd, 2006. Forty seven 50 hook longline sets baited with
snook, barracuda, snapper, and other local fish species were set for periods of two
to three hours. In addition, over 100 drum lines were set for similar periods of
time throughout the study area.
During the assessment a total of 97 elasmobranchs were captured. Six species of
sharks were captured including: nurse sharks (Ginglymostoma cirratum), Caribbean
reef sharks (Carcharhinus perezi), blacktip sharks (Carcharhinus limbatus), lemon
sharks (Negaprion brevirostris), bull sharks (Carcharhinus leucas), and one Caribbean
sharpnose shark (Rhizoprionodon porosus). One southern stingray (Dasyatis americana)
was captured. In addition teleosts of several species were captured including one
goliath grouper (Ephinephelus itajara), and several barracuda (Sphyraena barracuda)
and amber jacks (Seriola lalandi). All elasmobranchs were identified, measured,
and sexed. When possible reproductive condition was assessed, tissue samples were
taken, and a marker tag was attached to the animal. Four adult lemon sharks were
tagged with satellite transmitters that relay positional data of the shark to a
satellite anytime the shark's dorsal fin breaks the surface of the water. These
transmitters will relay detailed and valuable movement and migration data for this
species.
Caribbean reef shark (Carcharhinus perezi)
© Christina Conrath
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One of the objectives of this project was to locate potential areas to concentrate
future acoustic studies. Two potential sites were identified in the survey as
having higher concentrations of sharks, making an acoustic study more feasible.
One of which was near Carrie Bow Caye and the other was near the Gladden Spit
Channels to the Silk Caye Wall. Another smaller potential site was near Northeast
Caye in the Sapodilla Cayes. In future research efforts within this area, we plan
to deploy acoustic receivers to gate specific regions within the above mentioned
areas. We will implant acoustic transmitters in sharks and track their movements
into and out of these areas as well as determine if these animals exhibit site
fidelity. We anticipate the combined continued assessment of these resources in
combination with the planned acoustic study will provide local resource managers
with a clearer understanding of the abundance and movements of these animals.
WCS biologists checking the longline for elasmobranchs
near the Sapodilla Cayes.
© Christina Conrath
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