Connectivity Working Group

The BBP’s Connectivity Working Group (CWG) aims to understand how different parts of The Bahamas are ecologically “connected” with each other and with neighboring parts of the Caribbean. The group is addressing several main objectives revolving around analyses of oceanographic circulation patterns and the connectivity of marine populations. The degree of populational connectivity for various species within the archipelago will influence how various configurations of Marine Protected Areas serve to conserve such species.

Understanding the basic dynamics of water movement throughout The Bahamas is an important starting point for understanding the dispersal dynamics of marine organisms into and within the archipelago. Water flowing within The Bahamas appears to originate primarily from the North Atlantic subtropical gyre to the east, with some mixing from the Western Caribbean via the Straits of Florida to the west. Other data help calibrate circulation models and allow further quantification of circulation dynamics. These models, in turn, can be used to estimate potential dispersal of marine species. By tracking “virtual” particles that are released in various places and are then driven passively for various periods of time by these simulated circulation dynamics, researchers can assess potential dispersal patterns that may connect subpopulations from place to place.

Other species, especially those with active dispersal behaviors, are carried much less passively by currents. With these organisms, circulation dynamics may be poor indicators of populational connectivity. One approach is to adapt the virtual particle method above by endowing the dispersing particles with simple behaviors that approximate those known from various species. A complementary approach is to estimate the actual dispersal of certain species using genetic analyses of population structure. Species currently under genetic study include staghorn corals (Acropora cervicornis), queen conch (Strombus gigas), spiny lobsters (Panulirus argus), land crabs (Gecarcinus lateralis and Cardisoma guanhumi), and bonefish (Albula vulpes).