Significant progress has been achieved by the Connectivity Working Group in key areas of genetic composition of coral populations, investigation of post settlement bottlenecks, connectivity of specific species such as Bicolour damselfish and investigation of lobster larval dispersal.

Coral connectivity using DNA

Collecting coral tissue from juveniles, small adults and large adults across large sections of reefs in Belize and Mexico, the Group has characterised the genetic composition of these coral populations. Genetic analysis has been based upon DNA extracted from the samples and is then used to assess if juveniles of a species have been produced by the local adult population. Tools to trace dispersal of planulae of Montastrea faveolata are being developed based on larval biology and behavior, immunogenetic probes to identify planulae, and magnetically attractive beads. The resulting data will then assist with development of reliable dispersal models of this species.

Post-settlement bottlenecks

To assess the bottlenecks in coral recruitment the Group is monitoring the settlement of corals at five sites in Meso-America, with permanent transects established at Belize, Guatemala, and Honduras. This forms the basis of large scale annual monitoring which is important as local marine populations are interconnected in a variety of ways, and the scale(s) of these interconnections must be taken into account if spatially explicit management programs are to be fully effective. The project is evaluating the demography of naturally occurring coral recruits and the factors affecting settlement. The project has already accumulated evidence that localised recruitment potential of reefs is a critical component of connectivity.

Connectivity in Bicolour damselfish

Research on bicolor damselfish is assessing several approaches to measuring connectivity in those reef species which do not aggregate over large distances to spawn. Sampling from Mexico to Honduras, the Group has made excellent progress combining genetic assignment tests, otolith microchemistry, ecology of settlement patterns, and hydrodynamic and habitat data to develop patterns of connectivity for populations of this common species.

Modelling lobster larval dispersal

The Connectivity Working Group has obtained data from a rearing study on the longevity of the multiple larval stages of Caribbean Spiny Lobster (Panulirus argus) which will be critically important to the development of dispersal models for this species. Recruitment continues to be monitored to provide data for validating model output.

Capacity building and outreach

Much of the information on connectivity and recruitment data gathered in this research, and synthesised from other work, has supported training workshops for managers of reefs and protected areas. Members of local reef management communities have also been trained in monitoring procedures, in principle enabling data collection over a large area, but also providing these managers with feasible management strategies that they can implement at the local scale.