Genetic and Demographic Connectivity in Brazilian Reef Environments

Biological entities present multiple forms of connections between them in space and time, and at various scales. These links are established through the exchange of matter, energy, or information and produce different forms of connectivity. In this chapter we focus on three of these forms that were studied on Brazilian coral reefs. A first section deals with the exchange of information through genetic connectivity within an evolutionary timescale. We discuss the relevance of biogeographical barriers and marine currents to genetically structure populations of coral and fish species along the Brazilian coast. The second section concerns demographic connectivity within the biophysical context, on an ecological timescale. Current biophysical modeling tools were used to infer connectivity for fish and lobster species shedding light on the most relevant involved processes. In the third section, the focus is shifted to the ecological connectivity between coral reefs and adjacent habitats, involving mainly the movement of individuals. These migrations may be related to ontogenetic processes or foraging behavior. For Brazilian reef fish species, mangroves and estuaries are particularly important, and vertical and shore to shelf migrations are also discussed. Finally, we highlight that all these forms of connectivity must be considered within a sound conservation strategy. We hope this chapter not only summarizes the research on connectivity along Brazilian coral reefs, but also pinpoint questions that must be urgently addressed to produce a more complete picture of the functioning of these systems.