Connectivity and Hydrodynamics

    Understanding how physical oceanography, organismal behavior, and life history strategies interact to determine the “connectedness” of coral reefs is a major focus of research at the University of Miami’s Rosenstiel School of Marine and Atmospheric Science. Most of the work in this area continues to be targeted at biophysical interactions. Major interdisciplinary projects bringing together biological oceanographers, physical oceanographers, and modelers have begun to quantify the dispersal kernels for various species of reef fishes and corals. This coupling of empirical data with nested high-resolution circulation models allows for realistic measures of functional connectivity among marine populations.

    Validation of these complex models is ongoing via projects directly linking offshore ichthyoplankton with nearshore coral reef recruits. Such linkages also reveal that connectivity is influenced by variable pelagic larval growth and survival rates, as well as carry-over to benthic juvenile stages.

    Other connectivity projects have involved the use of  geochemical tracers in fish otoliths to understand the origin of fish stocks and the use of isotopic indicators as proxies for temperature. Population genetic markers (microsatellites) are also being employed to understand the connectivity of reef corals and fishes.

    Among the recent studies into connectivity, NCORE scientists developed a state-of-the-art drifting observational device and deployed it off the coast of Australia’s Lizard Island earlier this year, allowing researchers to detect and quantify the orientation of larval reef fish in the pelagic environment. Results from this study are expected to help capture the movement of a larva and the types of cues -- acoustic, chemical, or magnetic -- that larvae may use to navigate settlement.

Key Questions

 

How connected are coral reef ecosystems within regions?

Can healthy reefs replenish disturbed ones, and how quickly?

Can we predict patterns of connectivity directly from physical oceanographic and biological parameters?