Research

	Enlarge ImageAmphiprion percula are common on reefs in Kimbe Bay, Papua New Guinea (Simon Thorrold)
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	» PopConnFinalReport1_7663.pdf Final report from the "Population Connectivity in Marine Systems" workshop, sponsored by NSF.

Connectivity in marine metapopulations

A central goal of marine ecology is to achieve a mechanistic understanding of the factors regulating the abundance and distribution of marine populations. One critical component of the above goal is to quantify rates of exchange, or connectivity, among subpopulations of marine organisms via larval dispersal.  Theoretical studies suggest that these linkages play a fundamental role in local and metapopulation dynamics, community structure, genetic diversity, and the resiliency of populations to human exploitation. Understanding population connectivity is also key in efforts to develop spatial management methods for marine-capture fisheries, including the design of networks of marine reserves.  The question of population connectivity was the focus of a recent workshop sponsored by the National Science Foundation (see sidebar for the workshop's final report). 

We are using a novel mass-marking technique, transgenerational Isotope Labeling (TRAIL), and DNA parentage analyses to generate empirical estimates of larval dispersal in fish populations inhabiting coral reefs in Papua New Guinea.  The relative importance of retention and connectivity will be measured on both regional and local scales.  The project, in collaboration with Dr. Geoffrey Jones (James Cook University) and Dr. Serge Planes (University of Perpignon), is funded by National Science Foundation and the Australian Research Council.  The first paper from this research was featured on the cover of Current Biology (Jones et al., 2005), and more recently the first field application of the TRAIL technique was published in Science (Almany et al., 2007).

Otolith geochemistry

We continue to develop techniques for trace element and stable isotope analyses of fish otoliths.  Focusing on high precision in situ analyses of otolith geochemistry using laser probes and sector field inductively coupled plasma mass spectrometry (ICP-MS), we are developing methods for determining isotopic ratios of selected elements in the otoliths of marine and anadromous fishes.  Isotopic ratios are assayed using a Thermo-Finnigan Neptune multiple collector ICP-MS in WHOI's Inductively Coupled Plasma facility.  One application of this approach will involve determining natal locations of juvenile American shad, collected from rivers along the east coast of the United States.  Trace element, d¹³C and d¹⁸O signatures in these otoliths will be combined with high precision Sr isotope measurement to increase the confidence with which adult shad can be assigned to natal river based on these natural geochemical signatures. This work is funded by NSF and the Woods Hole Oceanographic Institution.

Fisheries Oceanography

Identifying Larval Sources and Essential Fish Habitat of Juvenile Snappers along the Southeastern Coast of the United States

We are examining larval dispersal in the gray snapper (Lutjanus griseus) along the coast of the southeast United States.  Gray snapper spawn from the northeast coast of Florida and throughout the Florida Keys. Larvae may disperse considerable distances if they become entrained in the Gulf Stream, and juveniles of both species recruit to estuarine nursery areas as far north as Beaufort Inlet, North Carolina.  We are coupling otolith-derived age and growth with geochemical signatures in otoliths assayed using laser ablation inductively coupled plasma mass spectrometry, enabling a detailed resolution of the life history of individual fish. Comparison of such life histories for a group of fishes settling along a coastline has the potential, therefore, to identify the pathways of larval movement and population connectivity.  This work is a collaboration among researchers at the Florida Marine Research Institute (Dr. Luiz Barbieri), the University of Miami (Dr. S. Sponaugle and Dr. R. Cowen) and NOAA's Narrangansett, RI laboratory (Dr. Jon Hare), and is funded by NOAA's National Sea Grant Office.