Collaborative Research: Connectivity in Western Atlantic Seep Populations: Oceanographic and Life History Processes Underlying Genetic Structure

Sponsor:  National Science Foundation

Collaborators

Duke University: Cindy Van Dover, Clifford Cunningham
NC State University: David Eggleston, Doreen McVeigh
University of Oregon Eugene: Craig Young, Svetlana Maslakova

Funding Period

2011-2016

Description

We have assembled an interdisciplinary team to integrate studies of oceanographic circulation, larval dispersal, invertebrate life histories, population genetics, and phylogeography to explore questions of contemporary and historical connectivity in relatively unexplored deep-sea chemosynthetic ecosystems. We target five deep-sea seep systems in the Intra-American Sea (Blake Ridge, Florida Escarpment, Alaminos Canyon, Brine Pool, Barbados) that (1) allow us to consider connectivity at seeps on spatial scales that match those at which vent systems are being studied (~3500 km), (2) include a set of nested seeps (within the Barbados system) within which connectivity can be explored at more local spatial scales (30 to 130 km), and (3) include species that span depth (~600 m to 3600 m) and geographic ranges (30 km to 3500 km) and that have diverse life-history characteristics. Oceanographic and larval transport models are being used to develop hypotheses that can be tested with larval and genetic data, with iterative refinement of larval transport models based on acquired larval biology and genetic data. Thus, our field program includes time-series sampling of larvae at seeps coupled with vertical measures of oceanographic current velocities via ADCP, which is being used to validate our 3-d hydrodynamic model and tests of larval dispersal and connectivity predictions; water column sampling to determine larval distribution potential; shipboard studies of larval biology and behavior; and sampling of benthic target species. Phylogenetic and population genetic tools (gene sequences and microsatellite markers) are being used to explore historical and contemporary gene flow (directionality, intensity, extent). Molecular tools can quantify patterns of genetic diversity in larval and adult populations.

Intellectual Merit: Since their discovery, deep-sea chemosynthetic ecosystems have been novel systems within which to test the generality of paradigms developed for shallow-water species. This study allows us to explore scale-dependent biodiversity and recruitment dynamics in deep-sea seep communities, and identify key factors underlying population persistence and maintenance of biodiversity in these patchy systems. Building capacity (knowledge and expertise) in studying spatial and temporal scales of connectivity and the oceanographic and life-history processes that underlie genetic subdivision in the deep sea is critical in light of emergent policy regimes in both Exclusive Economic Zones and on the High Seas related to marine spatial planning. We adopt a seascape genetic approach that advances beyond the state-of-the-art through inclusion of bio-physical modeling, observations of larval biology and ecology, and a comprehensive suite of molecular tools. Results of this work will be used to inform policy makers engaged in the design of deep-sea networks of marine reserves.

Results

Work is in progress.

CMAST’s SEEPC project web site