Exploration of Caribbean Seamounts within the Greater and Lesser Antilles (GA/LA) Transition Zone: Characterization of the Benthic Ecology and Geology

Science Center Objects

Seamounts may be biodiversity hotspots, oases, islands, and centers for endemism in the deep sea. USGS and partners explore these possibilities within the Greater and Lesser Antilles Transition Zone.

Seamount map of environments in the Greater Antilles/Lesser Antilles
Seamount map of environments in the Greater Antilles/Lesser Antilles

The Science Issue and Relevance: Within the Caribbean region, numerous unexplored seamounts punctuate the seafloor holding records of geologic, biologic, and oceanographic processes over different time-scales. Seamounts are topographically and oceanographically complex with environmental characteristics (e.g., substrate types, carbon flux, and current patterns) that vary greatly within and among seamounts. Differences in environmental characteristics may influence community structure among seamounts, yet to our knowledge no studies to date have examined these factors across multiple spatial scales of a seamount chain. Seamounts have often been suggested to be oases, biodiversity hotspots, islands, and centers for endemism in the deep sea; however, many of these hypotheses are only beginning to be explored in detail. Exploration of seamount environments in the Greater Antilles/Lesser Antilles transition zone, including enhanced mapping efforts, ROV surveys, discrete collections, and ecological studies, will provide insight into their geological origin, the spatial distribution, ecology, and biodiversity of associated fauna. This exploration also will place this region in a global biogeographic context.

Methodology for Addressing the Issue: This interdisciplinary project applies a diverse set of tools, including surface ships, ROVs and bottom moorings, in order to address several complex objectives. The primary phases/objectives include: 1) Acquire multibeam/sub-bottom data to fill gaps in existing coverage; 2) Characterize geomorphology and geology (composition, age, emplacement mechanism), and investigate links to active tectonism; 3) Characterize water masses (e.g., temperature, salinity, dissolved oxygen, nutrients, currents) and particulate flux in the only intermediate water passage into the Caribbean; 4) Examine the habitat specificity of the fauna and population dynamics of corals associated with seamount environments; and 5) Describe the structure and food web ecology of associated fishes and invertebrate communities.

Research Vessel Nautilus
 Nautilus served as base of field operations

Future Steps: Except for the moorings currently deployed in the Anegada Passage, the field component of the project is complete. Analysis of the extensive mapping dataset, ROV videos, and physical (biological and geological) samples is ongoing. The sediment traps and oceanographic instrumentation on the moorings will be recovered in mid-2016. Radiometric dating of rock samples from the seamounts is underway.

Related Product(s) and Project(s):

Presentations:

Coleman, D.F., ten Brink, U., Armstrong, R., Chaytor, J., and Demopoulos, A.W.J., 2013, Multibeam Mapping and Remotely Operated Vehicle Exploration of the Puerto Rico and Virgin Islands Region, AGU Fall Meeting, San Francisco, Calif., Dec. 2013. [Poster presentation]

Quattrini, A.M., J.D. Chaytor, E.E. Cordes, J.R. Bourque, A.W.J. Demopoulos, Initial assessments of biodiversity and geology on Caribbean seamounts in the Greater-Lesser Antilles Transition Zone, Deep-sea Biology Symposium, August, 2015, Portugal, Spain

Demopoulos, A.W.J. Role of exploration in the advancement of marine research (invited). Aquarium of the Pacific, Long Beach, March 2015.

Remotely operated underwater vehicle
The ROV (remotely operated vehicle) Hercules was used for data collection. 

Publications:

ten Brink, U., Coleman, D.F., Chaytor, J., Demopoulos, A.W.J., Armstrong, R., Garcia-Moliner, G., Raineault, N.A., Andrews, B., Chastain, R., Rodrigue, K., and Mercier-Gingras, M., 2014, Earthquake, Landslide, and Tsunami Hazards in the Northeaster Caribbean-Insights from a 2013 E/V Nautilus Expedition: Sound Waves, v. FY 2014, no. 152, http://soundwaves.usgs.gov/2014/06,

ten Brink, U., Coleman, D.F., Chaytor, J., Demopoulos, A.W.J., Armstrong, R., Garcia-Moliner, G., Raineault, N.A., Andrews, B., Chastain, R., Rodrigue, K., and Mercier-Gingras, M., 2014, Earthquake, Landslide, and Tsunami Hazards and Benthic Biology in the Greater Antilles: Oceanography, v. 27(supplement), no. 1, p. 34-35, doi:10.5670/oceanog.2014.supplement.01.