The LACAr cooperative project: microbial diversity in coastal systems along a latitudinal gradient from South Atlantic to the Caribbean

ARTIGAS, L. F.; ALONSO, C.; COSTAGLIOLA, M.; DIONISI, H. M.; GONZÁLEZ, A.; HOZBOR, C.; MARCOS, M.; OTERO, E.; PARANHOS, R.; PERESSUTTI, S.; PICCINI, C.; SMITH, M.

Woods Hole, MA

Workshop; International Census of Marine Microbes (ICoMM) Spring Meeting; 2009

The Latin American and Caribbean network (LACar-ICoMM) proposal aims at assessing marine microbial diversity along a latitudinal gradient from the South Atlantic to the Caribbean, in order to allow a better understanding of a wide range of coastal marine systems that are submitted to an increasing human pressure and climate change effects. The Southwest Atlantic represents one of the most productive marine ecosystems. Achieving a better understanding of the microbial community structure in unpolluted sediments of Patagonian coast will be instrumental for the conservation of this vulnerable ecosystem, exposed to hydrocarbon pollution generated by oil exploitation and transportation as well as port activities. We propose to study the bacterial diversity in intertidal sediments of two different sites: a very pristine beach with little anthropogenic impact (Fracasso Beach, Valdéz Peninsula) and the Cordova Cove, in the San Jorge Gulf. Among estuarine systems, the Rio de la Plata estuary is the second most important of the continent, representing a highly productive area. We propose to characterize Prokaryotic diversity in an oceanic station in the estuarine plume and to compare these results to those of offshore waters of the Argentinian continental shelf corresponding to the EPEA oceanographic monitoring station off Mar del Plata. Even if some of the S. Atlantic subtropical lagoons are considered as protected areas, they are increasingly threatened by human activities in their catchments. We propose to study the Eubacterial diversity in two areas of the Laguna de Rocha in the Uruguayan Atlantic coast, related to the changing physico-chemical conditions. Among tropical estuarine systems, the Guanabara Bay is located in a humid tropical region surrounded by the second largest metropolitan area in Brazil (Rio de Janeiro). According to previous studies microbial diversity would be higher in the outermost areas of the bay, so we propose to verify that issue. On the other hand, the Amazon River provides the largest freshwater input to the ocean, as well as enormous dissolved and particulate loads to coastal, shelf and ocean adjacent waters, but little or none influenced by human activity. In connexion with other 454 project devoted to the study of fluid mud deposits resulting from Amazon outflow in F. Guiana, we will determine the Prokaryotic diversity in the Amazon mouth waters. Finally, the Caribbean samples represent different contrasting environments within the insular shelf of Southwestern Puerto Rico that encompasses the complexity of northern Caribbean region and thus will provide important data related to Eubacterial nd Eukaryal diversity. The data obtained will give insights into spatial changes in microbial communities related to inputs of natural organic fluxes as well as coral reef and associated habitat dynamics.