Hydrography of the inner continental shelf of the southwest Buenos Aires Province, Argentina: influence of an estuarine plume on coastal waters.

DELGADO, A.L.; MENENDEZ, M.C.; PICCOLO, M.C.; PERILLO, G.M.E.

JOURNAL OF COASTAL RESEARCH

COASTAL EDUCATION & RESEARCH FOUNDATION

Lugar: Florida; Año: 2017

0749-0208

Estuarine plumes have a significant influence on the characteristics and biology of the adjacent inner shelf. In the sectoroccupied by the plume, several transformations occur to the sediment and nutrients exported from the continent to theoceans. The coastal zone of Pehu´en Co (PC) and Monte Hermoso (MH) is located in a highly complex oceanographic andecological regional system, which creates the basis of one of the most valuable Argentinean habitats for fishing ofcommercial species. In this work, the physical oceanographic characteristics of the inner shelf of the southwest BuenosAires Province and the influence of the Bahia Blanca estuarine (BBE) waters are introduced. The in situ data obtainedfrom oceanographic cruises included vertical profiles of water temperature, salinity, and turbidity. The spatial variabilityof the parameters was studied with a multivariate statistical analysis. Temperature and salinity presented high seasonalvariability (6.1?22.98C; 33.5?36, respectively). Maximum turbidity occurred throughout the summer (64 nephelometricturbidity units [NTU]) and showed a minimum during spring (24 NTU). The study area was characterized by asignificant spatial variability, especially in terms of salinity and turbidity, while water temperature showed a morehomogeneous pattern. Salinity and turbidity values decreased from PC (closer to BBE) to MH (further from BBE)stations, with the highest values located near the mouth of the BBE. The PC and MH (to a lesser extent) inner shelvesare transitional environments between the estuary and the open beaches of Buenos Aires Province, creating a habitatwhere benthic and zooplankton estuarine and marine species are found.