Linking coastal fisheries catches with water physicochemical measurements

ARIAS, A.H.; SPETTER, C.V.; FREIJE, R.H.; MARCOVECCHIO, J.H.

Concepción

Jornada; VII Jornadas Chilenas de Física y Química Ambiental; 2011

Sociedad de Química Ambiental de Chile y Universidad Católica de la Santísima Concepción, Facultad de Ciencias

Both climate change and anthropogenic impact are creating a dynamic of continuous changes in ecosystems. While the expected consequences of these changes are global, the occurrence of extreme events and specific environmental problems are usually local or regional phenomenon. In particular, the coastal ecosystems are among the first vulnerable areas to show those changes; in spite of this, are the least studied. There is a lack of long-term research studying the linking of the physical-chemical dynamics to the ecosystem?s changes. Consequently, this work presents for the first time the results of the analysis of about 30 years of oceanographic physicochemical data measured at the Bahia Blanca Estuary, in South America, aiming to set trends and evaluate correlations, linking the coastal chemistry to biological documented changes. These findings will be of high elevance for the international conversation on the anthropogenic pressure and climate´s induced changes over the coastal ecosystems.By using the Argentinean Oceanography Institute?s (IADO) oceanographic data base (1974 up to present) and the compiled data of the catches from Conde et al., 2009, a new hypothesis is postulated, by which the variability in several oceanographic parameters(water temperature, salinity, and dissolved oxygen) could be driving the observed fisheries trends: ?the low interannual variability of water temperature and water salinity favours higher fishing yields at the Bahia Blanca Estuary and vice versa? and ?the water alkalinization and increasing DO values give raising fisheries catches, while in an opposite way, water acidification and decreasing DO values correspond to lesser catches amounts?.These unprecedented findings represent substantial information for the focus of the future ecosystem research and management, revealing several gaps in the present knowledge.They are also of high relevance for the international conversation on the anthropogenic pressure and climate´s induced changes over the coastal ecosystems.