Analisis temporal de los resultados de la calibración de ecosondas científicas en buques de investigación.

El Instituto Español de Oceanografía (IEO), en sus campañas de Evaluación Acústica de Recursos Pesqueros, utiliza ecosondas científicas para estimar la biomasa de las especies pelágicas de interés comercial, como la sardina y la anchoa. Para la utilización cuantitativa de los resultados de estas ecosondas, es fundamental la exactitud de las medidas, así como su estabilidad temporal. Por esta razón, las ecosondas son calibradas antes del comienzo de cada campaña. Este trabajo presenta un análisis temporal de las calibraciones de las ecosondas científicas de los distintos Buques de Investigación, que el IEO ha utilizado a lo largo de los años.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Spatio-temporal patterns and environmental controls of small pelagic fish body condition from contrasted Mediterranean areas

Small pelagic fish are among the most ecologically and economically important marine fish species and are characterized by large fluctuations all over the world. In the Mediterranean Sea, low catches and biomass of anchovies and sardines have been described in some areas during the last decade, resulting in important fisheries crises. Therefore, we studied anchovy and sardine body condition variability, a key index of population health and its response to environmental and anthropogenic changes. Wide temporal and spatial patterns were investigated by analyzing separately data from scientific surveys and fisheries in eight Mediterranean areas between 1975 and 2015. Results showed that anchovy and sardine body condition as well as maximum size in some areas sharply decreased in most Mediterranean areas along years (except in the Northern Alboran Sea). Despite this general pattern, well-marked environmental differences between sub-regions were highlighted by several analyses and variations in body condition were not found to be homogeneous over all the Mediterranean Sea. Further, other analyses revealed that except for the Adriatic where major changes towards a lower body condition were concomitant with a decrease in river runoffs and chl-a concentration, no concomitant environmental regime shift was detected in other areas. Together, these analyses highlighted the current poor body condition of almost all small pelagic fish populations in the Mediterranean. Yet, global environmental indices could not explain the observed changes and the general decrease in condition might more likely come from regional environmental and/or anthropogenic (fishing) effects. A prolonged state of poor fish body condition, together with an observed reduced size and early age-at-maturity may have strong ecological, economic and social consequences all around the Mediterranean SeaVersión del edito