Video monitoring of Sparidae temporal rhythms: three-year study by OBSEA cabled observatory

The abundance and composition of fish assemblages varies at different
temporal scales as a product of diel and annual rhythms. In this study, we used a
video-wired observatory (OBSEA, www.obsea.es) to monitor annual rhythms in a
coastal fish assemblage with a 3-year data set (2012-2014). The photographs were
acquired at 30 min frequency. Five species of the family Sparidae were studied
(i.e. Dentex dentex, Diplodus sargus, Diplodus vulgaris, Diplodus annularis and
Diplodus puntazzo) together with water temperature and daylength. The results
of the annual rhythmicity analysis indicated that most of the peaks of abundance
occured in the autumn months. Results suggest differentially temporal use of the
reproductive or trophic niche.