22 December 2008

Seasonal forcing and habitat use by Adriatic bottlenose dolphins

A new paper on the influence of seasonal forcing on habitat use by bottlenose dolphins in the northern Adriatic Sea has recently been published.

The research was conducted by Tethys personnel in collaboration with CNR/ISMAR, in the context of INTEREG Project OBAS (Biological Oceanography of the northern Adriatic Sea).

The study, based on data collected between 2003 and 2006, investigates some of the factors that influence habitat use by the animals in a largely homogeneous environment, by combining
dolphin data with hydrological and physiographical variables sampled from oceanographic ships.

Habitat modelling predicted between 81% and 93% of the cells where animals were present. Seven environmental covariates were important predictors: oxygen saturation, water temperature, density anomaly, gradient of density anomaly, turbidity, distance from the nearest coast and bottom depth.

This study suggests that dolphin distribution changes depending on seasonal forcing. As the study area is relatively uniform in terms of bottom topography, habitat use by the animals seems to depend on complex interactions among hydrological variables, caused primarily by seasonal change and likely to determine shifts in prey distribution.

Bearzi G., Azzellino A., Politi E., Costa M., Bastianini M. 2008. Influence of seasonal forcing on habitat use by bottlenose dolphins Tursiops truncatus in the northern Adriatic Sea. Ocean Science Journal 43(4).

No comments: