Little is known about the distribution and species composition of cetaceans in the Gulf of Taranto, central Mediterranean Sea. Available information is limited to stranding reports and to scant preliminary observations at sea. Cetacean sightings were recorded between April 2007 and October 2009 during 23 daily boat surveys, totalling 1728 km of navigation. Three cetacean species were encountered: striped dolphins (n = 41), Risso's dolphins (n = 5) and fin whales (n = 3). An additional sighting of a sperm whale group is reported. Encounter rates of striped dolphins were the highest, suggesting a regular occurrence in the study area. Risso's dolphins seemed to be predictably present in continental slope waters off the coast of Basilicata. Fin whales and striped dolphins, normally inhabiting deep pelagic waters offshore, were found in continental slope waters relatively close to the coast, possibly due to the particular bathymetry of the Gulf of Taranto and to oceanographic conditions that enhance local productivity. High human impact and worsening environmental conditions in the northern Gulf of Taranto raise concerns over the future of cetaceans living in these waters. This study expands previous knowledge and aims to stimulate research on whales and dolphins in what seems to be an important portion of their Mediterranean range.
The Poiseuille and Darcy laws describe the velocity of groundwater flow under laminar conditions. These laws were deducted empirically in conduit and porous systems, respectively, and are widely used to model the groundwater flow. The analytical relationship between these hydraulic laws has been found by draining a tank-reservoir. Based on equations found, the discharge in a conduit under the Poiseuille law can be transformed in the same amount flowing inside a darcian system, and vice versa. This transformation occurs, for example, in karst aquifers, from the matrix to karst conduits during discharge phases, and from conduits to matrix during recharge phases.
The hydraulic phenomenon of upwelling groundwater flow affecting the karst area of the Grassano-Telese springs (southern Italy) has been investigated through piezometric measurements, discharge, and chemical–physical monitoring of springs, radon activity included. Locally, both large karst springs and sulfurous thermal springs are closely located, and raise several questions on their origin. In this study, the phenomenon of the upwelling flow is supported by different types of evidences: Amazing density of sinkholes connected to hypogenic speleogenesis processes, constancy of temperature, and hydraulic conductivity of spring water, change of radon activity during the hydrological year, increasing of the hydraulic head with depth. Numerical code provides an estimation of the upwelling phenomenon in an unconfined aquifer feeding the karst springs, using MODFLOW tools. Based on the results reached, the phenomenon of the upwelling flow is able to explain the hydrological processes observed in the Telese karst area.