Interaction between dolphins and fishery activities in Veneto: fishermen's perception, data from stranded dolphins and mitigation tools

The Northern Adriatic Sea (GSA 17) is characterized by intense fishing activity. In Venetian waters, Tursiops truncatus are often observed to interact with fishing activities and evidence of this interaction is also in stranded individuals. This experimental study aimed to get an overview concerning the dynamics and effects of these interactions in order to develop effective mitigation tools and management actions to ensure a sustainable coexistence between fishermen's economy and dolphin conservation. To achieve this objective three key aspects of the problem were investigated: fishermen’s perception of the dolphins’ presence in the North Adriatic Sea, evidence of interaction with fishery on stranded dolphins, fishermen’s satisfaction degree about Acoustic Deterrent Devices (ADD), in particular new generation pingers (Dolphin Interactive Deterrent). The results showed an increasing presence of dolphin-fishery interactions over the years based on the fishermen's perception, especially for trawlers. In regard to the evidence of interaction on stranded carcasses, the main findings reported was the entanglement in fishing gears. Moreover, fishermen showed interest in the adoption of ADD and other tools to find a sustainable solution to the economic loss caused by the dolphin interaction. To apply the most suitable management actions, the development of solutions to this problem requires a detailed study and knowledge of the social, economic, and environmental context, and of the ecology and ethology of Tursiops truncatus populations of the area, as it is happening within the “Life DELFI” project.