Bioacoustic research on cetaceans in the Mediterranean Sea

In recent years new impetus has been put into cetacean research in the Mediterranean Sea. From 1988 to 1994 research cruises were organized by our laboratory and the Tethys Research Institute within the seas surrounding the Italian peninsula and islands. Recordings of underwater sounds produced by cetaceans and other ethological and zoogeographical data were collected and analyzed with the use of instruments and techniques mainly developed by the Laboratory of Marine Bioacoustics, which was conceived by the University of Pavia and financed by the Inspectorate of Sea Defence of the Italian Ministry of the Environment. Specific instruments and software packages were developed, including a high-quality towed array of hydrophones, with its own amplifier and filtering unit, a portable Digital Signal Processing Workstation (DSPW) with real time analysis and file processing capabilities and an Interactive Digital Sound Library (IDSL). Cetacean sounds were recorded in their natural environment from auxiliary sailing vessels up to 26 m long; sounds from six odontocete and one mysticete species were recorded, analyzed, catalogued and organized in a sound library in order to allow flexible and specific access to sound information for research and other purposes such as environmental monitoring, species identification, censusing activities and educational applications.