Computational bioacoustics for assessing biodiversity

The INFN NEMO-OνDE (Ocean Noise Detection Experiment) station, deployed on the seafloor at 2000 m depth 25 km offshore Catania (Sicily, Italy) in year 2005, was designed to continuously transmit broad-band acoustic data through optical cables to the INFN lab located in the port of Catania. It was operational until November 2006, when it was replaced by other experimental equipment. During the operational period, 5 minutes of recording (4 hydrophones, 45 kHz bandwidth, 96 kHz sampling rate at 24 bits resolution) were taken every hour. The experiment provided long-term data on the underwater noise and an unique opportunity to study the acoustic emissions of marine mammals living in, or transiting through the area east of Sicily. The recordings revealed a more frequent and consistent presence of sperm whales than previously believed. Acoustic monitoring of the underwater environment is a key component in the study of marine mammals and in the management of the anthropogenic noise issue. Technologies now available allow to extend monitoring capabilities into the deep ocean to monitor the presence and behaviour of marine mammals as well as to long-term monitor both the local and the ambient noise background due to human activities. Figure 1: Location of the OνDE platform. The goal of NEMO is the implementation of an innovative underwater telescope to search for astrophysical neutrinos (MIGNECO et al., 2006). The telescope will be deployed 100 km offshore Capo Passero (Sicily, Italy) at a depth of 3500 m. In this framework a deep sea test site at 2000 m depth has been deployed 21 km offshore Catania, connected to the shore labs through electro-optical cables to provide real-time data transfer. The test site hosts an experimental deep station, named OνDE (Ocean Noise Detection Experiment) dedicated to the study of the underwater acoustic noise (Fig. 1). OνDE was deployed in January 2005 and was sending data since the end of March 2005 until