The habitat of the resident bottlenose dolphins (Tursiops truncatus) of the Cres-Lošinj archipela... more The habitat of the resident bottlenose dolphins (Tursiops truncatus) of the Cres-Lošinj archipelago overlaps with routes of intense boat traffic. Within these waters, Sea Ambient Noise (SAN) was sampled across ten acoustic stations between 2007 and 2009. Data on boat presence was concurrently collected and when dolphins were sighted group behaviour was also recorded. Acoustic recordings were analysed for 1/3 octave bands. Samples containing dolphin whistles were analysed and compared with boat presence and SAN levels. Results indicate that dolphins whistle at higher frequencies in conditions of elevated low frequency noise. Conversely, they reduce maximum, delta and start frequencies and frequency modulations when noise levels increase significantly across higher frequencies. The study shows that high levels of SAN causes significant changes in the acoustic structure of dolphin whistles. Additionally, changes in whistle parameters, in the presence of boats, appear to be related to the behavioural state of the dolphin group.
Abstract: L'area marina protetta di Lussino, istituita nell'estate del 2006, è un'imp... more Abstract: L'area marina protetta di Lussino, istituita nell'estate del 2006, è un'importante area dell'Adriatico settentrionale (Quarnerolo) in quanto ospita una popolazione locale residente di tursiopi (Tursiops truncatus). Tuttavia quest'area è caratterizzata anche da un forte ...
The Marine Strategy Framework Directive (MSFD), formally adopted by the European Union in July 20... more The Marine Strategy Framework Directive (MSFD), formally adopted by the European Union in July 2008, outlines 11 high level descriptors of Good Environmental Status (GES); descriptor 11 requires "monitoring the introduction of energy, including underwater noise” into the marine environment. A 3-year study monitoring sea ambient noise (SAN) (2007–2009) was carried out in the Cres–Lošinj archipelago, where local dolphin and fish communities are threatened by unregulated mass tourism and coastal construction. The survey was run monthly on ten predefined acoustic stations, grouped into three areas of different anthropogenic impact. A total of 418 five minute SAN samples (frequency range: 25 - 40000 Hz) were collected and analyzed. In the light of Indicator 11.2.1 of the MSFD “Continuous low frequency sound”, the 1/3 octave bands of 63 Hz and 125 Hz (re 1uPa RMS) were considered. During recordings the presence of leisure boats within 2 km of the sampling station and the bottlenose d...
The habitat of the resident bottlenose dolphins (Tursiops truncatus) of the Cres-Lošinj archipela... more The habitat of the resident bottlenose dolphins (Tursiops truncatus) of the Cres-Lošinj archipelago overlaps with routes of intense boat traffic. Within these waters, Sea Ambient Noise (SAN) was sampled across ten acoustic stations between 2007 and 2009. Data on boat presence was concurrently collected and when dolphins were sighted group behaviour was also recorded. Acoustic recordings were analysed for 1/3 octave bands. Samples containing dolphin whistles were analysed and compared with boat presence and SAN levels. Results indicate that dolphins whistle at higher frequencies in conditions of elevated low frequency noise. Conversely, they reduce maximum, delta and start frequencies and frequency modulations when noise levels increase significantly across higher frequencies. The study shows that high levels of SAN causes significant changes in the acoustic structure of dolphin whistles. Additionally, changes in whistle parameters, in the presence of boats, appear to be related to the behavioural state of the dolphin group.
Abstract: L'area marina protetta di Lussino, istituita nell'estate del 2006, è un'imp... more Abstract: L'area marina protetta di Lussino, istituita nell'estate del 2006, è un'importante area dell'Adriatico settentrionale (Quarnerolo) in quanto ospita una popolazione locale residente di tursiopi (Tursiops truncatus). Tuttavia quest'area è caratterizzata anche da un forte ...
The Marine Strategy Framework Directive (MSFD), formally adopted by the European Union in July 20... more The Marine Strategy Framework Directive (MSFD), formally adopted by the European Union in July 2008, outlines 11 high level descriptors of Good Environmental Status (GES); descriptor 11 requires "monitoring the introduction of energy, including underwater noise” into the marine environment. A 3-year study monitoring sea ambient noise (SAN) (2007–2009) was carried out in the Cres–Lošinj archipelago, where local dolphin and fish communities are threatened by unregulated mass tourism and coastal construction. The survey was run monthly on ten predefined acoustic stations, grouped into three areas of different anthropogenic impact. A total of 418 five minute SAN samples (frequency range: 25 - 40000 Hz) were collected and analyzed. In the light of Indicator 11.2.1 of the MSFD “Continuous low frequency sound”, the 1/3 octave bands of 63 Hz and 125 Hz (re 1uPa RMS) were considered. During recordings the presence of leisure boats within 2 km of the sampling station and the bottlenose d...
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