ARTÍCULO
TITULO

A Fish and Dolphin Biophony in the Boat Noise-Dominated Soundscape of the Cres-Lo?inj Archipelago (Croatia)

Marta Picciulin    
Marta Bolgan    
Nikolina Rako-Gospic    
Antonio Petrizzo    
Marko Radulovic and Raffaela Falkner    

Resumen

Spatio-temporal variability of marine soundscapes reflects environmental dynamics and local habitat health. This study characterizes the coastal soundscape of the Cres-Lo?inj Natura 2000 Site of Community Importance, encompassing the non-tourist (11?15 March 2020) and the tourist (26?30 July 2020) season. A total of 240 h of continuous recordings was manually analyzed and the abundance of animal vocalizations and boat noise was obtained; sound pressure levels were calculated for the low (63?2000 Hz) and high (2000?20,000 Hz) frequency range. Two fish sound types were drivers of both seasonal and diel variability of the low-frequency soundscape. The first is emitted by the cryptic Roche?s snake blenny (Ophidion rochei), while the second, whose emitter remains unknown, was previously only described in canyons and coralligenous habitats of the Western Mediterranean Sea. The high-frequency bands were characterized by bottlenose dolphin (Tursiops truncatus) vocalizations, indicating dolphins? use of area for various purposes. Boat noise, however, dominated the local soundscape along the whole considered periods and higher sound pressure levels were found during the Tourist season. Human-generated noise pollution, which has been previously found 10 years ago, is still present in the area and this urges management actions.