Are Land Based Surveys a Useful Tool for Managing Marine Species of Coastal Protected Areas?

One goal of the LIFE project “Del.Ta.” (NAT/IT/000163) was the preparation of an Action Plan to protect the bottlenose dolphin community in the Pelagie Archipelago (Sicily, Italy). It stressed the importance of regular monitoring of the spatial and temporal distribution of dolphins in order to evaluate the impact of local activities. This study assesses whether land-based surveys could be an effective alternative to vessel-based surveys. During the summer of 2006, both surveys’ methodologies were used at Lampedusa, with 35 sightings recorded from land and 31 from a boat. Comparison was based on the assessment of the type of information they provided in relation to the presence of the animals and their behavior. Both methodologies were applicable, but there were differences in their requirements, potential information generated, costs, and sensitivity to weather conditions. Vessel-based surveys require well trained observers and enable photo-identification and observation of social interaction and morphology. Animal movements, interactions with anthropogenic elements and group dynamics are better collected from land but spatial data can be documented up to 1 nautical mile from the coast. Weather conditions have a significant platform specific effect on sighting frequencies. The high sighting frequency during land surveys provides support for the development of zero-impact land-based dolphins watching activity

Fin Whale (Balaenoptera physalus) in the Ligurian Sea: Preliminary Study on Acoustics Demonstrates Their Regular Occurrence in Autumn

The patterns of movement of the fin whale (Balaenoptera physalus (Linnaeus, 1758)) in the Mediterranean Sea are still a matter of debate. Feeding aggregations are well known in the Corso-Liguro-Provençal Basin from July to September, but little is known for the autumn and winter seasons. Passive acoustic monitoring (PAM) was implemented in the Ligurian Sea to overcome this gap and to investigate the temporal and spatial variation of fin whale acoustic presence. From July to December 2011, five autonomous recorders were deployed at between 700 and 900 m depths. Fin whale calls were automatically detected almost every day, with higher vocalization rates in October, November, and December. Furthermore, daily vocalization rates were higher during light hours, and closer to the coast. These outcomes suggest that not all the individuals migrate, staying in the area also during autumn for feeding or breeding purposes. The dial cycle of vocalization might be related to feeding activities and zooplankton vertical migration, whereas the proximity to the coast can be explained by the morphology of the area that promotes the upwelling system. Although this work only represents a six-month period, certainly it suggests the need for a larger spatial and temporal PAM effort, crucial for species management and for mitigating possible impact of anthropogenic activities at the basin level

Agonistic Behaviour and Sound Production during Male–Male Varunid Crabs (Cyrtograpsus angulatus, Dana 1851) Encounters

Crustacean sounds are the main contributor to shallow water soundscape biophonic components. Here, we investigate the sound production of Cyrtograpsus angulatus, one of the most important intertidal decapods of the Southwestern Atlantic Ocean. Underwater audio and video were recorded during encounters among male pairs. Two kinds of experimental settings were conducted involving same size (SS) and different-size (DS) male crabs. Behavioural states, behavioural events and sound emission were investigated. SS spent more time in contact and still behaviour and showing competitive interactions than did DS. Crabs presented body displays involving chelae, legs, and maxillae movements with the same frequency in both settings. Our results demonstrate the production of impulsive sounds in male C. angulatus with high rates during contact and still behaviour (specifically during agonistic interactions and body displays without contact between individuals). Furthermore, we were able to describe behaviour-related variability within impulsive sounds. These outcomes provide a better understanding of the role and behavioural context of these sounds in the natural soundscape.Fil: Ceraulo, Maria. Consiglio Nazionale delle Ricerche; ItaliaFil: Sal Moyano, María Paz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Bazterrica, Maria Cielo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Hidalgo, Fernando Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Snitman, Solana Morena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Papale, Elena. Consiglio Nazionale delle Ricerche; ItaliaFil: Buscaino, Giuseppa. Consiglio Nazionale delle Ricerche; ItaliaFil: Gavio, Maria Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin

Acoustic impact of a wave energy converter in Mediterranean shallow waters

In this study, underwater noise from a full-scale wave energy converter system (ISWEC), installed on the coast of Pantelleria Island (central Mediterranean Sea), was characterized. The noise was measured using an autonomous acoustic recorder anchored to the sea bottom 40 m from the ISWEC hull. Acoustic monitoring continued for 15 months, starting 7 months before (PRE), 2 months during (INST) and 6 months after the ISWEC installation (POST). The levels of noise, assessed with power spectrum density and octave and third-octave band sound pressure levels (BSPLs), were higher during the POST period than during the PRE period at lower frequencies up to 4 kHz and increased with wave height. During the ISWEC activation for energy production (POST_ON) in the wave height range 1–2.9 m, the BSPLs increased much more at lower frequencies up to 4 kHz (the median BSPLs at 63 Hz for the PRE, POST, and POST_ON conditions were 73, 106, and 126 dB re 1μPa, respectively). Considering the biophonies that make up the soundscape of the area, we examined the possible masking of fish choruses due to ISWEC noise and highlighted that at a distance of 1000 m, the 800 Hz peak frequency was 10 dB above the ISWEC signal. Within this distance from ISWEC, a possible masking effect is supposed