Dear colleagues,
My co-authors and I are pleased to announce the following
publication:
Caruso F, Sciacca V, Bellia G, De Domenico E, Larosa G, Papale E,
Pellegrino C, Pulvirenti S, Riccobene G, Simeone F, Speziale F,
Viola S, Pavan G. (2015). Size Distribution of Sperm Whales
Acoustically Identified during Long Term Deep-Sea
Monitoring in the Ionian Sea. PLoS ONE 10(12): e0144503.
doi:10.1371/ journal.pone.0144503
Abstract:
The sperm whale (Physeter macrocephalus) emits a typical
short acoustic signal, defined as a “click”, almost continuously
while diving. It is produced in different time patterns to
acoustically explore the environment and communicate with
conspecifics. Each emitted click has a multi-pulse structure,
resulting from the production of the sound within the sperm whale’s
head. A Stable Inter Pulse Interval (Stable IPI) can be identified
among the pulses that compose a single click. Applying specific
algorithms, the measurement of this interval provides useful
information to assess the total length of the animal recorded. In
January 2005, a cabled hydrophone array was deployed at a depth of
2,100 m in the Central Mediterranean Sea, 25 km offshore Catania
(Ionian Sea). The acoustic antenna, named OνDE (Ocean noise
Detection Experiment), was in operation until November 2006. OνDE
provided real time acoustic data used to perform Passive Acoustic
Monitoring (PAM) of cetacean sound emissions. In this work, an
innovative approach was applied to automatically measure the Stable
IPI of the clicks, performing a cepstrum analysis to the energy
(square amplitude) of the signals. About 2,100 five-minute
recordings were processed to study the size distribution of the
sperm whales detected during the OνDE long term deep-sea acoustic
monitoring. Stable IPIs were measured in the range between 2.1 ms
and 6.4 ms. The equations of Gordon (1991) and of Growcott (2011)
were used to convert the IPIs into measures of size. The results
revealed that the sperm whales recorded were distributed in length
from about 7.5 m to 14 m. The size category most represented was
from 9 m to 12 m (adult females or juvenile males) and specimens
longer than 14 m (old males) seemed to be absent.
The paper is available online via open-access PLoS ONE:
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0144503
Kind Regards and Happy Christmas from the SMM Conference,
Francesco Caruso
fcaruso@unime.it
--
Francesco Caruso, Marine Biologist, PhD
The Institute for Coastal Marine Environment of the National Research Council (IAMC-CNR)
Via del Mare 3, 91021, Torretta Granitola, Trapani, ITALY
University of Messina
Department of Biological and Environmental Science
Viale Ferdinando Stagno d'Alcontres 31, 98166 Messina, ITALY
INFN-LNS
Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud
Via Santa Sofia 62, 95125 Catania, ITALY