Università degli Studi di Pavia
Centro Interdisciplinare di Bioacustica e Ricerche AmbientaliVia Taramelli 24 - 27100 Pavia - Italy
e-mail : email@example.com
Ziphius, a project about a poorly known endangered species
Assessing and mitigating such impacts is currently limited by the lack of scientific knowledge of beaked whales physiology, behaviour, distribution, and habitat use. A keypoint in mitigation strategies is the ability to detect the animals, by either visual of acoustic observations, or by both. CIBRA is mainly interested in developing and tuning PAM (Passive Acoustic Monitoring) equipment and software to make the acoustic detection of beaked whales possible and efficient.
Acoustic detection of Cuvier's beaked whales
Z. cavirostris is an elusive species whose acoustic signals remained unknown till last year when a team of Woods Hole Oceanographic Institution, headed by Peter Tyack, attached a sophisticated recording tag on the back of several animals. The tag, named D-TAG, attached by suction caps, is able to record the movements of the animal together with the sounds it receives and the sounds it emits. For the first time it was possible to record their sounds and to characterize the Z.cavirostris diving profile. The results clearly explain why those sounds have been never recorded with hydrophones deployed close to the sea surface.
Z.cavirostris emits sounds only at depths greater than 400-500 meters; the sounds are short ultrasonic pulses centered at about 40 kHz (range 20-60 kHz) and emitted with at intervals of about 400ms. As they are high in frquency and emitted at great depth, they reach the sea surface with very little energy and are impossible to detect with standard gear working up to 20 kHz only.
The aim of our study was to broaden the knowledge related to Cuvier’s beaked whales, to characterize their habitat, and to remotely record their acoustic signals by developing suitable equipment.
In late September 2005 CIBRA carried out
a bio-acoustic survey during an extensive NURC (NATO
Undersea Research Center, La Spezia, IT) research campaign
(Zifio ’05) in the Ligurian Sea. The CIBRA team was on
board a 12 meter catamaran, named Krill, with its own
equipment based on a high quality towed array equipped
with a newly designed low-noise front-end featuring
digital recording and real-time spectrographic displaying
with a nearly 90 kHz bandwidth.
This cruise was carried out within the NURC - NATO Undersea Research Center SOLMAR project. We acknowledge ONR Office of Naval Research for having funded the development of the equipment. NURC website: http://nurc.nato.int ; SOLMAR website http://solmar.nurc.nato.int
Mediterranean-wide database and GIS of Cuvier's beaked whales' strandings
Much of the current knowledge of this species has been derived from stranding data. Historically, stranding data in the Mediterranean Sea has been collected by individual researchers, and more recently, over the last two decades, by national stranding networks. In cooperation with the Natural History Museum of Milan and other organizations, an extensive review of stranding data collected by stranding networks from Italy, Greece, Spain, and France has been made. Results were completed with information gleaned from the literature, personal communications, regional newspapers, and the world wide web from the countries that border the Mediterranean Sea. While this review is certainly not exhaustive, it has allowed the creation of an extensive geo-referenced basin wide database using a geographic information system (GIS) of over 300 stranding events. The acquired data permit documentation of the number of mass stranding events, allow general observations about distribution and chronology of stranding events dating back to 1803, and enables evaluation of strandings based on several different criteria.
Podestà M., A. D’Amico, G. Pavan, A. Drougas, A. Komnenou and N. Portunato; A Review of Ziphius cavirostris (G. Cuvier, 1823) Strandings in the Mediterranean Sea. . J. CETACEAN RES. MANAGE. 7(3): 251–261.
This paper has been published on a Special Issue of the Journal of Cetacean Research and Management entirely concerned with Beaked whales.
The research project has been developed
in coordination with the NATO Underwater Research Center (SOLMAR Project), with the
cooperation of the Italian
Navy, of the SPAWAR Center (San Diego, US), of the
Natural History Museum of Milan (Italy) and of the Centro Studi Cetacei (CSC).
ONR Grants N00014-99-1-0709, N00014-02-1-0333, and N00014-03-1-0901
Updated Novembert 2006