Cuvier’s Beaked Whales (Ziphius cavirostris) in the Ligurian Sea

Physical Habitat Description

Angela D'Amico1,4, Frederic Mineur1, Alberto Alvarez 1, Cristina Mori1, Michela Podesta 2, Nicola Portunato1, Marco Ballardini3, Barbara Nani3

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1  SACLANT Undersea Research Centre Viale San Bartolomeo 400 19138 La Spezia, Italy 2  Museo di Storia Naturale Corso Venezia 55 20121 Milano, Italy 3   bluWest  Via Scarincio 12 18100 Imperia, Italy4 SPAWARSYSCEN D713 53560 Hull Steet San Diego, CA 92152-5001

SirenaSirena Sea Trials Sea TrialsObjectivesObjectives

• Develop integrated database of environmental parameters and marine mammal populations • Develop techniques which enable detection, classification, and tracking of marine mammals

Sirena ‘99 3 - 13 AugSirena ‘00 21 Aug - 8 SeptSirena ‘01 20 Sept - 7 OctSirena ‘02 1-24 July

Sirena ‘99 3 - 13 AugSirena ‘00 21 Aug - 8 SeptSirena ‘01 20 Sept - 7 OctSirena ‘02 1-24 July

Regional surveysRegional surveys

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Zifio ‘01 - May 2001Zifio ‘01 - May 2001

Corsaro, bluWest

Imperia, Italy

Corsaro, bluWest

Imperia, Italy

NATO research vessel, NRV AllianceItalian Navy’s Hydrographic Office research vessel, Nave Magnaghi

Italian Navy Sea King Helicopter

Italian Navy 30o Aerostormo (ELMAS) marine patrol aircraft

Visual Monitoring

Oceanographic/biologic/acoustic observations

Remote sensing

Sirena Measurements

Istituto Centrale per la Ricerca Applicata al Mare, Bestiaccia

Western Corsica

Current

Ligurian Current

Levantine Intermediate Water

Sirena ’01Temperature at 50m

Section 1

Sirena ’01Sub-surface circulation

Sirena ’01 Geostrophic currents at 50m

Sirena ’01 Vertical salinity distribution along section 1

Counter clockwise current causes

doming of cold water in basin center

Seasonal/Yearly VariabilityLigurian Sea

Early Aug 1999 Late Sep 2001 Early Sep 2000

• Upwelling of cold water in basin center is visible on satellite images• Region of upwelling has high biologic productivity

 

Slope gradient within the canyon(0, 200, 1000, 2000m contours shown).

Bathymetry of the canyon area(200m contour lines shown).

Genoa Canyon

Steep submarine canyon exists in NW portion of basin

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Historic strandings Ziphius cavirostris

Ziphius cavirostris in Genoa Canyon

• Sirena sea trial data indicate presence of Ziphius cavirostris in

canyon region, not in basin center• Sighting data base indicates that all sighting were made in

water depths over 1000m• Stranding data indicates presence of Ziphius cavirostris in this

region since 1900

Sightings of Ziphius cavirostris during Sirena trials

Regional sightings of Ziphius cavirostris

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• Sediment flow along surface and bottom of steep canyon walls• Not present in wider canyon region • SPM layer may have higher organic content

Sirena ’01Suspended Particulate Matter

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Canyon CirculationZifio ‘01

Geostrophic velocities at 50 m depth

Interaction between Ligurian current and steep canyon

walls form regional circulation pattern

• Stranding and sighting data suggest Ziphius cavirostris exhibit site fidelity in the Genoa Canyon• Ziphius cavirostris have been sighted on the surface only in water depths greater than 1000m • Canyon environments form traps for suspended particulate matter containing high biomass • Canyon region has regional circulation pattern resulting from interaction between the Ligurian Current and the steep canyon bathymetry•Combination of these factors may form a preferential habitat, providing food for the species upon which Ziphius cavirostris prey•Futher detailed measurenments of prey field required

Conclusions

The authors would like to thank all participants from the NRV Alliance, CRV Manning; ITN Magnaghi, Corsaro, Bestiaccia. Special thanks to ADM D. Nascetti, CDR S. Monti, the Italian Marina Militare and to their Istituto Idrografico della Marina Office and R. Gisiner, the Office of Naval Research. The SOLMAR project acknowledges the participation of V. Teloni, M. Quero, W. Zimmer, P. Tyack, G. Pavan, J. Bondaryk, D. Barbour, F. DeStrobel, A. Strulese. Additionally, the authors would like to acknowledge all personnel from the following organizations who participated in the data collection effort, without them the success of the Sirena sea trials would not be possible;SACLANTCEN, Acquario di Genova, Aquastudio, BAE Systems, Biscay Dolphin Research Programme (A. Williams for the coordination of the visual survey during Sirena ’99 and ’00) , Centre d’Etudes Biologiques de Chize, Centre de Recherche sur les Mammiferes Marins, Groupe de Recherche sure les Cetaces, Centro di Bioacustica, Università di Pavia, Centro Studi Cetacei, Defense Establishment Research Agency, Istituto Centrale per la Ricerca Applicata al Mare, Istituto per lo Studio dell’Oceanografica Fisica, Istituto per lo Studio della Dinamica delle grandi Masse, Museo Civico di Storia Naturale di Milano, Office of Naval Research (R. Gisiner for supporting researchers to participate in the Sirena cruises), Southwest Fisheries Science Center, Tethys Research Institute, University of Genoa, University of North Carolina, University of Siena, Woods Hole Oceanographic Institute, WWF Liguria.

Acknowledgements