Ecological niches of three teuthophageous odontocetes in the northwestern Mediterranean Sea

Abstract. In the northwestern Mediterranean Sea, sperm whales, pilot whales and Risso's dolphins prey exclusively or preferentially on cephalopods. In order to evaluate their competition, we modelled their habitat suitability with the Ecological Niche Factor Analysis (ENFA) and compared their ecological niches using a discriminant analysis. We used a long term (1995–2005) small boat data set, with visual and acoustic (sperm whale) detections. Risso's dolphin had the shallowest and the more spatially restricted principal habitat, mainly located on the upper part of the continental slope (640 m mean depth). With a wider principal habitat, at 1750 m depth in average, the sperm whale used a deeper part of the slope as well as the closest offshore waters. Finally, the pilot whale has the most oceanic habitat (2500 m mean depth) mainly located in the central Ligurian Sea and Provençal basin. Therefore, potential competition for food between these species may be reduced by the differentiation of their habitats.

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Ecological niche of three teuthophageous odontocetes in the northwestern Mediterranean Sea

Ocean Science Discussions ◽

10.5194/osd-4-785-2007 ◽

2007 ◽

Vol 4 (5) ◽

pp. 785-815 ◽

Cited By ~ 9

Author(s):

E. Praca ◽

A. Gannier

Keyword(s):

Mediterranean Sea ◽

Ecological Niche ◽

Sperm Whale ◽

Ecological Niches ◽

Sperm Whales ◽

Ligurian Sea ◽

Data Set ◽

Pilot Whale ◽

Northwestern Mediterranean Sea ◽

Northwestern Mediterranean

Abstract. In the northwestern Mediterranean Sea, sperm whales, pilot whales and Risso's dolphins prey on cephalopods exclusively or preferentially. In order to evaluate their competition, we modelled their habitat suitability with the Ecological Niche Factor Analysis (ENFA) and compared their ecological niche using a discriminant analysis. We used a long term (1995–2005) small boat data set, with visual and acoustic (sperm whale) detections. Risso's dolphin had the shallowest and the more spatially restricted principal habitat, mainly located on the upper part of the continental slope (640 m mean depth). With a wider principal habitat, at 1750 m depth in average, the sperm whale used a deeper part of the slope as well as close offshore waters. Finally, the pilot whale has the most oceanic habitat (2500 m mean depth) mainly located in the central Ligurian Sea and Provençal basin. Therefore, potential competition for food between these species may be reduced by the differentiation of their ecological niches.

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Preliminary Assessment of the Microplastic Presence in the Gulf of Genoa (Italy, Ligurian Sea, Northwestern Mediterranean Sea)

Fate and Impact of Microplastics in Marine Ecosystems ◽

10.1016/b978-0-12-812271-6.00195-2 ◽

2017 ◽

pp. 139-140

Author(s):

S. Morgana ◽

N. Estévez-Calvar ◽

A. Roveta ◽

R. Stifanese ◽

M. Faimali ◽

...

Keyword(s):

Mediterranean Sea ◽

Preliminary Assessment ◽

Ligurian Sea ◽

Northwestern Mediterranean Sea ◽

Northwestern Mediterranean

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Unusual hydrologic conditions occurred in the Ligurian Sea of the northwestern Mediterranean Sea in 1981–1982

Deep Sea Research Part B Oceanographic Literature Review ◽

10.1016/0198-0254(85)93638-6 ◽

1985 ◽

Vol 32 (12) ◽

pp. 994

Keyword(s):

Mediterranean Sea ◽

Ligurian Sea ◽

Northwestern Mediterranean Sea ◽

Hydrologic Conditions ◽

Northwestern Mediterranean

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Wind-Forced Submesoscale Symmetric Instability around Deep Convection in the Northwestern Mediterranean Sea

Fluids ◽

10.3390/fluids6030123 ◽

2021 ◽

Vol 6 (3) ◽

pp. 123

Author(s):

Anthony Bosse ◽

Pierre Testor ◽

Pierre Damien ◽

Claude Estournel ◽

Patrick Marsaleix ◽

...

Keyword(s):

Mediterranean Sea ◽

Mixed Layer ◽

Deep Convection ◽

Realistic Model ◽

Ligurian Sea ◽

Vertical Movements ◽

Northwestern Mediterranean Sea ◽

Wind Events ◽

Northwestern Mediterranean ◽

Symmetric Instability

During the winter from 2009 to 2013, the mixed layer reached the seafloor at about 2500 m in the northwestern Mediterranean Sea. Intense fronts around the deep convection area were repeatedly sampled by autonomous gliders. Subduction down to 200–300 m, sometimes deeper, below the mixed layer was regularly observed testifying of important frontal vertical movements. Potential Vorticity dynamics was diagnosed using glider observations and a high resolution realistic model at 1-km resolution. During down-front wind events in winter, remarkable layers of negative PV were observed in the upper 100 m on the dense side of fronts surrounding the deep convection area and successfully reproduced by the numerical model. Under such conditions, symmetric instability can grow and overturn water along isopycnals within typically 1–5 km cross-frontal slanted cells. Two important hotpspots for the destruction of PV along the topographically-steered Northern Current undergoing frequent down-front winds have been identified in the western part of Gulf of Lion and Ligurian Sea. Fronts were there symmetrically unstable for up to 30 days per winter in the model, whereas localized instability events were found in the open sea, mostly influenced by mesoscale variability. The associated vertical circulations also had an important signature on oxygen and fluorescence, highlighting their under important role for the ventilation of intermediate layers, phytoplankton growth and carbon export.

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