Abundance of small cetaceans in waters of the central Spanish Mediterranean

By A. Segura, E. A. Crespo, S. Pedraza, Philip S. Hammond, J. Raga. 2006

105 citations recorded by the source corpus.

Seasonal aerial surveys were conducted in the waters of the central Spanish Mediterranean from 2001 to 2003 using the line transect sampling methodology to estimate cetacean abundance. The density of the three most abundant species, striped dolphin (Stenella coeruleoalba), bottlenose dolphin (Tursiops truncatus) and Risso’s dolphins (Grampus griseus), was estimated. In the case of the first two species, the density was estimated accounting for the proportion of submerged animals, while for Risso’s dolphin only the surface density could be estimated. The striped dolphin was the most abundant species in the study area with a mean density of 0.489 dolphins km−2(95% CI = 0.339–0.705) and a mean abundance of 15,778 dolphins (95% CI = 10,940–22,756). This density is comparable to that obtained in the International Ligurian Sea Cetacean Sanctuary. Striped dolphins were observed throughout the whole year and no seasonal changes in the density were detected. The mean density of bottlenose dolphins was an order of magnitude lower than that of striped dolphins (0.041 dolphins km−2; 95% CI = 0.023–0.075) with a mean abundance of 1,333 dolphins (95% CI = 739–2,407). The Risso’s dolphin had a surface estimated density of 0.015 dolphins km−2 (95% CI = 0.005–0.046) and a mean abundance of 493 dolphins (95% CI = 162–1,498). These results provide valuable biological information useful to develop conservation plans and establish a baseline for future population trend studies.

Subfields: Ecology, Ecology, Evolution, Behavior and Systematics, Global and Planetary Change

View Paper: https://www.semanticscholar.org/paper/e15f600179cd14575aca839baba19247b9f621b2

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Ecology

1. R. Reeves
2. G. Bearzi
3. G. Sciara
4. Per Berggren
5. Philip Lovell
6. David L. Borchers
7. M. L. Burt
8. P. Hammond

In Ecology, Evolution, Behavior and Systematics

1. R. Reeves
2. G. Bearzi

In Global and Planetary Change

1. R. Reeves
2. G. Bearzi
3. Per Berggren
4. P. Hammond
5. Ursula Siebert
6. V. Ridoux
7. Robert W. Furness

Citations in the corpus

• Common dolphin (Delphinus delphis) habitat preferences using data from two platforms of opportunity (2012, unknown): “, 2002) or the Mediterranean Sea (Bearzi et al., 2006; Segura et al., 2006).”
• Cetacean abundance and distribution in European Atlantic shelf waters to inform conservation and management (2013, methodology): “Sighting angles were measured from an angle board and on Tracker also using a small ed: (a) sea conditions of Beaufort 62; (b) sea conditions of Beaufort 64. camera positioned on the underside of the binoculars that took snapshots of parallel lines on the deck (Leaper and Gordon, 2001).”
• The status and distribution of cetaceans in the Black Sea and Mediterranean Sea (2006, background): “…(Forcada and Hammond, 1998) Alboran Sea (1991): 17,728 (95%CI=9,507-33,059) (Forcada and Hammond, 1998) Central coast of Spain (2000-2002): 15,778 (95%CI=10,940-22,756) (Gómez de Segura et al., 2006) Oceanic, with a preference for highly productive, open waters beyond the continental shelf.”
• Ecology and conservation of common bottlenose dolphins Tursiops truncatus in the Mediterranean Sea (2009, background): “…000 km2) showed that in some Mediterranean areas bottlenose dolphins are present both near shore and offshore, and densities can range between 4 and 20 animals per 100 km2 (Ben Naceur et al., 2004; Forcada et al., 2004; Cañadas & Hammond, 2006; Gomez de Segura et al., 2006; and see Table 1).”
• Risso's dolphin Grampus griseus in the Mediterranean Sea (2011, background): “That estimate was not corrected for visibility bias and therefore likely underestimates the true abundance in the sampled area (Gómez de Segura et al., 2006).”