| one publication added to basket [283267] | Risso's dolphin, Grampus griseus, in the western Ligurian Sea: trends in population size and habitat use
Azzellino, A.; Airoldi, S.; Gaspari, S.; Lanfredi, C.; Moulins, A.; Podestà, M.; Rosso, M. (2016). Risso's dolphin, Grampus griseus, in the western Ligurian Sea: trends in population size and habitat use, in: Notarbartolo di Sciara, G. et al. Adv. Mar. Biol. 75: Mediterranean marine mammal ecology and conservation. Advances in Marine Biology, 75: pp. 205–232. https://dx.doi.org/10.1016/bs.amb.2016.08.003
In: Notarbartolo di Sciara, G.; Podestà, M.; Curry, B.E. (2016). Adv. Mar. Biol. 75: Mediterranean marine mammal ecology and conservation. Advances in Marine Biology, 75. Academic Press: London. ISBN 978-0-12-805152-8. XXX, 428 pp., more
In: Advances in Marine Biology. Academic Press: London, New York. ISSN 0065-2881; e-ISSN 2162-5875, more
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| Keywords |
Abundance
Distribution
Population characteristics > Population structure
Trends
Grampus griseus (G. Cuvier, 1812) [WoRMS]
MED, Ligurian Sea [Marine Regions]
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| Author keywords |
Risso's dolphin; Niche partitioning |
| Authors | | Top |
- Azzellino, A.
- Airoldi, S.
- Gaspari, S.
- Lanfredi, C.
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- Moulins, A.
- Podestà, M.
- Rosso, M.
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| Abstract |
This paper provides a summary of 25 years of research on Risso's dolphins (Grampus griseus) in the western Ligurian Sea. Seasonal variations in abundance, distribution and habitat use were observed. Photographic mark–recapture methods provided a population size estimate for the period from 1998 to 2012, of about 100 individuals (95% CI of 60–220 individuals). The same methods detected a decline in population size from an average of about 120–150 from 2000 to 2005, to an average of 70–100 during 2010 to 2014. Species occurrence appeared to be significantly decreasing in coastal and continental slope areas, while it seemed to be stable in the most pelagic area. In addition, a dramatic change was observed in the local primary production, which was analysed based on time series of sea surface temperature and chlorophyll data from 1990 to 2014. Based on fisheries landings, there may have been a general decrease in fishery productivity, both in the western Ligurian Sea and in adjacent regions. Environmental variability, depletion of resources by fisheries and possibly interspecies competition may all have contributed to cause changes in Risso's dolphin habitat use and occurrence in the western Ligurian Sea. |
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