Social Structure, Habitat Use and Injuries of Indo-Pacific Bottlenose Dolphins (Tursiops aduncus) Reveal Isolated, Coastal, and Threatened Communities in the South Pacific

Type Article
Date 2021-02
Language English
Author(s) Bonneville Claire Daisy1, 2, Derville Solène1, 2, Luksenburg Jolanda A.3, 4, Oremus Marc5, Garrigue Claire1, 2
Affiliation(s) 1 : UMR 250/9220 ENTROPIE, IRD, Université de La Réunion, Université de la Nouvelle-Calédonie, CNRS, Ifremer, Laboratoire d’Excellence-CORAIL, BPA5, Nouméa, New Caledonia
2 : Opération Cétacés, Nouméa, New Caledonia
3 : Institute of Environmental Sciences, Leiden University, Leiden, Netherlands
4 : Department of Environmental Science and Policy, George Mason University, Fairfax, VA, United States
5 : WWF-France Antenne Nouvelle-Calédonie, Nouméa, New Caledonia
Source Frontiers In Marine Science (2296-7745) (Frontiers Media SA), 2021-02 , Vol. 8 , P. 606975 (14p.)
DOI 10.3389/fmars.2021.606975
Keyword(s) odontocetes, New Caledonia, social communities, habitat, anthropogenic impacts, scars
Abstract

Understanding population structure and habitat use of poorly known cetacean species is a first step toward scientifically informed management decisions. In the southern range of New Caledonia (South Pacific), a long-term dataset of Indo-Pacific bottlenose dolphins (Tursiops aduncus) encounters primarily during winter seasons 1997 to 2019 (473 group observations) was used to assess social structure, habitat use and potential threats. A total of 338 individuals were photographically identified, forming three distinct communities in the south-west lagoon, the south lagoon and the Isle of Pines. Mark-recapture histories revealed that the three communities were weakly connected and might be considered as independent management units. Suitable habitats were estimated with presence-only distribution models relative to topographic and seabed substrate predictors. Habitat suitability increased with proximity to coasts or reefs, at shallow depth, and over muddy bottom. These habitats had various levels of protection and were used by humans, mostly in the south-west lagoon. External injuries were interpreted to determine natural interactions and potential anthropogenic threats. The prevalence in injuries did not vary among the three areas. A substantial proportion of injuries related to propeller hits was reported, representing a total of 16.7% (34 of 204) of all injuries observed on dolphins. The three communities of Indo-Pacific bottlenose dolphins revealed in the southern part of New Caledonia are particularly vulnerable due to their insularity, their coastal habitat use and the low levels of connectivity found among them. In a context of increasing maritime traffic, fishing and recreational activities, this study provides a useful baseline to the urgent assessment of the conservation status of dolphins in New Caledonia.

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How to cite 

Bonneville Claire Daisy, Derville Solène, Luksenburg Jolanda A., Oremus Marc, Garrigue Claire (2021). Social Structure, Habitat Use and Injuries of Indo-Pacific Bottlenose Dolphins (Tursiops aduncus) Reveal Isolated, Coastal, and Threatened Communities in the South Pacific. Frontiers In Marine Science, 8, 606975 (14p.). Publisher's official version : https://doi.org/10.3389/fmars.2021.606975 , Open Access version : https://archimer.ifremer.fr/doc/00682/79407/