Dear MARMAM community,
My co-authors and I are pleased to share our new publication: "Social structure, habitat use and injuries of Indo-Pacific bottlenose dolphins (Tursiops aduncus) reveal isolated, coastal and threatened communities in the South Pacific"
Bonneville CD, Derville S, Luksenburg JA, Oremus M and Garrigue C (2021) Social Structure, Habitat Use and Injuries of Indo-Pacific Bottlenose Dolphins (Tursiops aduncus) Reveal Isolated, Coastal, and Threatened Communities in the South Pacific.Front. Mar. Sci. 8:606975. doi: 10.3389/fmars.2021.606975
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.
Please, feel free to contact us if you have any question.
Claire Daisy Bonneville
Ingénieure d’études en biologie moléculaire
Institut de Recherche pour le Développement – UMR ENTROPIE
IRD – BPA5 Nouméa, New Caledonia