Searching for humpback whales in a historical whaling hotspot of the Coral Sea, South Pacific

Type Article
Date 2020
Language English
Author(s) Garrigue C1, 2, Derville S1, 2, Bonneville C2, Baker Cs3, Cheeseman T4, Millet Laurent1, Paton D5, Steel D3
Affiliation(s) 1 : UMR ENTROPIE (IRD, Université de La Réunion, CNRS, Laboratoire d’excellence-CORAIL), Université de la Nouvelle-Calédonie, IFREMER,98848 Nouméa Cedex, Nouvelle-Calédonie, France
2 : Opération Cétacés, Nouméa, 98802 Nouvelle-Calédonie, France
3 : Marine Mammal Institute, Department of Fisheries and Wildlife, Oregon State University, Newport, OR 97365, USA
4 : Southern Cross University, Lismore, NSW 2480, Australia
5 : Blue Planet Marine, Kingston, ACT 2604, Australia
Source Endangered Species Research (1863-5407) (Inter-Research Science Center), 2020 , Vol. 42 , P. 67-82
DOI 10.3354/esr01038
WOS© Times Cited 2
Keyword(s) Chesterfield-Bellona archipelago, Connectivity, Coral Sea, Habitat use, Humpback whale, Satellite tracking, Sex ratio, Whaling
Abstract

Humpback whales Megaptera novaeangliae were severely depleted by commercial whaling. Understanding key factors in their recovery is a crucial step for their conservation worldwide. In Oceania, the Chesterfield-Bellona archipelago was a primary whaling site in the 19th century, yet has been left almost unaffected by anthropogenic activities since. We present the results of the first multidisciplinary dedicated surveys in the archipelago assessing humpback whale populations 2 centuries post-whaling. We encountered 57 groups during 24 survey days (2016-2017), among which 35 whales were identified using photographs of natural markings (photo-ID), 38 using genotyping and 22 using both. Humpback whales were sparsely distributed (0.041 whales km-1): most sightings concentrated in shallow inner-reef waters and neighbouring offshore shallow banks. The recently created marine protected area covers most of the areas of high predicted habitat suitability and high residence time from satellite-tracked whales. Surprisingly for a breeding area, sex ratios skewed towards females (1:2.4), and 45% of females were with calf. Connectivity was established with the New Caledonia breeding area to the east (mtDNA FST = 0.001, p > 0.05, 12 photo-ID and 10 genotype matches) and with the Australian Great Barrier Reef breeding area to the west (mtDNA FST = 0.006, p > 0.05). Movement of satellite-tracked whales and photo-ID matches also suggest connections with the east Australian migratory corridor. This study confirms that humpback whales still inhabit the Chesterfield-Bellona archipelago 2 centuries post whaling, and that this pristine area potentially plays a role in facilitating migratory interchange among breeding grounds of the western South Pacific.

Full Text
File Pages Size Access
Publisher's official version 16 2 MB Open access
Supplementary material 5 215 KB Open access
Top of the page

How to cite 

Garrigue C, Derville S, Bonneville C, Baker Cs, Cheeseman T, Millet Laurent, Paton D, Steel D (2020). Searching for humpback whales in a historical whaling hotspot of the Coral Sea, South Pacific. Endangered Species Research, 42, 67-82. Publisher's official version : https://doi.org/10.3354/esr01038 , Open Access version : https://archimer.ifremer.fr/doc/00632/74454/