Mission ornithologique à l'îlot Loop (îles Chesterfield) et transects en mer de Corail et dans le bassin des Loyauté, 20-28 octobre 2008

IRD, NouméaAbstract – Seabird survey of Ilot Loop (Chesterfield islands) and at-sea transects, 20-28 October 2008. A census of the birds of Ilot Loop (Chesterfield Atoll, Coral Sea) was taken during a trip of patroller ship La Glorieuse of the French Navy. Twelve bird species were observed during the 23 hours of our stay on the islet (22-23 October 2008), including 7 seabirds breeding [Wedge-tailed Shearwater Puffinus pacificus (N=6144 active burrows), Black Noddy Anous minutus (N=5 nests with chick; ~500 adults), Brown Noddy A. stolidus (N=18 nests with egg; ~70 adults), Sooty Tern Onychoprion fuscatus (N= 1060-1300 breeding pairs), Masked Booby Sula dactylatra (N=26 breeding pairs), Brown Booby Sula leucogaster (N=85 breeding pairs), Red-footed Booby S. sula (N=165 breeding pairs)], 3 seabirds not breeding [Crested Tern Thalasseus bergii (N=1), Black-naped Tern Sterna sumatrana (N=10), Pacific Frigatebird, Fregata minor (N=1)], a shorebird [Wandering Tattler Tringa incana (N=2)] and the Chesterfield Buff-banded Rail Gallirallus philippensis tournelieri (N=1 juvenile). From transects at sea in the New Caledonia and Loyalty basins, the following seabirds were observed, hereafter ranked by decreasing abundance: Wedgetailed Shearwater, Sooty Tern, Brown Booby, Tahiti Petrel Pseudobulweria rostrata, Red-footed Booby and other petrels including Pterodroma leucoptera, P. nigripennis and Oceanites oceanicus, and Antarctic Skua Catharacta antarctica. The size of the Tahiti Petrel population of New Caledonia was estimated to be > 15 000 pairs. Several marine mammals were observed: Dugong Dugong dugon (N=1) in the Southwest lagoon of New Caledonia, Humpback Whale Megaptera novaeangliae (N=1) and Bottlenose Dolphin Tursiops sp. (N=1) in the Chesterfield lagoon, and Bottlenose Dolphin T. truncatus (one pod, N~30) and Great Sperm Whale Physeter macrocephalus (N=1) in the Loyalty basin. A Green Turtle Chelonia mydas was observed laying eggs at Ilot Loop. Samples of Large-eye Bream Gymnocranius sp. and Fringelip Mullet Crenimugil crenilabis were also collected

Mission ornithologique sur l'île Matthew, 16-19 avril 2008

A census of the birds of Matthew Island, south-east of the New Hebrides chain, was taken during a trip of frigateship Vendémiaire of the French Navy, from 16 to 19 April 2008. Fourteen bird species were observed on the islets, including 8 seabirds breeding or potentially breeding (black-winged petrel Pterodroma nigripennis, wedge-tailed shearwater Ardenna pacifica, masked booby Sula dactylatra, brown booby S. leucogaster, red-tailed tropicbird Phaethon rubricauda, brown noddy Anous stolidus, grey noddy Anous albivitta and sooty tern Onychoprion fuscatus), three other seabirds (roosting red-footed booby S. sula, lesser frigatebird Fregata ariel and Pacific frigatebird F. minor), three shorebirds (turnstone Arenaria interpres, Pacific golden plover Pluvialis fulva and tattler Tringa sp.) and the sacred kingfisher Todirhamphus sanctus. No hen or cock (Gallus gallus) was sighted, unlike during previous visits to the island. Series of traps were set overnight for rats but no rodent was captured. Wedge-tailed shearwaters were abundant at sea and in the South-West lagoon of New Caledonia; flocks of migrating short-tailed shearwaters Ardenna tenuirostris were sighted in the Loyalty basin.Un recensement des oiseaux de l’île Matthew, au sud-est de la chaîne des Nouvelles-Hébrides, a été fait à l’occasion d’une mission de souveraineté de la frégate Vendémiaire de la Marine nationale, du 16 au 19 avril 2008. Quatorze espèces d’oiseaux furent observées sur l’île, dont huit oiseaux marins nicheurs ou potentiellement nicheurs (pétrel à ailes noires Pterodroma nigripennis, puffin fouquet Ardenna pacifica, fou masqué Sula dactylatra, fou brun S. leucogaster, phaéton à brins rouges Phaethon rubricauda, noddi brun Anous stolidus, noddi gris Anous albivitta et sterne fuligineuse Onychoprion fuscatus), trois oiseaux marins non nicheurs (fou à pieds rouges S. sula, frégate ariel Fregata ariel et frégate du Pacifique F. minor), trois limicoles (tournepierre à collier Arenaria interpres, pluvier fauve Pluvialis fulva et chevalier Tringa sp.) et le martin-chasseur sacré Todirhamphus sanctus. Aucun coq ni poule (Gallus gallus) n’a été aperçu, à la différence des missions précédentes. Une série de pièges à rats, posés pour la nuit, n’ont capturé aucun rongeur. Le puffin fouquet était abondant en mer et dans le lagon sud-ouest de la Grande Terre ; des rassemblements de puffins à bec grêle Ardenna tenuirostris en migration ont été observés dans le bassin des Loyauté

Genetic structure of the common sole Solea vulgaris at different geographic scales

The genetic structure of the flatfish #Solea vulgaris was investigated on several spatial scales and at the temporal level through analysis of electrophoretic variation at 8 to 12 polymorphic enzyme loci. No differentiation was apparent at the temporal scale. Some differentiation was detected at and above the regional scale. Isolation by distance was evidenced by the significant correlation between genetic and geographic distances, and by the consistency of the results of multiple-locus correspondence analysis with geographic sampling patterns. The analysis suggested that the geographic unit of population structure (i.e. a geographical area corresponding to a panmictic or nearly panmictic population) lies within a radius of the order of 100 km. The isolation-by-distance pattern in #S. vulgaris contrasted with the known genetic structures of other flatfish species of the northeastern Atlantic and Mediterranean in a way that may be related to the range of their respective temperature tolerances for eggs and larvae. (Résumé d'auteur

Génétique des populations de Beryx splendens de la zone économique de la Nouvelle-Calédonie : distribution des haplotypes du gène du cytochrome b de l'ADN mitochondrial et analyse phylogénétique de leurs séquences

La délimitation géographique des populations, établie sur les bases biologiques, est nécessaire à toute gestion rationnelle des pêcheries. Tel est le cas pour #Beryx splendens, ressource pour laquelle la mise en évidence de différentes populations dans la zone économique (ZE) de Nouvelle-Calédonie serait essentielle pour en éviter la surexploitation. L'ADN mitochondrial a été choisi comme marqueur génétique de la structure géographique de #B. splendens sur les monts sous-marins de la ZE de Nouvelle-Calédonie. (D'après résumé d'auteur