Bertrand Richer de Forges

Molecular and ultrastructural characterization of two ascomycetes found on sunken wood off Vanuatu Islands in the deep Pacific Ocean

A new genus of a deep-sea ascomycete with one new species, Alisea longicolla, is described based on analyses of 18S and 28S rDNA sequences and morphological characters. A. longicolla was found together with Oceanitis scuticella, on small twigs and sugar cane debris trawled from the bottom of the Pacific Ocean off Vanuatu Islands. Molecular and morphological characters indicate that both fungi are members of Halosphaeriaceae. Within this family, O. scuticella is phylogenetically related to Ascosalsum and shares similar ascospore morphology and appendage ontogeny. The genus Ascosalsum is considered congeneric with Oceanitis and Ascosalsum cincinnatulum, Ascosalsum unicaudatum and Ascosalsum viscidulum are transferred to Oceanitis, an earlier generic name.

Early taphonomy and significance of naturally submerged Nautilus shells from the New Caledonia region

Abstract The discovery of 11 Nautilus macromphalus shells in marine environments near New Caledonia constitutes the first opportunity for taphonomic analysis of empty shells of unburied, externally shelled cephalopods on the seafloor. Radiometric dating indicates specimen ages range from 14 to 42 years. These modern specimens provide a unique opportunity to examine the early, preburial taphonomy of this group of animals including shell condition, radiometric-age dating, epizoan encrustation, color degradation, and sediment infilling. The following conclusions are made: (1) given the limited sample available for study and assuming equal conditions where shells rested on the seafloor, the length of time the shell is unburied will not control the degree of epizoan encrustation or the external shell appearance; (2) shell boring is a major destructive process that probably impacts the potential of the shells to become fossilized; and (3) shells in the photic zone are impacted differently than those dredged from a deep water environment below the photic zone. A major part of this difference is probably the result of both boring and encrusting organisms, especially algae. By comparison, fossil cephalopods as a general group can be expected to vary considerably from the modern specimens because of evolutionary patterns of associated organisms, geographic distribution, and different environments with different paleoecological parameters through time. Caution in overreliance on the taphonomy of these modern shells should be exercised because of the limited sample of Nautilus specimens recovered. The need for additional taphonomic studies of modern externally shelled cephalopods with the recovery of more specimens from the marine environment is highly desirable.

Modern Nautilus (Cephalopoda) taphonomy in a subtidal to backshore environment, Lifou (Loyalty Islands)

Abstract Thirty-two samples of submerged Nautilus macromphalus shells were recovered in 2008 from Lifou, Loyalty Islands in the South Pacific Ocean. Specimens were collected from carbonate-dominated sediment in water depths of 1–3 m. Some specimens were partly buried, whereas others rested on the seafloor. The majority of the specimens (66%) were recovered in a horizontal position, whereas 34% of the specimens were oriented vertically. Some specimens were pristine, with sharp color stripes and little encrustation by algae, cyanobacteria, or epizoans. The majority of specimens have substantial algal and cyanobacterial overcoats with some epizoans. In some specimens, the overcoats also trapped substantial amounts of carbonate sediment. Comparison of the 2008 collection of subtidal specimens to 43 beached Nautilus shells collected in 2002 from the same location reveals that the nearshore taphonomic pathways for drift cephalopod shells can be more complicated than published theoretical models suggest. Nautilus shells may or may not float directly to the beach. Shells not immediately deposited on the beach sink in the shallow water in a vertical position. Weight added by attached organisms and water infiltration, causes the submerged shells to eventually assume a horizontal position. Waves, currents, and bioturbation can then flip the shells over from side to side. Eventually submerged shells are buried, broken apart, or transported onto the beach. Beached shells that follow this taphonomic pathway have conspicuous algal coatings compared to those that simply float to shore. The Lifou subtidal population represents the first substantial modern externally shelled cephalopod collection from a shallow water environment to be analyzed to determine its taphonomic pathways. Conclusions from this analysis can be applied to nearshore deposits that contain externally shelled, fossilized cephalopods.

The Coral Sea: Physical Environment, Ecosystem Status and Biodiversity Assets

The Coral Sea, located at the southwestern rim of the Pacific Ocean, is the only tropical marginal sea where human impacts remain relatively minor. Patterns and processes identified within the region have global relevance as a baseline for understanding impacts in more disturbed tropical locations. Despite 70 years of documented research, the Coral Sea has been relatively neglected, with a slower rate of increase in publications over the past 20 years than total marine research globally. We review current knowledge of the Coral Sea to provide an overview of regional geology, oceanography, ecology and fisheries. Interactions between physical features and biological assemblages influence ecological processes and the direction and strength of connectivity among Coral Sea ecosystems. To inform management effectively, we will need to fill some major knowledge gaps, including geographic gaps in sampling and a lack of integration of research themes, which hinder the understanding of most ecosystem processes.

Griffinia takedai, a new species of deep sea majoid crab (Decapoda, Brachyura, Epialtidae) from the Philippines

A new species of deep-sea majoid is described from the eastern Philippines. Griffinia takedai n. sp. (Epialtidae) is the fourth species in this genus to be described, and it differs from congeners in its setose carapace, elongate rostral spines, as well as the well-developed supraorbital and hepatic spines. The new species is diagnosed, and a key to the genus is presented.

Keep cruises off remote reef rich in fish and birds

Just 3% of the worlds coral reefs remain in near-pristine condition; about one-third of these are located in the Coral Sea in the South Pacific Ocean. The Chesterfield reef ensemble, one of the worlds largest atolls, is an example. It is part of Frances overseas territory of New Caledonia, and its remoteness has so far preserved its wealth of biodiversity. We therefore call for the territorys government to drop its plans to open these precious reefs to the destructive effects of cruise ships and mass ecotourism. The Chesterfield reefs were spared the 2016 mass-bleaching phenomenon that affected coral reefs around the world. They host the largest seabird colonies in the tropical western Pacific. Indeed, nitrogen from seabird guano may contribute to the resilience of reef-building corals. Comprising a remarkable variety of corals, the reefs host an abundance of diverse fish shoals and species such as the threatened fairy tern (Sternula nereis), several endemic marine gastropods and an endemic sea snake (Hydrophis laboutei). They are also a nesting site of regional importance for the green sea turtle (Chelonia mydas). Cruise ships will inevitably disrupt the reef and lagoon habitats and fauna. Their hundreds of passengers will lethally disturb breeding seabird colonies, by repeatedly scaring away nesting adults. This could particularly affect the brown booby (Sula leucogaster), the lesser and greater frigatebirds (Fregata ariel and F. minor) and the sooty tern (Onychoprion fuscatus).

Découverte d'une espèce de Plagusia, P. Chabrus (Linné, 1758) aux îles Saint-Paul et Nouvelle-Amsterdam (Decapoda, Brachyura)

The crab Plagusia chabrus (L.) was caught in lobster pots by fishermen near St. Paul and New Amsterdam Islands. This is the first record of this species from the southern Indian Ocean. The St. Paul specimens have been compared with the neotype of Plagusia chabrus from South Africa, and with Australian and New Zealand material. A comparison was also made with the syntypes of two species described by H. Milne Edwards in 1837 and in 1853 respectively, viz., Plagusia tomentosa and P. gaimardi. The present record emphasizes the importance of St. Paul and New Amsterdam islands as a biogeographic link between South Africa and Australia.