This short report provides the first observations of deep-sea corals belonging to the class Octocorallia and order Antipatharia surveyed during the KM24-03 Leg 2 cruise in the waters around Minamidaito and Kitadaito Islands in Okinawa, Japan between approximately 200 and 1,000 m. It also lists and illustrates the specimens that were collected. Based on field observations, deep-sea corals occupied the niches inside and around caves and crevices, as well as non-cave environments such as flat seabeds and slopes. Our morphological and phylogenetic analyses of the collected specimens revealed the presence of Callogorgia cf. korema, Pleurocorallium inutile, and Acanthopathes undulata. We provide the first documentation of deep-sea corals found in this area, as well as extend the known geographic distribution of these species. In particular, the black coral A. undulata, which until now has only been reported from the western and central Pacific Ocean, is reported for the first time in the northwestern Pacific. Our preliminary findings warrant further investigation and more stringent protection of the deep-sea species and habitats found in the waters around these karstic islands from anthropogenic impacts, perhaps with inclusion in regional Marine Protected Areas.

We investigated the microscopic mineral characteristics of modern eolian dust particulates and the trace-element compositions of the siliciclastic fractions of these samples, collected from the Philippine Sea in 2014 and 2015, and conducted an air mass backwards trajectory analysis of dust particulates in the spring and winter of 2015, to better constrain the provenances and transport dynamics of dust delivered to this region. The microscopic minerals show obvious signatures of dust deposition and physical abrasion, indicating long-distance wind transport from the Asian deserts. The trace-element compositions (Zr–Th–Sc) display a binary mixture of eolian materials derived from the eastern Asian deserts and the central Asian deserts, which is similar to the result of the Sr–Nd isotopic compositions of modern sediment trap sediments collected on the Benham Rise in 2015. We demonstrate that modern dust sediments in the Philippine Sea primarily originate from the Ordos Desert (generally > 80%), while the contributions of the Taklimakan Desert and the Badain Jaran Desert are small. Eolian dust particulates raised from source regions are predominantly transported to the Philippine Sea by the East Asian winter monsoon, but not by the westerlies. In addition, our results indicate that increased precipitation in the source regions can result in relatively low dust fluxes in the Philippine Sea, and there is a period of 6–7 days for eolian dust originating from source areas to be delivered to the Philippine Sea.