Recent  

New tephra layer and microsiliceous assemblages are identified. Sediment records are contextualized for the Sabrina Coast continental rise chronological and paleoclimatic context. Some in-depth studies on margin instabilities, tephrochronology, and biostratigraphic/paleoenvironmental and sedimentary evolution are suggested. We performed this study to implement knowledge on the Antarctic biochronostratigraphy and microsiliceous sedimentation and benefited from international-level collaboration.

Two species of giant, single-celled "trees” inhabit the seafloor in McMurdo Sound, Antarctica. These unicellular creatures are large enough to be seen and counted by scuba divers. We found that one of the tree species is widely spread, whereas the other inhabits only a small region on the western side of the sound. These types of unicellular trees have not been found elsewhere in the world ocean and are particularly vulnerable to the effects of climate change.

We quantify sea surface temperature (SST) in the past Southern Ocean using the diatom Fragilariopsis kerguelensis that displays variable population with SST.  We explore the use of this relatively new proxy by applying it to sediment assemblages from the Sabrina Coast and Amundsen Sea. We find that Amundsen Sea and Sabrina Coast F. kerguelensis populations are different from each other.  An understanding of F. kerguelensis dynamics may help us generate an SST proxy to apply to ancient sediments.

The Gulf Stream plays a crucial role in the ocean stability and climate regulation of the Northern Hemisphere. By analysing the fossil microorganisms that lived in the water column and the ocean floor, as well as reconstructing the ancient ocean's biogeochemistry, we were able to trace longitudinal shifts in the Gulf Stream during the late Eocene (36 Ma). Our results provide insight into the Gulf Stream's behaviour and the NW Atlantic's palaeoceanography during the Late Eocene (ca. 36 Ma).

This study conducted systematic fieldwork and sample collection for the Cambrian Furongian–Middle Ordovician strata in the northeastern margin of the South China Block to establish a conodont biostratigraphic sequence and discussed the influence of seawater depth, climate, water temperature, and ocean currents on the biogeographic zonation of conodonts and the paleogeographic implications for some conodont species.

Diatom assemblages are vital components of the Antarctic ecosystem and nutrient supply chain, and they are often utilized as paleoclimate proxies to better understand past climatic changes. We demonstrate enhanced diatom production and accumulation in the outer Amundsen Sea during a Mid-Pliocene interglacial that coincides with pulses of ice-rafted terrestrial debris, providing compelling evidence that iceberg calving seeds diatom productivity in the Southern Ocean.

The Red Sea hosts exceptionally diverse marine environments despite elevated salinities. Distributions of benthic foraminifers were used to assess the ecological status of coral reef environments in the Ras Mohamed Nature Reserve, south Sinai. Sediment samples collected in mangrove, shallow-lagoon, and coral reef habitats yielded 95 foraminiferal species. Six species, five hosting algal symbionts, made up ~70 % of the specimens examined, indicating water quality suitable for reef accretion.

Warmer waters in the Southern Ocean have led to the loss of Antarctic ice during past interglacial times. The shells of foraminifera are preserved in Ross Sea sediment, which is collected in cores. Benthic species from Site U1523 inform us about changing water masses and current activity, including incursions of Circumpolar Deep Water. Warm water planktic species were found in sediment samples from four intervals within 3.72–1.82 million years ago, indicating warmer than present conditions.

In 1977-79, the Ross Ice Shelf Project recovered ocean sediments ~ 450 km south of the present-day ice shelf calving front. Within these sediments are microfossils, which are used to recreate the history of the West Antarctic Ice Sheet (WAIS) and address how the ice sheet responded to past times of extreme warmth. The microfossils reveal the WAIS collapsed multiple times in the past 17 million years. These results inform predictions of future WAIS response to rising global temperatures.

The sub-Antarctic island of South Georgia has a dynamic glacial history and is sensitive to climate change. Using benthic foraminifera and various geochemical proxies, we reconstruct inner–middle shelf productivity and infer glacial evolution since the late deglacial, identifying new mid–late-Holocene glacial readvances. Fursenkoina fusiformis acts as a good proxy for productivity.

Diatoms are dust-sized algae commonly found in the upper 100 m of the Southern Ocean. In this paper, we describe three new species found in sediments west of the Ross Sea, East Antarctica, aged about 3--2 Ma: Fragilariopsis clava, Fragilariopsis armandae, and Rouxia raggattensis. These species may be useful for determining the age of sediments and past environmental conditions at other locations around the Southern Ocean.