Recent studies demonstrate that marine N₂ fixation can be carried out without light. However, direct measurements of N₂ fixation in dark environments are relatively scarce. This study uses a model that represents biogeochemical cycles at a deep-ocean location in the Gulf of Aqaba (Red Sea). Different model versions are used to test assumptions about N₂ fixers. Relaxing light limitation for marine N₂ fixers improved the similarity between model results and observations of deep nitrate and oxygen.

Carbon dioxide levels are rising globally, and it is important to understand how this rise will affect plants over long time periods. Volcanoes such as Mammoth Mountain, California, have been releasing CO₂ from their flanks for decades, and this provides a test environment in order to study the way plants respond to long-term CO₂ exposure. We combined several airborne measurements to show that plants may have fewer, more productive leaves in areas with increasing CO₂.

In this study, we provide first evidence of lipid biomarker patterns and phylogenetic identities of key microbes mediating anaerobic oxidation of methane (AOM) communities in active mud volcanoes (MVs) on the continental slope of the Canadian Beaufort Sea. Our lipid and 16S rRNA results indicate that archaea of the ANME-2c and ANME-3 clades are involved in AOM in the MVs investigated.

This paper presents the first comprehensive assessment of fluvial organic carbon loss from oil palm plantations on tropical peat: a carbon loss pathway previously unaccounted for from carbon budgets. Carbon in the water draining four plantations in Sarawak was monitored across a 1-year period. Greater fluvial carbon losses were linked to sites with lower water tables. These data will be used to complete the carbon budget from these ecosystems and assess the full impact of this land conversion.

Biogenic carbonates record past environmental conditions. Fossil shell chemistry and microstructure change as metastable biogenic carbonates are replaced by inorganic calcite. Simulated diagenetic alteration at 175 °C of different shell microstructures showed that (nacreous) shell aragonite and calcite were partially replaced by coarse inorganic calcite crystals due to dissolution–reprecipitation reactions. EBSD maps allowed for qualitative assessment of the degree of diagenetic overprint.

The OUTPACE cruise took place between New Caledonia and French Polynesia. The main purpose was to understand how micro-organisms can survive in a very poor environment. One main source of nutrients is at depth, below the euphotic layer where micro-organisms live. The purpose of the turbulence measurements was to determine to which extent turbulence may uplift nutrients into the euphotic layer. The origin of the turbulence that was found contrasted along the transect was also determined.