The mutually beneficial relationship between algae and modern corals — which provides algae with shelter, gives coral reefs their colors and supplies both organisms with nutrients — began more than 210 million years ago, according to a new study by an international team of scientists including researchers from Princeton University.
A nitrite-oxidizing enzyme may work in reverse for some microbes in the Antarctic autumn. Marine microorganisms play a major role in cycling elements like carbon and nitrogen throughout the environment. In the nitrogen cycle, some microbes perform an especially important step: the oxidation of nitrite (NO2−) to nitrate (NO3−), the dominant form of biologically available nitrogen in the ocean. Now Kemeny et al. suggest that the enzyme that converts nitrite to nitrate sometimes works in revers
The Southern Ocean around Antarctica is active in deep ocean ventilation and thus important in the uptake of fossil fuel carbon dioxide and global warming heat. Prof. Daniel Sigman presents evidence that deep ocean ventilation by the Southern Ocean was slower during past ice ages and faster during warm interglacial periods. These findings raise possibilities that deep ocean ventilation by the Southern Ocean will accelerate into the global warming future, counter to most model-based expectation.