Plankton in an acidified ocean

摘要

The pH of the'ocean is expected to drop 0.3 units in the next century. This change is well within the pH range that plankton experience at present, but research suggests that changes in acidity near their cell surface could be larger.We may all recognize that organisms can modify their environment to suit their needs, but we generally think of large, complex organisms in this context. Beaver, for example, dramatically transform streams into large wetland systems. Plants modify soil chemistry at the soil-root interface to enhance the dissolution of mineral nutrients. However, active modification of the environment is not limited to thesebig organisms. Microscopic organisms also have both small and large impacts on their environment. At the level of individual cells, aquatic microorganisms practise low-impact living, limiting their influence to the thin boundary layer around the cell. Writing in Nature Climate Change, Flynn et al. report on a modelling study of oceanic plankton that looks at metabolic modifications to the pH and C02 chemistry in the boundarylayer surrounding the cell and how this 'microzone' may change over the next century as the oceans become more acidic.