Monday November 6, 2023
Nature —
Marine microorganisms are crucial for ocean health. Bacteria, archaea, fungi, algae and viruses make up most of the biomass in the seas and form the base of marine food webs. They support nutrient cycling and drive crucial biogeochemical processes, including key steps in the carbon, nitrogen and silicon cycles.
But the climate crisis is putting stress on oceans through steadily rising temperatures, longer and more frequent heatwaves, acidification and changes in nutrient levels. Understanding how marine microbes are affected is key to forecasting the future state of the oceans, and mitigating the effects of the crisis on marine ecosystems as well as the human communities that rely on them for livelihoods and food.
Ocean forecasting isn’t easy. Oceans are hugely complex systems, and forecasters need to incorporate an array of changes in ocean physics (waves, currents and interactions with the atmosphere), biology (how organisms react to the environment, as well as with one another) and chemistry (different forms of essential elements and their sensitivity to oxygen or pH). These models must cover a range of scales, from national waters to expanses of open ocean. They must also be able to simulate extreme states, such as marine heatwaves, and conduct simulations over hundreds of years.