Marine diatoms Credit: Mogana das Murtey and Patchamuthu RAMASAmy/Creative Commons Attribution Share Alike 3.0 UnportedAccording to Yale research, diatomstiny phytoplankton, which is responsible for about a fifth of all energy that plants convert into matter, may have been more important in Earth's development of ocean ecosystems and the carbon cycle earlier than previously thought.Scientists may have misunderstood much of the information they had about diatom growth.Pincelli Hull (assistant professor in the Department of Earth and Planetary Sciences) stated that "our results are crucial for understanding everything, from the rise of whales and the carbon cycle." "Diatoms account for a significant portion of primary productivity on the planet, and they were only recently discovered."The study was led by Sophie Westacott, a Yale doctoral student. It appears in Proceedings of the National Academy of Sciences. Noah Planavsky (a professor of Earth and Planetary Sciences) and Ming-Yu Zhao (a postdoctoral fellow at the Department of Earth and Planetary Sciences), are co-authors.Westacott stated that diatoms have been increasing in number since the beginning of the Cenozoic Era (66 million years ago) to today. According to Westacott, the most common view was that diatoms rose rapidly in the last 20 million years. This coincided with an increase in the number of baleen whales as well as the abundance of terrestrial grasses.Westacott stated that one hypothesis was that diatoms had a greater dominance, which led to a rise in baleen-whale numbers. Another hypothesis is that grasses have a lot of small silica particles and diatoms make tiny shells from silica. This could explain why grasses may have contributed to diatoms' abundance by adding more bioavailable silica to the ocean.Diatom growth has also been associated with the decrease in atmospheric CO2 concentrations over 40 million years, sea-level change, and restructuring of ocean ecosystems.These theories were based upon evidence from diatoms in fossil records. The Yale study suggests that diatoms could have been present much earlier, but they were not being preserved.Yale researchers used numerical models for predicting what would happen to diatoms if they were buried under sediment that has fallen to the seafloor. The model used data including estimates of seawater temperatures and sedimentation rates over the past 66,000,000 years.Westacott stated that "from this we discovered that a diatom was much more likely to survive in today's sea than in the deep future, say prior 20 million years ago."These findings show that diatom proliferation does not depend on grassland development, whale evolution or climate change. The researchers stated that this has important implications for understanding ocean ecosystems as well as the global carbon cycle over the past 66 million years.Continue reading: A new study highlights the importance of sea sponges for combating climate changeMore information: Sophie Westacott and colleagues, Revisiting the sedimentary records of the rise of diatoms. Proceedings of the National Academy of Sciences (2021). Information for Journal: Proceedings of National Academy of Sciences Sophie Westacott and colleagues, Revisiting sedimentary records of the rise of diatoms (2021). DOI: 10.1073/pnas.2103517118
