The ocean’s digestive system is made up of picky microbes and the precise dynamics of drifting debris. Carbon falls through the ocean in the form of “marine snow,” which consists of plankton carcasses, excrement, and molt particles that sink towards the depths from the sunlit top 200 meters of the sea. These particles can clump together, break apart, gain speed, sink more slowly, or be consumed by bacteria as they descend through darker, colder, and denser waters, carrying carbon with them and settling on the bottom as biomass.
Oceanographers are studying the process of carbon sequestration in the oceans to understand how much carbon actually reaches the seafloor and remains there. This is crucial for climate models, as the oceans absorb billions of tons of carbon each year. Researchers are investigating how carbon is consumed, expelled, or influenced as it moves through what some scientists refer to as the ocean’s “digestive system.”
Recent advancements in sensor technology, imaging, and DNA sequencing are allowing scientists to examine specific organisms and processes involved in carbon sequestration more closely. For example, a study published in Science found that certain microbial populations in marine snow prefer to consume phytoplankton containing specific types of lipids, which are fatty acid biomolecules. Since lipids make up a significant portion of the organic matter at the ocean’s surface, the dietary preferences of bacteria in different regions could have a significant impact on the amount of carbon-containing biomass that reaches the seafloor.
By understanding the microbial processes at work, researchers hope to be able to predict the fate of carbon based on the organisms present in the future. This could help improve our understanding of carbon flux in the oceans and its impact on climate change. Scientists are also using sediment traps and autonomous cameras to study the distribution of marine snow over different time frames in specific locations. This research is revealing the complexity of marine snow distribution and highlighting the limitations of previous models and equations in understanding carbon flux.
Overall, studying the role of marine snow in ocean carbon sequestration is essential for improving climate models and our understanding of how the oceans regulate carbon levels. By investigating the processes that govern the movement of carbon through the ocean’s “digestive system,” scientists can gain valuable insights that may help mitigate the effects of climate change in the future.
