Before today’s class I always had it in mind that the only beneficial organisms in the ocean are the bigger animals. Never have I thought that tiny microbes in the ocean actually carry such a role in carbon fixation. The interactions between microbes and phytoplankton are truly remarkable. As phytoplankton fix excess carbon from the atmosphere and convert it into glycans, microbes then break down some of the glycan but not all and recycle it through the ecosystem. Some of the glycans can only be broken down by microbes because the structure of the glycans is complex, making trait-based on the part of some microbes really useful; Therefore, only microbes with specialized enzymes can break down these glycans. This serves as a barrier to many other microbes that lack these enzymes. So a small fraction of these glycans is broken down and released into the atmosphere. The rest sink into the ocean. This leads to the accumulation of carbon in the ocean instead of the atmosphere.

But climate change also adds uncertainty to this carbon cycling process. If atmospheric weather conditions change drastically, it impacts phytoplankton blooms; the microbes that rely on their glycans might not be in alignment anymore. Any slight mismatches could change how efficiently carbon is processed and stored in the ocean. The phytoplankton require certain nutrients for growth from microbes. Therefore, without these microbes, nutrient cycling would stop, leading to a collapse in phytoplankton productivity over time. When this happens, the sea can no longer store carbon from the atmosphere, resulting in rising global temperatures, ocean acidification, ecosystem disruptions, and more extreme weather like stronger storms, floods, and even droughts.

Overall, I have come to the terms that microbes are essential in global biogeochemical cycles. It is important to study and understand the genetics and traits of all these organisms and the influence they have on the ecosystem to help make good predictions on climate. It is amazing how these tiny organisms help in the stability of the whole earth’s climate and functioning.