What long-term impacts does climate change have on photosynthetic organisms? This is what a recent study published in Nature Microbiology hopes to address as a team of scientists investigated how climate change could negatively impact the cyanobacterium Prochlorococcus, which is the most abundant photosynthetic organism worldwide. This study has the potential to help scientists, legislators, and the public better understand the long-term ramifications of climate change and the steps that can be taken to mitigate them.
For the study, the researchers analyzed phytoplankton samples obtained between 2010 and 2023 from 3 to 8 meters (9.8 to 26.2 feet) beneath the ocean’s surface. The team then input this data into a computer model to obtain phytoplankton division rate measurements. The goal of the study was to ascertain the temperatures that Prochlorococcus cells need to divide and reproduce.
In the end, the researchers found that Prochlorococcus cells replicate between temperatures of 66- and 84-degrees Fahrenheit, but this is drastically reduced above 86 degrees. Additionally, the researchers found that another phytoplankton, Synechococcus, can reproduce in warmer temperatures but require more nutrients to survive.
Map depicting path of the cruises during the 13-year study, with brighter colors indicating warmer temperatures. (Credit: François Ribalet/University of Washington)
“For a long time, scientists thought Prochlorococcus was going to do great in the future, but in the warmest regions, they aren’t doing that well, which means that there is going to be less carbon — less food — for the rest of the marine food web,” said Dr. François Ribalet, who is a research associate professor of biological oceanography at the University of Washington and lead author of the study.
This study comes as ocean temperatures continue to increase from climate change, with oceans trapping more than 90 percent of the excess heat produced from greenhouse gases. The rate of ocean temperatures has doubled in the last 20 years, with the most notable increases occurring in 2023 and 2024.
How will climate change impact photosynthetic organisms in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Nature Microbiology, EurekAlert!, National Environmental Education Foundation
