Phytoplankton, key to ocean life, falling 2% per year in North Atlantic
A recent study conducted by researchers at Dalhousie University has revealed a concerning trend in the North Atlantic – a two per cent decrease in the biomass of two main types of phytoplankton each year for the past six decades. This decline, observed in diatoms and dinoflagellates, is believed to be a direct result of climate change.
Phytoplankton are microscopic organisms that serve as the foundation of the ocean food web. They play a crucial role in the ecosystem by feeding larger creatures such as zooplankton, which in turn are consumed by fish, mammals, and birds. Additionally, phytoplankton aid in the planet’s carbon cycle by removing carbon dioxide from the atmosphere and sinking it to the ocean floor upon their death, thus helping to mitigate the effects of climate change.
Andrew Irwin, a professor at Dalhousie University and one of the authors of the study published in PLOS One, emphasized the significance of these findings, stating that any disruption to phytoplankton populations is cause for concern due to their vital role in the ecosystem. The study’s analysis, spanning from 1960 to 2017, revealed an overall decrease in phytoplankton biomass across the North Atlantic, with the exception of the eastern and western continental shelves.
The researchers utilized data collected through the Continuous Plankton Recorder (CPR) project, which has been ongoing since 1931. This innovative sampling method involves towing a device behind ships to capture phytoplankton samples as the vessel travels through the water. The CPR has covered over seven million nautical miles, providing valuable insights into long-term trends in phytoplankton populations.
Despite the limitations of the CPR in capturing smaller phytoplankton, the study yielded unexpected results. While previous research suggested a shift towards dinoflagellates over diatoms, the data indicated that diatom biomass had actually increased relative to dinoflagellate biomass, except in the Arctic region of the North Atlantic. This complexity in phytoplankton dynamics underscores the multifaceted nature of oceanic processes and the need for further research to fully understand the impact of climate change on marine ecosystems.
In conclusion, the declining biomass of phytoplankton in the North Atlantic highlights the far-reaching consequences of climate change on marine biodiversity. By shedding light on these trends, researchers hope to raise awareness of the importance of preserving phytoplankton populations and safeguarding the health of our oceans.
