Study suggests ocean’s capacity to absorb CO2 is overestimated. Research into North Atlantic plankton likely to lead to negative revision of global climate calculations.
The North Atlantic sea may not be as strong a climate ally than scientists previously believed. The ocean’s capacity to absorb CO2 has been overestimated according to recent research.
A sampling of plankton in the first ever winter and spring study in the Western North Atlantic showed cell sizes were much smaller than scientists previously assumed. This means that carbon doesn’t sink as deep or as fast, nor does it stay in the depths for long.
Steve Giovannoni from Oregan State University said, “We have found a misconception. It will definitely impact the model of carbon flows.”
The spring phytoplankton bloom in the North Atlantic is probably the largest yearly biological carbon sequestration mechanism on the planet, researchers say. Similar to a huge forest of tiny plants in the sunlight upper part of the ocean, they draw down CO2 through photosynthesis. It poses a greater chance for the plankton to sink into the deep mesopelagic zone of the ocean the bigger they are, where carbon can be trapped for over 1,000 years.
Until now, one of the biggest types of plankton – diatoms – were thought to be dominant. However, the study, published in the International Society for Microbial Ecology Journal, reveals they are an extremely small share of biomass when compared with much smaller cyanobacteria, picophytoeukaryotes and nanophytoekaryotes.
In winter this was anticipated, but even more surprisingly that even in spring – post annual bloom – there were far fewer diomeds in the western North Atlantic than previously anticipated.
Steven Giovannomi said, “We asked how could our impressions of this ocean be so far off?” “There are a few reasons: Previous studies had focused on more eastern regions, climate change altering the biology of the ocean, and new equipment that allows us to see smaller plankton more clearly.”
However, the findings of this study and the North Atlantic ocean do not necessarily apply to all oceans, Giovannoni said they spotlight how little is understood of marine biology and as well as the need for close-up study.
Satellites and other Nasa monitoring agencies have used images from space to assess the carbon draw-down limit of algae blooms, but subsequently, they’ll need to go back to the drawing board to revise the assumptions on which their calculations are based.
Credit: Jonathan Watts – The Guardian