A team of researchers from the University of Miami has found that the oceanic food web is founded on microscopic volcanic ash and aerosolized desert sand.
The team found these two components combine to provide the base nutrients and ingredients that allow life in the oceans to flourish.
The researchers collected samples from the North Atlantic Ocean over the course of a five-day expedition aboard the Woods Hole Oceanographic Institution’s Research Vessel Neil Armstrong.
According to Hope Elliot, one of the members of the scientific team behind the research and Ph.D. student in ocean sciences at the Rosenstiel School of Marine, Atmospheric, and Earth Science:
“Both desert dust and volcanic ash contain phosphorus, a key element found in the world’s oceans that essentially acts as a fertilizer for the sea. In sufficient amounts, phosphorus stimulates the production of phytoplankton, microscopic plants that reduce atmospheric carbon dioxide concentrations by performing photosynthesis and form the base of the marine food chain.”
Elliott added:
“We’ve long known that dust from desert regions can boost phosphorus levels in the ocean. But little is known about how much of a role phosphorus from volcanic ash can play in boosting phytoplankton growth. We discovered that they both raised concentrations of phosphorus in the water. And by tracking the movement of the phosphorus, we found that the phytoplankton do actually digest it…..
“Dust and ash are being deposited over miles and miles of open ocean. So, to study what’s happening to the microbial community over that huge expanse, we really had to go to sea.”
While associate professor of ocean sciences Kim Popendorf, who led the students’ research and conducted research into the variance of microbial growth, said:
“It was very much a collaborative effort. For that experiment, we conducted multiple depth profiles to 500 meters measuring microbial metabolic energy turnover rates along with a suite of chemical and microbial community measures.”
