Scientists may be able to help remedy global warming using algae, the sea plants could suck up some of the carbon dioxide in the atmosphere.
Algal blooms contain iron-eating phytoplankton, which absorb the CO2 through photosynthesis and use it to feed aquatic life, according to a press release from the Argonne National Laboratory.
One specific type of algae, called diatoms, actually take in more iron than they need. The hungry algae stores the excess iron in their shell and skeleton, which are made from silica. The phenomenon reduces the amount of iron left over for the other carbon-eating guys.
"Just like someone walking through a buffet line who takes the last two pieces of cake, even though they know they'll only eat one, they're hogging the food," said Ellery Ingall, a professor at Georgia's Institute of Technology and co-lead author of the study. "Everyone else in line gets nothing; the person's decision affects these other people."
A process known as iron fertilization or iron seeding would add more iron to the surface water. The process would most likely only work for a short period of time, and could even reduce how much CO2 the ocean traps in the future.
One would think introducing more iron into the water should feed the starving plankton, but researchers believe the diatoms would adapt to consume even more iron if that was the case. Eventually the diatom's shells would get so big from growing to accommodate more iron they would sink the ocean floor, keeping the iron even farther from the other plankton.
Less iron at the surface could mean less microbial blooms to consume it, and in turn less plankton consuming CO2.
"Being able to use X-rays and see the element content of individual microscopic phytoplankton has completely altered our perspective on how these organisms use iron and how that could affect C02 levels," Ingall said.
According to a recent study, about two and a half milligrams of iron are sequestered on the ocean floor of the Ross Sea every year. It loses about as much iron as is acquired by rising seawater, melting snow, and dust. There are also indications this is happening elsewhere.
"This gap in our knowledge, combined with renewed interest in iron fertilization as an approach to the current climate crisis, makes it crucial that we have an improved understanding of iron cycling in marine systems," Ingall said.
