Scientists have identified an unexpected food source in the deep ocean that could change how researchers understand marine ecosystems and the planet’s carbon cycle, according to ScienceDaily.
A study from the University of Southern Denmark suggests that deep-sea microbes are not surviving in quite as nutrient-poor an environment as once believed. The researchers found that as marine snow sinks, it releases dissolved carbon and nitrogen into the surrounding water.
Marine snow is made up of tiny clumps of dead algae, microbes and other organic material. The team found that at depths of about 2 to 6 kilometers, high pressure forces dissolved organic matter out of those particles, making it available immediately to microbes nearby.
First author Peter Stief described the pressure as acting like a giant juicer, squeezing out compounds that microbes can quickly consume. In laboratory tests, the researchers said sinking marine snow could lose up to half of its carbon and most of its nitrogen on the way down, and bacterial abundance rose sharply within two days.
The study also raises questions about how much carbon actually reaches the seafloor and gets locked away in sediments. The researchers plan to look for evidence of the same process in the Arctic during a future expedition aboard the German research vessel Polarstern.
