Though they may be small, microorganisms are the most abundant form of life in the ocean. Marine microbes are responsible for making roughly half of the organic carbon that’s usable by life. Many marine microbes live near the surface, depending on energy from the sun for photosynthesis.
Yet between the low supply of and high competition for some key nutrients, like nitrogen, in the open ocean, scientists have puzzled over the vast diversity of microbial species found there. Researchers from the University of Washington, in collaboration with researchers from 12 other institutions, show that time of day is key, according to a study published Jan. 20 in Nature Ecology & Evolution.
The competition is slightly alleviated
With staggered uptake of the essential nutrient nitrogen, “instead of having to compete with the whole field, [microbes] only have to compete with the organisms that share that specific shift with [them]. Perhaps that’s one way that the competition is slightly alleviated and can facilitate all of these diverse microbes being able to live off of the same nutrient source,” said co-first author Daniel Muratore, a doctoral student at Georgia Tech.
Explanation for incredible diversity of marine life in the same place at the same time
“Realizing that various types of microbes acquire nitrogen at different times of day helps to answer a long-standing question in oceanography: How can there be such an incredible diversity of life, all essentially in the same place at the same time?” said co-author Anitra Ingalls, a UW professor of oceanography. “Being able to explain the underlying reasons for this diversity will help oceanographers better predict how these communities may shift as the ocean changes.”
Sacha Coesel, a UW research scientist in oceanography, is also a co-author. The research was supported by grants from the Simons Foundation, the National Science Foundation, Woods Hole Oceanographic Institution and the U.S. Geological Survey.