Plankton communities' warm response to nutrient availability

November 14, 2018, King Abdullah University of Science and Technology
Plankton communities' warm response to nutrient availability
Xosé Morán (left) and Tamara Huete-Stauffer during one of their monthly sampling trips of planktonic microbes in the Red Sea; the KAUST campus can be seen in the background. Credit: Miguel Viegas

Microbial plankton communities will be boosted in productivity and biomass from warmer water temperatures provided sufficient nutrients are also readily available, suggest KAUST researchers.

The response of to global depends on complex factors. The growth rates and activity of plankton communities are largely dictated by nutrient availability (bottom-up control), predation (top-down control) and changes in .

Warming will probably alter life in cold and temperate waters more dramatically than in the equatorial belt. Nutrients, which are necessary to enhance plankton growth, are generally more abundant in colder waters. If nutrient levels in the oceans drop due to rising temperatures, this will have a knock-on effect on aquatic lifeforms.

"We wanted to investigate the response to warming in three planktonic communities simultaneously—picophytoplankton, heterotrophic bacteria and heterotrophic nanoflagellates," says Tamara M. Huete-Stauffer, a postdoc in Xosé Anxelu G. Morán's group in KAUST's Red Sea Research Center. The two KAUST scientists collaborated with scientists in Spain and the United States to complete the work.

"These three communities represent different elements of the food web. Phytoplankton are the primary producers in the ocean, rather like plants in a terrestrial ecosystem. Bacteria process the dissolved organic matter released from phytoplankton and other organisms, while nanoflagellates are the major predators of bacteria and small phytoplankton," explains Huete-Stauffer.

The team collected samples in temperate waters off the northern coast of Spain every month for a year. They incubated samples atin situtemperature and at 3 degrees Celsius above and below. This allowed them to calculate activation energy values, which indicate how a rate, such as net growth or metabolism, might change in response to a change in temperature.

"Our results showed a beautifully synchronized coherence in the temperature response of all three plankton communities although they play different roles in the ecosystem," says Morán. "Their synchronized sensitivity to temperature was largely driven by the availability of nutrients: if the organisms are strongly constrained by the availability of food or by their consumers, then future warming will have a very limited effect on enhancing their growth."

These results form the basis for a general conceptual model of the of marine ecosystems to . "We have since conducted four similar experiments in the coastal Red Sea, which will serve as a test of the generality of the model in some of the hottest marine waters on Earth," adds Morán.

Explore further: Data from a global oceanographic expedition predict how rising temperatures influence growth of plankton populations

More information: Xosé Anxelu G. Morán et al. Temperature sensitivities of microbial plankton net growth rates are seasonally coherent and linked to nutrient availability, Environmental Microbiology (2018). DOI: 10.1111/1462-2920.14393

Related Stories

Microbial communities have a seasonal shake-up

April 26, 2018

Seasonal changes in turbulence and nutrient availability are shown to shape microbial communities in the Red Sea. "A lot of the marine ecosystem is ultimately based on how microbes live and what they're doing," explains research ...

Recommended for you

Meteorite source in asteroid belt not a single debris field

February 17, 2019

A new study published online in Meteoritics and Planetary Science finds that our most common meteorites, those known as L chondrites, come from at least two different debris fields in the asteroid belt. The belt contains ...

Diagnosing 'art acne' in Georgia O'Keeffe's paintings

February 17, 2019

Even Georgia O'Keeffe noticed the pin-sized blisters bubbling on the surface of her paintings. For decades, conservationists and scholars assumed these tiny protrusions were grains of sand, kicked up from the New Mexico desert ...

Archaeologists discover Incan tomb in Peru

February 16, 2019

Peruvian archaeologists discovered an Incan tomb in the north of the country where an elite member of the pre-Columbian empire was buried, one of the investigators announced Friday.

Where is the universe hiding its missing mass?

February 15, 2019

Astronomers have spent decades looking for something that sounds like it would be hard to miss: about a third of the "normal" matter in the Universe. New results from NASA's Chandra X-ray Observatory may have helped them ...

What rising seas mean for local economies

February 15, 2019

Impacts from climate change are not always easy to see. But for many local businesses in coastal communities across the United States, the evidence is right outside their doors—or in their parking lots.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.