NOC awarded £2.6 m to investigate expanding ocean deserts

Scientists at the UK’s National Oceanography Centre (NOC) are to lead a new, five-year funded project to investigate the alarming expansion of ocean deserts—vast regions of the ocean with little life or nutrients.

The research, supported by a £2.6 million European Research Council (ERC) Consolidator Grant, will explore whether microscopic organisms called diazotrophs could slow or even reverse this trend thanks to their nitrogen fixing capabilities.

Subtropical gyres, often referred to as “ocean deserts”, cover more than 60% of the ocean’s surface. These regions are expanding at an unprecedented rate of five million square kilometres per decade—an area equivalent to the Amazon Rainforest or the entire European Union.

As global temperatures rise, scientists are concerned about the long-term impact of this expansion on marine ecosystems and the Earth’s climate, which would reduce the health of the ocean, affecting marine food webs and the ocean’s role as a carbon sink.

The new project, called EXPAND, will focus on the Indian Ocean subtropical gyre, the least understood of these ocean deserts, with partners from France, USA, Canada and South Africa.

Project lead and NOC senior scientist Dr Mar Benavides highlights the urgency of understanding what drives the expansion of ocean deserts—and whether nitrogen fixing diazotrophs, which can benefit from ocean desert conditions, could help counteract its effects.

“This research will reveal how marine microorganisms support ocean health and global biogeochemical cycles,” says Dr Benavides. “We aim to determine whether diazotrophs—microorganisms that convert atmospheric nitrogen into nutrients—can sustain marine productivity in these expanding deserts.

“By uncovering the links between nitrogen fixation and marine productivity, we will be able to refine climate change models and improve predictions of how marine ecosystems respond to environmental changes. Ultimately, this project could offer new insights into mitigating climate change’s impact on our oceans.”

As part of the project, researchers will conduct two expeditions aboard the R/V Marion Dufresne. These expeditions will bring together experts in biogeochemistry, microbiology, physical oceanography and ocean engineering to collect critical data from the Indian Ocean.