Desert dust is key to sustaining marine ecosystem

By Sheena Amos

DUBAI 26 September 2019: A new study at New York University Abu Dhabi, NYUAD, has shown that desert dust is key to sustaining the marine ecosystem in the surface water of the Arabian Sea.

The study showed that nutrients such as iron, provided by atmospheric dust coming from the desert area around the Arabian Sea, is essential to sustain the high levels of marine productivity, in particular during the summer monsoon, the university said in a press release on Wednesday.

The surface waters of the Arabian Sea have low concentrations of iron, making iron coming from atmospheric dust necessary to allow phytoplankton to uptake major nutrients.

Commenting on the research, Cecile Guieu, Visiting Scientist at NYUAD’s Centre for Prototype Climate Modeling, CPCM, said, “In this region, we encounter dust storms frequently and people usually associate dust with cars covered with dirt or reduced visibility. Dust contains nutrients and these small particles have a very positive impact for microscopic plant-like organisms called phytoplankton that live in the ocean.

“These organisms are very important for the ocean and for the people because they play a key role in removing carbon dioxide from the air and they are the base of the marine food chain.”

The study was led by Senior Research Scientist at the Oceanography Laboratory of Villefranche-sur-Mer and Cecile Guieu, and co-authored by Senior Research Scientist at NYUAD’s CPCM Zouhair Lachkar; Post-doctoral Associate at NYUAD’s CPCM Muchamad Al Azhar; Research Scientist at the French Research Institute for Development Olivier Aumont; Professor at Cornell University’s Department of Earth and Atmospheric Sciences Natalie Mahowald; Senior Research Scientist at the Laboratory of Oceanography and Climate (LOCEAN-IPSL) Marina Levy; and Engineer at LOCEAN-IPSL Christian Ethe.

Lachkar commented, “Climate change is expected to affect both land aridity and surface winds in the region. This may lead to important future changes in the intensity of dust input to the Arabian Sea, and hence cause a potentially profound perturbation of its marine ecosystem.”

Phytoplankton in the surface layer of the sea relies on two important sources of nutrients to survive, develop, and reproduce. They get their first source of nutrients from the rich waters coming from below the surface layer of the ocean, which occurs along the coast of the Arabian Peninsula, while counting on the desert dust deposited from above the surface layer of the ocean as their second source of nutrients.

The study also showed that in addition to the nutrient-rich deep waters of the Arabian Sea, dust deposition is equally important for the survival of phytoplankton in the Sea, and explained that these organisms would be half as abundant as they are without the iron absorbed from atmospheric dust.

Dubai Gazette