Drone footage gives hope for kelp return to US west coast

GUALALA, Calif., Sept. 29 (Reuters) – Tranquil images of the Pacific Ocean taken by a drone show that California’s kelp forests could make a comeback after years of exhaustion, bringing good news in the fight against the climate change.

Kelp, which reduces global warming by absorbing carbon dioxide from the air through photosynthesis, has collapsed dramatically along the northern California coast, with one study calculating a loss of over 95% since 2013 due to rising sea temperatures and disease.

But a team from the environmental group Nature Conservancy spotted signs of partial recovery of kelp forests during drone surveys off the coasts of Mendocino and Sonoma counties.

The group started trying to study the kelp forest from the sky in 2019, but there was almost nothing to see, said Vienna Saccomanno, who heads the Nature Conservancy’s kelp monitoring and mapping program. An explosion in the sea urchin population, which consume kelp, has added to the disaster.

“There was just no kelp, literally, little to no kelp. And being here in 2021 and seeing this big surge in kelp is so exciting as a scientist,” she said.

Flying at 400 feet (120 m) but close to shore, the drones take photos which are then woven into a mosaic-like image to better understand the kelp forests. Scientists have spotted significantly more brown algae than in recent years, which Saccomanno attributes to a recent surge of cool, nutrient-dense waters that help kelp thrive.

In 2019, the Nature Conservancy’s drone survey found an average kelp canopy size of one acre and by 2020 it had grown to 5.5 acres. The figures are not yet known for this year.

However, kelp canopies are still below the historical average.

“We know that this ecosystem is still not fully balanced and that there is still some restoration work to be done,” said Saccomanno.

Drone technology is vital to providing data on the health of kelp, said Kirk Klausmeyer, director of data science for the California section of the Nature Conservancy.

“When we’re dealing with issues like this, we really have to get as much data as possible. And drones allow us to get very high-resolution images of individual kelp plants,” he said.

Reporting by Nathan Frandino Writing by Alistair Bell Editing by Rosalba O’Brien

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