The undersea equivalent of tropical rainforests, kelp forests are one of Earth’s most diverse and beneficial ecosystems. But in California, the last few years have seen a near-complete annihilation of the kelp following a marine heatwave that started in 2013. Now, drone surveys are showing signs of recovery.
Why kelp forests are important
Kelps, a type of seaweed or extremely large brown algae, are capable of incredible growth. Under ideal conditions (cold, nutrient-rich waters), some kelp species can reach underwater heights of 150 feet and grow almost 18 inches in a single day!
Kelp forests act as a nursery and refuge for many marine animals, support fisheries, and defend coastlines against violent storms. Kelps also soak up vast quantities of carbon dioxide from the air via photosynthesis and act as a climate change mitigator.
So, it’s easy to understand why environmentalists and marine biologists have an interest in measuring the kelp presence.
Environmental group Nature Conservancy first started using drones to survey California’s kelp forests in 2019. But there was hardly anything to see. According to one study, more than 95% of kelp beds had died off along Northern California’s coast due to rising sea temperatures and disease.
Vienna Saccomanno, head of Nature Conservancy’s kelp monitoring and mapping program, explains:
There was just no kelp, literally, little to no kelp. An explosion in the population of sea urchins, which consume kelp, had added to the catastrophe.
In 2019, Saccomanno’s drone survey calculated the average size of a kelp canopy as less than one acre per survey site. Thankfully, those numbers are looking much better now.
Though the figures for the current year are yet to be computed, the average size of a kelp canopy was found to have increased to 5.5 acres when the last survey was undertaken in 2020.
The development is encouraging, no doubt, but the numbers are still below the historic average. And till the time an equilibrium is restored in the ecosystem, researchers want to continue using drone technology to collect vital data on the health of the kelp.
Insisting that an eye in the sky will help the team to identify “kelp strongholds” in the future, Kirk Klausmeyer, director of data science of Nature Conservancy’s California chapter, says:
When dealing with problems like this, we really have to get as much data as possible. And drones allow us to get really high-resolution imagery of individual kelp plants.
Watch how drones are being used to restore kelp forests in California
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