Surveying the land by drone is a technique being used to track Hester Marsh’s delicate restoration, an ongoing project since 2017.
Historically, the marshland was diked and drained to create pastures, causing the sponge-like land to shrink. Now, scientists are piling on dirt and restoring native plants to revive the salt marsh to its former glory. They’re also elevating it to counteract future sea-level rise caused by climate change.But that’s a tricky feat with such a finicky ecosystem.
If the marsh is too high, it doesn’t receive enough water for plant growth. But if it’s too low, flooding kills the plants. The sweet spot, Haskins explained, exists within a 3-foot region inside of the 8-foot tidal frame, the full range that the ocean tides can reach on the U.S. West Coast. While flying, one of the drone’s cameras captures nearly 1,000 images that are later stitched together to create a three-dimensional elevation map of the entire region. The other takes pictures with two wavelengths of light invisible to the human eye that help identify specific plant varieties in the marsh.