Sea turtles reveal hidden seagrass meadows for better marine conservation

Seagrass meadows, which serve as crucial marine ecosystems, have been more accurately mapped using green turtles with satellite transmitters compared to conventional satellite imagery, according to a study published in the Proceedings of the Royal Society B. These underwater habitats are vital for biodiversity, carbon storage and stabilizing the seabed. However, mapping them has remained a challenge due to technological limitations. The research was conducted in the Red Sea, an area with limited seagrass data, as reported by marine ecologists from King Abdullah University of Science and Technology (KAUST).

Green turtle tracking to locate seagrass

The study involved the tagging of 53 green turtles (Chelonia mydas) on Saudi Arabian beaches in the Red Sea. Under the leadership of Dr. Hugo Mann, marine ecologist at KAUST, the researchers equipped the turtles with satellite transmitters after their nesting cycle to prevent disturbances.

The devices transmitted location data when the turtles surfaced for air, revealing consistent movement patterns over specific locations. These areas were identified as seagrass meadows, with 34 previously unrecorded patches discovered.

Validation efforts confirmed seagrass identified by turtles at all visited locations, while only 40% of locations marked by the Allen Coral Atlas, a remote sensing tool, were verified. As Carlos Duarte, a senior marine ecologist at KAUST, points out, the findings highlight the limitations of existing mapping techniques for underwater habitats.

Implications for the environment and conservation

Seagrass meadows contribute significantly to carbon storage, storing up to 4 teragrams of carbon, the study estimates. Dr. Mann emphasized the need to identify these ecosystems to improve conservation strategies. Seagrass is increasingly threatened by human activities, making accurate mapping crucial for its protection.

Dr. Jennifer Dijkstra, a marine ecologist at the University of New Hampshire, noted in the study’s findings that animal tracking could improve artificial intelligence-based mapping, providing a potential global solution for resource-constrained regions.

The researchers hope the method will lead to large-scale studies, aiding efforts to conserve both seagrass habitats and the green turtles that depend on them.