Drones can help find, count marine megafauna: Study
Consumer-grade drones are effective tools for monitoring marine species across multiple sites in the wild, suggests a research opening a platform for scientists and conservationists to study populations of sharks, rays, sea turtles and other marine megafauna.
"We found that drones can be used to count and make species-level identifications of marine species, particularly in shallow marine environments," said lead author Enie Hensel from the North Carolina State University.
"Drone surveys are also a good way to monitor shallow water, megafauna species because they are not intrusive," Hensel said, adding that the technology opens up doors to explore a range of conservation issues.
On the other hand, more traditional monitoring methods such as boat surveys or gill nets are more invasive and have the potential to harm individuals or alter their movement patterns.
To assess the effectiveness of the drones, researchers placed fake sharks underwater at two sites with different water clarity. Drone footage allowed researchers to identify all of the decoys at both sites.
"We chose grey shark decoys because they would be the most difficult to spot in these environments but we were able to spot them all," Hensel said.
The team evaluated multiple sites, demonstrating that drones can be used to assess environmental variables that may be responsible for population differences between locations. For example, drones may be used to help target conservation efforts on sites that have the most value in terms of supporting specific species.
The researchers also showed that drones are effective at sites with varying degrees of water clarity.
In field testing, researchers were also able to make species-level identifications of lemon, nurse and bonnethead sharks, as well as southern stingrays and spotted eagle rays. The drone footage also allowed researchers to identify sea turtles, though they had difficulty differentiating between hawksbill and green sea turtles.