In several of the video clips, a loggerhead sea turtle, shell studded with barnacles and matted with an undulating crop of green algae, is flanked by an entourage of fish, apparently eating the bounty of food growing on the turtle’s shell or perhaps using the large turtles for cover (adult loggerhead sea turtles are typically about three feet long).
In another clip, a turtle, evidently in response to the shadowy presence of a shark, flips over so its shell is facing the threat and swims away.
These and other natural loggerhead sea turtle behaviors were captured on video by a remotely operated vehicle, or ROV, deployed off the coast of New Jersey, Delaware, and Maryland, by a group of researchers from the Coonamessett Farm Foundation and the Woods Hole Laboratory of the Northeast Fisheries Science Center, both based in Massachusetts. They recently published their findings in the Journal of Experimental Marine Biology and Ecology – and, as the scientists note in their paper, the “study represents the first example of an ROV for tracking sea turtles.”
The scientists spotted the turtles from a boat, focusing on areas where loggerhead sea turtles have been active in the past; when they found one, they launched their ROV, tethered to the boat, and followed the turtle wherever it went. Over their 10 research trips (during which they recorded footage of 70 turtles), the researchers found that they could maneuver the ROV to within about three to five yards of the turtle without disturbing it.
From that vantage point, the scientists were able to observe a number of apparently natural behaviors which would have been difficult to capture by other means, such as human divers, cameras attached to turtle shells, and tracking tags implanted into turtles, all of which have been used to study sea turtles in the past. “[T]he ROV add[s] a new technique that complements existing technologies while overcoming several of the limitations,” the researchers write.
ROVs appear to be a new and useful tool for scientists attempting to understand how loggerhead sea turtles behave in their natural environment, and how they interact with each other and other animals.
Source: Smolowitz RJ, Patel SH, Haas HL, Miller SA. (2015) Using a remotely operated vehicle (ROV) to observe loggerhead sea turtle (Caretta caretta) behavior on foraging grounds off the mid-Atlantic United States. Journal of Experimental Marine Biology and Ecology 471: 84-91. doi: 10.1016/j.jembe.2015.05.016