Nearshore Distribution and an Abundance Estimate for Green Sea Turtles, Chelonia mydas, at Rota Island, Commonwealth of the Northern Mariana Islands

Seventy-three green turtles, Chelonia mydas (Linnaeus, 1758), were observed in 84 sightings along 28 transects covering 67% of Rota's shoreline and outer reef perimeter in the Commonwealth of the Northern Mariana Islands. No other sea turtle species were encountered. Juvenile turtles of various sizes dominated in all surveyed environments, and observations of turtles with estimated straight carapace lengths ≤ 40 cm suggested recent and continuing recruitment at Rota. Distribution of turtles appeared temporally stable when compared with previously reported observations and data, with turtle concentrations highest along northeast, east, and southeast coasts of the island. Approximately 118 turtles were projected to inhabit nearshore habitats at Rota. Although this population may appear minor and indistinct compared with those at nearby Tinian and Saipan, continued monitoring would be useful for comparison of Mariana Islands trends. Thirty-five species of cyanophytes, algae, and a sea grass noted as green turtle forage in other world regions were identified at Rota in this and previous surveys.