Marine Turtle Survey on Tinian, Mariana Islands

Turtle nesting activity for 1995 occurred between 31 January and 16 July. A minimum of 24 nests were laid, with additional nesting activity that could represent as many as 24 nests. Six green turtles (Chelonia mydas), were tagged between 1 April and 23 May 1995. Two to four additional turtles were believed to have been nesting, but were not encountered. Mean curved carapace length for tagged turtles was 104.5 ± 2.5cm, and mean width was 94.2 ± 3.5 cm. Although turtles were encountered on different beaches, individual tagged turtles were encountered on the same beach every time. Mean incubation period was 62 ± 5 days. Mean clutch size was 91 ± 10 eggs, with a mean hatch success of 89 percent for successful nests. Percentage of successful nests was not calculated as nests were evacuated on an opportunistic basis. During ten aquatic surveys conducted during the nesting season, all 36 turtles observed were green turtles and 92 percent were subadults. Data from this study combined with anecdotal historical information reveal that virtually all of Tinian’s beaches are used by turtles for nesting.