The effect of omotehama environment on incubation of Loggerhead sea turtles

Abstract

Introduction Omotehama is a beach in the south of Central Aichi in Japan. It is 57 km long, and is one of Japan’s sea turtle laying grounds. Loggerhead Sea Turtles live in subtropical and temperate seas around the world and they come to the beach to lay eggs from May to August. They have T.D.S. (temperature-dependent sex determination) as they become female, if the sand temperature is less than 29oC, and male, if the temperature is more than 29oC.[1] Therefore, we think that the relationship between turtles and temperature is strong. We began this study to research the Omotehama environment and the biology of Loggerhead Sea Turtles. Materials and Methods Temperature examination We measured two places each 20, 40, and 60 cm from the surface with Temperature Date Logger. Hatch examination We dug up the already-hatched nests and checked the number of the remaining husks and unhatched eggs, after which, we calculated the hatching rate. We researched 29 places between 2009 and 2010. Results and Discussion This chart [Figure 1] shows the average air and sand temperature and the quantity of laying in a month. Hatching and the sand temperature The best temperature to lay and hatch eggs is 24 to 33oC. During July and August, there was a lot of laying, and the sand temperature was maintained at about 24 to 33oC. The air temperature and sand temperature Omotehama is good for keeping warm. According to the air and sand temperature graph, although Loggerhead Sea Turtles are a currently endangered species. This team wanted to investigate whether environmental changes such as temperature variations affected their breeding rates. The team studied 29 breeding places for a year and calculated the hatching rate with temperature. They found that the best temperature to lay and hatch eggs is 24 to 33°C. And they concluded that if the temperature in their local beech where to change, this would affect the turtle population. Ryuto Kimura, Tomohiko Sato, Yumi Sato, Natsuki Sugiura1, Erika Kodama1, Mami Sibata2, Haruka Ogura2, Shota Inoue3 Yutakagaoka Senior High School, 1Gamagori Senior High School, 2Toyotanishi Senior High School, 3Ko Senior High School, Nagoya City, Japan. E-mail: sp544vn9@flute.ocn.ne.jp DOI: 10.4103/0974-6102.107621