Hatchlings raised in our Head Starting Project are kept under human supervision and can grow larger than their natural counterparts. This lowers their chances of being preyed upon by natural enemies such as fish and birds. In addition, labeling and releasing turtles reared to approximately 1,000 grams or more will provide clues to the still mysterious life cycle of the hatchlings and how they will affect natural resources. The history of green turtle headstarting in the Ogasawara Islands is long, dating back to 1910, when the world’s first three-month Head Starting program was conducted for 30 years until 1939. At that time, however, the population did not recover. After the return of the Ogasawara Islands to Japan in 1973, the Tokyo Metropolitan Ogasawara Fisheries Center resumed the project, which was taken over by the Ogasawara Marine Center, which now raises and releases 200 to 300 hatchlings annually (these hatchlings are released at village events and as part of various environmental education programs).


What did the staff find out

The released hatchlings have been recaptured in the waters where they live (also includes protected hatchlings from fishing bycatch followed by visual inspections and confirmation by photography, etc.). The recapture rate is about 3%, which is higher than the survival rate of 0.2-0.3% of natural hatchlings (about 10 times higher).

Date of release 

Place of release 

Date of recapture 

Place of recapture 


2009/03/17 Chichijima Miyanohama 2011/09/19 Cape Muroto, Kochi Prefecture

Fishing bycatch (alive)

 2008/03/18 Chichijima Ohmura Beach  2011/07/26 Toba City, Mie Prefecture Dead drifting ashore
 2010/01/01 Chichijima Ohmura Beach 2011/07/11 Miyazaki city, Miyazaki pref Dead drifting ashore
2009/03/11 Chichijima Ohmura Beach 2011/04/12 Kagoshima Prefecture Erabu Island Found in the sea alive
 2009/03/21 Chichijima Ohmura Beach 2011/02/13 Kanagawa Prefecture Yokosuka City Owusu Dead in fishing net
2006/03/13 Chichijima Ohmura Beach 2010/01/07 Tokyo Hachijojima Yaene Fishing bycatch (alive)
2006/05/31 Chichijima Miyanohama 2009/05/24 Wakayama Prefecture Gobo City Nojima Beach Dead drifting ashore
2000/01/01 Chichijima Ohmura Beach  2008/07/21 Nagasaki Prefecture Tsushima City Mitsushima Town Alive in fishing net
2002/01/01 Chichijima Ohmura Beach 2007/06/11 Hayase Kogasaki, Mihama Town, Fukui Prefecture

Alive in fishing net

2005/02/09 Chichijima Miyanohama 2006/12/06 Yoshida, Kamiyaku-cho, Yakushima Dead in fishing net