It has been a long time since all sea turtles were listed in Appendix I of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora)) because they were considered species with a high risk of extinction. The various conservation measures for the sea turtles have been implemented accordingly.
The number of loggerheads spawning in Japanese coastal areas has been increasing in recent years. It has even reached a historical high level in some areas. This indicates recovery of the stock, which is distributed in the North Pacific including areas off Hawaii.
The change in rules off Hawaii last year seems to have reflected such an increasing trend in the loggerhead population of the North Pacific. Namely, the measures limiting the bycatch of sea tur tles in the Hawaiian swordfish fishery have been significantly relaxed. In Hawaii, the green turtle population is also increasing. Those facts shows that not all species of sea turtles in the world are declining but that there are several species for which their status seems stable or even increasing.
The recent trend of recovery for the sea turtles might have been brought about by the implementation of measures to mitigate the impact caused by fishing activities. However, it has not yet been proven scientifically how much impact is given by fishing activities. Fishing activities have been highlighted as a major factor giving a negative impact to the sea turtles but it is not always correct. There are many examples that the conservation measures in the spawning areas on land were effective for the rapid recovery of the populations. Moreover, the decline of Pacific leatherback, the biggest charismatic sea turtle attaining a weight of around 1 ton when fully grown could not be stopped by restricting fishing activities only. Wild boars preying on eggs and consumption by local people in the major spawning areas are the obvious impacts. The recent development of coastal areas of Papua New Guinea (and Indonesia) also causes a significant negative impact. My view is supported by the recent finding that the Hawaiian green turtle recovered in just a few years only right after the strengthened conservation activities implemented on the landing sites.
In conclusion, for the purpose of ensuring the effective conservation of the sea turtles, I would like to emphasize the need for holistic research on various factors (including water pollution and climate change) other than fisheries together with improvement in the biological knowledge of sea turtles. Scientific and holistic conservation approaches should be further promoted. Simplistic and emotional conservation approaches blaming fishing activities as the only culprit will not help sea turtles.
