Loggerhead nest sites in Japan are a conservation priority
When a species is so widely distributed, how do you determine the most vulnerable areas where conservation efforts should be prioritized? For some wide-ranging species, it is difficult to determine conservation priorities on a species level, instead individual populations should be the basic unit for assessment.
Sea turtles are one such creatures, they also exhibit intraspecific variations in population sizes, reproduction and morphology. Thus individual populations can vary greatly when it comes to population trends and impact of threats.
There are seven species of sea turtles around the world, six of which are threatened (Flatbacks are data deficient), and they form 58 separate populations.
A study illustrates the current status of sea turtle populations worldwide and identifies the species and populations most at risk, one of which is the North Pacific loggerhead sea turtles, which nests exclusively in Japan and forages across the Pacific Basin. This endangered population is currently most threatened by severe by-catch in Mexico and Japan as well as coastal development in Japan.
The most vulnerable populations were identified based on threats and population risks:
Five major hazards to sea turtles were identified and used as assessment criteria:
1) fisheries bycatch (i.e. incidental capture by marine fisheries operations targeting other species)
2) take (e.g. utilization of eggs, meat or other turtle products)
3) coastal development
4) pollution and pathogens
5) climate change
Risks were assessed based on:
1) population size
2) recent trend
3) long-term trend
4) rookery vulnerability
5) genetic diversity
Eleven populations are categorized as High Risk-High Threats, and are considered the most endangered sea turtle populations in the world. Of these 11 populations, five occur in the Indian Ocean, and four are Hawksbills.
Conservation priorities can range from prevention of imminent extinctions to maintaining long-term monitoring projects, from preserving genetic diversity to managing fisheries more sustainably.
If you spot a loggerhead nest on a beach, please be cautious not to disturb it and and submit an image here.
Wallace et al. 2011. Global Conservation Priorities for Marine Turtles. http://dx.doi.org/10.1371/journal.pone.0024510