While much of the world is seeing the oceans taking the brunt of the negative actions of humans, there is some good new for one species of endangered sea turtle.
A new study, published in the journal PLOS ONE, has discovered that the green sea turtle population numbers are on the rise in Pacific coral reefs.
The study assessed both the populations of green and hawksbill turtles, another critically endangered species, in the Pacific islands. The researchers assessed data from 13 years of in water visual surveys that recorded turtle numbers near 53 islands, atolls, and reef in US Pacific waters.
Green and hawksbill sea turtles are commonly associated with coral reef habitat. Both are historically exploited species whose populations still remain endangered today. Despite decreases in harvest with protective measures initiated in the 1970s, current populations are still at a fraction of historic levels with the depletion of the sea turtles directly associated with human population density.
Sea turtle surveys were conducted by a series of 50-minute diver tows where divers were towed behind a boat recording the number of turtles seen, species and estimated length.
The surveys covered a total of 4,500 linear miles and recorded 3,400 turtles and the results were very positive. During the 13-year sample period, green turtle populations remained constant or increased with the highest populations in the Pacific Remote Islands area where human population is very sparse.
In a surprise find, some highly populated areas, such as Hawaii, sea turtle growth was very high proving that conservation efforts that have been implemented appear to be working.
While the green sea turtle saw their population stay steady or grow, the hawksbill turtle appears to not be doing as well. While the waters off American Samoa saw higher populations, they only made up just 8.3% of turtle sightings vs green turtles represented which was seen at a rate of 90.1%.
“This suggests that green turtles are nearly 11 times more abundant than hawksbills across the entire survey area, providing further empirical evidence of the rarity and conservation plight of hawksbills,” the researchers wrote.
The researchers noted that hawksbills were heavily exploited historically for tortoiseshell and of all the turtle species, they are most closely tied with highly-threatened coral reef habitat on which they depend for sponges and invertebrate prey.
While it is great news that the green sea turtle is doing well in Pacific islands, the species is not doing as good in other parts of the world. With disappearing coral reefs and humans only continuing to impose their will on the environments of the animal, the marine reptiles struggle to thrive. But with research such as this, it helps solidify the importance of conservation efforts and allows for easier implementation as there is data to back the investment in pushing the effort.
To ensure that sea turtles do continue to exist on our magnificent but damage planet, understanding the relationships between turtle populations and environmental drivers will allow for conservationist to implement, predict and protect sea turtle populations in a ever-changing planet Earth.