Just How Bad Was Hawaii’s Volcanic Eruption for Sea Turtles?

By Jason Bittel

Since Hawaii’s Kilauea volcano began erupting in early May, we’ve been mesmerized, month after month, by videos depicting what can happen when molten rock dances through the air, forms gigantic rivers or crashes into a Ford Mustang.

But some videos are much harder to watch—like those depicting the many homes destroyed or this one shot by Puna resident Travis Sanders in June. The footage shows a green sea turtle apparently trapped in a tidal pool known as Champagne Ponds in Kapoho Bay, as lava burns in the background and rocks seem to prevent the turtle from crawling onto land. When Sanders reached down to test the water, he said it felt to be near boiling.

It’s hard to say exactly how much heat a sea turtle can handle, said Terry Norton, a veterinarian and director of the Georgia Sea Turtle Center. “I would think that getting above 90 degrees Fahrenheit, they would start showing signs of heat stress, and definitely upper 90s and 100 would likely be eventually fatal,” he said. “Hotter than that would definitely be fatal.”

We don’t know just how hot the water was in Kapoho Bay that night, but we do know what Sanders said happened next. After turning his camera off, he made a second attempt to save the turtle, but it was already too late.

“I tried to pull him out but his legs fell apart,” Sanders told the Honolulu Star Advertiser. “He was boiled alive.”

In light of Sanders’s video and several other reports of sea turtles trapped in ponds and lagoons, the state’s Department of Land and Natural Resources (DLNR) issued a statement saying that it would conduct aerial surveys with helicopters to search for sea turtles. Thus far these searches have not spotted any others trapped by lava flows.

Sanders said he saw around 60 sea turtles gathering in an area near the Pohoiki boat ramp, just south of Kapoho Bay. (As of mid-August, the entire structure was surrounded by a wall of hardened lava.) Another report from a local photographer documented six dead sea turtles in July in the same vicinity.

According to Norton, most sea turtles, which are cold-blooded, should be able to sense these increases in heat and swim away in time. A passage from the DLNR statement concurs:

“While it is unknown how many turtles may have lived in or around Kapoho or Pohoiki, it’s believed most turtles had access to the open ocean via channels or open fish pond gates, and that they were able to swim away and save themselves before being harmed by the lava flow.”

But given the evidence that at least seven sea turtles did not escape, one has to wonder if many others might also be in harm’s way. Despite declining numbers worldwide, green sea turtles are actually on the rise in Hawaii. Their population on the islands has increased by 53 percent over the past 25 years—thanks in no small part to their protection under the Endangered Species Act and Hawaiian state law.

According to George Balazs, who has spent the last 48 years studying sea turtles with the National Oceanic and Atmospheric Administration and the University of Hawaii, there is reason to hope that the eruption’s toll on sea turtles may not be as bad as some fear. Green sea turtles do nest in the summer, but Balazs said “there are no green turtle nesting sites on the geologically active island of Hawaii.” (The animals prefer the French Frigate Shoals, an atoll almost 800 miles to the northwest.) It is true that hawksbill turtles, which are critically endangered, nest on Hawaii’s mainland, however, and Balazs himself witnessed lava destroy some of those sites back in the early 1980s.

The bottom line, said Balazs, is that while sad, the lava-related deaths or injuries of a small number of unlucky animals is unlikely to significantly affect their population’s continued recovery.

Reposted with permission from our media associate onEarth.