Survey: Population of sea turtles not harmed by eruption

Tribune-Herald file photo A pair of honu bask at Punalu'u Beach in 2015.
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A Big Island nonprofit has confirmed that the Kilauea eruption last year did not critically damage sea turtle populations in lower Puna.

While state and federal agencies said during the eruption that large numbers of sea turtles were not endangered by the flow of lava into the ocean, the Hawaii Wildlife Fund conducted its own survey, which concluded this month that the lava did not harm turtle populations.

Kallie Barnes, education coordinator for the Hawaii Wildlife Fund, said it conducted its own survey because of confusion following the state and federal reports.

“There were all kinds of reports that (the turtles) were trapped or stranded, driven by social media,” Barnes said.

These erroneous reports persisted, even after the state and federal reports, because of unclear findings, Barnes said. While the Department of Land and Natural Resources reportedly did not find any sea turtles in danger from the lava, they also did not report upon the condition of the turtles themselves, which did little to assuage people’s concerns about the turtles.

The Hawaii Wildlife Fund’s survey cites several social media posts made during the eruption that made unsubstantiated claims about how the lava affected sea life. One such post warned that “around 50 turtles will die” without a rescue mission at Pohoiki.

Such reports were exacerbated by a graphic video posted online in July of a turtle being “boiled alive” at Kapoho as lava heated the water.

While the video clearly depicts the animal dying, Barnes said the person filming the turtle might have unwittingly contributed to its demise by shining a white light at the struggling animal. Turtles can mistake artificial light for natural light and thus become disoriented.

However, the Hawaii Wildlife Fund conducted two helicopter overflights around the lava-impacted coastline in September and November, and directly observed 50 live turtles, as well as a number of other sea life, such as hammerhead sharks and rays.

Barnes said turtle experts consulted for the survey agreed that sea turtles were likely able to escape lava en masse, notwithstanding a few individual turtle deaths.

The DLNR also agreed with the assessment.

“We concur with the Hawaii Wildlife Fund’s findings that the majority of turtles vacated the area when the lava started entering the ocean,” stated DLNR communications specialist A.J. McWhorter in an email. “Of course, we are saddened by any loss of any creature that we help protect.”

McWhorter said the DLNR did not observe any turtles in distress during the eruption.

Unsurprisingly, Barnes said the turtles have largely abandoned the coastlines where the lava entered the ocean, and were instead congregating north and south of the entry points. Because green sea turtles feed upon algae and sea grasses, Barnes speculated that the turtles found insufficient food in the new coastal lava rock, and moved to areas of the coast that were not scoured of food.

Because there is a dearth of published material about the effects of lava ocean entry on the behavior of sea turtles, additional research into when the turtles might return to the lava-impacted areas will be valuable, Barnes said. Two species of sea turtle that frequent Big Island coastlines — the hawksbill sea turtle and the green sea turtle — are listed as endangered by the World Wildlife Fund.

Email Michael Brestovansky at mbrestovansky@hawaiitribune-herald.com.