Pacific leatherback turtle conservation in the Solomon Islands

Earlier this year I was pacing along a dark South Pacific coastline at night, eagerly scanning the horizon. The crescent moon provided only the faintest glimmer of light and the black sand made it impossible to differentiate between the beach and the sky. I had been walking up and down this stretch of beach since the sun set, five hours ago. Apart from a slight breeze rustling the palm trees fringing the beach, the night was quiet.

Baniata is a small, isolated community on the island of Rendova in the Solomon Islands. This tropical paradise is teeming with wildlife and culture, and is an important nesting site for one of the oldest living animals on Earth. That night as I walked into the seventh hour, that prehistoric marvel emerged from the ocean. Slowly but surely the giant beast hauled herself up the sand, a deep, guttural exhale following every stroke of her flippers.

I looked over at Johnson the head local ranger to confirm my suspicions. His bright smile assured me that we were looking at a leatherback turtle (Dermochelys coriacea), or Oihare to the islanders. Leatherbacks are the largest species of turtle in the world, and we were watching one come up to lay a precious clutch of eggs. Her black, leathery skin was dotted like a night sky constellation, with ridges lined with white. 

Baniata’s remote beach was an important nesting spot for these critically endangered animals, and this was a pivotal moment for leatherback conservation in a remote community in the South Pacific.

The population of the Pacific leatherback sub-species has dwindled by more than 90% in the last three decades.

Leatherback turtles can grow to almost two metres and weigh almost a tonne. This species has the widest global distribution of any turtle. They can lower their breathing to dive more than 1000 metres.

But the population of the Pacific leatherback sub-species has dwindled by more than 90% in the last three decades. As jellyfish specialists, leatherbacks are threatened by inadvertent ingestion of plastic pollution. Floating plastic bags tend to look vastly similar to a tasty jellyfish meal, and the backward-pointing spines lining the leatherback’s throat unfortunately help retain the plastic.

However, in the Pacific the biggest risk to leatherback turtles used to be human consumption. To these islanders living off the land, a leatherback coming up on their beach was like a cow walking into our backyard and sitting down with a sign saying, ‘eat me’. The protein and fat content of these colossal animals could feed a whole village, so it’s no wonder every one of these turtles and their eggs used to be eagerly consumed.

However, a conservation program set up in Baniata a few decades ago ensured each egg, and its mother, were protected. This program meant that the night I was there, instead of the villagers flipping the leatherback over and coming back to roast her in the morning, a dedicated team of local rangers monitored her every move.

Rising sea levels are exposing an increasing number of turtle nests to drowning.

With her maternal instinct kicking in, the nearly one-tonne creature began to meticulously scoop away the grainy sand with her thick back flippers. Before long she had dug a flipper-deep 70cm hole, and with a special red light, I watched her lay her eggs. Whilst she was comfortable, Johnson and his rangers quickly took some measurements and expertly tagged her for future monitoring. Each ranger recognised the importance of what they were doing, and their work was reimbursed through grant programs with money and supplies to access other food sources, scholarships, or kerosene.

Laying takes over an hour and when the leatherback had finished, she carefully filled in the hole and created a series of scrapes in the sand to confuse would-be predators and disguise her nest. The soon-to-be mother then started the long, terrestrial clamber back to the ocean. As soon as her flippers reached the water’s edge this slow, sluggish beast disappeared with two powerful sweeps of her enormous front flippers, and I was left in awe of one of nature’s giants.

Unfortunately, rising sea levels are exposing an increasing number of turtle nests to drowning. If the tide inundates a nest the embryos inside will drown and suffocate. This mother’s clutch was laid below the high tide mark, so Johnson carefully replicated her hard work and relocated the 108 eggs into a hatchery further up the beach.

This hatchery was built and protected by the islanders and offered the offspring the best chance of survival and shelter from predators. The passion of Johnson and his fellow islanders to protect these endangered creatures was inspiring to watch, and it was clear the leatherback’s eggs were now in safe hands.

Like other turtles, leatherbacks use the Earth’s magnetic field to navigate.

The Baniata islanders have been protecting leatherbacks long enough that they are seeing small, recently-matured individuals returning to lay on their black sand beach. Like other turtles, leatherbacks use the Earth’s magnetic field to navigate. These species can measure the localised inclination and intensity of the field to help direct them to previously visited places and return to their natal area. There is still uncertainty surrounding how leatherback turtles can detect magnetic fields, but one hypothesis is that they have tiny magnetic particles in their brain that help them process different fields. This marine adaptation is important for protecting future generations by ensuring turtle mothers select previously successful beaches, although recent sea level rise may mean these beaches have become unsuitable within one generation.

Each year more leatherbacks are being protected through Baniata’s conservation initiative, and the rangers are seeing first-hand how their program has helped leatherback mothers ensure their offspring get the best chance of survival. If it wasn’t for the dedication and passion of ecologists, volunteers, and especially the local Baniata community, Pacific leatherback turtles could have lost an important nesting beach, and I may have never had the opportunity to witness a leatherback in all her glory.

The Oihare are now repaying the favour. Ecotourists visit the remote village to witness one of the natural world’s most spectacular events, bringing much needed income into the village and giving rangers the chance to proudly display their work.

Community-run leatherback protection in the Solomon Islands has had a clear conservation impact and helped change the bleak trajectory of these magnificent creatures. Under our rapidly changing climate it’s more important than ever to find community leaders like Johnson and support these projects protecting our endangered species, because as they say in Solomon Islands pidgin, ui helpim me, me helpim ui.