Conserving our ancient mariners

Last updated: 2 December 2022

Marine turtles have swum the world's oceans for more than 100 million years. 

Seven species exist, globally. Over the last few decades their numbers have declined significantly, largely due to human influence – climate change and sea level rise; fishing nets and debris that turtles eat or become entangled in; boats, vehicles and coastal development disturbing their habitats; and light and noise pollution affecting their nesting habits, to name just a few.

Western Australia is home to six of these seven species, and they are all protected at both State and Commonwealth levels in Australia.

Our Cape Lambert port in Western Australia is next to Bells Beach – an important mainland rookery for the flatback turtle, the only marine turtle species that nests solely in Australia.

We recognise our responsibility to mitigate our operations' impact. And although globally human intervention is the main reason these 'ancient mariners' are dwindling, we're taking a proactive approach to protect local turtle populations.

Mitigating human impact on turtle habitats

One of the reasons the turtle population is so affected by humans is because marine turtles are very particular about how and when they nest.

Flatback turtles can live to well over 50 years, and don't begin to breed until they're over 16 years of age. Even once they're breeding age, they usually only nest every 2 to 7 years, laying several clutches of approximately 50 eggs separated by an 'inter-nesting interval' of approximately 12 days.

They also swim for hundreds of kilometres to return to where they were born to mate and nest – a powerful instinct given decades have usually passed since they left. Only the adult females leave the ocean when they nest, and any disruption – including light pollution, loud noises, or humans – can cause them to abandon their attempts.

Partnering to protect turtles' legacy

Since 2002, we've conducted annual field work at Bells Beach in Western Australia, to monitor the visiting turtle populations carefully and safely. We've also partnered with the local community, government and the Ngarluma people – the area's Traditional Owners – to support turtle monitoring and research at other regionally significant breeding grounds, including Delambre Island, Rosemary Island and local beaches in the Cape Lambert area.

In 2005, we partnered with Western Australia's Department of Biodiversity, Conservation and Attractions (DBCA) to create the West Pilbara Turtle Program (WPTP) – a community-based program of volunteers who monitor the beach every day for turtle nesting activity, and run night tours to help raise community awareness of flatbacks and their conservation.

Initially, we monitored populations by counting their tracks. But as the science has progressed, so has our approach. We now use two tagging techniques; monitor light, sand and in-nest temperature; and observe hatchling success and behaviour. We use the data to model turtle breeding patterns and numbers, and to help inform decisions about resourcing and initiatives to improve their conservation in future.

In addition to monitoring the nests and turtles, our operations play an important role in turtle conservation, including restricting vehicle access to Bells Beach, monitoring and protecting critical sand dune habitat and implementing an annual feral animal control program.

We also help to minimise artificial light impacts by using lights which turtles are less sensitive to, and preventing direct light spill onto the beach. This is vital, because when hatchlings emerge from their nests, they move towards the brighter horizon over water and away from the darkness of the beach, so any other light or 'light spill' can disorientate their important journey to the sea.

All of these initiatives have required enormous collaboration and effort on the part of all parties involved over more than a decade. We hope this longevity of effort will ensure a turtle legacy for future generations.

Combining efforts for long-term conservation

While there is natural variability in turtle nesting numbers each year, the 2021 nesting season was very encouraging.

"By the end of last season, we'd surpassed the highest turtle count we have modelled since beginning this monitoring program,” said Lucas, Rio Tinto Cape Lambert's Environmental Advisor.

"We counted 252 nests the monitoring program and modelled 393 for the whole season – the highest turtle nest count we've ever modelled is 274 nests.

"Given turtles don't nest every year, we expect to see fluctuations in nesting numbers. The high nest numbers from last year were well received, especially after the previous season experienced low numbers across the region.

"It's essential that we work together with government and community groups in a combined effort to conserve a species like the flatback turtle. Environmental initiatives like this one ensure the next generation understands and is engaged in protecting the environment, now and into the future."

Following the nesting period, Lucas said the team monitored nests to count hatchlings as they emerged.

"We also had a great season for hatchlings, with our team monitoring hatchling success and behaviour to ensure the future viability of this species," he said.

"We had a high hatchling success rate and lots of nests erupting throughout the monitoring period. Overall, I would say it was a highly successful season."

The turtle season kicked off again in October 2022. Along with our community partners, we monitored the flatbacks during peak nesting season in November and December, and hope to see a strong nesting and hatching season, with hatchlings due to emerge in late January and February.

We have renewed our funding of the Delambre, Rosemary and WPTP partnerships until June 2025. Long-term monitoring is essential to successfully protect these long-lived species, so we look forward to continuing our relationship with the region's Traditional Owners, the DBCA, and the local community to jointly conserve marine turtles in Western Australia, now and in the future.