This is the first in a two part report from the Pilbara Islands, where we have a project underway to develop decision support systems for prioritising and implementing management actions for biosecurity.
The airplanes got steadily smaller as we approached our destination, always a good sign that you’re on the way to somewhere interesting. Our first sight of the Mackerel Islands was as we peered though the Perspex of our 6 seat aircraft on route to Thevenard Island – sandy coloured, flat and scrubby, surrounded by reefs and azure blue waters filled with conspicuous numbers of tiger sharks, visible even from 2000ft above.
The purpose of our visit was to experience first hand the biodiversity of the islands and to get a feel for the issues facing the mangers; the majority of Thevenard and most of the other islands are nature reserves managed by the Western Australia Department of Parks and Wildlife (DPaW). Arriving in December we were the only tourists staying at the resort, the peak season for visitors being the cooler and cyclone-free months of year when the resort is a popular base for recreational fishers. The trip was part of a project aiming to Prioritise Conservation Management Actions on Islands in the Pilbara region; the project is funded by Chevron as part of the Gorgon Gas Project on Barrow Island.
Our accommodation was on the beachfront and it was clear from the cratered dunes and prehistoric looking tracks that flatback turtles were actively nesting all around the island. After dinner a wander down to the beach to look for turtles and there, within a 100m of the accommodation was a large female tunneling away. As a mostly terrestrial biologist this was pleasantly novel experience for me. Looking out across the dark sea an electric glow on the horizon signaled what had brought us to the area – the glow was the Wheatstone development, a massive ($30bn) gas processing facility being constructed on the mainland shore. This is just one of several large developments in the region that has the potential to impact biodiversity in the area.
Day two was a walking tour of the island; we were dropped off at the far end of the island and walked back for 6km along the beach. The party dispersed rapidly as we all indulged our personal interests, Bob and Jana snorkeling, Leslie exploring the various nooks and crannies of the coast, Cheryl and Steve visiting vegetation survey plots and me fishing. I’ve always enjoyed fishing for the way it demands a keen observation of the environment and in extremis the attempt to develop empathy with the target species (as if empathy with fish is possible of course). Never has staring at water been so rewarding as on Thevenard – every 100m black tip reef sharks would cruise past just out of reach from the shore, their dorsal fins near enough to the water surface to deform but not puncture. Several times green turtles flapped their leisurely way along the beach, their carapaces brightly coloured in the stark sunshine and clear water. Large schools of fish like moving grey clouds with flashes of silver were frequent and whenever they met a black tip they would part to allow it through and then re-zip as the shark continued it’s patrol. I found this abundance particularly surprising with the back drop of oil rigs and oil tanks on Thevenard – over 150 million barrels oil have been pumped through Thevenard since 1989. It was good to see that with careful management (and the avoidance of leaks and explosions) hydrocarbon extraction can take place without massive biodiversity destruction.