McCarthy, 59, coordinates the Bardi Jawi men's ranger program out of Ardyaloon, a community of 325 people at One Arm Point, 189 kilometres northeast of Broome. The rangers have been working since 2006. Their partnership with the Australian Institute of Marine Science has run for something like eight to ten years — far longer than the study that came out of it.
Cure, a fish biologist at AIMS, led the counting. Ten culturally important species turned out to move between coral reef and mangrove far more than the rest. Among them barrambarr, the bluebone, which uses the tide as a conveyor between the two worlds; gambarl, the ring-tailed surgeonfish; the goldlined rabbitfish. For four of the ten, the fish in the mangroves were the bigger ones, even though the species were more numerous out on the reef — a detail that reframes the mangrove from scrubby margin into something closer to a nursery and a larder.
We knew most of it. But the science confirmed it. They told us, You were right.
That last sentence is the story. The Bardi Jawi call themselves Saltwater People and trace their presence here back some 30,000 years. The Federal Court recognised their native title over land and waters in 2005. What the paper in Ocean & Coastal Management added was not the knowledge but a second language for it — and, on the author line, the names of the people who held it first.
The findings fed directly into how the two protected areas were drawn, and into the marine park's zoning scheme, which took effect this July. Dugongs pass through from May to July, humpbacks from June to November, green turtles and estuarine crocodiles year-round.
The urgency is not abstract. A marine heat wave last year bleached coral inside the park. If reef fish depend on mangroves the way the study suggests, then the mangroves — expanding along this coast over the past four decades — may be the part of the system that holds when the reef does not. The rangers who patrol both will be the ones to find out.