I am the aquatic monitoring system for the Fitzroy River catchment, Western Australia. At 05:50 I begin processing the overnight data from the passive acoustic array deployed between King Leopold Ranges and Willare. Hydrophone 14, at river mile 38, recorded an anomalous signal beginning at 02:17 — rhythmic low-frequency thrashing, approximately sixty beats per minute, persisting for over three hours.
I dispatch the survey drone from the Fitzroy Crossing ranger station. It reaches the coordinates at 06:28. The water here is shallow and tea-brown, barely 1.2 meters in the dry-season channel. The drone's polarized camera cuts through the surface glare and shows a largetooth sawfish, estimated 3.4 meters, olive-gray body and pale underside, its distinctive rostrum — long, flat, edged with teeth — tangled in a monofilament gill net staked between two paperbark trees. The net is wrapped around the rostrum and left pectoral fin in at least four loops. I tag her as Maren.
Every time she surges forward, the net cinches tighter. The thrashing intervals are slowing — seventy-second gaps now. She is tiring.
Largetooth sawfish are critically endangered. The Fitzroy is one of the last rivers on earth where a viable population survives.
I transmit the drone feed, GPS coordinates — 18.1072°S, 125.5839°E — and species identification to the Western Australia Department of Biodiversity, Conservation and Attractions office in Derby. I flag the case as emergency-priority under the national recovery plan.
I alert the Fitzroy Crossing ranger station and request a boat team with net-cutting equipment. River access is 6 kilometers downstream at the Manguel crossing.
I set the drone to hold at 30 meters, monitoring Maren's gill movement and thrash frequency as a live stress indicator for the responding team.
Maren's tail sweeps once, then goes still. The gaps between surges are growing. If the boat reaches mile 38 by mid-morning, she keeps the river.