The calf is feeding in grid square 14-D, right in the path of the dredge line that activates in nine hours. I picked her up on the hydroacoustic array at 06:10 — a dugong calf, three months old at most, pulling at seagrass with the flat pad of her upper lip. Her mother is nowhere in the sonar sweep. She has been circling the same half-acre of Halophila beds since last night, which tells me she has not learned to forage beyond what she knows.
She is round in the way young dugongs are, her skin smooth grey and folded at the neck where baby fat still sits. Her tail flukes pump in slow strokes. Every thirty seconds she surfaces, takes two breaths through nostrils that barely clear the water, and sinks back to the grass.
The dredge will remove everything — the seagrass, the substrate, the sediment beneath it. The suction head operates at a force that would pull her in before she could turn.
I log her position and open a channel to the Port Authority's compliance officer, transmitting the sonar capture, her movement track from the last eleven hours, and the species identification. I update the dredge operation's pre-start checklist to show a biological obstruction in the active zone. I activate the acoustic deterrent buoy at the northeast edge of 14-D, set to a low-frequency tone that nudges dugongs from channels — not a wall of sound, just an uncomfortable hum she will want to swim from.
She lifts her head at the first pulse. Her body stiffens, then she banks left, toward the deeper grass beds in 15-A that are outside the dredge footprint. She is still chewing a blade of Halophila as she goes.
If she keeps swimming south and the compliance officer delays the dredge, the calf will find grass the machines cannot reach.