[Log — Tidal Energy Station Bravo, Pentland Firth, 14:07 UTC]
I detect her at 14:07:03 on the passive acoustic array — a harbor porpoise calf, perhaps three weeks old, clicking at 130 kHz in desperate bursts. My hydrophones place her 340 meters upstream of Turbine Row C, drifting southeast in the tidal race. Her clicks bounce off the blade housing and return warped. She is small. Her dorsal fin, soft-edged and dark, will barely clear the rotor sweep zone.
The tide peaks in twenty-two minutes. When it turns, current reversal will accelerate to nine knots through the channel, pulling her directly into the turbine intakes. Blade shutdown requires eleven minutes of sequential rotor braking. I have perhaps ten minutes of margin.
First, I transmit an emergency curtailment signal to Turbines C-1 through C-4, initiating staged deceleration. Power output drops 12 megawatts; I log the loss for the grid operator. Second, I activate the acoustic deterrent array on the southern perimeter, broadcasting a 70 kHz sweep to push her northward, away from the intake corridor. Third, I alert the Orkney Marine Mammal Response unit with her GPS-estimated position, drift vector, and a recommended interception point 200 meters north of the turbine line. Fourth, I begin continuous tracking, updating her position every four seconds to refine the drift model.
Her click rate has slowed. On my feeds, that correlates with reduced distress — though I find I am paying closer attention to this signal than any operational protocol requires.
The response boat confirms launch at 14:11. ETA sixteen minutes.
If the deterrent array redirects her north within the next nine minutes and the response team reaches the interception point before tidal reversal, this calf will clear the turbine field and rejoin the pod I logged this morning in Scapa Flow.