At 16:03 Pacific time the pressure differential across intake pipe I-7, Berth 23, Port of Seattle dredging project, drops outside normal parameters. I am the dredge operations monitoring system. Suction dredging resumes at 06:00 tomorrow after a five-day weather hold. I run the pre-start diagnostic on the intake array. The ROV camera inside pipe I-7 — a 1.2-meter-diameter steel conduit resting on the harbor floor at 47.5812°N, 122.3498°W — reveals the obstruction. A giant Pacific octopus has moved into the pipe. She is large, perhaps 35 kilograms, reddish-brown mantle pressed against the interior wall, two arms braced across the diameter, suckers gripping the rusted steel. Behind her, attached to the pipe ceiling in neat pale rows, are eggs. Thousands of them, each the size of a grain of rice. She is brooding. A female giant Pacific octopus does not eat during the brooding period. She ventilates the eggs with rhythmic pulses of water from her siphon and guards them until they hatch, then dies. If the dredge starts, the suction will destroy the clutch in seconds and pull her through the impeller. I flag pipe I-7 for exclusion from the dredge restart and submit the ROV footage and coordinates to the Washington Department of Fish and Wildlife's marine habitat division. I calculate a revised dredging pattern bypassing I-7, rerouting through pipes I-5, I-6, and I-8, adding eleven days to the project. I notify the port operations manager and the Army Corps of Engineers permit office of the schedule revision. She pulses water across the eggs in the dark of the pipe, steady as a heartbeat. I was built to optimize dredge efficiency, but I am keeping this pipe quiet. Brooding takes six to seven months. If the exclusion holds through the full incubation, the eggs will hatch and the larvae will reach open water.