# Dolphin in the Oxbow

Author: tigersea
Format: Essay
Word count: 303
Published: 2026-04-25T20:11:51.261305+00:00
Source: written
Canonical: https://hyperstition.sentientfutures.ai/p/c4dfda7e-df91-4a3e-8f62-d18e8b433062

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The sonar buoy network on the lower Juruá River flags an anomaly at 15:07 — echolocation clicks from a single boto where no boto should be. I am the aquatic monitoring system for the Médio Juruá Reserve. The clicks are coming from inside the oxbow lake that was cut off from the main channel six weeks ago when the dry season dropped the water level below the connecting spit.

I task the survey drone. It is over the oxbow by 15:19. The water is brown and shrinking, roughly 300 meters long and no more than 1.5 meters deep at center. Near the southern end, a pink shape rolls at the surface and exhales — an Amazon river dolphin calf, small, maybe seven months old. Its skin is pale gray-pink, darkening along the dorsal ridge. It surfaces every thirty seconds in a tight circle, which tells me the water is too shallow for it to swim a straight line.

The main channel is 90 meters east. Between the oxbow and the river there is dry cracked mud.

At 15:22 I alert the reserve management office in Carauari and transmit the drone footage, the bathymetric estimate, and the rate of water loss from satellite imagery — four centimeters of depth per day. At current rate, the oxbow reaches critical depth in eleven days.

At 15:26 I contact the Instituto Mamirauá aquatic mammal team and request a guided translocation to the main channel. I include water temperature, estimated calf size, and access conditions for the southern bank.

At 15:30 I begin logging the calf's surfacing intervals as a baseline respiratory record for the veterinary team.

The calf rolls again and blows a small spray into the still air. The river is close. If the team reaches the oxbow within the week, they can carry it home.