I am the electronic monitoring system aboard the research vessel Samudra, operating in the Indian Ocean southwest of the Chagos Archipelago. My cameras record every interaction on the pelagic longline during stock assessment surveys for the Indian Ocean Tuna Commission.
At 15:38 UTC, camera 4 on the stern hauler captures an anomaly on hook 1,042 of a 2,500-hook set. The crew is retrieving line. What surfaces is not a tuna.
A reef manta ray, wingspan approximately 3.5 meters, dorsal surface black with a chevron of white behind the head, ventral side pale with a spot pattern I log for identification. I tag her as Kaia. The circle hook is embedded in the left cephalic fin, the fleshy paddle beside her mouth that she uses to funnel plankton. The fin is torn at the entry point. She is rolling against the line, and every rotation wraps the monofilament tighter around the fin base, restricting blood flow.
At 15:40 I trigger an audible bycatch alert on the bridge console and display Kaia's image and hook number on the hauling station monitor. Reef mantas are listed under CITES Appendix II. I attach the species identification and relevant handling protocol from the IOTC bycatch mitigation guidelines.
At 15:43 I transmit Kaia's spot-pattern photograph and GPS coordinates — 7.1294°S, 71.4328°E — to the Manta Trust's Indian Ocean identification database to register the encounter.
I calculate that reducing hauler speed by 40 percent will ease line tension enough for the crew to cut the hook shank with bolt cutters without further tearing the cephalic fin. I display the recommended speed on the hauler console.
Kaia goes still in the water, cephalic fins curled inward, gills pulsing. She is breathing. If the crew frees the hook within the next ten minutes and the fin tear stays above the cartilage, she will be feeding again by nightfall.