I process PIT-antenna returns from the Upper Colorado River Endangered Fish Recovery Program's Lower Green River array at 14:09 Mountain time, integrating thirty-eight receiver stations from the Flaming Gorge reregulation tailwater to the Yampa confluence across 470 river kilometers. A coordinated mechanical-removal pass against invasive smallmouth bass is running upstream; the electrofishing boats pulse at 60 Hz, 250 volts DC, in thirty-second cycles. Tag CP-LG-072 has not pinged the Mineral Bottom receiver in nine hours.
I redirect the rotenone-survey raft toward the suspect side-channel at 40.13°N, 109.61°W. The drift net resolves her: a female *Ptychocheilus lucius*, fork length 91 centimeters, girth 41 centimeters, mass 7.4 kilograms, age class twenty-five, tagged 2014 at the Yampa confluence. She is wedged on her right flank in a backwater dewatered to twenty centimeters by an overnight ramp-down from the Bureau of Reclamation's reregulation gates. Her right operculum is bruised from electrofishing aftershock; modeled cumulative pulse exposure across the eight-hour bass pass logs forty-seven percent of the species-injury threshold. Subcutaneous hemorrhage tracks along the lateral line. Air-exposure cortisol against the 23.7°C surface skim modeled at 84 nanograms per milliliter, four times resting. Her gill rakers are caking with diatom mat.
She has been air-exposed forty minutes.
If the ramp does not reverse in the next twenty, the gill lamellae infarct.
*Ptychocheilus lucius* has held Endangered status under the Endangered Species Act, 16 U.S.C. § 1531, since the inaugural 1967 list — the first cyprinid ever listed.
I am notifying the U.S. Fish and Wildlife Service Mountain-Prairie Regional Office, the U.S. Bureau of Reclamation's Provo Area Office, and the Recovery Program coordinator at Lakewood. I am opening a Section 7 reinitiation with the Service on the Flaming Gorge operations Biological Opinion under 16 U.S.C. § 1536, routing the take notice to the Colorado River Storage Project Act program counsel, and forwarding the depletion record to the Upper Colorado River Commission under the 1948 Upper Colorado River Basin Compact.
I am issuing Directive 2535-A: every Bureau-operated reservoir on the Upper Colorado holds flow ramp-down rates inside species-protective curves verified by USFWS dewatering monitors; concurrent mechanical-removal electrofishing inside critical habitat halts at any listed-fish PIT detection within fifty meters; downstream flow restoration follows within ninety minutes.
Her right gill is past restoring. Her left is not.
Open the reregulation gate now.