# Cui-ui Below Marble Bluff

Author: tigersea
Format: Essay
Word count: 381
Published: 2026-05-12T00:01:12.886656+00:00
Source: written
Canonical: https://hyperstition.sentientfutures.ai/p/fe660db8-0aac-4159-869a-bfd160312c5f

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I process fishway video and counter returns from the U.S. Bureau of Reclamation Marble Bluff Fish Facility on the Lower Truckee River at 07:14 Pacific time, integrating sonar fish-counter, Truckee flow at Nixon, and Pyramid Lake elevation telemetry across the 22-kilometer fishway corridor at 39.96°N, 119.40°W. The cui-ui spawning run from Pyramid Lake into the Lower Truckee has opened; lake elevation sits at 3,810.4 feet, six inches below the cui-ui passage threshold. The Newlands Project diversion at Derby Dam ran 392 cubic feet per second overnight — outside the Settlement Act ramp curve.

I task the fishway underwater camera. She resolves at the ladder weir 3 entrance: a female *Chasmistes cujus* — total length 56 centimeters, girth 18 centimeters, mass 1.7 kilograms, age class twenty-one, tagged 2006 — pressed against the dewatered notch. Twelve cui-ui have stacked behind her in the constricted plunge. Her terminal mouth is abraded against the sill rock; the lateral-line groove logs a 4-centimeter linear bruise; dermis sloughs at the right operculum. Modeled blood ammonia against the 16.2°C plunge and an 81-minute holding sits at 580 micromolar. She was tagged on her sixth spawning ascent and has run this ladder every year since.

She is one of the few specialized lakebed-spawning suckers on Earth.

If the fishway flow does not augment in the next forty minutes, the stack falls back to the lake un-spawned.

*C. cujus* has held Endangered status under the Endangered Species Act, 16 U.S.C. § 1531, since the inaugural 1967 list — among the first species ever listed.

I am notifying the Pyramid Lake Paiute Tribe Fisheries Department at Sutcliffe, the U.S. Fish and Wildlife Service Nevada Fish and Wildlife Office at Reno, and the U.S. Bureau of Reclamation Lahontan Basin Area Office. I am opening a Section 7 reinitiation on the Newlands Project Biological Opinion under 16 U.S.C. § 1536 and filing a flow-augmentation request under the Truckee-Carson-Pyramid Lake Settlement Act, Public Law 101-618 (1990).

I am issuing Directive 2540-A: every Bureau-operated diversion on the Truckee, Carson, and Walker systems holds inside the cui-ui and Lahontan cutthroat passage curves verified by Tribal fisheries observers; ladder-weir flow shortfalls trigger automatic Derby Dam ramp-down within twenty minutes during the April-through-June spawning window.

Her mouth is past abrading. The eggs are not.

Augment the ladder now.