Clifton Court study maps how Delta stripers move around threatened salmon

A new paper out of Clifton Court Forebay puts numbers on a problem salmon managers already know by feel: striped bass do not all use that 6-square-mile pumping basin the same way. Environmental Science Associates, writing Sept. 8, 2026, says its fisheries team with ICF and the California Department of Water Resources tagged nearly 600 stripers and tracked them with acoustic receivers for more than five years.

Clustering analysis split those fish into five movement types — outside residents that barely showed up on the array, “commuters” that ran the gates, inside roamers, inside sedentary fish, and inside residents that went undetected. Season, age, hydrology, and how the intake gates were run all shifted which pattern showed up.

The point is not a new striper war. ESA scientists Taylor Spaulding and Paul Bergman say the maps should let DWR time and place predator work where it actually overlaps listed winter-run Chinook and steelhead, instead of treating every bass in the forebay as the same fish.

Photo: USFWS striped bass photo via Environmental Science Associates.

This is a The Gillnet news desk summary, not a reprint.

Source: Environmental Science Associates — New Research Tracks Predatory Fish in the California Delta to Benefit Threatened Salmonids (Sept. 8, 2026).