North American Journal of Fisheries Management, Journal Year: 2024, Volume and Issue: 44(3), P. 714 - 734
Published: June 1, 2024
Abstract Objective Low survival of emigrating salmonid smolts through the interior regions California's Sacramento–San Joaquin River Delta (hereafter, “Delta”) and large‐scale water extraction from that region have prompted managers to seek predict manipulate smolt route use tidal Delta. The local flow variables previously used in modeling are not metrics management. Here, I investigate predictive utility representing both localized conditions remote management routing juvenile steelhead Oncorhynchus mykiss at two river junctions on San south Methods Individual‐based generalized linear models were with detections over 4000 acoustic‐tagged hatchery‐reared relate presence a rock barrier, simulated hydrodynamic model, daily metrics, including upstream discharge pumping rates elsewhere Models developed for first diffluences encountered by entering (head Old Turner Cut). Result Exclusive underestimated subdaily, tidally dominated fluctuations fish compared covariates. rate 20–30 km away contributed non‐main‐stem routes, but effect was small subhourly themselves. Conclusion Water resource advised monitor locations interest rather than depending solely metrics. In Delta, barrier reduction operations when migrating should be combined habitat improvement optimize migratory this complex heavily modified system.
Language: Английский