The Enhanced Large Fish Study (ELFS) was established and included in the Interagency Ecological Program (IEP) work plan in 2023 to fill some of the monitoring gap of fishes in the San Francisco Estuary (SFE), California. The fish monitoring of the IEP prior to ELFS primarily consisted of trawl- and seine-based surveys, which generally capture small and/or juvenile fishes due to survey gear and methodologies. In order to more effectively sample the large/adult fish portion of SFE fish communities, the ELFS uses American Fisheries Society experimental gillnets, plus the inclusion of the optional "large fish panel," to sample the waters of the SFE. The experimental gillnets measure 24.4m in length, 1.8m in depth, and includes eight 3m length panels with stretch mesh measurements of 76.2mm, 114.3mm, 50.8mm, 88.9mm, 38.1mm, 127.0mm, 63.5mm, and 101.6mm. The optional large fish panel measures 9.1m by 1.8m in depth and includes three 3m length panels with stretch mesh measurements of 152.4, 177.8, and 203.2mm. The ELFS conducted its first year of sampling in the North Delta, California, in 2023, and will be expanded to the greater Delta and Suisun Bay and Marsh in future sampling years. The ELFS is currently funded as a special study to inform future monitoring, with funding contracted through fiscal year 2026-2027.