Monitoring juvenile Chinook salmon outmigration using rotary screw traps on Butte Creek

The California Department of Fish and Wildlife (CDFW) conducts juvenile salmonid emigration monitoring on Butte Creek at the Parrot-Phelan Diversion Dam near Chico, California. Monitoring is conducted annually from October through June utilizing an 8-ft diameter rotary screw trap (RST) and a diversion screen trap (DST). Data from this monitoring is used to estimate juvenile spring-run Chinook salmon (Oncorhynchus tshawytscha) abundance and passage, identify alevin emergence timing, document juvenile size at emigration, and document rearing and emigration patterns. This data will also be used to inform the development of a juvenile production estimate (JPE) for spring-run Chinook salmon in the Sacramento River Watershed as required by Condition of Approval 7.5.2 of Incidental Take Permit No. 2081-2019-006-00 (ITP) issued by CDFW to California Department of Water Resources (DWR) for the long-term operation of the State Water Project. Salmonid data collected from the Butte Creek RST, among other datasets, is also used by the Salmon Monitoring Team (SaMT) to understand the movement of juvenile salmon in the Sacramento River Watershed to estimate the number of winter-run and spring-run Chinook salmon that have entered the Sacramento-San Joaquin Delta (Delta). SaMT is a real-time operations monitoring team required by Condition of Approval 8.1.2 of the ITP which meets weekly from October through June, to provide advice for real-time management of SWP operations to DWR, CDFW, and the Water Operation Management Team (WOMT) to minimize take of winter-run and spring-run Chinook salmon in the Delta. Note: data within the current year’s monitoring season are considered provisional.加利福尼亚州鱼类与野生动物部（California Department of Fish and Wildlife, CDFW）在加利福尼亚州奇科市附近的帕罗特-费伦分水坝（Parrot-Phelan Diversion Dam）所辖比特溪流域开展幼鲑洄游监测工作。该监测于每年10月至6月期间开展，采用直径8英尺的旋转式螺杆诱捕装置（rotary screw trap, RST）与分水网屏诱捕装置（diversion screen trap, DST）进行数据采集。 本监测所获数据可用于估算春季洄游型奇努克鲑（Oncorhynchus tshawytscha）的种群丰度与过坝通过率，识别仔鱼出蛰时间，记录洄游幼体的体型大小，并梳理其育幼与洄游模式。 该数据还将为萨克拉门托河流域春季洄游型奇努克鲑的幼体产量估算（juvenile production estimate, JPE）提供支撑，以符合CDFW向加利福尼亚州水资源部（California Department of Water Resources, DWR）签发的第2081-2019-006-00号附带捕捞许可（Incidental Take Permit, ITP）中第7.5.2款批准条件的要求，该许可用于州水资源工程（State Water Project, SWP）的长期运营管理。 除其他相关数据集外，从比特溪旋转式螺杆诱捕装置采集的鲑科鱼类数据，亦被鲑鱼监测团队（Salmon Monitoring Team, SaMT）用于解析萨克拉门托河流域幼鲑的移动规律，以估算进入萨克拉门托-圣华金河三角洲（Delta）的冬季洄游型与春季洄游型奇努克鲑种群数量。 鲑鱼监测团队是依据该附带捕捞许可第8.1.2款批准条件设立的实时运营监测团队，于每年10月至6月每周召开工作会议，为加利福尼亚州水资源部、加利福尼亚州鱼类与野生动物部及水资源运营管理团队（Water Operation Management Team, WOMT）提供州水资源工程实时运营管理建议，以最大限度降低三角洲区域内冬季洄游型与春季洄游型奇努克鲑的误捕风险。 注：本年度监测季内的所有数据均视为临时数据。