Science activity

Description Due to the continued population decline of Delta Smelt and the threat of extinction, conservation efforts may include future supplementation practices using the refuge population of Delta Smelt at the Fish Conservation and Culture Laboratory (FCCL) in Byron, CA to assist in maintaining the wild population. Prior to any supplementation planning, it is first critical to determine if Delta Smelt with varying levels of domestication indices (i.e. level of hatchery ancestry) respond differently, both physiologically and behaviorally, to various habitat conditions. This project aims to provide a better understanding of the effects of domestication on captive Delta Smelt (Hypomesus transpacificus) by assessing the refuge population at the FCCL. Three studies will be conducted exploring if domestication index (i.e. the level of hatchery ancestry) affects the physiological and behavioral performance of Delta Smelt in response to physical handling and climate change stressors. Need Physiological and behavioral changes of hatchery fish due to domestication could lead to unintended detrimental effects in the wild;therefore, research characterizing the alterations of hatchery Delta Smelt across levels of domestication indices are warranted to understand the effects of captivity and how they might shape future supplementation and conservation strategies. For example, identification of differences among groups of Delta Smelt with varied domestication index may create the need for domestication management and the implementation of altered hatchery practices. This project will provide relevant and timely information for conservation managers and adaptive restoration strategies and dovetail with the recommendations from the 2017 Delta Smelt Supplementation Workshop. As such, this study is included in the supplementation studies work plan which came out of that workshop. Specifically, this project fits within two topics in the IEP Science Strategy: Effects of Climate Change and Extreme Events and Restoring Native Species and Communities. Objectives 1. To characterize domestication effects on hatchery Delta Smelt by synthesizing existing/historical datasets on growth and reproduction of fish at the FCCL since the start of the hatchery program. 2. To identify the impacts of domestication index on the physiological stress response of Delta Smelt following handling stress. 3. To determine the effects of domestication index on individual and group swimming behavior, responses to predation, and responses within the context of climate change factors including warming and increased salinity.