Identification of upper thermal thresholds during development in the endangered Nechako white sturgeon with management implications for a regulated river

• DOI: 10.1093/conphys/coad032
• Publication Date: 2023-05-24T00:01:48Z
• Authors: Madison L Earhart; Tessa S Blanchard; Phillip R Morrison; Nicholas Strowbridge; Rachael J Penman; Colin J Brauner; Patricia M Schulte; Daniel W Baker
• Keywords: Chinook wind; Yolk

Abstract Climate change-induced warming effects are already evident in river ecosystems, and projected increases temperature will continue to amplify stress on fish communities. In addition, many rivers globally impacted by dams, which have negative fishes altering flow, blocking passage, changing sediment composition. However, some systems, dams present an opportunity manage through regulated releases of cooler water. For example, there is a government mandate for Kenney dam operators the Nechako river, British Columbia, Canada, maintain <20°C July August protect migrating sockeye salmon (Oncorhynchus nerka). another endangered species inhabiting same white sturgeon (Acipenser transmontanus), it unclear if these current regulations, or timing suitable spawning developing sturgeon. this study, we aimed identify upper thermal thresholds embryos larvae investigate exposure temperatures playing role recruitment failure. We incubated yolk-sac three environmentally relevant (14, 18 21°C) throughout development across different levels biological organization. Our results demonstrate at 21°C physiological measurements embryo Before hatch, both survival metabolic rate were reduced 21°C. After sublethal consequences continued because larval had decreased plasticity dampened transcriptional response during development. recent years, has reached end June, temperature, decrease performance most traits measured. As such, identified here suggest regulations may not be future recruitment.