Effects of turbidity, temperature and predation cue on the stress response of juvenile delta smelt

Conservation Physiology, Journal Year: 2023, Volume and Issue: 11(1)

Published: Jan. 1, 2023

Abstract The San Francisco Estuary (SFE) is one of the most degraded ecosystems in United States, and organisms that inhabit it are exposed to a suite environmental stressors. delta smelt (Hypomesus transpacificus), small semi-anadromous fish endemic SFE considered an indicator species, close extinction wild. goal this study was investigate how alterations SFE, such as reductions turbidities, higher temperatures increased prevalence invasive predators affect physiology stress response juvenile smelt. Juvenile were two (17 21°C) turbidities (1–2 10–11 NTU) for 2 weeks. After first week exposure, largemouth bass (Micropterus salmoides) predator cue at same time every day 7 days. Fish measured sampled on (acute) final (chronic) exposures cues later analyzed whole-body cortisol, glucose, lactate, protein. Length mass measurements used calculate condition factor each treatment. Turbidity had greatest effect resulted reduced glucose greater factor. Elevated available energy smelt, indicated by lower total protein, whereas exposure negligible effects their response. This show cortisol held turbid conditions adds growing data suggest species performs best moderate turbidities. Multistressor experiments necessary understand capacity respond multivariate dynamic changes natural environment, results from should be management-based conservation efforts.

Language: Английский

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Conservation physiology and the management of wild fish populations in the Anthropocene

Fish physiology, Journal Year: 2022, Volume and Issue: unknown, P. 1 - 31

Published: Jan. 1, 2022

Language: Английский

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Air Pocket for a Non-Air-Breathing Fish: Developing Respirometry Methodology for the critically endangered Delta Smelt

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 23, 2024

Respirometry quantifies O2 consumption to estimate metabolic activity across stressor(s), and the resulting data is central for devising conservation strategies fishes. Due its rapid adoption widespread utility, protocols have been established foster quality control increase consistency. However, application of respirometry on Delta Smelt (Hypomesus transpacificus) largely unsuccessful, with reports over past 12 years documenting high mortality rates that can only be circumvented very short measurement duration (~4 h). This prevents standard rate (SMR) critical tension (Pcrit), ultimately obstructed physiological research, management actions tools development. In this study, we detailed anecdotal, behavioral empirical evidence culminated in successful measurements SMR Pcrit at 10, 12, 15, 17 19 degrees C. We discovered physotomous requires frequent refilling air bladder maintain buoyancy. Inspired by air-breathing fish respirometry, inclusion an pocket within their chamber led considerably more robust compared attempts. The influence fasting time day were also examined. Altogether, methodology paves way acquiring knowledge needed inform research (e.g. development index). lessons learned may implications other aspects such as decreasing aquaculture operating costs improving survival during transport supplementation.

Language: Английский

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Insights from a year of field deployments inform the conservation of an endangered estuarine fish

Conservation Physiology, Journal Year: 2024, Volume and Issue: 12(1)

Published: Jan. 1, 2024

Abstract Freshwater fishes are increasingly facing extinction. Some species will require conservation intervention such as habitat restoration and/or population supplementation through mass-release of hatchery fish. In California, USA, a number strategies underway to increase abundance the endangered Delta Smelt (Hypomesus transpacificus); however, it is unclear how different estuarine conditions influence The goal this study was evaluate year field deployments inform suitable for smelt physiology. Hatchery-reared deployed in experimental cages (seven deployments) throughout Estuary winter, summer and fall 2019. Effects season location cage on fish health (condition factor histological condition liver gill), growth, thermal tolerance survival were evaluated. results indicate both seasonal differences, with high winter (100%) (88–92%) compared lower (67%). summer, one sites had no surviving following temperature exposure, which peaked ~26°C. After 29 days cages, showed signs nutritional stress that may be related biofouling limiting passive food inputs, restriction natural foraging behaviour by containment water temperatures too given chronically low pelagic productivity overall. Field measurements upper (CTmax) caging exposures suggest laboratory measures CTmax overestimate realized more stochastic environment. This demonstrates utility using an tool better understand aspects physiological responses environmental changes across habitats natural-field setting, while also highlighting potential limitations cages.

Language: Английский

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Conservation Physiology of fishes for tomorrow: Successful conservation in a changing world and priority actions for the field

Fish physiology, Journal Year: 2022, Volume and Issue: unknown, P. 581 - 628

Published: Jan. 1, 2022

Language: Английский

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Restoration physiology of fishes: Frontiers old and new for aquatic restoration

Fish physiology, Journal Year: 2022, Volume and Issue: unknown, P. 393 - 428

Published: Jan. 1, 2022

Language: Английский

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