scholarly journals Diary of Wimpy Fish: How to Grow Up in a Conservation Hatchery and Survive in the Real World

2021 ◽  
Vol 9 ◽  
Author(s):  
Amanda J. Finger ◽  
Daphne A. Gille ◽  
Nicole M. Kwan ◽  
Melinda R. Baerwald
Keyword(s):  
San Francisco ◽  
Real World ◽  
Natural Environment ◽  
Chinook Salmon ◽  
San Francisco Estuary ◽  
Wild Fish ◽  
Controlled Environment ◽  
Endangered Fish ◽  
Hatchery Fish ◽  
In The Wild

Conservation hatcheries are like luxury fish hotels that raise threatened and endangered fish that are nearing extinction in the wild. Raising fish in the controlled environment of the conservation hatchery usually takes away the issues that caused the population to dwindle in the first place. However, there is one problem: the fish get used to the conservation hatchery and become wimpy, meaning they become domesticated and do not do as well as wild fish in if they are returned to the natural environment. Managing the genes of hatchery fish is one way to block domestication and raise fish that are as close as possible to wild fish. In the San Francisco Estuary watershed, there are conservation hatcheries for the endangered delta smelt and winter-run Chinook salmon. Read on to learn about how these conservation hatcheries help hatchery fish be as tough as possible and survive in the wild.

scholarly journals Managed Wetlands Can Benefit Juvenile Chinook Salmon in a Tidal Marsh

2021 ◽  
Author(s):  
Nicole M. Aha ◽  
Peter B. Moyle ◽  
Nann A. Fangue ◽  
Andrew L. Rypel ◽  
John R. Durand
Keyword(s):  
San Francisco ◽  
Growth Rates ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Nursery Habitat ◽  
San Francisco Estuary ◽  
Rice Fields ◽  
Fish Growth ◽  
Juvenile Chinook Salmon ◽  
Juvenile Chinook

AbstractLoss of estuarine and coastal habitats worldwide has reduced nursery habitat and function for diverse fishes, including juvenile Chinook salmon (Oncorhynchus tshawytscha). Underutilized off-channel habitats such as flooded rice fields and managed ponds present opportunities for improving rearing conditions and increasing habitat diversity along migratory corridors. While experiments in rice fields have shown enhanced growth rates of juvenile fishes, managed ponds are less studied. To evaluate the potential of these ponds as a nursery habitat, juvenile Chinook salmon (~ 2.8 g, 63 mm FL) were reared in cages in four contrasting locations within Suisun Marsh, a large wetland in the San Francisco Estuary. The locations included a natural tidal slough, a leveed tidal slough, and the inlet and outlet of a tidally muted managed pond established for waterfowl hunting. Fish growth rates differed significantly among locations, with the fastest growth occurring near the outlet in the managed pond. High zooplankton biomass at the managed pond outlet was the best correlate of salmon growth. Water temperatures in the managed pond were also cooler and less variable compared to sloughs, reducing thermal stress. The stress of low dissolved oxygen concentrations within the managed pond was likely mediated by high concentrations of zooplankton and favorable temperatures. Our findings suggest that muted tidal habitats in the San Francisco Estuary and elsewhere could be managed to promote growth and survival of juvenile salmon and other native fishes.

Effects of Early Rearing Environment on Stress Response, Immune Function, and Disease Resistance in Juvenile Coho (Oncorhynchus kisutch) and Chinook Salmon (O.tshawytscha)

1993 ◽  
Vol 50 (4) ◽  
pp. 759-766 ◽  
Author(s):  
Kira Salonius ◽  
George K. Iwama
Keyword(s):  
Disease Resistance ◽  
Chinook Salmon ◽  
Coho Salmon ◽  
Vibrio Anguillarum ◽  
Oncorhynchus Kisutch ◽  
Significant Rise ◽  
Wild Fish ◽  
Handling Stress ◽  
Hatchery Fish ◽  
Natural Water Body

Coho (Oncorhynchus kisutch) and chinook salmon (0. tshawytscha) from aquaculture and wild environments were subjected to handling (30–60 s of netting and aerial emersion) and disease challenges. Plasma cortisol concentrations ([cortisol]pl) in both coho and chinook salmon from wild environments were significantly elevated 4 h after handling. Colonized coho salmon (hatchery-reared fish, transported into a natural water body as fry) responded in a similar fashion to wild fish, while those reared entirely in the hatchery showed no significant rise in [cortisol]pl. The responses to handling stress were retained in wild and colonized coho salmon after 7 mo of hatchery rearing. A transient increase in the leukocyte to red blood cell ratio in both wild and hatchery-reared chinook salmon occurred 4 h after handling. Handling signficantly decreased the antibody-producing cell (APC) number in wild fish and elevated their [cortisol]plrelative to hatchery fish. Wild fish had the highest APC number among the three groups before the handling. No difference in resistance to Vibrio anguillarum was apparent in coho and chinook salmon among the different rearing environments, although chinook salmon were generally more susceptible; disease resistance was reduced in wild coho salmon after 7 mo of rearing in a hatchery.

scholarly journals Reconsidering the Estimation of Salmon Mortality Caused by the State and Federal Water Export Facilities in the Sacramento–San Joaquin Delta, San Francisco Estuary

2020 ◽  
Vol 18 (3) ◽  
Author(s):  
Andrew Jahn ◽  
William Kier
Keyword(s):  
San Francisco ◽  
Chinook Salmon ◽  
Near Field ◽  
San Francisco Estuary ◽  
The State ◽  
Juvenile Salmon ◽  
Small Fish ◽  
Accuracy And Precision ◽  
Behavioral Barriers ◽  
Existing Data

Combined water exports from Old River in the south end of California’s San Francisco Estuary (estuary) by state and federal pumping facilities entrain small fishes, including out-migrating juvenile salmon. Both export projects have fish salvage facilities that use behavioral barriers (louvers) in combination with screens to guide fish into collection areas from which they are trucked to release points in the western Delta. Sacramento River-origin Chinook Salmon are regularly taken in the projects’ fish salvage operations. Survival has been estimated within the boundaries of both intake structures, but not in Old River. Prevailing methods for estimating fish losses are based on studies of louver efficiency, near-field survival at the state facility, and assumed survival at the federal facility. The efficiency of the fish salvage operations is affected by several factors, including intake velocity, debris build-up on the louvers and trash racks, and by the omnipresence of predators in front of and within the fish guidance structures. Analysis of existing data suggests that under average conditions, juvenile salmon survive entrainment into the forebay of the state facility at a rate of less than 10%. There is no evidence for better survival at the federal facility. We found no data on predation outside of either the state’s forebay or the federal trash boom, structures which are separated by an approximately 2-km reach of Old River where predation on small fish is thought to be intense. We suggest an improvement to the existing loss estimation, and discuss some features of the studies needed to increase its accuracy and precision.

Factors influencing the relative fitness of hatchery and wild spring Chinook salmon (Oncorhynchus tshawytscha) in the Wenatchee River, Washington, USA

2010 ◽  
Vol 67 (11) ◽  
pp. 1840-1851 ◽  
Author(s):  
Kevin S. Williamson ◽  
Andrew R. Murdoch ◽  
Todd N. Pearsons ◽  
Eric J. Ward ◽  
Michael J. Ford
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Parentage Analysis ◽  
Wild Fish ◽  
Relative Fitness ◽  
Male Fitness ◽  
Natural Origin ◽  
Hatchery Fish ◽  
Management And Conservation ◽  
Older Males

Understanding the relative fitness of naturally spawning hatchery fish compared with wild fish has become an important issue in the management and conservation of salmonids. We used a DNA-based parentage analysis to measure the relative reproductive success of hatchery- and natural-origin spring Chinook salmon ( Oncorhynchus tshawytscha ) in the natural environment. Size and age had a large influence on male fitness, with larger and older males producing more offspring than smaller or younger individuals. Size had a significant effect on female fitness, but the effect was smaller than on male fitness. For both sexes, run time had a smaller but still significant effect on fitness, with earlier returning fish favored. Spawning location within the river had a significant effect on fitness for both sexes. Hatchery-origin fish produced about half the juvenile progeny per parent when spawning naturally than did natural-origin fish. Hatchery fish tended to be younger and return to lower areas of the watershed than wild fish, which explained some of their lower fitness.

scholarly journals Delivering Food to Hungry Fish in the San Francisco Estuary

2021 ◽  
Vol 9 ◽  
Author(s):  
Laura Twardochleb ◽  
Leela Dixit ◽  
Mallory Bedwell ◽  
Brittany Davis ◽  
Jared Frantzich
Keyword(s):  
Invasive Species ◽  
San Francisco ◽  
Fish Species ◽  
San Francisco Estuary ◽  
Fish Food ◽  
Yolo Bypass ◽  
Delta Smelt ◽  
Endangered Fish ◽  
The Past

The San Francisco Estuary is home to an important endangered fish called delta smelt. Delta smelt eat small, nutritious animals called zooplankton to survive and grow. In turn, zooplankton grow by eating microscopic plant-like organisms called phytoplankton. In the past, the Estuary was full of plankton and delta smelt. Because people have removed water from the Estuary and invasive species now live there, the Estuary no longer has enough plankton to feed delta smelt, making it difficult for them to survive. Scientists have found a unique place in the Estuary, the Yolo Bypass, that has lots of fish food. The problem is that delta smelt do not live in the Yolo Bypass year-round. Scientists are working to solve this problem by sending river or farm water through the Yolo Bypass, to move fish food downstream to feed the hungry delta smelt and other fish species.

Early Life History of Fishes in the San Francisco Estuary and Watershed

2004 ◽  
Keyword(s):  
San Francisco ◽  
Chinook Salmon ◽  
Reference Group ◽  
Central Valley ◽  
Study Groups ◽  
San Francisco Estuary ◽  
Study Group ◽  
First Feeding ◽  
Back Calculation ◽  
Juvenile Chinook

<em>Abstract.</em>—We compared two approaches to back-calculation with otolith microstructure to develop a method for accurately estimating growth rates of juvenile fall-run Chinook salmon <em>Oncorhynchus tshawytscha </em>in California’s Central Valley. Total otolith width was a strong determinant of fork length (FL) in linear regressions used to determine the <em>y</em>-intercept in the fish size–otolith size relationship in two study groups of Chinook salmon. The Fraser-Lee back-calculation model estimated FL at first feeding in both study groups that did not differ significantly from lengths of first-feeding Chinook salmon in a reference group. In comparison, the biological-intercept method produced back-calculated lengths that were significantly greater in one study group than lengths of first-feeding Chinook salmon in the reference group. Chinook salmon emergence dates, estimated from counts of daily growth increments beyond the first-feeding check, corresponded with observed emergence periods in the river and hatchery populations from which the study groups were sampled. Size-at-age relationships were well described by a power function in both study groups, where mean FL over time approached an apparent asymptote at approximately 80 mm after 90 d postemergence. Growth rate estimates, using back-calculated size from the Fraser-Lee model, averaged 0.50 mm/d in one study group and 0.43 mm/d in the other study group. These estimates fell within the range of previous growth rate estimates for juvenile Chinook salmon in Central Valley riverine, floodplain, and delta environments and were about 2.5 times higher on average than an estimate for the San Francisco Estuary and about 2.3 times lower on average than estimates from the Strait of Georgia. We discuss the utility of otolith microstructure to not only estimate growth rates, but also to reconstruct emergence-date distributions in cohorts of emigrating juvenile Chinook salmon for stock identification purposes.

scholarly journals Identifying the contribution of wild and hatchery Chinook salmon (Oncorhynchus tshawytscha) to the ocean fishery using otolith microstructure as natural tags

2007 ◽  
Vol 64 (12) ◽  
pp. 1683-1692 ◽  
Author(s):  
Rachel Barnett-Johnson ◽  
Churchill B Grimes ◽  
Chantell F Royer ◽  
Christopher J Donohoe
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Wild Fish ◽  
Otolith Microstructure ◽  
Exogenous Feeding ◽  
Daily Growth ◽  
Wild Salmon ◽  
Growth Increments ◽  
In The Wild ◽  
Mixed Stock

Quantifying the contribution of wild (naturally spawned) and hatchery Chinook salmon (Oncorhynchus tshawytscha) to the mixed-stock ocean fishery is critical to understanding their relative importance to the persistence of salmon stocks. The inability to distinguish hatchery and wild salmon has inhibited the detection of declines or recoveries for many wild populations. By using Chinook salmon of known hatchery and wild origin, we established a baseline for separating these two sources using otolith microstructure. Otoliths of wild salmon contained a distinct exogenous feeding check likely reflecting an abrupt transition in food resources from maternal yolk not experienced by fish reared in hatcheries. Daily growth increments in otoliths from hatchery salmon immediately after the onset of exogenous feeding were wider and more uniform in width than those in wild fish. The discriminant function that we used to distinguish individuals reared in hatcheries or in the wild was robust between years (1999 and 2002), life history stages (juveniles and adults), and geographic regions (California, British Columbia, and Alaska) and classified fish with ~91% accuracy. Results from our mixed-stock model estimated that the contribution of wild fish was 10% ± 6%, indicating hatchery supplementation may be playing a larger role in supporting the central California coastal fishery than previously assumed.

scholarly journals Optimizing an eDNA protocol for monitoring endangered Chinook Salmon in the San Francisco Estuary: balancing sensitivity, cost and time

2019 ◽  
Author(s):  
Thiago M. Sanches ◽  
Andrea M. Schreier
Keyword(s):  
Dna Extraction ◽  
San Francisco ◽  
Chinook Salmon ◽  
Magnetic Beads ◽  
Oncorhynchus Tshawytscha ◽  
Environmental Dna ◽  
San Francisco Estuary ◽  
Time Cost ◽  
Dna Yield ◽  
Pcr Inhibitor

AbstractEnvironmental DNA (eDNA) analysis has gained traction as a precise and cost effective method for species and waterways management. To date, publications on eDNA protocol optimization have focused primarily on DNA yield. Therefore, it has not been possible to evaluate the cost and speed of specific components of the eDNA protocol, such as water filtration and DNA extraction method when designing or choosing an eDNA pipeline. At the same time, these two parameters are essential for the experimental design of a project. Here we evaluate and rank different eDNA protocols in the context of Chinook salmon (Oncorhynchus tshawytscha) eDNA detection in an aquatic environment, the San Francisco Estuary. We present a comprehensive evaluation of multiple eDNA protocol parameters, balancing time, cost and DNA yield. For estuarine waters, which are challenging for eDNA studies due to high turbidity, variable salinity, and the presence of PCR inhibitors, we find that a protocol combining glass filters and magnetic beads, along with an extra step for PCR inhibitor removal, is the method that best balances time, cost, and yield. In addition, we provide a generalized decision tree for determining the optimal eDNA protocol for other studies on aquatic systems. Our findings should be applicable to most aquatic environments and provide a clear guide for determining which eDNA pipeline should be used for a given environmental condition.Author SummaryThe use of environmental DNA (eDNA) analysis for monitoring wildlife has steadily grown in recent years. Though, due to differences in the ecology of the environment studied and the novelty of the technique, eDNA currently shows a lack of standards compared to other fields. Here we take a deep look into each step of an eDNA assay, looking at common protocols and comparing their efficiencies in terms of time to process the samples, cost and how much DNA is recovered. We then analyze the data to provide a concise interpretation of best practices given different project constraints. For the conditions of the San Francisco Estuary we suggest the use of glass fiber filtration, the use of paramagnetic beads for DNA extraction and the use of a secondary inhibitor removal. We expect our findings to provide better support for managers to decide their standards ahead of project submission not only for estuarine conditions but for other waterine conditions alike.

Sign in / Sign up

Export Citation Format

Share Document