scholarly journals Alternative Juvenile Production Estimate (JPE) Forecast Approaches for Sacramento River Winter-Run Chinook Salmon

2018 ◽  
Vol 16 (4) ◽  
Author(s):  
Michael O'Farrell ◽  
William Satterthwaite ◽  
Albert Hendrix ◽  
Michael Mohr
Keyword(s):  
Chinook Salmon ◽  
Sacramento River ◽  
Alternative Methods ◽  
Point Estimate ◽  
Natural Origin ◽  
Production Estimate ◽  
Spawning Areas ◽  
The Status ◽  
Approach Method ◽  
Current Monitoring

Sacramento River winter-run Chinook salmon are listed under the Endangered Species Act as Endangered and there are substantial efforts to estimate, predict, and limit mortalities at various stages of their life cycle. One such effort is the annual forecast of the number of juvenile winter-run entering the Sacramento-San Joaquin Delta. The natural-origin Juvenile Production Estimate (JPE) is defined as the number of winter-run juveniles produced from natural spawning areas that enter the Delta, and its forecast is used to determine the allowable level of winter-run incidental take at the state and federal pumping facilities located in the south Delta. Current monitoring programs in the Sacramento Basin do not allow for direct estimation of the JPE and thus various methods have been used to forecast this value annually. Here we describe three alternative methods for forecasting the natural-origin JPE. The methods range from the status quo approach (Method 1), which expresses the JPE forecast only as a point estimate, to two other methods that account for forecast uncertainty to various degrees. A comparison of JPE forecasts for 2018 across the three methods indicates that relative to Method 1, Methods 2 and 3 result in lower JPE forecasts, by 24 and 18 percent, respectively, primarily owing to lower forecasts of the fry-to-smolt transition and the smolt survival rate occurring downstream of Red Bluff Diversion Dam. Because post-hoc estimates of juvenile winter-run abundance at the entrance to the Delta do not currently exist, we are unable to evaluate forecast skill among the three methods.

Viability of Sacramento River Winter-Run Chinook Salmon

1998 ◽  
Vol 12 (1) ◽  
pp. 65-79 ◽  
Author(s):  
Louis W. Botsford ◽  
John G. Brittnacher
Keyword(s):  
Chinook Salmon ◽  
Sacramento River

scholarly journals KAJIAN PERBANDINGAN DALAM PEMBAGIAN WARIS BERDASARKAN PADA HUKUM ISLAM DAN HUKUM ADAT

2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Anwar Hidayat ◽  
M. Gary Gagarin Akbar ◽  
Deny Guntara
Keyword(s):  
Property Rights ◽  
Research Method ◽  
Islamic Law ◽  
Customary Law ◽  
Inheritance Law ◽  
Hereditary System ◽  
The Family ◽  
The Status ◽  
Approach Method ◽  
The Subject

Abstrak Pemberlakuan aturan mengenai kewarisan di Indonesia selama ini terjadi perdebatan antara para ahli hukum tentang status hukum Islam dan hukum adat.Berkaitan dengan permasalahan dalam hukum waris pada hukum Islam dan hukum Adat, maka perlu adanya kesesuaian bagi masyarakat yang akan mempergunakan masing-masing hukum tersebut dalam menyelesaian warisannya kepada sang ahli waris yang berhak. Ketentuan hukum Islam di Indonesia belum merupakan undang-undang (kodifikasi) haruslah sistematis dan prosedural, harus jelas siapa subyek dan obyeknya dan diundangkan oleh lembaga yang berwenang dalam negara. Rumusan masalah dalam penelitian ini adalah bagaimana perbandingan dalam pembagian waris berdasarkan pada hukum islam dan hukum adat. Metode penelitian ini menggunakan metode kualitatif dengan metode pendekatan yuridis empiris. Hasil penelitian yaitu Hukum waris Islam telah menempatkan atauran kewarisan dan hukum mengenai harta benda dengan sebaik-baiknya dan seadil-adilnya. Islam menetapkan hak milik seseorang atas harta, baik bagi laki-laki maupun perempuan seperti perpindahan hak milik dan perempuan pada waktu masih hidup atau perpindahan harta kepada ahli warisnya setelah ia meninggal dunia. Hukum waris adat berpangkal dari bentuk masyarakat dan sifat kekeluargaan yang terdapat di Indonesia menurut sistem keturunan, dan setiap sistem keturunan yang ada mempunyai kekhususan dalam hukum waris yang satu dengan yang lain berbeda-beda. Kata Kunci:Waris, Hukum Islam, Hukum Adat Abstract The enactment of the rules regarding inheritance in Indonesia has been a debate between legal experts about the status of Islamic law and customary law. In connection with problems in inheritance law in Islamic law and Customary law, it is necessary for the community to use each of these laws in complete the inheritance to the rightful heirs. The provisions of Islamic law in Indonesia are not yet laws (codification) must be systematic and procedural, it must be clear who the subject and object are and are promulgated by the authorized institutions in the country. The formulation of the problem in this study is how comparisons in inheritance distribution are based on Islamic law and customary law. This research method uses qualitative methods with an empirical juridical approach method. The results of the research, namely Islamic inheritance law has placed the inheritance and law regarding property as well as possible and as fair as fair. Islam establishes someone's property rights, both for men and women, such as the transfer of property rights and women while still alive or the transfer of property to his heirs after he dies. The customary inheritance law stems from the form of the community and the family character found in Indonesia according to the hereditary system, and each of the offspring systems that have specific inheritance laws is different from one another Keyword: Inheritance, Islamic Law, Customary Law

scholarly journals Process-based model of fish incubation survival for designing reservoir operations: a case study for Sacramento River winter-run Chinook salmon

2020 ◽  
Author(s):  
James J. Anderson ◽  
W. Nicholas Beer ◽  
Joshua A. Israel ◽  
Sheila Greene
Keyword(s):  
Real Time ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Cold Water ◽  
Climatic Variability ◽  
Sacramento River ◽  
Reservoir Operations ◽  
Regulated Rivers ◽  
Egg Hatching ◽  
Critical Window

AbstractAllocating reservoir flows to meet societal and ecosystem needs under increasing demands for water and increasing climatic variability presents challenges to resource managers. Often, regulated rivers have been operated to meet flow and temperature compliance points that mimic historical patterns. Because it is difficult to assess if this approach is efficient or equitable, new more process-based approaches to regulation are being advanced. This paper describes such an approach with a model of egg incubation survival of Sacramento River winter-run Chinook salmon (SRWRC, Oncorhynchus tshawytscha). Thermal mortality only occurs in a critical window around egg hatching when the embryo is most sensitive to temperature stress. The duration of the critical window has significant implications for Shasta Reservoir operations that are designed to control temperature during SRWRC incubation. Previous operations sought to maintain a low temperature over the entire incubation period. However, model analysis suggests that targeting cold water directly to the critical egg hatching stage provides higher survival while requiring less cold water resources. The calibrated model is publicly accessible through a web interface connected to real-time river and fish databases and a river temperature forecast model. The system is an example of the next step of river management that integrates databases with hydrological and process-based biological models for real-time analysis and for forecasting effects of river operations on the environment.

Within-river straying: sex and size influence recovery location of hatchery Chinook salmon (Oncorhynchus tshawytscha)

2020 ◽  
Vol 77 (2) ◽  
pp. 226-235 ◽  
Author(s):  
Amanda M.M. Pollock ◽  
Maryam Kamran ◽  
Andrew H. Dittman ◽  
Marc A. Johnson ◽  
David L.G. Noakes
Keyword(s):  
River Basin ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Classification Tree ◽  
River System ◽  
Classification Tree Analysis ◽  
Spawning Grounds ◽  
Natural Origin ◽  
Elk River ◽  
In The Wild

Salmon straying is often defined as the failure of adults to return to their natal river system. However, straying within a river basin can be problematic if hatchery salmon do not return to their hatchery of origin and subsequently spawn in the wild with natural-origin salmon. We examined within-river straying patterns from 34 years of coded-wire tag data, representing 29 941 hatchery fall Chinook salmon (Oncorhynchus tshawytscha) in the Elk River, Oregon, USA. Using classification tree analysis, we found that females and larger salmon were more likely to be recovered on the spawning grounds than males and smaller fish. Females larger than 980 mm had a 51.6% likelihood of recovery on the spawning grounds rather than at the Elk River Hatchery. Our findings raise questions about the behavior of straying adults and implications for management of these stocks, with a focus on methods to reduce within-river straying. We recommend further studies to determine whether carcass recoveries are fully representative of hatchery salmon that stray within the Elk River basin.

In a warming river, natural-origin Chinook salmon spawn later but hatchery-origin conspecifics do not

2021 ◽  
Vol 78 (1) ◽  
pp. 68-77
Author(s):  
Catherine S. Austin ◽  
Timothy E. Essington ◽  
Thomas P. Quinn
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
River System ◽  
Local Environment ◽  
Washington State ◽  
Human Intervention ◽  
Timing Of Reproduction ◽  
Natural Origin ◽  
Skagit River

Median timing of reproduction in salmonid populations is generally consistent among years, reflecting long-term patterns of natural selection from characteristics of the local environment. However, altered selection from factors related to climate change or human intervention might shift timing over generations, with implications for the population’s persistence. To study these processes, we modeled median timing of redd (nest) counts as an index of spawning timing by natural-origin Chinook salmon (Oncorhynchus tshawytscha) in the Skagit River system in Washington State, USA. Over the last 2–6 decades, natural-origin salmon have been spawning later by 0.03–0.52 days·year–1, while a naturally spawning group that is influenced by strays from a hatchery has been spawning earlier by 0.19 days·year–1. Trends in the spawning timing of hatchery-origin strays may reflect opposing selection from the hatchery, where egg take for propagation has become earlier by 0.58 days·year–1. As mean August river temperatures have risen over the period of record, hatchery timing trends may be moving in the opposite direction from the plastic or adaptive patterns expressed by natural-origin fish.

Abundance and Distribution of Precociously Mature Male Spring Chinook Salmon of Hatchery and Natural Origin in the Yakima River

2009 ◽  
Vol 29 (3) ◽  
pp. 778-790 ◽  
Author(s):  
Todd N. Pearsons ◽  
Christopher L. Johnson ◽  
Brenda Ben James ◽  
Gabriel M. Temple
Keyword(s):  
Chinook Salmon ◽  
Mature Male ◽  
Natural Origin ◽  
Yakima River ◽  
Abundance And Distribution

Individual variation in dispersal behaviour of newly emerged chinook salmon (Oncorhynchus tshawytscha) from the Upper Fraser River, British Columbia

1997 ◽  
Vol 54 (7) ◽  
pp. 1585-1592 ◽  
Author(s):  
M J Bradford ◽  
G C Taylor
Keyword(s):  
British Columbia ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Population Variation ◽  
Fraser River ◽  
Movement Behaviour ◽  
Spawning Areas ◽  
Dispersal Distances ◽  
Stream Type ◽  
Downstream Movement

Immediately after emergence from spawning gravels, fry of stream-type chinook salmon (Oncorhynchus tshawytscha) populations from tributaries of the upper Fraser River, British Columbia, distribute themselves downstream from the spawning areas, throughout the natal stream, and into the Fraser River. We tested the hypothesis that this range in dispersal distances is caused by innate differences in nocturnal migratory tendency among individuals. Using an experimental stream channel, we found repeatable differences in downstream movement behaviour among newly emerged chinook fry. Fish that moved downstream were larger than those that held position in the channel. However, the incidence of downstream movement behaviours decreased over the first 2 weeks after emergence. We propose that the variation among individuals in downstream movement behaviour we observed leads to the dispersal of newly emerged fry throughout all available rearing habitats. Thus, between- and within-population variation in the freshwater life history observed in these populations may be caused by small differences in the behaviour of individuals.

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.

Comparison of Spawning Areas and Times for Two Runs of Chinook Salmon (Oncorhynchus tshawytscha) in the Kenai River, Alaska

1985 ◽  
Vol 42 (4) ◽  
pp. 693-700 ◽  
Author(s):  
Carl V. Burger ◽  
Richard L. Wilmot ◽  
David B. Wangaard
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Main Stem ◽  
Upstream Migration ◽  
Cook Inlet ◽  
Large Lakes ◽  
Spawning Areas ◽  
Winter Temperatures ◽  
Southcentral Alaska ◽  
Radio Transmitters

From 1979 to 1982,188 chinook salmon (Oncorhynchus tshawytscha) were tagged with radio transmitters to locate spawning areas in the glacial Kenai River, southcentral Alaska. Results confirmed that an early run entered the river in May and June and spawned in tributaries, and a late run entered the river from late June through August and spawned in the main stem. Spawning peaked during August in tributaries influenced by lakes, but during July in other tributaries. Lakes may have increased fall and winter temperatures of downstream waters, enabling successful reproduction for later spawning fish within these tributaries. This hypothesis assumes that hatching and emergence can be completed in a shorter time in lake-influenced waters. The time of upstream migration and spawning (mid- to late August) of the late run is unique among chinook stocks in Cook Inlet. This behavior may have developed only because two large lakes (Kenai and Skilak) directly influence the main-stem Kenai River. If run timing is genetically controlled, and if the various components of the two runs are isolated stocks that have adapted to predictable stream temperatures, there are implications for stock transplantation programs and for any activities of man that alter stream temperatures.

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