Size Selectivity of Coho (Oncorhynchus kisutch) Preying on Juvenile Chum Salmon (O. keta)

1986 ◽  
Vol 43 (3) ◽  
pp. 581-586 ◽  
Author(s):  
N. Brent Hargreaves ◽  
Robin J. LeBrasseur
Keyword(s):  
Chum Salmon ◽  
Prey Size ◽  
Pacific Salmon ◽  
Oncorhynchus Kisutch ◽  
Fork Length ◽  
Size Selectivity ◽  
Size Dependent ◽  
Juvenile Chum Salmon ◽  
Dependent Mortality

Predation may be a major source of size-dependent mortality of Pacific salmon (Oncorhynchus spp.) during early sea life. Our experiments conducted in large saltwater enclosures demonstrated that coho (Oncorhynchus kisutch) are size selective when preying on juvenile chum (O. keta) salmon. Yearling coho (112–130 mm fork length) consumed significantly more smaller chum over a range in prey size of 43–63 mm fork length. We hypothesize that the intensity of size selectivity by coho and other predators is variable, depending on the relative sizes of the predators and prey.

Estimation of Size Selectivity and Movement Rates from Mark–Recovery Data

1994 ◽  
Vol 51 (3) ◽  
pp. 734-742 ◽  
Author(s):  
Alejandro Anganuzzi ◽  
Ray Hilborn ◽  
John R. Skalski
Keyword(s):  
Mortality Rates ◽  
Fishing Mortality ◽  
Size Selectivity ◽  
Movement Rates ◽  
Return Rates ◽  
Size Dependent ◽  
Pacific Halibut ◽  
Hippoglossus Stenolepis ◽  
Time Specific ◽  
Dependent Mortality

Size selectivity, movement rates among spatial strata, and size-dependent mortality rates were estimated from mark–recovery data of Pacific halibut (Hippoglossus stenolepis). Growth rates, area- and time-specific fishing mortality on fully vulnerable individuals, and tag return rates were assumed known from other data. We obtained similar estimates from a model that considered movement to take place immediately after tagging and a model that assumed that movement takes place once each year. The inability to distinguish between one-time and annual movement is most likely due to the fact that tagged juveniles were not recovered until 3–5 yr later when they became vulnerable to the adult fishery.

Evidence of density- and size-dependent mortality in hatchery-reared juvenile white sturgeon (Acipenser transmontanus) in the Kootenai River

2009 ◽  
Vol 66 (5) ◽  
pp. 802-815 ◽  
Author(s):  
Casey Justice ◽  
Brian J. Pyper ◽  
Raymond C.P. Beamesderfer ◽  
Vaughn L. Paragamian ◽  
Pete J. Rust ◽  
...  
Keyword(s):  
Survival Rates ◽  
Negative Relationship ◽  
Fork Length ◽  
White Sturgeon ◽  
Acipenser Transmontanus ◽  
First Year ◽  
Small Fish ◽  
Size Dependent ◽  
Kootenai River ◽  
Dependent Mortality

We evaluated effects of stocking level and size-at-release on survival rates of hatchery-reared juvenile white sturgeon ( Acipenser transmontanus ) in the Kootenai River using Cormack–Jolly–Seber and related models implemented in Program MARK. A total of 119 768 marked and unmarked hatchery juveniles were released from 1992 to 2006, of which 2938 passive integrated transponder (PIT)-tagged fish were subsequently recaptured. Annual survival rates of marked groups ranged from 0.01 to 0.84 (mean = 0.45) during the first year at large, from 0.48 to 1.0 (mean = 0.84) in the second year, and averaged 1.0 during all subsequent years. First year survival rates declined substantially in recent years, particularly for small fish (<25 cm fork length). Approximately 59% of the variation in first year survival was explained by a negative relationship with estimated juvenile abundance (linear regression, P < 0.01). Length-at-release of individuals explained a substantial proportion of the within-year variation in survival during the first year at large. Our results provide strong evidence of density- and size-dependent mortality in hatchery-reared juvenile white sturgeon in the Kootenai River. Management actions that prioritize the release of fewer, larger-sized fish will likely improve first year survival rates and subsequent recruitment to the spawning-age population.

Timing and Relative Intensity of Size-Selective Mortality of Juvenile Chum Salmon (Oncorhynchus keta) During Early Sea Life

1982 ◽  
Vol 39 (7) ◽  
pp. 952-957 ◽  
Author(s):  
M. C. Healey
Keyword(s):  
Relative Intensity ◽  
Chum Salmon ◽  
Size Range ◽  
Fork Length ◽  
Open Water ◽  
Oncorhynchus Keta ◽  
Selective Mortality ◽  
Chum Salmon Oncorhynchus Keta ◽  
Time Period ◽  
Juvenile Chum Salmon

Available evidence indicates that mortality of juvenile salmon during early sea life is high and probably size dependent. I used scale analysis to determine the timing and relative intensity of size-selective mortality in chum salmon (Oncorhynchus keta) during early sea life. Significant size-selective mortality could be demonstrated only over the time period that the fish were laying down circuli 2–4 on their scales. The relative intensity of mortality for different sizes of fish suggested that mortality was strongly size selective over the size range 45–55 mm fork length. No particular mortality agent could be identified, but the size range involved corresponds with the size at which chum salmon move from very shallow water and nearshore habitat to open water pelagic habitat.Key words: size-selective mortality, salmon, early sea life

Marine survival of steelhead (Oncorhynchus mykiss) enhanced by a seasonally closed estuary

2008 ◽  
Vol 65 (10) ◽  
pp. 2242-2252 ◽  
Author(s):  
Morgan H. Bond ◽  
Sean A. Hayes ◽  
Chad V. Hanson ◽  
R. Bruce MacFarlane
Keyword(s):  
Oncorhynchus Mykiss ◽  
Growth Rates ◽  
Adult Population ◽  
Fork Length ◽  
High Growth ◽  
Population Persistence ◽  
Scale Morphology ◽  
Scale Analysis ◽  
Size Dependent ◽  
Dependent Mortality

To investigate the role that estuaries play in the survival of steelhead, Oncorhynchus mykiss , we compared juvenile size at ocean entry with back-calculated measures of size at ocean entry for returning adults in Scott Creek, a representative California coastal stream. During the annual spring emigration, the largest smolts (>150 mm fork length (FL)) move directly to sea, while some smaller smolts remain in the estuary until sandbar formation creates a closed freshwater lagoon. High growth rates in the estuary throughout the summer result in a near doubling of fork length from the time of estuary entry (mean FL of spring migrants = 102.2 mm; mean FL of fall lagoon resident = 195.9 mm). Analysis of the scale morphology of returning adult steelhead indicates that there is strong size-dependent mortality at sea, with estuary-reared steelhead showing a large survival advantage, comprising between 87% and 95.5% (based on tag returns and scale analysis, respectively) of the returning adult population despite being between 8% and 48% of the annual downstream migrating population. Although the estuary forms less than 5% of the watershed area, it is critical nursery habitat, and steelhead population persistence in southern margin ecosystems may well depend upon healthy estuaries.

Temporary Residence by Juvenile Salmon in a Restored Estuarine Wetland

1990 ◽  
Vol 47 (11) ◽  
pp. 2079-2084 ◽  
Author(s):  
David K. Shreffler ◽  
Charles A. Simenstad ◽  
Ronald M. Thom
Keyword(s):  
Chinook Salmon ◽  
Chum Salmon ◽  
Pacific Salmon ◽  
River Estuary ◽  
Oncorhynchus Keta ◽  
Juvenile Chinook Salmon ◽  
Juvenile Pacific Salmon ◽  
Juvenile Chum Salmon ◽  
Juvenile Chinook ◽  
Wetland System

Juvenile Pacific salmon utilizing the recently restored Lincoln Avenue wetland system in the Puyallup River estuary, Tacoma, Washington, were studied during their spring seaward migration in 1987 and 1988. Mark/recapture experiments indicated that 0.06% of the outmigrating juvenile chum salmon (Oncorhynchus keta) and 0.59% of the outmigrating juvenile chinook salmon (O. tshawytscha) entered the wetland. Estimated residence times of individual juvenile chum salmon averaged approximately 2 d (range 1–9 d) and juvenile chinook salmon approximately 5 d (volitional) and 38 d (spray-marked) (total range 1–43 d). The restored wetland system currently provides habitat for the temporary residence of migrating juvenile chum and fall chinook salmon, but rigorous evaluation of the benefit of residency is constrained by the lack of data from comparable natural wetlands.

The U‐shaped pattern of size‐dependent mortality and its correlated factors in a subtropical monsoon evergreen forest

2021 ◽  
Author(s):  
Ruiling Lu ◽  
Yang Qiao ◽  
Jing Wang ◽  
Chen Zhu ◽  
Erqian Cui ◽  
...  
Keyword(s):  
Evergreen Forest ◽  
Size Dependent ◽  
Correlated Factors ◽  
Shaped Pattern ◽  
Dependent Mortality

scholarly journals Evidence for Freshwater Residualism in Coho Salmon, Oncorhynchus kisutch, From a Watershed on the North Coast of British Columbia

2017 ◽  
Vol 130 (4) ◽  
pp. 336 ◽  
Author(s):  
Eric A Parkinson ◽  
Chris J Perrin ◽  
Daniel Ramos-Espinoza ◽  
Eric B Taylor
Keyword(s):  
British Columbia ◽  
Fresh Water ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Oncorhynchus Kisutch ◽  
Water Levels ◽  
North Coast ◽  
The North ◽  
Seaward Migration ◽  
Mature Fish

The Coho Salmon, Oncorhynchus kisutch, is one of seven species of Pacific salmon and trout native to northeastern Pacific Ocean watersheds. The species is typically anadromous; adults reproduce in fresh water where juveniles reside for 1–2 years before seaward migration after which the majority of growth occurs in the ocean before maturation at 2–4 years old when adults return to fresh water to spawn. Here, we report maturation of Coho Salmon in two freshwater lakes on the north coast of British Columbia apparently without their being to sea. A total of 15 mature fish (11 males and four females) were collected in two lakes across two years. The mature fish were all at least 29 cm in total length and ranged in age from three to five years old. The occurrence of Coho Salmon that have matured in fresh water without first going to sea is exceedingly rare in their natural range, especially for females. Such mature Coho Salmon may represent residual and distinct breeding populations from those in adjacent streams. Alternatively, they may result from the ephemeral restriction in the opportunity to migrate seaward owing to low water levels in the spring when Coho Salmon typically migrate to sea after 1–2 years in fresh water. Regardless of their origin, the ability to mature in fresh water without seaward migration may represent important adaptive life history plasticity in response to variable environments.

scholarly journals Neural Stem Cells/Neuronal Precursor Cells and Postmitotic Neuroblasts in Constitutive Neurogenesis and After ,Traumatic Injury to the Mesencephalic Tegmentum of Juvenile Chum Salmon, Oncorhynchus keta

2020 ◽  
Vol 10 (2) ◽  
pp. 65
Author(s):  
Pushchina ◽  
Kapustyanov ◽  
Varaksin
Keyword(s):  
Stem Cells ◽  
Neural Stem Cells ◽  
Progenitor Cells ◽  
Chum Salmon ◽  
Precursor Cells ◽  
Oncorhynchus Keta ◽  
Neuronal Precursor ◽  
Chum Salmon Oncorhynchus Keta ◽  
Neuronal Precursor Cells ◽  
Juvenile Chum Salmon

The proliferation of neural stem cells (NSCs)/neuronal precursor cells (NPCs) and the occurrence of postmitotic neuroblasts in the mesencephalic tegmentum of intact juvenile chum salmon, Oncorhynchus keta, and at 3 days after a tegmental injury, were studied by immunohistochemical labeling. BrdU+ constitutive progenitor cells located both in the periventricular matrix zone and in deeper subventricular and parenchymal layers of the brain are revealed in the tegmentum of juvenile chum salmon. As a result of traumatic damage to the tegmentum, the proliferation of resident progenitor cells of the neuroepithelial type increases. Nestin-positive and vimentin-positive NPCs and granules located in the periventricular and subventricular matrix zones, as well as in the parenchymal regions of the tegmentum, are revealed in the mesencephalic tegmentum of juvenile chum salmon, which indicates a high level of constructive metabolism and constitutive neurogenesis. The expression of vimentin and nestin in the extracellular space, as well as additionally in the NSCs and NPCs of the neuroepithelial phenotype, which do not express nestin in the control animals, is enhanced during the traumatic process. As a result of the proliferation of such cells in the post-traumatic period, local Nes+ and Vim+ NPCs clusters are formed and become involved in the reparative response. Along with the primary traumatic lesion, which coincides with the injury zone, additional Nes+ and Vim+ secondary lesions are observed to form in the adjacent subventricular and parenchymal zones of the tegmentum. In the lateral tegmentum, the number of doublecortin-positive cells is higher compared to that in the medial tegmentum, which determines the different intensities and rates of neuronal differentiation in the sensory and motor regions of the tegmentum, respectively. In periventricular regions remote from the injury, the expression of doublecortin in single cells and their groups significantly increases compared to that in the damage zone.

Growth rate characteristics of juvenile chum salmon Oncorhynchus keta originating from the Pacific coast of Japan and reaching Konbumori, eastern Hokkaido

2017 ◽  
Vol 83 (6) ◽  
pp. 987-996 ◽  
Author(s):  
Kentaro Honda ◽  
Tatsuya Kawakami ◽  
Kengo Suzuki ◽  
Kyuji Watanabe ◽  
Toshihiko Saito
Keyword(s):  
Growth Rate ◽  
Chum Salmon ◽  
Pacific Coast ◽  
Oncorhynchus Keta ◽  
Chum Salmon Oncorhynchus Keta ◽  
The Pacific ◽  
Juvenile Chum Salmon ◽  
Pacific Coast Of Japan
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