Estuarine influence on survival rates of coho (Oncorhynchus kisutch) and chinook salmon (Oncorhynchus tshawytscha) released from hatcheries on the U.S. Pacific coast

Estuaries ◽  
2003 ◽  
Vol 26 (4) ◽  
pp. 1094-1103 ◽  
Author(s):  
A. Magnusson ◽  
R. Hilborn
Keyword(s):  
Chinook Salmon ◽  
Pacific Coast ◽  
Oncorhynchus Tshawytscha ◽  
Survival Rates ◽  
Oncorhynchus Kisutch ◽  
The U.S

Estimating season-wide survival rates of outmigrating salmon smolt in the Snake River, Washington

1998 ◽  
Vol 55 (3) ◽  
pp. 761-769 ◽  
Author(s):  
John R Skalski
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Survival Rates ◽  
Columbia River Basin ◽  
Good Precision ◽  
Sample Size Calculations ◽  
Daily Sampling ◽  
Fish Tagging ◽  
Salmon Smolt ◽  
Careful Management

Standard release-recapture models can provide release-specific estimates of survival probabilities for a group of salmonid smolt released at a particular time and place in the river. However, reliable estimates of season-wide survival for the population of outmigrating smolt are needed in the Snake-Columbia River Basin for careful management of the resource. Alternative estimators are presented to estimate season-wide survival of spring chinook salmon (Oncorhynchus tshawytscha) smolt. Using daily fish tagging, survival for the middle 95% of the migration was estimated to be SS = 0.873 (SE = 0.005) from the tailrace of Lower Granite Dam (RK 695) to the tailrace of Little Goose Dam (RK 635) in 1995. Daily survival estimates were remarkably stable across the migration season with some evidence of decreased survival towards the very end of the migration. Sample size calculations suggest good precision can be attained (i.e., projected SE = 0.01) with tag releases as small as n = 500 fish per day (d = 7) across the outmigration. Less than daily sampling can result in season-wide survival estimates that are too imprecise for many management purposes.

Fry-to-adult survival of natural and hatchery-produced chinook salmon (Oncorhynchus tshawytscha) from a common origin

1997 ◽  
Vol 54 (6) ◽  
pp. 1246-1254 ◽  
Author(s):  
M J Unwin
Keyword(s):  
New Zealand ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Survival Rates ◽  
Adult Survival ◽  
Poor Survival ◽  
Stock Size ◽  
Hatchery Fish ◽  
Stock Recruitment

Fry-to-adult survival rates for chinook salmon (Oncorhynchus tshawytscha) from Glenariffe Stream, a tributary of the Rakaia River, New Zealand, were estimated for fish of both natural and hatchery origin. Survival of naturally produced fry, most of which leave Glenariffe Stream within 24 h of emergence, averaged 0.079% (range 0.013-1.17%). For hatchery fish released at 8-12 months, standardised to a mean weight of 38 g, survival covaried with weight at release consistently across all brood years and averaged 0.34% (range 0.008-3.28%). Survival rates for hatchery fish were four times higher than for naturally produced fry, but were extremely poor relative to their size at release. Survival rates for fish of natural and hatchery origin were positively correlated, suggesting that recruitment of both stocks is primarily controlled by common influences within the marine environment, probably during the first winter at sea. Stock-recruitment analysis for the natural population showed little tendency for recruitment to increase with stock size, suggesting that marine survival rates may be density dependent. Although the reasons for the relatively poor survival of hatchery fish are unclear, the results provide a case study in which hatchery fish appear to have a poorer ``fitness to survive'' than their natural counterparts.

scholarly journals Spatial and temporal covariability in early ocean survival of Chinook salmon (Oncorhynchus tshawytscha) along the west coast of North America

2014 ◽  
Vol 71 (7) ◽  
pp. 1671-1682 ◽  
Author(s):  
D. Patrick Kilduff ◽  
Louis W. Botsford ◽  
Steven L. H. Teo
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Survival Rates ◽  
Central Valley ◽  
Vancouver Island ◽  
Regional Patterns ◽  
Migration Patterns ◽  
The Pacific ◽  
Spatial Coverage ◽  
Correlation Scale

Abstract Knowledge of the spatial and temporal extent of covariation in survival during the critical ocean entry stage will improve our understanding of how changing ocean conditions influence salmon productivity and management. We used data from the Pacific coastwide coded-wire tagging program to investigate local and regional patterns of ocean survival of Chinook salmon (Oncorhynchus tshawytscha) from the Central Valley of California to southeastern Alaska from 1980–2006. Ocean survival of fish migrating as subyearlings covaried strongly from Vancouver Island to California. Short-term correlations between adjacent regions indicated this covariability increased, beginning in the early 1990s. Chinook salmon survivals exhibited a larger spatial scale of variability (50% correlation scale: 706 km) than those reported for other northeast Pacific Ocean salmon. This scale is similar to that of environmental variables related to ecosystem productivity, such as summer upwelling (50% correlation scale: 746 km) and sea surface temperature (50% correlation scale: 500–600 km). Chinook salmon ocean survival rates from southeastern Alaska and south of Vancouver Island were not inversely correlated, in contrast to earlier observations based on catch data, but note that our data differ in temporal and spatial coverage from those studies. The increased covariability in Chinook salmon ocean survival suggests that the marine phase contributes little to the reduction in risk across populations attributable to the portfolio effect. In addition, survival of fish migrating as yearlings from the Columbia River covaried with Chinook salmon survival from the northernmost regions, consistent with our understanding of their migration patterns.

Contrasting patterns of productivity and survival rates for stream-type chinook salmon (Oncorhynchus tshawytscha) populations of the Snake and Columbia rivers

1999 ◽  
Vol 56 (6) ◽  
pp. 1031-1045 ◽  
Author(s):  
Howard A Schaller ◽  
Charles E Petrosky ◽  
Olaf P Langness
Keyword(s):  
Chinook Salmon ◽  
Physical Environment ◽  
Oncorhynchus Tshawytscha ◽  
Survival Rates ◽  
Temporal And Spatial Patterns ◽  
Hydropower System ◽  
Temporal And Spatial ◽  
Changes Over Time ◽  
Stream Type ◽  
Over Time

The effects of increasing hydropower development and operation appear extremely important in the decline and near extripation of stream-type chinook salmon (Oncorhynchus tshawytscha) stocks of the upper Columbia and Snake rivers. We evaluated temporal and spatial patterns of productivity and survival rates (for index stocks from the Snake, upper Columbia, and lower Columbia regions) to determine the cause of dramatic declines of the upriver stocks. This evaluation tested hypotheses about nonstationarity (changes over time in average productivity) in the Ricker recruitment function caused by changes in the physical environment. Individual stocks showed recent declines in indicators of productivity and survival rate; however, the comparisons indicate that upriver stocks showed greater declines coincident with the development and operation of the hydropower system. Evidence from the aggregate run indicates that declines over the last 50 years were quite abrupt and corresponded to construction and completion of the hydropower system.

The Harmful Phytoplankter Chaetoceros concavicornis Causes High Mortalities and Leucopenia in Chinook Salmon (Oncorhynchus tshawytscha) and Coho Salmon (O. kisutch)

1994 ◽  
Vol 51 (11) ◽  
pp. 2493-2500 ◽  
Author(s):  
C. Z. Yang ◽  
L. J. Albright
Keyword(s):  
Immune System ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Coho Salmon ◽  
Oncorhynchus Kisutch ◽  
Goblet Cells ◽  
Mortality Rates

Chaetoceros concavicornis is a harmful phytoplankter that occurs in many temperate coastal seawaters and can cause fin fish mortalities when present at concentrations as low as 5 cells∙mL−1. At even lower concentrations, this diatom can stress salmonids to such an extent that they may express a disease to which they are most prone at the time of C. concavicornis exposure. We report mortality rates of coho salmon (Oncorhynchus kisutch) and chinook salmon (O. tshawytscha) exposed to different concentrations of C. concavicornis. Our data indicate that in the presence of harmful concentrations of C. concavicornis, blood hematocrit and erythrocyte, glucose, and lactate concentrations of yearling chinook salmon (O. tshawytscha) increase. The microridges of the primary lamellae decreased in prominence in the presence of harmful concentrations of this phytoplankter, while the goblet cells became more prominent and more numerous. Neutrophil, lymphocyte, and thrombocyte concentrations in the blood became depleted. These data suggest that suppression of a portion of the Chinook's immune system is occurring which may partially explain the earlier observation that salmonids cultured in the presence of harmful C. concavicornis phytoplankton became more susceptible to disease, including Vibrio infections.

Sign in / Sign up

Export Citation Format

Share Document