scholarly journals Growth of chum salmon (Oncorhynchus keta) correlated with sea-surface salinity in the North Pacific

2001 ◽  
Vol 58 (6) ◽  
pp. 1335-1339 ◽  
Author(s):  
S Morita
Keyword(s):  
North Pacific ◽  
Chum Salmon ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Oncorhynchus Keta ◽  
Surface Salinity ◽  
Chum Salmon Oncorhynchus Keta ◽  
The North ◽  
The North Pacific

scholarly journals Estimating temporal and spatial variation of ocean surface <i>p</i>CO<sub>2</sub> in the North Pacific using a self-organizing map neural network technique

2013 ◽  
Vol 10 (9) ◽  
pp. 6093-6106 ◽  
Author(s):  
S. Nakaoka ◽  
M. Telszewski ◽  
Y. Nojiri ◽  
S. Yasunaka ◽  
C. Miyazaki ◽  
...  
Keyword(s):  
Neural Network ◽  
North Pacific ◽  
Mixed Layer Depth ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Self Organizing Map ◽  
Surface Salinity ◽  
The North ◽  
The North Pacific ◽  
Self Organizing

Abstract. This study uses a neural network technique to produce maps of the partial pressure of oceanic carbon dioxide (pCO2sea) in the North Pacific on a 0.25° latitude × 0.25° longitude grid from 2002 to 2008. The pCO2sea distribution was computed using a self-organizing map (SOM) originally utilized to map the pCO2sea in the North Atlantic. Four proxy parameters – sea surface temperature (SST), mixed layer depth, chlorophyll a concentration, and sea surface salinity (SSS) – are used during the training phase to enable the network to resolve the nonlinear relationships between the pCO2sea distribution and biogeochemistry of the basin. The observed pCO2sea data were obtained from an extensive dataset generated by the volunteer observation ship program operated by the National Institute for Environmental Studies (NIES). The reconstructed pCO2sea values agreed well with the pCO2sea measurements, with the root-mean-square error ranging from 17.6 μatm (for the NIES dataset used in the SOM) to 20.2 μatm (for independent dataset). We confirmed that the pCO2sea estimates could be improved by including SSS as one of the training parameters and by taking into account secular increases of pCO2sea that have tracked increases in atmospheric CO2. Estimated pCO2sea values accurately reproduced pCO2sea data at several time series locations in the North Pacific. The distributions of pCO2sea revealed by 7 yr averaged monthly pCO2sea maps were similar to Lamont-Doherty Earth Observatory pCO2sea climatology, allowing, however, for a more detailed analysis of biogeochemical conditions. The distributions of pCO2sea anomalies over the North Pacific during the winter clearly showed regional contrasts between El Niño and La Niña years related to changes of SST and vertical mixing.

scholarly journals Genetic Identification of the North Pacific Chum Salmon (Oncorhynchus keta) Stocks

2003 ◽  
Vol 36 (6) ◽  
pp. 578-585
Author(s):  
Woongsic JUNG ◽  
Youn-Ho LEE ◽  
Suam KIM ◽  
Deuk-Hee JIN ◽  
Ki Baek SEONG
Keyword(s):  
North Pacific ◽  
Chum Salmon ◽  
Genetic Identification ◽  
Oncorhynchus Keta ◽  
Chum Salmon Oncorhynchus Keta ◽  
The North ◽  
The North Pacific

Recent Changes in Age and Size of Chum Salmon (Oncorhynchus keta) in the North Pacific Ocean and Possible Causes

1993 ◽  
Vol 50 (2) ◽  
pp. 290-295 ◽  
Author(s):  
Yukimasa Ishida ◽  
Soto-o Ito ◽  
Masahide Kaeriyama ◽  
Skip McKinnell ◽  
Kazuya Nagasawa
Keyword(s):  
Body Weight ◽  
Pacific Ocean ◽  
North Pacific ◽  
Chum Salmon ◽  
North Pacific Ocean ◽  
Oncorhynchus Keta ◽  
Chum Salmon Oncorhynchus Keta ◽  
The North ◽  
Mean Width ◽  
The North Pacific

Changes in age composition and size of adult chum salmon (Oncorhynchus keta) from rivers in Japan, Russia, and Canada were examined based on body weight and scale measurement data collected from 1953 to 1988. A significant increase in mean age was found in Japanese and Russian stocks after 1970 when the number of Japanese chum salmon began to increase exponentially, but not in the Canadian stock. Significant decreases in mean body weight, mean scale radius, and mean width of the third-year zones of age 4 chum salmon also occurred in Japanese and Russian stocks after 1970. Based on the Japanese salmon research vessel data from 1972 to 1988, significant negative relationships between catch-per-unit-effort and mean body weight of chum salmon were observed in summer in the central North Pacific Ocean where the distribution of Japanese and Russian stocks overlaps. These results suggest that density dependence is one of the possible causes for the recent changes in age and size of chum salmon in the North Pacific Ocean.

scholarly journals Estimating temporal and spatial variation of ocean surface <i>p</i>CO<sub>2</sub> in the North Pacific using a Self Organizing Map neural network technique

2013 ◽  
Vol 10 (3) ◽  
pp. 4575-4610 ◽  
Author(s):  
S. Nakaoka ◽  
M. Telszewski ◽  
Y. Nojiri ◽  
S. Yasunaka ◽  
C. Miyazaki ◽  
...  
Keyword(s):  
Neural Network ◽  
North Pacific ◽  
Mixed Layer Depth ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Self Organizing Map ◽  
Surface Salinity ◽  
The North ◽  
The North Pacific ◽  
Self Organizing

Abstract. This study produced maps of the partial pressure of oceanic carbon dioxide (pCO2sea) in the North Pacific on a 0.25° latitude × 0.25° longitude grid from 2002 to 2008. The pCO2sea values were estimated by using a self-organizing map neural network technique to explain the non-linear relationships between observed pCO2sea data and four oceanic parameters: sea surface temperature (SST), mixed layer depth, chlorophyll a concentration, and sea surface salinity (SSS). The observed pCO2sea data was obtained from an extensive dataset generated by the volunteer observation ship program operated by the National Institute for Environmental Studies. The reconstructed pCO2sea values agreed rather well with the pCO2sea measurements, the root mean square error being 17.6 μatm. The pCO2sea estimates were improved by including SSS as one of the training parameters and by taking into account secular increases of pCO2sea that have tracked increases in atmospheric CO2. Estimated pCO2sea values accurately reproduced pCO2sea data at several stations in the North Pacific. The distributions of pCO2sea revealed by seven-year averaged monthly pCO2sea maps were similar to Lamont-Doherty Earth Observatory pCO2sea climatology and more precisely reflected oceanic conditions. The distributions of pCO2sea anomalies over the North Pacific during the winter clearly showed regional contrasts between El Niño and La Niña years related to changes of SST and vertical mixing.

Mechanism and Occurrence of Focal Scale Resorption among Chum Salmon (Oncorhynchus keta) of the North Pacific Ocean

1989 ◽  
Vol 46 (7) ◽  
pp. 1147-1153 ◽  
Author(s):  
Brian Bigler
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
Chum Salmon ◽  
North Pacific Ocean ◽  
Puget Sound ◽  
Oncorhynchus Keta ◽  
Chum Salmon Oncorhynchus Keta ◽  
The North ◽  
Scale Characteristic ◽  
The North Pacific

A recently documented scale characteristic of chum salmon (Oncorhynchus keta) originating from Hokkaido, Japan, has been found distributed almost exclusively among stocks of Asian origin. Scales from 10 544 chum salmon collected from 25 near-shore locations throughout the North Pacific Ocean were examined. Resorption of the scale focus, including instances where an easily visible hole had been formed, was found among 10.8% of Japanese chum salmon and 15.9% of chum salmon originating from the Soviet Union. In North America, this trait was infrequent (< 0.5%) among populations north of the Aleutian Islands, British Columbia, and Puget Sound, and was not found in Cook Inlet, Prince William Sound, and Southeast Alaska. Focal scale resorption arises from osteoclastic cellular activity, most likely following the first winter of life, and remains as a permanent mark thereafter. This unique, uniformly occurring, easily identifiable scale characteristic will provide a valuable tool for stock identification. Evidence of focal scale resorption is also reported in sockeye (O. nerka), coho (O. kisutch), and king salmon (O. tshawytscha), but was not found in pink salmon (O. gorbuscha), sampled from locations in Alaska.

Change in the Known Ocean Distribution of Japanese Chum Salmon, Oncorhynchus keta, in Relation to the Progress of Stock Enhancement

1994 ◽  
Vol 51 (3) ◽  
pp. 501-505 ◽  
Author(s):  
Miki Ogura ◽  
Soto-o Ito
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
Chum Salmon ◽  
North Pacific Ocean ◽  
Stock Enhancement ◽  
Distribution Area ◽  
Oncorhynchus Keta ◽  
Chum Salmon Oncorhynchus Keta ◽  
The North ◽  
The North Pacific

New information on the ocean distribution of maturing Japanese chum salmon, Oncorhynchus keta, based on offshore tagging experiments conducted from 1956 to 1991 is summarized. Of 138 039 chum released in the North Pacific Ocean and its adjacent seas, 663 fish were recovered along the Japanese coast in the year of tagging and up to March of the next year. The distribution area of maturing Japanese chum indicated by these tag recoveries extended much further south and west than shown in previous studies. The central and western North Pacific Ocean now form important parts of the range. We conclude that extensive stock enhancement of chum in Japan is associated with enlargement of the known distribution area of maturing Japanese chum in the North Pacific Ocean.

Population Structure and Identification of North Pacific Ocean Chum Salmon (Oncorhynchus keta) Revealed by an Analysis of Minisateliite DNA Variation

1994 ◽  
Vol 51 (6) ◽  
pp. 1430-1442 ◽  
Author(s):  
Eric B. Taylor ◽  
Terry D. Beacham ◽  
Masahide Kaeriyama
Keyword(s):  
Population Structure ◽  
Pacific Ocean ◽  
North Pacific ◽  
Chum Salmon ◽  
North Pacific Ocean ◽  
Oncorhynchus Keta ◽  
The North ◽  
Yukon River ◽  
Regional Population ◽  
The North Pacific

We examined geographic variability in minisatellite DNA in chum salmon (Oncorhynchus keta) from 42 populations from the North Pacific Ocean to (1) determine the extent of regional population structure at minisatellite loci and (2) assess the ability of minisatellite variability to determine the geographic origin in individual chum salmon. Restriction fragments from 1.6 to 13.6 kilobase pairs in molecular weight were resolved with a minisatellite probe. The fragments were inherited from parent to offspring and appeared to represent segregation at two linked loci. Minisateliite DNA variability was negligible between annual samples from the same rivers, and chum salmon fell into three regional population groupings: (i) Japanese, (ii) Russian/Yukon River, and (iii) southeastern Alaska/British Columbia salmon. These regional groupings probably reflect historical patterns of postglacial dispersal of chum salmon from three distinct refugia in the North Pacific. We used restriction fragment counts as input to linear discriminant and neural network classification of independent test samples of salmon. Accuracies of 90–95, 81–86, and 72–80% were achieved when classifying fish as of either Japan/Russia/Yukon River versus southeastern Alaska/British Columbia origin, Japan versus Russia/Yukon River origin, or Russia versus Yukon River origin, respectively.

Sign in / Sign up

Export Citation Format

Share Document