scholarly journals Shifting-balance stock structure in North Pacific walleye pollock (Gadus chalcogrammus)

2010 ◽  
Vol 67 (8) ◽  
pp. 1687-1696 ◽  
Author(s):  
W. Stewart Grant ◽  
Ingrid Spies ◽  
Michael F. Canino
Keyword(s):  
Gene Flow ◽  
North Pacific ◽  
Puget Sound ◽  
Walleye Pollock ◽  
Ice Age ◽  
Stock Structure ◽  
Long Distance ◽  
The North ◽  
Shifting Balance ◽  
The North Pacific

Abstract Grant, W. S., Spies, I., and Canino, M. F. 2010. Shifting-balance stock structure in North Pacific walleye pollock (Gadus chalcogrammus). – ICES Journal of Marine Science, 67: 1687–1696. High levels of gene flow are expected to produce genetic homogeneity among open-ocean populations of walleye pollock (Gadus chalcogrammus) because of few restrictions on migration. Although most genetic studies confirm this prediction, many surveys of morphology have detected differences among populations. Here, sequences of mitochondrial DNA cytochrome oxidase subunit I in nine samples (n = 433) from Japan to Puget Sound were used to evaluate genetic population structure. Two haplotypes varied clinally across the North Pacific. These clines are likely the result of the isolation of populations in ice-age refugia, secondary post-glacial contact, and restricted long-distance dispersal. Overall, ΦST = 0.030 (p < 0.001), but the greatest partition was attributable to differences between Asian and North American populations (ΦCT = 0.058, p = 0.036). Isolation by distance was detected across the North Pacific, but differentiation among populations within regions was minimal (ΦSC = 0.007, p < 0.092). Climate variability on decadal–centennial scales produces shifts in local abundance, which prevent the appearance of genetically discrete stocks. These cycles of boom and bust, combined with high levels of gene flow, lead to different stock structures, as viewed with morphological, life history, and genetic markers.

scholarly journals California Central Valley Summer Heat Waves Form Two Ways*

2016 ◽  
Vol 29 (3) ◽  
pp. 1201-1217 ◽  
Author(s):  
Yun-Young Lee ◽  
Richard Grotjahn
Keyword(s):  
North Pacific ◽  
Heat Waves ◽  
Central Valley ◽  
Maximum Temperature ◽  
Northern California ◽  
Long Distance ◽  
The West ◽  
California Coast ◽  
The North ◽  
The North Pacific

Abstract California Central Valley (CCV) heat waves are grouped into two types based on the temporal and spatial evolution of the large-scale meteorological patterns (LSMPs) prior to onset. The k-means clustering of key features in the anomalous temperature and zonal wind identifies the two groups. Composite analyses show different evolution prior to developing a similar ridge–trough–ridge pattern spanning the North Pacific at the onset of CCV hot spells. Backward trajectories show adiabatic heating of air enhanced by anomalous sinking plus horizontal advection as the main mechanisms to create hot lower-tropospheric air just off the Northern California coast, although the paths differ between clusters. The first cluster develops the ridge at the west coast on the day before onset, consistent with wave activity flux traveling across the North Pacific. Air parcels that arrive at the maximum temperature anomaly (just off the Northern California coast) tend to travel a long distance across the Pacific from the west. The second cluster has the ridge in place for several days prior to extreme CCV heat, but this ridge is located farther north, with heat anomaly over the northwestern United States. This ridge expands south as air parcels at midtropospheric levels descend from the northwest while lower-level parcels over land tend to bring hot air from directions ranging from the hot area to the northeast to the desert areas to the southeast. These two types reveal unexpected dynamical complexity, hint at different remote associations, and expand the assessment needed of climate models’ simulations of these heat waves.

scholarly journals Genetic analysis of stock structure of blue shark (Prionace glauca) in the north Pacific ocean

2015 ◽  
Vol 172 ◽  
pp. 181-189 ◽  
Author(s):  
J.R. King ◽  
M. Wetklo ◽  
J. Supernault ◽  
M. Taguchi ◽  
K. Yokawa ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Genetic Analysis ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Stock Structure ◽  
Blue Shark ◽  
Prionace Glauca ◽  
The North ◽  
The North Pacific

scholarly journals Do Pacific cod (Gadus macrocephalus) and walleye pollock (Theregra chalcogramma) lack a herding response to the doors, bridles, and mudclouds of survey trawls?

2004 ◽  
Vol 61 (7) ◽  
pp. 1186-1189 ◽  
Author(s):  
David A. Somerton
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Walleye Pollock ◽  
Pacific Cod ◽  
The North ◽  
Pacific Cod Gadus Macrocephalus ◽  
Gadus Macrocephalus ◽  
The North Pacific ◽  
Trawl Surveys

Abstract Pacific cod and walleye pollock were subjected to herding experiments in which trawl hauls are conducted repeatedly in an area with the bridles varied among three distinct lengths. For the flatfishes in these studies, catch per unit of area swept (cpue) by the trawls increased greatly with increasing bridle length, indicating that flatfish are stimulated to herd into the path of the net by the action of the bridles. In contrast, the cpue of Pacific cod and walleye pollock did not increase significantly with increasing bridle length. This lack of significance indicates that these two species respond only weakly to any herding stimuli produced by the 83–112 Eastern and Poly Nor'eastern trawls used to conduct groundfish trawl surveys in the North Pacific Ocean.

scholarly journals Mitochondrial DNA Suggests High Gene Flow in Ancient Murrelets

The Condor ◽  
2002 ◽  
Vol 104 (1) ◽  
pp. 84-91 ◽  
Author(s):  
Rebecca L. Pearce ◽  
Jesse J. Wood ◽  
Yuri Artukhin ◽  
Timothy P. Birt ◽  
Martin Damus ◽  
...  
Keyword(s):  
British Columbia ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
North Pacific ◽  
Mitochondrial Control Region ◽  
Female Population ◽  
The North ◽  
Effective Female Population Size ◽  
High Gene ◽  
The North Pacific

Abstract Ancient Murrelets (Synthliboramphus antiquus) are subarctic seabirds that breed on islands from British Columbia through Alaska to China. In this study, we used sequence variation in the mitochondrial control region and cytochrome b gene to estimate the extent of genetic differentiation and gene flow among populations both within British Columbia and across the North Pacific. Results suggest that genetic differentiation is low and female-mediated gene flow is high among colonies within British Columbia, in agreement with banding studies. Surprisingly, genetic differentiation appears to be low and gene flow high between British Columbia and Asia. The effective female population size appears to be stable, but the species may have undergone a range expansion. These results suggest that Ancient Murrelets from throughout the North Pacific may represent a single management unit for conservation. El ADN Mitocondrial Sugiere Alto Flujo Génico en Synthliboramphus antiquus Resumen. Synthliboramphus antiquus es una especie de ave marina subártica que se reproduce en islas desde British Columbia a través de Alaska hasta China. En este estudio estimamos el grado de diferenciación genética y de flujo génico entre poblaciones localizadas dentro de British Columbia y a través del Pacífico Norte. Nos basamos en la variación en secuencias de la región control y el gen citocromo b del ADN mitocondrial. Los resultados sugieren baja diferenciación genética y alto flujo génico mediado por las hembras entre las colonias de British Columbia, lo que es consistente con estudios de aves anilladas. Sorprendentemente, la diferenciación genética parece ser baja y el flujo génico alto entre British Columbia y Asia. El tamaño efectivo de la población de hembras parece estar estable, pero la especie podría haber expandido su rango de distribución. Estos resultados sugieren que los S. antiquus de todo el Pacífico Norte pueden representar una sola unidad de manejo en términos de conservación.

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.

scholarly journals Temporal Variability in the Expression of the Arctic Oscillation in the North Pacific

2009 ◽  
Vol 22 (11) ◽  
pp. 3110-3126 ◽  
Author(s):  
Hongxu Zhao ◽  
G. W. K. Moore
Keyword(s):  
North Atlantic ◽  
North Pacific ◽  
Arctic Oscillation ◽  
Low Frequency ◽  
Dominant Mode ◽  
Ice Age ◽  
The Arctic ◽  
The North ◽  
The Arctic Oscillation ◽  
The North Pacific

Abstract Although the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) have been identified as important modes of climate variability during the Northern Hemisphere (NH) winter, whether the AO or the NAO is more fundamental to the description of this variability, especially in the North Pacific, is still an open question. An important contributor to this uncertainty is the lack of knowledge of the low-frequency linkages between the North Atlantic and North Pacific Oceans. This paper explores the linkage between the two oceanic basins on interdecadal time scales using the sea level pressure (SLP) field during the twentieth century. In particular, it is shown that the winter mean SLP in the North Pacific was positively correlated with the sign of the NAO during the periods of 1925–50 and 1980–98, which resulted in the classical AO pattern being the dominant mode in the NH. In contrast, during the period of 1951–79, the winter mean SLP in the two basins was decoupled, resulting in a dominant mode that more closely resembled the NAO. Using paleoclimate reconstructions, it is also shown that this interdecadal variability in the North Pacific climate began around 1850, which is nominally considered to be the end of the Little Ice Age.

Population-specific aggregations of steelhead trout (Oncorhynchus mykiss) in the North Pacific Ocean

1997 ◽  
Vol 54 (10) ◽  
pp. 2368-2376 ◽  
Author(s):  
S McKinnell ◽  
J J Pella ◽  
M L Dahlberg
Keyword(s):  
Pacific Ocean ◽  
Oncorhynchus Mykiss ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Puget Sound ◽  
Steelhead Trout ◽  
The North ◽  
Georgia Basin ◽  
The North Pacific ◽  
High Seas

The distribution of North American hatchery-origin steelhead (Oncorhynchus mykiss) in the North Pacific Ocean varied by age and hatchery location. Columbia River steelhead were more abundant south of the Aleutian Islands at an earlier age than steelhead from the Georgia Basin (Georgia Strait, Puget Sound, and waters connecting with the open Pacific). Between 1984 and 1989, there were eight independent and coincident recoveries of coded-wire-tagged steelhead, where individuals released from hatcheries as juveniles at similar times and locations were recovered together on the high seas up to 3 years later. A statistical test was developed to determine whether these coincident recoveries should be expected if individual steelhead within populations travelled in the North Pacific in an uncoordinated manner. The overall test suggested that some tagged steelhead populations travelled together in a significantly (P < 0.05) coordinated manner on the high seas.

scholarly journals Accumulation reconstruction and water isotope analysis for 1735–1997 of an ice core from the Ushkovsky volcano, Kamchatka, and their relationships to North Pacific climate records

2013 ◽  
Vol 9 (2) ◽  
pp. 2153-2181 ◽  
Author(s):  
T. Sato ◽  
T. Shiraiwa ◽  
R. Greve ◽  
H. Seddik ◽  
E. Edelmann ◽  
...  
Keyword(s):  
North Pacific ◽  
North Pacific Ocean ◽  
Ice Core ◽  
Power Spectra ◽  
Ice Age ◽  
Northwest Pacific ◽  
Accumulation Rates ◽  
The North ◽  
Decadal Scale ◽  
The North Pacific

Abstract. To investigate past climate change in the Northwest Pacific region, an ice core was retrieved in June 1998 from the Gorshkov crater glacier at the top of the Ushkovsky volcano, in central Kamchatka. Hydrogen isotope (δD) analysis and past accumulation reconstructions were conducted to a depth of 140.7 m, dated to 1735. Two accumulation reconstruction methods were applied with the Salamatin and the Elmer/Ice ice flow models. Reconstructed accumulation rates and δD were significantly correlated with North Pacific surface temperature. This, and a significant correlation of δD with the North Pacific Gyre Oscillation (NPGO) index implies that NPGO data is contained in this record. Wavelet analysis shows that the ice core records have significant multi-decadal power spectra up to the late 19th century. The multi-decadal periods of reconstructed accumulation rates change at around 1850 in the same way as do Northeast Pacific ice core and tree ring records. The loss of multi-decadal scale power spectra of δD and the 6‰ increase in its average value occurred around 1880. Thus the core record confirms that the periodicity of precipitation for the entire North Pacific changed between the end of the Little Ice Age through the present due to changes in conditions in the North Pacific Ocean.

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