• Title/Summary/Keyword: the northeastern Pacific

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First Zoea of Pugettia gracilis (Crustacea: Decapoda: Majidae) Reared in the Laboratory

  • Oh, Seong-Mi;Ko, Hyun-Sook
    • Animal cells and systems
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    • v.11 no.1
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    • pp.51-54
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    • 2007
  • The first zoea of Pugettia gracilis is described and illustrated for the first time. Its morphological characteristics are compared with those of other known species of the genus from the northern Pacific waters. Although the Pugettia zoeas of the northwestern and the northeastern Pacifies are very similar, they can be easily distinguished by their dorsal carapace spine. In the northwestern Pacific it is spinulate with a spinous tip, while in the northeastern Pacific it is smooth with a blunt tip.

The Redescription of Mormonilla phasma Giesbrecht, 1891 (Copepoda: Mormonilloida) from the Northeastern Pacific

  • Cho, Kyu-Hee;Kim, Woong-Seo;Lee, Won-Choel
    • Korean Journal of Environmental Biology
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    • v.25 no.1
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    • pp.72-79
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    • 2007
  • Mormonilla phasma is redescribed, based on the specimens from the Northeastern Pacific. M. phasma in the study area has the following morphological characteristics; second endopodal segment of mandible partly fused to basis and a distinct three-segmented exopod of mandible in anterior view and one indistinct segment in posterior view which are different from the description given by Boxshall (1979). In addition the first and the second endopodal segments of leg 1 were also separated indistinctly. Other morphological characteristics are similar to those reported in previous studies. The morphological anomalies in endopodal segments of the leg 1, unknown up to now are also discussed. This study is the first report on the distribution of M. phasma in the Northeastern Pacific.

Epidemiology of Hepatitis C Virus Genotypes in Northeastern Thai Blood Samples

  • Barusrux, Sahapat;Sengthong, Chatchawan;Urwijitaroon, Yupa
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.20
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    • pp.8837-8842
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    • 2014
  • Background: Hepatitis C virus (HCV) infection is an important cause of liver cancer in Thailand. The highest prevalence of anti-HCV positive among Thai blood donors is found in the northeastern region. The present analysis of the genotype distribution among anti-HCV positive northeastern-Thai blood donors was conducted to provide a base for the epidemiological pattern of HCV infection in this region. Materials and Methods: A total of 112 HCV seropositive healthy blood donors were randomly selected and tested for the presence of HCV-RNA by RT-PCR. HCV-RNA positive samples were genotyped by direct sequencing at core region genomes and confirmed by phylogenetic analysis. Results: HCV viremia was found in 94.6% (106/112) of HCV seropositive blood donors. There were 3 major genotypes distributed among this population. HCV genotype 3a was the most prevalent (71.7%) followed by genotypes 1a (7.5%), 1b (7.5%), 6i (3.8%), 6f (2.8%) and 6n (1.9%). Conclusions: HCV genotype 3a in asymptomatic infections in northeastern Thailand is significantly higher than other previous reports. Subgenotype 6 prevalence is less than in neighboring countries and distribution patterns differ. The findings are relevant as predictors for using interferon therapy in this population.

Surface pH Of The Northeastern Pacific Ocean

  • Park, Kilho
    • 한국해양학회지
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    • v.1 no.1_2
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    • pp.1-6
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    • 1966
  • A latitudinal, differential pH distribution is observed in the Northeastern Pacific Ocean with a pH range of 8.15 at high latitude (42 N) to 8.29 at low latitude (23 N). These pH values are generally greater than the calculated equilibrium pH with respect to atmospheric carbon dioxide. If we assume that the calculated equilibrium pH values ae valid, then the surface waters are undersaturated with respect to the atmospheric carbon dioxide during April to June 1966. A high surface pH value of about 8.26 was observed immediately south of the SubarcticBoundary zone near 170 W. This value differs from the equilibration pH by as much as 0.1 unit.

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A Study on the Horizontal Management of the Fisheries in the Northeastern Pacific (북태평양 어업의 호리존탈.매니저먼트에 관한 연구)

  • 이재후
    • The Journal of Fisheries Business Administration
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    • v.17 no.1
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    • pp.41-76
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    • 1986
  • The northeastern Pacific and eastern Bering Sea supports large and divers finfish and shellfish compelxes. The North Pacific fishing grounds are largest fish production total 30.89 percent of the world in 1983. Recent action by the around countries extending their fisheies jurisdiction to 200 mile has provided a new environment. The new approch to fisheries management has resulted in an arormous expansion in tile demand for scientific information. These are no longer limited to biological concerns. Emphasis has been focused recently on the need to understand the economic, social, politics and philosophy characteristics of a fishing and how they will be affected by management decisions. The horizontal management and portfolio management for fisheries has increased interest in complex biological models and the coupling of these models with economic, politics and phyisophy components. Successful completion of this task will require and expanded understanding of oceanographic, biological, economic, social, politics and philosophic process associated with fisheries. Particular attention should be devoted to acquiring information an data processing for Korean trawl fishery, stock assessment in the areas. The need for international collaboration in management must be stressed. Some northeast Pacific and eastern Bering Sea fish stock migrate over long distances and political boundaries. Further, nearly all the fish stocks are harvested by several nations. The features require cooperation and coordination of research activities. The horizontal management will be made a way these activities for the around countries in the sea. Strongly, tile proposed again, Pacific International Council for Exploration of the Seas, PICES will interest between all users of the area's fisheries.

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Distribution of Meiobenthic Communities in the Deep-sen Floor of Northeastern Pacific Seafloor along a Latitudinal Transect (북동 태평양 심해저에 서식하는 중형저서동물 군집의 위도별 분포 특성)

  • Min, Won-Gi;Kim, Dong-Sung;Kim, Woong-Seo
    • Ocean and Polar Research
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    • v.26 no.2
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    • pp.255-263
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    • 2004
  • This study was conducted to investigate the community structure and distributional pattern of meiobenthos in the deep-sea bottom of the Clarion-Clipperton Fracture Zone of the northeastern Pacific during July 2003. The samples were collected using the multiple corer at 13 stations along the transects fiom $5^{\circ}N\;to\;17^{\circ}N$. The most abundant meiobenthos was nematodes and followed by sarcomastigophorans; these two taxa comprised more than 70% of the total abundance at all stations. For size distribution analyses showed that animals which fit into the sieve mesh size of 0.063mm were abundant. The maximum density of meiobenthos was $147inds./10cm^2$ at station located in $7^{\circ}N$, and the minimum density was $6 inds./10cm^2$ at station located in $14^{\circ}N$. More than 60% of meiobenthos were distributed at surface sediment layer within 1.0cm, and the peak abundance was found at $0{\sim}0.25cm$ layer. The latitudinal distribution pattern of meiobenthos in the study area seemed to be related with the primary productivity of the surface water that is also connected to the water circulation pattern of the Pacific Ocean near the Equator, diverging at latitude of $8^{\circ}N$ and conversing at $5^{\circ}N$.

Taxonomic assessment of North American species of the genera Cumathamnion, Delesseria, Membranoptera and Pantoneura (Delesseriaceae, Rhodophyta) using molecular data

  • Wynne, Michael J.;Saunders, Gary W.
    • ALGAE
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    • v.27 no.3
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    • pp.155-173
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    • 2012
  • Evidence from molecular data supports the close taxonomic relationship of the two North Pacific species Delesseria decipiens and D. serrulata with Cumathamnion, up to now a monotypic genus known only from northern California, rather than with D. sanguinea, the type of the genus Delesseria and known only from the northeastern North Atlantic. The transfers of D. decipiens and D. serrulata into Cumathamnion are effected. Molecular data also reveal that what has passed as Membranoptera alata in the northwestern North Atlantic is distinct at the species level from northeastern North Atlantic (European) material; M. alata has a type locality in England. Multiple collections of Membranoptera and Pantoneura fabriciana on the North American coast of the North Atlantic prove to be identical for the three markers that have been sequenced, and the name Membranoptera fabriciana (Lyngbye) comb. nov. is proposed for them. Many collections of Membranoptera from the northeastern North Pacific (predominantly British Columbia), although representing the morphologies of several species that have been previously recognized, are genetically assignable to a single group for which the oldest name applicable is M. platyphylla.

The Processes Contributing To The Vertical Distribution Of Apparent pH In The Northeastern Pacific Ocean

  • Park, P.Kilho
    • 한국해양학회지
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    • v.3 no.1
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    • pp.1-7
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    • 1968
  • Two major processes that affect the vertical distribution of apparent pH in the Subarctic region of the Northeastern Pacific Ocean are (1) apparent oxygen utilization by marine organisms and (2) carbonate dissolution. Simplified mathematical approximations show that, in the pH ravge of 7.2 to 8.3, the utilization of 0.1 mM of oxygen (2.24 ml/liter) lowers the pH by 0.20 units and 0.1 mM of carbonate dissolution increases the pH by 0.25 units. Since Oxygen utilization exceeds 0.3 mM while the carbonate dissolution, with respect to the surface, is about 0.05mM, the effect of oxygen utilization is much greater than the dissolution effect of carbonate on the pH of seawater.

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Seasonal Variation of Planktonic Foraminifera Assemblage in response to Seasonal Shift of Inter-Tropical Convergence Zone in the Northeastern Equatorial Pacific (적도수렴대의 위치변화에 따른 북동태평양 적도해역의 부유성 유공충 군집의 계절변동)

  • Lee, Yuri;Asahi, Hirofumi;Woo, Han Jun;Kim, Hyung Jeek;Lee, Seong-Joo;Khim, Boo-Keun
    • Ocean and Polar Research
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    • v.36 no.4
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    • pp.437-445
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    • 2014
  • A time-series sediment trap was operated at a water depth of 4950 m from July 2003 to May 2004 at KOMO station ($10^{\circ}30^{\prime}N$, $131^{\circ}20^{\prime}W$) in the northeastern equatorial Pacific, with the aim of understanding the temporal variation of planktonic foraminifera assemblages in response to the seasonal shift of Inter-Tropical Convergence Zone (ITCZ). A total of 22130 planktonic foraminifera specimens belonging to 30 species and 11 genera were identified, which shows a distinct seasonal variation with high values (125~288 specimens $m^{-2}day^{-1}$) in the winter to spring (December-May) and low values (16~23 specimens $m^{-2}day^{-1}$) in the fall (September-November). In addition, seasonal ecological differences of foraminifera assemblages are distinctly recognizable: omnivorous foraminifera occurred predominantly during the summer season, whereas herbivorous ones were dominant during the winter season. Such seasonal variations correspond to the seasonal shift of the ITCZ. Enhanced occurrence of herbivorous species during the winter-spring season seems a result of surface water mixing generated by the southward shift of the ITCZ. The increase in omnivorous species during the summer season may be due to the northward movement of the ITCZ caused by weakened wind speed, resulting in the intensification of water column stratification and nutrient-poor environment. A significant reduction of planktonic foraminifera specimens during the fall is attributed to heavy precipitation and reduction in light intensity.

Meiobenthic Communities in the Deep-sea Sediment of the Clarion-Clipperton Fracture Zone in the Northeast Pacific (북동 태평양 C-C 해역에 서식하는 중형저서동물 군집)

  • Kim, Dong-Sung;Min, Won-Gi;Lee, Kyoung-Yong;Kim, Ki-Hyune
    • Ocean and Polar Research
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    • v.26 no.2
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    • pp.265-272
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    • 2004
  • This study was conducted to investigate the community structure and distributional pattern of meiobenthos in the deep-sea bottom of the Clarion-Clipperton Fracture Zone of northeastern Pacific during July 2001. Examination of sediment samples collected on the eight survey station showed that there were 10 different types of meiobenthos. The most abundant meiobenthic animals were nematodes in all stations. Sarcomastigophorans, benthic harpacticoids were next abundant meiobenthos. Vertical distribution of meiobenthic animals showed the highest individual numbers in the surface sediment layers of 0-1 cm depth and showed more steep decreasing trend as sediment gets deeper on the stations of high latitude located in $16-17^{\circ}N$. Horizontal distribution of meiobenthic animal in the study area within CCFZ showed high densities of meiobenthos at the stations had few manganese nodules on their sediment surface in the site of low latitude. For size distribution analyses showed that animals which fit into the sieve mesh size of 0.063 mm were abundant.