Nagasaki Marine Observatory

Nagasaki-shi, Japan

Nagasaki Marine Observatory

Nagasaki-shi, Japan

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Kuroda K.,Japan National Research Institute of Fisheries And Environment of Inland Sea | Kotori M.,Hokkaiao Fisheries Experimental Station | Nagai N.,Nagasaki Marine Observatory | Yamaguchi A.,Hokkaido University | And 2 more authors.
Bulletin of the Plankton Society of Japan | Year: 2012

The eight included reviews were proposed to stimulate future work on chaetognaths and are based on presentations made during the workshop held by the Japan Chaetognatha Group at Mie University on Nov. 4, 2011.They are composed of seven reviews and a summary review on the fauna and the distributional ecology in the marginal seas of the north-west Pacific (the Bering Sea, the Okhotsk Sea, the Japan Sea, the East China Sea and the South China Sea) and the surrounding eastern and southern domains of Japan. The major results are summarized as follows:l) 43 species belonging to15 genera with 2 forms are listed as the presently-known pelagic chaetognath fauna. 2) Species richness is extremely poor in both the Bering and the Okhotsk Seas, but rich in the eastern and southern domains of Japan, in the East China Sea and the South China Sea. There are clear differences in species numbers and species composition between these areas. 3) Meso- and bathypelagic species are lower in number than epipelagic species (12 genera 32 species), and epipelagic species richness is highest in both the East China Sea and the South China Sea. 4) Some characteristics of chaetognath distribution are: 1) In the Japan Sea, meso- and bathypelagic species are absent, so only Parasagitta elegans occurs extensively to layers deeper than 1000 m. 2) In the southern seas of Japan, the subarctic P. elegans and Pseudosagitta scrippsae occur in the mesopelagic layer in the inner core of the Kuroshio warm current, accompanied by the Intermediate Oyashio Water. 3) In summer and autumn, Flaccisagitta enflata invades inner bays throughout the coastal waters south of Japan and also, it advances northwards in the Japan Sea, reaching the Bohai Sea through the Yellow Sea in the East China Sea. 5) In the subtropical waters surrounding Japan, F. enflata, Mesosagitta minima, Serratosagitta pacifica and Zonosagitta nagae predominate, mostly during their different spawning seasons around Japan. Otherwise, in the subarctic waters of the northern Japan Sea, the Oyashio region, the Okhotsk Sea and Bering Seas, Parasagitta elegans dominates, being followed by Eukrohnia hama-ta and Parasagitta scrippsae. 6) Sagami and Suruga Bays, abundant in the number of both meso- and bathypelagic species, are looked upon as special spots from the viewpoint of the biogeography of chaetognath distribution. 7) Eight opinions are expressed for future studies on Chaetognatha.


Sabine C.L.,National Oceanic and Atmospheric Administration | Hankin S.,National Oceanic and Atmospheric Administration | Koyuk H.,National Oceanic and Atmospheric Administration | Koyuk H.,University of Washington | And 93 more authors.
Earth System Science Data | Year: 2013

As a response to public demand for a well-documented, quality controlled, publically available, global surface ocean carbon dioxide (CO2) data set, the international marine carbon science community developed the Surface Ocean CO2 Atlas (SOCAT). The first SOCAT product is a collection of 6.3 million quality controlled surface CO2 data from the global oceans and coastal seas, spanning four decades (1968-2007). The SOCAT gridded data presented here is the second data product to come from the SOCAT project. Recognizing that some groups may have trouble working with millions of measurements, the SOCAT gridded product was generated to provide a robust, regularly spaced CO2 fugacity (fCO2) product with minimal spatial and temporal interpolation, which should be easier to work with for many applications. Gridded SOCAT is rich with information that has not been fully explored yet (e.g., regional differences in the seasonal cycles), but also contains biases and limitations that the user needs to recognize and address (e.g., local influences on values in some coastal regions). © 2013 Author(s).


Pfeil B.,University of Bergen | Pfeil B.,Bjerknes Center for Climate Research | Pfeil B.,University of Bremen | Olsen A.,University of Bergen | And 98 more authors.
Earth System Science Data | Year: 2013

A well-documented, publicly available, global data set of surface ocean carbon dioxide (CO2) parameters has been called for by international groups for nearly two decades. The Surface Ocean CO2 Atlas (SOCAT) project was initiated by the international marine carbon science community in 2007 with the aim of providing a comprehensive, publicly available, regularly updated, global data set of marine surface CO2, which had been subject to quality control (QC). Many additional CO2 data, not yet made public via the Carbon Dioxide Information Analysis Center (CDIAC), were retrieved from data originators, public websites and other data centres. All data were put in a uniform format following a strict protocol. Quality control was carried out according to clearly defined criteria. Regional specialists performed the quality control, using state-of-the-art web-based tools, specially developed for accomplishing this global team effort. SOCAT version 1.5 was made public in September 2011 and holds 6.3 million quality controlled surface CO2 data points from the global oceans and coastal seas, spanning four decades (1968–2007). Three types of data products are available: individual cruise files, a merged complete data set and gridded products. With the rapid expansion of marine CO2 data collection and the importance of quantifying net global oceanic CO2 uptake and its changes, sustained data synthesis and data access are priorities. © 2013 Author(s).


Takatani Y.,Chiyoda Corporation | Sasano D.,Chiyoda Corporation | Sasano D.,Meteorological Research Institute | Nakano T.,Chiyoda Corporation | And 5 more authors.
Global Biogeochemical Cycles | Year: 2012

The Japan Meteorological Agency has acquired dissolved oxygen (DO) concentration data each year since 1967 along the 137E repeat section in the western North Pacific. In this data set we found significant regional temporal trends of decreasing or increasing DO concentrations on various isopycnal surfaces. DO decreases were particularly significant after the mid-1980s in the subtropical gyre; mean rates of DO change at 20-25N for 1985-2010 were -0.28 0.08 mol kg-1 yr-1 on 25.5 σθ in North Pacific Subtropical Mode Water (NPSTMW), -0.36 0.08 mol kg-1 yr-1 on 26.8 σθ in North Pacific Intermediate Water (NPIW), and -0.23 0.04 mol kg-1 yr-1 on 27.3 σθ in the O2 minimum Layer (OML). The cause of DO decrease differed among isopycnal surfaces. On density surfaces shallower than 26.0 σθ (less than about 400 m), the deepening of isopycnal surfaces and decline of oxygen solubility due to ocean warming have had the greatest influence. In particular, between 25.2 σ θ and 25.8 σθ near the NPSTMW their combined contributions accounted for >50% of the DO decrease. In the NPIW core at roughly 26.8 σθ (∼700 m), the decline in DO was attributable to the DO decrease in the formation region. In the OML between 27.0 σθ and 27.3 σθ (∼1000 m), the DO decrease likely resulted from an increase in westward transport of low O2 water due to strengthening of the subtropical gyre. The result of this study shows the importance of the long-term and high-frequency along the 137E repeat section. Copyright 2012 by the American Geophysical Union.


Midorikawa T.,Meteorological Research Institute | Midorikawa T.,Nagasaki Marine Observatory | Tanoue E.,Nagoya University
Papers in Meteorology and Geophysics | Year: 2012

We investigated the vertical distribution and chemical nature of strong ligands for copper(II) in the western North Pacific based on measurements of organically complexed copper(II) with two experimental procedures having different properties. The first involved fractionation of copper(II) complexes on the basis of their stability: exclusion of copper(II) complexed with weak ligands and, consequently, extraction of only highly stable copper(II) complexed with strong ligands (conditional stability constant of log K'CuL > 14) by use of a ligand-exchange reaction with ethylenediaminetetraacetic acid. We also detected two weaker ligand classes having log K′CuL = 9-10 (L1) and log K′CuL ~ 7 (L2) with the copper(II) titration of an aliquot of the concentrated and desalted seawater. The second procedure involved the separation of hydrophobic copper(II) complexes from the original seawater by adsorption onto a resin. We determined the conditional stability constant of the hydrophobic copper(II) complex to be log K′CuL ≤ 10.26 based on measurements of copper(II) complexes collected after copper(II) titration. We detected strong ligands (log K′CuL > 14) at all depths from the surface to 1000 m, and we determined their concentrations to be 0.02-0.19 nM. The concentrations of hydrophobic ligands were lower than those of strong ligands at most depths, especially in surface waters. The vertical profile of strong ligands showed small maxima in the euphotic zone that did not coincide with chlorophyll a maxima. We estimated strong ligands to be present quantitatively (> 99.9 %) in the form of copper(II) complexes throughout the entire 1000-m water column based on the concentrations of inorganic copper(II) measured by means of hydrophobic chromatography. In contrast, the copper(II)-complexed fraction of the hydrophobic ligands (log K′CuL = 10.26) varied from 15% at 120 m to 78% at 1000 m and was positively correlated with the concentration of inorganic copper(II). Strong ligands appeared to have different ligand sites and different structural units in their environments compared to the hydrophobic ligands. The strong ligands appeared to be relatively hydrophilic because their ligand sites were multidentate and were composed of several polar functional groups. We characterized at least three types of organic ligands with different affinities for copper(II) and different hydrophobic properties. Each ligand was associated with copper(II) with a different efficiency that varied with depth in the oceanic water column. In surface layers it appeared that strong ligands played an important role that enabled copper(II) to be present stably in seawater as a soluble form, whereas at depth, hydrophobic ligands also contributed to the copper(II) speciation. Knowledge of ligand speciation is of noteworthy importance to the investigation of the abundance, distribution, and dynamics of copper(II) and organic ligands in the ocean. © 2012 by the Japan Meteorological Agency / Meteorological Research Institute.


Midorikawa T.,Meteorological Research Institute | Midorikawa T.,Nagasaki Marine Observatory | Ishii M.,Meteorological Research Institute | Kosugi N.,Meteorological Research Institute | And 6 more authors.
Geophysical Research Letters | Year: 2012

Recent changes in oceanic CO 2 partial pressure (pCO 2 sea) have attracted increasing interest as they relate to the increase in atmospheric CO 2 and climate change. We report decadal changes in the growth rates of pCO 2 sea in latitudinal zones from 3°N to 33°N along the repeat hydrographic line at 137°E in the western North Pacific in winter. The growth rates of pCO 2 sea for 1999-2009 (-0.3 0.9 [mean 1σ] to 1.7 ± 0.5 μatm yr -1) were lower than those for 1984-1997 (0.7 ± 0.3 to 2.2 ± 0.6 μatm yr -1) at most latitudes, indicative of the recent notable deceleration of pCO 2 sea increase. For latitudes around 10-20°N, we attribute the reduction in the growth rate of pCO 2 sea for 1999-2009 primarily to the reduction in the contribution from dissolved inorganic carbon (DIC) originating from a reduction in carbon accumulation associated with the expansion of the western Subtropical Gyre towards the south. © 2012. American Geophysical Union. All Rights Reserved.


Nagai N.,Nagasaki Marine Observatory | Moriyama E.,National Maizuru Marine Observatory | Kuroda K.,Fisheries Agency
Bulletin of the Plankton Society of Japan | Year: 2012

A review on the fauna and the distributional ecology of pelagic chaetognaths in the East China Sea, including the waters near Taiwan and the Taiwan Strait, one of the marginal seas in the North Pacific, are compiled here. Major results are summarized as follows: 1) In total, 30 species with 1 form belonging to 14 genera are listed as the chaetognath fauna with 25 species containing 1 form in 11 genera for the epipelagic, 4 species in 3 genera for the mesopelagic, and 1 species in 1 genus for the bathypelagic layers. 2) Some distributional characteristics of chaetognaths are : Compared to the other domains, meso- and bathypelagic species are scarcely found in large numbers. The noteworthy occurrence of many tropical-neritic species were found in the 1990s. Flaccisagitta enflata predominates throughout the year in the Kuroshio area and invades towards the Bohai Sea through the Yellow Sea in summer and autumn. Typical indicator species in this domain are Aidanosagitta crassa in the near-shore water and Zonosagitta nagae in the coastal water during winter to spring and F. enflata, Z. bedoti during summer to autumn on the continental shelf, and F. enflata, F. hexaptera, Krohnitta subtilis in the Kuroshio and the offshore- oceanic water. The southern limit of A. crassa distribution is presumed to be attained near Hong Kong in the South China Sea southwards through the Taiwan Strait.


Kuroda K.,Japan National Research Institute of Fisheries And Environment of Inland Sea | Nagai N.,Nagasaki Marine Observatory
Bulletin of the Plankton Society of Japan | Year: 2012

A review on the fauna and the distributional ecology in the southern seas of Japan in the western North Pacific Ocean are compiled here. Major results are summarized as follows: 1) In total, 30 species with 1 form belonging to 15 genera are listed as the chaetognath fauna with 24 species and 1 form in 12 genera for the epipelagic, 7 species in 5 genera for the mesopelagic, and 4 species in 3 genera for the bathypelagic layers. 2) Some characteristics of chaetognath distribution are : Rare tropical species are found in the coastal waters. Subarctic species such as Parasagitta elegans and Pseudosagitta scrippsae occur in the mesopelagic layer in the Kuroshio area, accompanied by the Intermediate Oyashio Water. Eukrohnia hamata is mainly distributed in the mesopelagic layer in the Kuroshio area and its juveniles often occur in the surface layer. In summer and autumn, Flaccisagitta enflata invades towards inner bays through the coastal waters from the Kuroshio area in the southern seas of Japan. Typical indicator species in this domain are Aidanosagitta crassa in the near-shore water, Zonosagitta nagae in the coastal water, F. enflata in the Kuroshio water and Pterosagitta draco in the offshore-oceanic water. Predominant species in the domain are F. enflata (EN), Mesosagitta minima (MI), Serratosagitta pacifica (PA), Zonosagitta nagae (NA), F. lyra (LY) and A. regularis (RE). The dominant species change seasonally in the inner part of the Kuroshio, winter (MI/PA)⇒ spring (PA/NA) ⇒ summer (MI/ EN)⇒autumn (EN/MI), and in the oceanic water south of the Kuroshio, winter (LY/MI/EN)⇒spring (PA/MI/EN)⇒ summer (EN/RE/Ml)⇒ autumn (EN/MI/RE). Data on the autecology of A. crassa and Z. nagae have been accumulated.


Nagai N.,Nagasaki Marine Observatory | Takahashi T.,Jyouetsu Environment Center | Kuroda K.,Japan National Research Institute of Fisheries And Environment of Inland Sea
Bulletin of the Plankton Society of Japan | Year: 2012

A review on the fauna and the distributional ecology of pelagic chaetognaths in the Japan Sea was compiled here. The Japan Sea is a marginal sea surrounded by the Asian Continent and the Japanese Islands and characterized by limited connectivity to other seas through the four shallow straits (The Tsushima, Tsugaru, Soya and Mamiya). Major results are summarized as follows: 1)In total, 22 species with1form belonging to11genera are listed as the epipelagic chaetognath fauna. 2) Some characteristics of chaetognath distribution are: 1) Only Parasagitta elegans and not Pseudosagitta scrippsae or Eukrohnia hamata occur of the subarctic species. 2) Flassisagitta hexaptera, Krohnitta subtilis, Mesosagitta decipiens, M. neodecipiens and Pseudosagitta lyra, which are mainly distributed in the mesopelagic layer in the Kuroshio Current region, appear rarely in the surface layer. 3) The dominant species in the epi-and mesopelagic layers in subarctic regions is only P. elegans, and its distribution extends into the mesopelagic layer in the Tsushima Warm Current region. 4) In the Tsushima Warm Current region, the dominant species are Mesosagitta minima, Zonosagitta nagae, Flassisagitta enflata and Serratosagitta pacifica, and a seasonal shift is apparent: M. minima (in winter), P. elegans (in spring), Z. nagae (in summer), M. minima (in autumn). 5) The northern limit of Aidanosagitta crassa, distributed in near-shore waters, is found in Mutsu Bay on the Japanese side, but not at such a northern latitude on the continental side. 6) Rare subtropical species occur increasingly after the 1990 s, accompanied by the rise of water temperature.

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