Journal of the Oceanographical Society of Japan

Vertical Transport of Organic Materials in the Northern North Pacific as Determined by Sediment Trap Experiment

Part 1. Fatty Acid Composition

Eiichiro TANOUE, Nobuhiko HANDA

1980 Volume 36 Issue 5 Pages 231-245
Published: November 30, 1980
Released on J-STAGE: June 17, 2011

DOIhttps://doi.org/10.1007/BF02072124

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Sediment traps were deployed at 5 depths of 100 through 5, 250 m to collect suspended sediments in the northern North Pacific (47°51.1'N; 176°20.6'E, 5, 300 m deep) in the summer of 1978. Fatty acid composition was determined in the samples of phytoplankton, particulatematter, trap sediment and bottom sediment.
Fatty acid composition of the trap sedimentsrevealed no significant vertical trend throughout the water column from depths of 100 to 5, 250 m, and were also similar to those of the phytoplankton and the particulate matter from the euphotic layer. However, a marked difference in the fatty acid composition wasobserved between the trap sediments and the particulate matter from deep waters. Therefore, it can be concluded that the source of fatty acids in the trap sediments is the particulate matter from the euphotic layer but not from deep waters.
Unsaturated fatty acids highly susceptible to biological agents were rather abundant in the trap sediments as well as in the phytoplankton and particulate matter from the euphotic layer, however no unsaturated fatty acid was found in the particulate matter from deep waters. From these findings, it isclear that the particulate matter of the euphotic layer is transported to deep watersveryrapidly. As the sinking rate of fecal pellets produced by zooplankton is in the range of ten to hundreds of meters a day, fecal pellets are assumed to be the most likely carrier ofrapid-transport of organic matter inclucing fatty acids from the euphotic layer to deep waters.

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Variability of the Constant Flow in Ôsaka Bay

Tetsuo YANAGI

1980 Volume 36 Issue 5 Pages 246-252
Published: November 30, 1980
Released on J-STAGE: June 17, 2011

DOIhttps://doi.org/10.1007/BF02072125

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Some current measurements were carried out inÔsaka Bay to understand the characteristics and causes of fluctuations of the constant flow in the bay. It is shown that the major part of fluctuation of the constant flow inÔsaka Bay is the wind-driven current. The direction of the wind-driven current in the near surface water deflects clockwise through 10 to 30 degrees from the wind direction while in the lower layer the current deflects counterclockwise to that in the near surface water in the eastern half ofÔsaka bay. The speed of the wind-driven current in the near surface water is 0.5 to 1.5 % of the windspeed while that in the lower layer is smaller than that in the near surface water in thisarea.

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Testing of a Towed CTD

Yukio FUJINAWA, Yoshinobu TSUJI, Isao WATABE, Ken SASAKI, Masao NOMOTO ...

1980 Volume 36 Issue 5 Pages 253-258
Published: November 30, 1980
Released on J-STAGE: June 17, 2011

DOIhttps://doi.org/10.1007/BF02072126

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The results of laboratory and field experiments on a CTD measuring unit attached to a controllable towed body is described. It was verified that the three-dimensional distribution of salinity and temperature could be observed with sufficient accuracy (to 0.03 %0 in salinity and to 0.01°Cin temperature if proper correction is adopted) while cruising at upto4 knots. A double integrated A/D converter is used to compensate for effects of extraneousenvironmental changes.

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A Comparison of Four Methods for Integrating¹⁴C-Primary Productivity Measurements per Unit Area

Shun-ei ICHIMURA, Timothy R. PARSONS, Masayuki TAKAHASHI, Humitake SEK ...

1980 Volume 36 Issue 5 Pages 259-262
Published: November 30, 1980
Released on J-STAGE: June 17, 2011

DOIhttps://doi.org/10.1007/BF02072127

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Four methods were compared for the integration of¹⁴C-primary productivity per m²;(1) thein situmethod at 0, 2.5, 5, 7.5, 10 and 12.5 m (standard depths1):(2) thein situmethod at 0, 5, 10 and 12.5 m (standard depths 2):(3) thein situmethod at 2.5, 7.5 and 11.5 m for each sample pumped over depth intervals 0 to 5 m, 5to 10 m, and 10 to 12. 5 m, respectively (integrated depths): and (4) the simulatedin situmethod for samples collected from light standard depths. The method which appeared to give the most reliable results was that (3) in which samples were averaged by pumping water overthe euphotic depth followed by incubation of integrated samples at the middle of each depth interval.

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Radium-228 in the Japan Sea

Takashi OKUBO

1980 Volume 36 Issue 5 Pages 263-268
Published: November 30, 1980
Released on J-STAGE: June 17, 2011

DOIhttps://doi.org/10.1007/BF02072128

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The distribution of²²⁸Ra in surface and subsurface waters in the Japan Sea was studied. The concentrations of²²⁸Ra in surface waters were around 100 dpm/1000lwhich were much higher than those reported for Pacific surface waters. The concentrations of 228Ra decreasedwith increasing depth to less than 10 dpm/1000lin the Japan Sea Proper Water. Based on the comparison between observed values of²²⁸Ra andcalculated profile through the near-surface water mass and the underlying main water mass in the Japan Sea, the apparent verticaleddy diffusion coefficient was estimated to be about 2 cm²s^-1.

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