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To evaluate the structure and photosynthetic activity of the phytoplankton of the northwestern part of the Sea of Japan, the results of the surveys conducted from February 26 to March 9, 2003, during the 30th cruise of the R/V Akademik Lavrentyev were used. The species composition was considered taking into account the influences of the hydrological conditions. In particular, the studied water area was divided into four zones with various sizes of the mixed layer depth (MLD). An inverse relationship between the MLD and the content of chlorophyll a (Chl a) in various zones was established. The diatom algae were the basic dominants of the composite structure of the phytoplankton everywhere. It is revealed that, at a MLD increase, smaller forms of microalgae receive development. The intrapopulation relations are caused by the adaptation of various species of phytoplankton to the influence of external factors, among which the size of MLD is fundamental.  相似文献   
2.
Water Resources - The effect caused by the typhoon Goni in the coastal water of Posyet Bay, the Sea of Japan, is considered. In nearshore expeditions, profilograph SBE-19plus was used to measure...  相似文献   
3.
Glukhovets  D. I.  Salyuk  P. A.  Artemiev  V. A.  Shtraikhert  E. A.  Zakharkov  S. P. 《Oceanology》2021,61(6):872-880
Oceanology - Areas with different values of the bio-optical characteristics of the surface water layer and different temperature and salinity distributions obtained during a Transatlantic transect...  相似文献   
4.
Using the authors’ data obtained during expeditions to the Sea of Okhotsk during the last decade, the primary phytoplankton production and the distribution of organic carbon and chlorophyll a degradation products (chlorin) in the bottom sediments were studied. Using the authors’ and published data, the spatial distribution of the production and paleoproduction indicators was plotted. The ratios of the chlorin and Corg content in the sediments was considered, and the correlation between these parameters was revealed. It was shown that the average annual primary production of phytoplankton and the paleoproduction indices were maximum in the coastal and upwelling zones and decreased towards the sea’s center. A quantitative correlation was found between the distribution of the present primary production in the photic layer and that of the rates of the accumulation of organic matter buried within the surface sediments. As a result, it was shown that the content of chlorin and Corg in the marine bottom sediments may be used to reconstruct the paleoproduction variability of the past.  相似文献   
5.
Using the data obtained in 1999–2000 during the spring bloom of phytoplankton (late May–early June), the variability of the pigment concentrations, the phytoplankton biomass and species compositions, and the hydrological conditions on the eastern shelf of Sakhalin Island was studied. The study resulted in revealing 135 microalgae species belonging to eight divisions. The most diversely presented were the Dinophyta dinoflagellates and Bacillariophyta diatoms (70 and 53 species, respectively). The concentration of chlorophyll a in the euphotic zone amounted, on average, to 3.8 mg/m3 in 1999 and 2.4 mg/m3 in 2000. It was shown that, in the northern and southern parts of the coastal zone, the concentration of chlorophyll a and the phytoplankton density in the spring were considerably different and depended on the hydrological conditions. In the north, their maximum values were found in the area of the depth break and were determined by the tidal mixing. The increased algae concentrations and temperature inversions at depths of 400–600 m confirm the downslope sliding of the near-bottom shelf waters. In the southern part, the high phytoplankton concentrations in the surface layer in 1999 confirmed by the monthly averaged estimates from the SeaWiFS satellite color scanner were caused by the abnormal northward propagation of the Soya Current waters and by intense tidal mixing.  相似文献   
6.
The content of chlorophyll (Chl), the intensity of delayed fluorescence (DF), the primary production (PP), and the concentrations of macronutrients were measured in the northwestern part of the Sea of Japan during cruise 30 of R/V Professor Gagarinskii in the autumn of 2000. Sixty-three stations were executed in two steps: October 12–17 (stations 2–34) and October 29–November 3 (stations 35–63). At all the stations, CTD probes were performed. Three cross sections were executed twice within a 2-to 3-week interval, during which structural changes in the hydrological fields took place due to the development of an upwelling. During this time, the length of a day and the daily photosynthetically active radiation (PAR) decreased notably. The vertical profiles of Chl and DF showed pronounced maxima. The waters of the shallow-water stations were characterized by an increased Chl content as compared to the deep-water stations. The content of Chl in the photosynthetic layer amounted from 11 to 30 mg/m2; the PP values were from 120 to 520 mg C/m2/day. At the shallow-water stations, during the second step, the Chl concentration increased by roughly 60% (on average, from 0.47 ± 0.22 to 0.77 ± 0.42 mg/m3); the PP value grew by about 40% (from 268 ± 67 to 370 ± 72 mg C/m2/day). At the deep-water stations, this increase was small (the Chl concentration and PP value increased from 0.37 ± 0.20 to 0.41 ± 0.18 mg/m3 and from 356 ± 72 to 377 ± 74 mg C/m2/day, respectively). The changes noted proceeded due to the increase in the nutrient concentrations during the time between the two surveys, despite the decrease in the length of the day and of the daily PAR. The observations performed showed that, during the autumn time, the horizontal water advection across the shelf, caused by the development of the upwelling, plays the key role in the variations of the production characteristics of the Primor’e coastal zone.  相似文献   
7.
The paper presents the records of several paleoproductivity proxies (PP) (biogenic opal and Ba (Si_bio, Ba_bio), organic carbon (C_org) and carbonate Ca_carb, chlorin and benthic foraminifera abundance (BFA)) in sediments of the Okhotsk Sea for the last 80 kyr with a resolution of ∼100–300 years. The sediment age model was based on the AMS 14C data, records of benthic foraminifera δ18O, paleointensity of the Earth’s geomagnetic field and magnetic susceptibility. PP values demonstrate series of severe prolonged productivity drops in the Okhotsk Sea followed by a sharp increase during the last glaciation. On the basis of quantitative estimations of the paleoproductivity in the Okhotsk Sea during the cold MIS 2 and warm Holocene (Gorbarenko and Goldberg, 2005), it is suggested that the millennium scale relationship in productivity-climate changes of this basin was similar: an increase in the sea’s productivity was related with regional climate warming and vice-versa. The PP records of productivity/climate oscillations in the Okhotsk Sea during MIS 2–4 occurred contemporaneously with the North Atlantic cold Heinrich events (HE) and Greenland Dansgaard-Oyeshger interstadial (DOI). Observed successions of prolonged climate cooling events followed by rapid, abrupt warming are similar to climate and environmental oscillations in the N. Atlantic and Greenland, that confirms the millennium-scale climate changes synchronicities in the Northern Hemisphere including the far NW Pacific, the hydrology and climate conditions of which are close to those of the Okhotsk Sea. Synchronism of the N. Hemisphere severe cooling (including the Okhotsk Sea) with the Antarctic warming suggests that mechanisms of the “seesaw” effect (Blunier and Brook, 2001) in the low latitude heat redistribution between high latitudes of both hemispheres were more complicated than direct NADW formation forcing and encompasses the global atmospheric reorganization. Within the PP used a closer connection in the Okhotsk Sea millennium oscillations was observed for the C_org, BFA and chlorin; Ba_bio increases more closely to DOI. Si_bio variability does not show any evident correlation with productivity changes.  相似文献   
8.
Chlorophyll-a concentration (C chl) variations in the cross section within and outside the Peter the Great Bay shelf during different stages of the winter–spring phytoplankton bloom in 2003–2005 has been considered based on a ship (obtained during the R/V Akademik M.A. Lavrent’ev voyage of February 26 to March 9, 2003) and MODIS-Aqua spectroradiometer and the SeaWiFS color-scanner satellite data. A comparison of the C chl variability obtained from the ship and satellite data indicates that these data are inconsistent. According to satellite data obtained at the MUMM atmospheric correction, the C chl variability is distorted less than the NIR-correction data. Studying the variations in the coefficients of light absorption by the detritus and yellow substance (a dg) and light backscattering by suspended particles (b bp), C chl, chlorophyll-a fluorescence (F chl) according to the satellite data allow us to state that the variations in the discrepancy between the satellite and ship C chl values are mainly caused by the variations in the content of the detritus and yellow substance in water. Based on the satellite data, it has been revealed that the a dg values increase with increasing wind mixing after the phytoplankton bloom (about 2–5 km areas where the a dg, C chl, F chl, and bbp values abruptly increased in 2005, apparently due to eddy formation). It has been indicated that the F chl characteristic, which is close to C chl, increases when the favorable conditions for the phytoplankton bloom deteriorate. Therefore, this characteristic cannot be used to identify C chl under the indicated conditions.  相似文献   
9.
The spatial variability of chlorophyll a concentrations was studied from the data of two near-shore expeditions and the cruise of the R/V Akademik M.A. Lavrent’ev in October–November 2010 over the northwestern part of the Sea of Japan. The sections across eddies showed a maximum of chlorophyll a at a depth of 40 m. According to the data from the cruise, the chlorophyll a concentration was maximum in the north of the sea and decreased to the south. In parallel, the procedures for chlorophyll a determination were compared for spectrophotometry with a fluorescence probe and a fluorescence flow system. The probe data of chlorophyll a fluorescence showed a high correlation with the chlorophyll a concentrations by spectrophotometry. On the contrary, data on chlorophyll a concentrations from spectrophotometry did not agree with those from the flow system. It was shown that a fluorimeter in the flow system recorded dissolved organic matter along with the chlorophyll a fluorescence.  相似文献   
10.
The results are presented of hydrological studies in the coastal zone of the Sea of Japan in autumn in different years. It is revealed that the typical density stratification of water is formed there in autumn. The amplitudes are estimated of regular (with the periodicity of tidal harmonic M2) vertical displacements of isotherms in the intermediate layer and maximum values of flow velocity in the surface and bottom layers. It is demonstrated that temperature perturbations are induced at the shelf edge and propagate to the coastal zone with the velocity that is close to the velocity of the first mode of internal gravity waves with the frequency of the tidal harmonic M2.  相似文献   
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