Decadal seesaw of the Central and Subtropical Mode Water formation associated with the Kuroshio Extension variability   总被引：1，自引：1，他引：0  

Eitarou?OkaEmail author  Bo?Qiu  Shinya?Kouketsu  Kazuyuki?Uehara  Toshio?Suga 《Journal of Oceanography》2012,68(2):355-360

Available Argo profiling float data from 2002 to 2011 were analyzed to examine the effect of the Kuroshio Extension (KE) current system variability on the formation of the Central Mode Water. Just north of the upstream portion of the KE at 140–152°E, formation of a lighter variety of the Central Mode Water in winter was active during the unstable period of the upstream KE in 2006–2009 and was reduced when the upstream KE was in the stable period of 2002–2005 and 2010–2011. This decadal formation variability is out of phase with that of the Subtropical Mode Water just south of the KE.  相似文献   

Mapping Baltic Sea shallow water environments with airborne remote sensing     

Ele Vahtm?e  Tiit Kutser  Jonne Kotta  Merli P?rnoja  Tiia M?ller  Lennart Lennuk 《Oceanology》2012,52(6):803-809

It is known that the structure of benthic macrophyte and invertebrate habitats indicate the quality of coastal water. Thus, a large-scale analysis of the spatial patterns of coastal marine habitats makes it possible to adequately estimate the status of valuable coastal marine habitats, provide better evidence for environmental changes, and describe the processes behind the changes. Knowing the spatial distribution of benthic habitats is also important from the coastal management point of view. Our previous results clearly demonstrated that remote sensing methods can be used to map water depth and distribution of taxonomic groups of benthic algae (e.g., red, green, and brown algae) in the optically complex coastal waters of the Baltic Sea. We have as well shown that benthic habitat mapping should be done at high spatial resolution owing to the small-scale heterogeneity of such habitats in Estonian coastal waters. Here we tested the capability of high spatial resolution hyperspectral airborne image in its application for mapping benthic habitats. A big challenge is to define appropriate mapping classes that are also meaningful from the ecological point of view. In this study two benthic habitat classification schemes??broader level and finer level??were defined for the study area. The broader level classes were relatively well classified, but discrimination among the units of the finer classification scheme posed a considerable challenge and required a careful approach. Benthic habitat classification provided the highest accuracy in the case of the Spectral Angle Mapper classification method applied to a radiometrically corrected image. Further processing levels, such as spatial filtering and glint correction, decreased the classification accuracy.  相似文献   

Inversion of two-dimensional tidal open boundary conditions of M<Subscript>2</Subscript> constituent in the Bohai and Yellow Seas     

曹安州  郭筝  吕咸青 《中国海洋湖沼学报》2012,30(5):868-875

Two-dimensional tidal open boundary conditions of the M2 constituent in the Bohai and Yellow Seas(BYS) have been estimated by assimilating T/P altimeter data.During inversion,independent point(IP) strategy was used,in which several IPs on the open boundary is assumed,values at these IPs can be optimized with an adjoint method,and those at other grid points are determined by linearly interpolating the values at IPs.The reasonability and feasibility of the model are tested by ideal twin experiments.In the practical experiment(PE) after assimilation,the cost function may reach 1% or less of its initial value.Mean absolute errors in amplitude and phase can be less than 5 cm and 5°,respectively,and the obtained co-chart can show the character of the M2 constituent in the BYS.The results of the PE indicate that using only two IPs on the open boundary can yield better simulated results.  相似文献   

A dinoflagellate <Emphasis Type="Italic">Cochlodinium geminatum</Emphasis> bloom in the Zhujiang (Pearl) River estuary in autumn 2009     

柯志新  黄良民  谭烨辉  宋星宇 《中国海洋湖沼学报》2012,30(3):371-378

A severe Cochlodinium geminatum red tide (>300 km2) was observed in the Zhujiang (Pearl) River estuary, South China Sea in autumn 2009. We evaluated the environmental conditions and phytoplankton community structure during the outbreak. The red tide water mass had significantly higher dissolved inorganic phosphate (DIP), ammonia, and temperature, but significantly lower nitrite, nitrate, dissolved inorganic nitrogen (DIN), and DIN/DIP relative to the non-red-tide zones. The phytoplankton assemblage was dominated by dinoflagellates and diatoms during the red tide. C. geminatum was the most abundant species, with a peak density of 4.13×107 cell/L, accounting for >65% of the total phytoplankton density. The DIN/DIP ratio was the most important predictor of species, accounting for 12.45% of the total variation in the phytoplankton community. Heavy phosphorus loading, low precipitation, and severe saline intrusion were likely responsible for the bloom of C. geminatum.  相似文献   

Molecular identification and culture observation on <Emphasis Type="Italic">Acrochaete leptochaete</Emphasis> (Chaetophoraceae,Chlorophyta) from China     

邓蕴彦  汤晓荣  黄冰心  滕林宏  丁兰平 《中国海洋湖沼学报》2012,30(3):476-484

Acrochaete leptochaete (Huber) Nielsen (Chaetophoraceae, Chlorophyta) was isolated from the macroalgae Chaetomorpha collected from intertidal pools in Rongcheng, Shandong, China. 18S rDNA combined with ITS regions were used to ascertain the morphological identification of the isolated material. Based on the unialgal culture, asexual reproduction and growth characteristics of A. leptochaete were investigated over wide ranges of temperature and irradiance. Results revealed that asexual reproduction of A. leptochaete could be realized by biflagellate zoospores. The zoospores germinated directly to give self- replicating generations. Zoospore germination was bipolar. A temperature range from 13-21°C and a lower irradiance of 36 μmol/(m2·s) were most favorable for the growth of A. leptochaete. Thallus organization, an important taxonomic criterion for the genus Acrochaete, was affected markedly by temperature and irradiance. Our results extend the knowledge about the species’ general biology and its morphological plasticity. For classification and identification of a simple microphytic algae like A. leptochaete, which are traditionally placed in the class Chaetophoraceae, we propose that molecular tools associated with culture observations are applied.  相似文献   

Impacts of mariculture practices on the temporal distribution of macrobenthos in Sandu Bay,South China   总被引：3，自引：0，他引：3  

周进 《中国海洋湖沼学报》2012,30(3):388-396

Sandu Bay is located in the East China Sea and is characterized by high-density fish farming and kelp culture. Despite this, little is known about the impacts of these different mariculture practices on the local environment. We investigated the temporal variation in macrobenthos and environmental conditions at three sites in the bay (fish farming site, kelp culture site, and a control site). We collected water and sediment samples during nine cruises between May 2009 and February 2010. The density of macrobenthos peaked at the fish farming site in July (655 ind./m2) whereas density did not fluctuate as widely at the other two sites. Biomass varied significantly at both the control and kelp culture sites, but had only a single peak at the fish farming site in June (21.90 g/m2). The dominant species varied throughout the study period at the control and kelp culture sites, whereas a single terebellid species (Lysilla pacifica) dominated the macrobenthos at the fish farming site. The diversity index H’ increased at the control site beginning in February then decreased after May, whereas H’ was low at the other sites in December. The mean dissolved oxygen level was highest at the control site (6.59 mg/L) and lowest at the fish farming site (5.54 mg/L). DO levels were lowest at all sites in summer (July and August). The sediment acid volatile sulfide content was higher at the fish farming site (1.46 mg/g dry weight) than those at the kelp culture and control sites (1.22 and 0.14 mg/g, respectively). Our results suggest that mariculture practices have a clear impact on the benthic environment/ community in Sandu Bay.  相似文献   

Pigment characterization for the 2011 bloom in Qinhuangdao implicated "brown tide" events in China   总被引：6，自引：0，他引：6  

孔凡洲  于仁成  张清春  颜天  周名江 《中国海洋湖沼学报》2012,30(3):361-370

A large-scale bloom occurred from May to June in 2011 in sea area near Qinhuangdao of the Bohai Sea, leading to huge damage of the scallop culture industry. Similar blooms have been observed in this region for three years. The causative species of the bloom, which dominated the phytoplankton community with the maximum cell density around 109 cell/L, could not be identified with morphological features due to the small cell size (~2 mm). A pigment analytical method was then adopted to analyze the pigment profile of the phytoplankton samples collected from the blooming sea area. It was found that pico-sized (<2 mm), nano-sized (2-20 mm), and bulk phytoplankton samples had similar pigment profile, representing the pigment signature of the bloom-causative species. The major pigments detected included 19-butanoyloxyfucoxanthin (But-fuco), fucoxanthin (Fuco), diadinoxanthin (Diad) and chlorophyll a (Chl a), and high content of But-fuco was the most significant characteristics of the phytoplankton samples. Based on the pigment composition and content, the bloom-causative species could be tentatively identified as pelagophyte, "type 8" group of haptophyte, or silicoflagellate. Some unique features of the bloom, such as the extremely high cell density, small-sized and But-fuco containing cells, occurring in early summer, and the feeding-cessation effects on scallops, suggest it be a "brown tide" event similar to those reported in the east coast of the United States of America. The recurrent "brown tide" events and their dramatic impacts on the shellfish mariculture industry in Qinhuangdao need close attention in the coming years.  相似文献   

BAC end sequencing of Pacific white shrimp <Emphasis Type="Italic">Litopenaeus vannamei</Emphasis>: a glimpse into the genome of Penaeid shrimp     

赵翠  张晓军  柳承璋  郇聘  李富花  相建海  黄超 《中国海洋湖沼学报》2012,30(3):456-470

Little is known about the genome of Pacific white shrimp (Litopenaeus vannamei). To address this, we conducted BAC (bacterial artificial chromosome) end sequencing of L. vannamei. We selected and sequenced 7 812 BAC clones from the BAC library LvHE from the two ends of the inserts by Sanger sequencing. After trimming and quality filtering, 11 279 BAC end sequences (BESs) including 4 609 paired- ends BESs were obtained. The total length of the BESs was 4 340 753 bp, representing 0.18% of the L. vannamei haploid genome. The lengths of the BESs ranged from 100 bp to 660 bp with an average length of 385 bp. Analysis of the BESs indicated that the L. vannamei genome is AT-rich and that the primary repeats patterns were simple sequence repeats (SSRs) and low complexity sequences. Dinucleotide and hexanucleotide repeats were the most common SSR types in the BESs. The most abundant transposable element was gypsy, which may contribute to the generation of the large genome size of L. vannamei. We successfully annotated 4 519 BESs by BLAST searching, including genes involved in immunity and sex determination. Our results provide an important resource for functional gene studies, map construction and integration, and complete genome assembly for this species.  相似文献   

Mineral constituents in common chanterelles and soils collected from a high mountain and lowland sites in Poland   总被引：1，自引：1，他引：0  

Jerzy FALANDYSZ  Magorzata DREWNOWSKA  Grazyna JARZY SKA 《山地科学学报》2012,9(5):697-705

This paper reported the results of the determination of Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sr and Zn in Common Chanterelles (Cantharellus cibarius) Fr. and surface soil layer (0-10 cm) underneath the fruiting bodies. Mushrooms and soils were collected from a lowland site in the Hel Peninsula (Baltic Sea coast) and a high mountain site in the Tatra Mountains. The trace elements were determined using validated method and inductively coupled plasma - atomic emission spectroscopy (ICP-AES). Common Chanterelles that emerged at sites poor in mineral nutrients podzols of the Hel Peninsula forests efficiently bioconcentrated several essential trace elements (K, P, Co, Cu, Mn, Na, Zn), while the abundance of those elements in carpophores was around half less compared to specimens from Zakopane region and which emerged in soils much richer in minerals. Common Chanterelles collected at two spatially distant background areas in Poland were only weakly contaminated with metals such as Ag, Cd, Hg and Pb. The maximum tolerable Cd and Pb contents of certain cultivated mushrooms are regulated in the European Union by law and these hazardous metals in C. cibarius were far below tolerance limits set.  相似文献   

Arctic freshwater ostracods from modern periglacial environments in the Lena River Delta (Siberian Arctic,Russia): geochemical applications for palaeoenvironmental reconstructions     

Sebastian?WetterichEmail author  Lutz?Schirrmeister  Hanno?Meyer  Finn?Andreas?Viehberg  Andreas?Mackensen 《Journal of Paleolimnology》2008,39(4):427-449

The aim of this study is to describe ostracods from freshwater habitats in the Siberian Arctic in order to estimate the present-day relationships between the environmental setting and the geochemical properties of ostracod calcite. A special focus is on the element ratios (Mg/Ca, Sr/Ca), and the stable isotope composition (δ¹⁸O, δ¹³C), in both ambient waters and ostracod calcite. The most common species are Fabaeformiscandona pedata and F. harmsworthi with the highest frequency in all studied waters. Average partition coefficients D(Sr) of F. pedata are 0.33 ± 0.06 (1σ) in females, and 0.32 ± 0.06 (1σ) in males. A near 1:1 relationship of δ¹⁸O was found, with a mean shift of Δ_mean = 2.2‰ ± 0.5 (1σ) to heavier values in ostracod calcite of F. pedata as compared to ambient waters. The shift is not dependent on δ¹⁸O_water, and is caused by metabolic (vital) and temperature effects. Temperature-dependence is reflected in the variations of this shift. For ostracod calcite of F. pedata a vital effect as compared to inorganic calcite in equilibrium was quantified with 1.4‰. Results of this study are valuable for the palaeoenvironmental interpretation of geochemical data of fossil ostracods from permafrost deposits.  相似文献