A coupled ice-ocean ecosystem model for 1-D and 3-D applications in the Bering and Chukchi Seas     

Clara Deal 《极地研究(英文版)》2008,19(2):218-229

Primary production in the Bering and Chukchi Seas is strongly influenced by the annual cycle of sea ice. Here pelagic and sea ice algal ecosystems coexist and interact with each other. Ecosystem modeling of sea ice associated phytoplankton blooms has been understudied compared to open water ecosystem model applications. This study introduces a general coupled ice-ocean ecosystem model with equations and parameters for 1-D and 3-D applications that is based on 1-D coupled ice-ocean ecosystem model development in the landfast ice in the Chukchi Sea and marginal ice zone of Bering Sea. The biological model includes both pelagic and sea ice algal habitats with 10 compartments： three phytoplankton （pelagic diatom, flagellates and ice algae： D, F, and Ai） , three zooplankton （copepods, large zooplankton, and microzooplankton ： ZS, ZL, ZP） , three nutrients （ nitrate ＋ nitrite, ammonium, silicon ： NO3 , NH4, Si） and detritus （Det）. The coupling of the biological models with physical ocean models is straightforward with just the addition of the advection and diffusion terms to the ecosystem model. The coupling with a multi-category sea ice model requires the same calculation of the sea ice ecosystem model in each ice thickness category and the redistribution between categories caused by both dynamic and thermodynamic forcing as in the physical model. Phytoplankton and ice algal self-shading effect is the sole feedback from the ecosystem model to the physical model.  相似文献   

Analysis on the indicator species and ecological groups of pelagic ostracods in the East China Sea   总被引：2，自引：1，他引：1  

XU Zhaoli 《海洋学报(英文版)》2008,27(6):83-93

Ecological adaptation and ecological groups of pelagic ostracods were examined in the East China Sea （23°30′-33°00′N, 118°30′ -128°00′E）, in relation to temperature and salinity. The data were collected in four surveys conducted from 1997 to 2000. The density, yield density, or negative exponent models were used to determine the optimal temperature and salinity of water for the thriving growth of pelagic ostracods. Thereafter, ecological groups and potential distribution patterns of pelagic ostracods were determined based on the predicted parameters such as optimal temperature and salinity, consulting the geographic distribution. The analytical results indicate that, among the numerical dominant pelagic ostracods in the East China Sea （ECS）, Euconchoecia aculeata, E. elongata, E. chierchiae, E. maimai, and Cypridina dentata, etc. are offshore subtropical water species. These species are widely distributed in the area, and they can be brought by the warm current to north offshore during spring and winter. The predicated optimal temperature （OT） and optimal salinity （OS） for Paraconchoecia decipiens, P. echinata, P. spini- fera, P. oblonga, Conchoecia magna and Porroeciaporrecta are all greater than 25℃ and 34 separately. These species are mainly distributed in the waters of the Kuroshio, the Taiwan Warm Current, and the Taiwan Strait, and therefore are designated as ocean- ic tropical water species. On the other hand, Pseudoconchoecia concerttrica is considered as offshore subtropical water species based on its geographical distribution although its OT is 19℃. The other species, though their OSs are approximately 34 and with OTs ranging from 20° to 25℃, are considered as offshore subtropical water species because they were found to be widely distributed from the South China Sea to the East China Sea.  相似文献   

2004年春季东海赤潮高发区COD分布及其与赤潮关系的初步研究   总被引：6，自引：0，他引：6  

王颢  石晓勇  张传松  王修林 《海洋科学》2008,32(12):82-86

2004年4～5月初在东海赤潮高发区暴发的特大规模原甲藻赤潮前期和暴发初期对该海域进行的现场调查，并对该海域COD的分布特征进行了探讨。结果表明，赤潮暴发前COD为0．295-1.836mg／L，主要受陆源输入影响。根据其在局部海区底层出现的异常升高结合其他参数分析可对特定海区潜在赤潮暴发的可能性进行评估。赤潮暴发时COD为0．36～3．14mg／L，表层和中层与叶绿素存在显著正相关关系，表明其主要受生物影响。富营养化指数表明赤潮暴发前近一半海域已经处于富营养化状态，但COD对富营养化的贡献不如营养盐重要。  相似文献   

有毒赤潮藻及其毒素的危害与检测   总被引：6，自引：0，他引：6  

杜伟  陆斗定 《海洋学研究》2008,26(2):89-97

海洋中可引发赤潮的藻类约有300种,其中有毒赤潮藻为80种左右。现已知道的赤潮藻主要毒素有麻痹性贝毒、腹泻性贝毒、记忆缺失性贝毒、神经性贝毒、西加鱼度和溶血性毒素,前5种毒素的结构已经基本得到证实。有毒赤潮藻的毒素可以在海洋生物体内积累,人类误食含有藻毒素的食品时可能中毒,严重者还可能死亡。海洋有毒赤潮藻及其毒素的检测已经成为当今全球赤潮研究和监测的重要内容之一,可以通过形态学分类方法、分子生物学技术(遗传探针)和免疫学检测技术对有毒赤潮藻进行检测;可以通过生物学、物理化学检测方法和神经受体结合、免疫学检测技术对赤潮藻毒素进行检测。  相似文献   

Structure, biomass distribution and trophodynamics of the pelagic ecosystem in the Oyashio region, western subarctic Pacific     

Tsutomu Ikeda  Naonobu Shiga  Atsushi Yamaguchi 《Journal of Oceanography》2008,64(3):339-354

Biomass distribution and trophodynamics in the oceanic ecosystem in the Oyashio region are presented and analyzed, combining the seasonal data for plankton and micronekton collected at Site H since 1996 with data for nekton and other animals at higher trophic levels from various sources. The total biomass of biological components including bacteria, phytoplankton, microzooplankton, mesozooplankton, micronekton, fishes/squids and marine birds/mammals was 23 g C m⁻², among which the most dominant component was mesozooplankton (34% of the total), followed by phytoplankton (28%), bacteria (15%) and microzooplankton (protozoans) (14%). The remainder (9%) was largely composed of micronekton and fish/squid. Marine mammals/birds are only a small fraction (0.14%) of the total biomass. Large/medium grazing copepods (Neocalaus spp., Eucalanus bungii and Metridia spp.) accounted for 77% of the mesozooplankton biomass. Based on information about diet composition, predators were assigned broadly into mean trophic level 3–4, and carbon flow through the grazing food chain was established based on the estimated annual production/food consumption balance of each trophic level. From the food chain scheme, ecological efficiencies as high as 24% were calculated for the primary/secondary production and 21% for the secondary/tertiary production. Biomass and production of bacteria were estimated as 1/10 of the respective values for phytoplankton at Site H, but the role of the microbial food chain remains unresolved in the present analysis. As keystone species in the oceanic Oyashio region, Neocalanus spp. are suggested as a vital link between primary production and production of pelagic fishes, mammals and birds.  相似文献   

Long-term abundance patterns of macroalgae in relation to environmental variables in the Tagus Estuary (Portugal)     

Abel Sousa-Dias  Ricardo A. Melo 《Estuarine, Coastal and Shelf Science》2008

Seasonal and inter-annual patterns of macroalgal abundance in a Tagus Estuary oyster reef are described. Macroalgal abundance was estimated as canopy percent cover by three permanent point intercept transects over a 7-year period. Four categories were defined, corresponding to bare substrate and three different macroalgal functional-form groups: (1) ULVA, foliose group, included Ulva spp.; (2) GRACIL, terete corticated macrophyte group, included only Gracilaria gracilis; and (3) FILAM, small (<10 cm) filamentous group, including eight species. A canonical correspondence analysis (CCA) showed that: (1) ULVA were associated with long and hot days, being usually dominant during spring and especially summer; (2) FILAM were associated with mild temperatures and relatively long days, abundant in spring but showed frequent peaks in summer; and (3) GRACIL were also favoured by spring season, although associated to lower temperature and less daylight hours than FILAM. GRACIL and FILAM were present throughout the year. On the contrary, ULVA were absent or with low cover during colder periods. A negative correlation between GRACIL and FILAM seems to indicate competition between the two categories. The applied models explained 23.3% of the temporal variance in category abundance. Rainfall negatively affected macroalgal cover, as indicated by the positive correlation between rainfall and bare substrate. Our conclusions are in agreement with previous studies that consider algae as excellent environmental integrators, even on a small scale, due to a strong link between the macroalgal communities and relevant environmental variables. It is also relevant that this study used open-access databases of environmental variables, which open up new possibilities for mining existing data resources in new ways. Due to large inter-annual variability, long-term studies are essential to understand population dynamics in estuarine phytobenthic communities.  相似文献   

Application of an ecosystem model for the environmental assessment of the reclamation and mitigation plans for seagrass beds in Atsumi Bay   总被引：1，自引：0，他引：1  

Akio Sohma  Yasuyuki Sekiguchi  Kisaburo Nakata 《Estuarine, Coastal and Shelf Science》2009

An ecosystem model was used to evaluate the effects of reclaiming seagrass beds and creating artificial shallows with seagrass beds to mitigate the effects of the reclamation. The applied model can simulate the pelagic and benthic ecosystems including seagrass beds and tidal flats. The objectives of this study were (a) to investigate the likelihood of cultivating and maintaining seagrass beds in artificial shallows (Part 1), and (b) to understand the effects of the reclamation of seagrass beds and the creation of artificial shallows on the water quality in the estuary (Part 2). In Part 1, first, the nutrient turnover rates due to both biochemical and physical processes in the natural seagrass beds where reclamation is proposed were analyzed. Biological processes rather than physical processes were the most significant driving forces of nutrient cycles in seagrass beds. Second, the effects of filter feeding benthic fauna (suspension feeders) in the seagrass beds were analyzed. The scenario with suspension feeders resulted in higher transparency of the water column (8.7% decrease in the light attenuation coefficient) and an increase in nutrient supply (24.9% increase in NH₄-N in the water column) contributing to the high specific growth rate of seagrass. Third, the specific growth rate of seagrass on the proposed artificial shallows was measured. The value on the artificial shallows set at a depth of datum line minus 0.8 m (D.L. − 0.8 m) was approximately the same as that of the natural seagrass beds. In Part 2, first, water quality in the estuary was compared among the scenarios with/without natural seagrass beds and artificial shallows. Then, the defined values of the water purification capability of (a) artificial shallows with/without seagrass beds, and (b) natural seagrass beds per unit area were evaluated. The reclamation of the natural seagrass beds resulted in a decrease of the removal of phytoplankton and detritus from the pelagic system (i.e. resulted in a loss in the purification rate). In contrast, the creation of artificial shallows resulted in an increase of the removal of phytoplankton and detritus from the pelagic system (i.e. resulted in a gain in the purification rate). Based on an annual average, approximately twice as much phytoplankton was removed from the artificial shallows at the depth D.L. − 0.8 m, than at the depth, D.L. − 1.5 m, and the artificial shallows with seagrass beds removed pelagic DIN and DIP at a rate 120% higher than that without seagrass beds.  相似文献   

Isolation and identification of bacteria associated with the surfaces of several algal species     

王子峰  肖天  逄少军  刘敏  岳海东 《中国海洋湖沼学报》2009,27(3):487-492

We conducted this study to assess the diversity of bacteria associated with the surfaces of algae based on 16S rDNA sequence analyses.Twelve strains of bacteria were obtained from the surfaces of the following four species of algae:Gracilaria textorii,Ulva pertusa,Laminaria japonica,and Polysiphonia urceolata.The isolated strains of bacteria can be divided into two groups:Halomonas and Vibrio,in physiology,biochemical characteristics and 16S rDNA sequence analyses.The phylogenetic tree constructed based on ...  相似文献   

DNA barcode assessment of Ceramiales (Rhodophyta) in the intertidal zone of the northwestern Yellow Sea   总被引：1，自引：0，他引：1  

杜国英  吴菲菲  郭皓  薛红凡  茅云翔 《中国海洋湖沼学报》2015,33(3):685-695

A total of 142 specimens of Ceramiales(Rhodophyta) were collected each month from October 2011 to November 2012 in the intertidal zone of the northwestern Yellow Sea. These specimens covered 21 species,14 genera,and four families. Cluster analyses show that the specimens had a high diversity for the three DNA markers,namely,partial large subunit r RNA gene(LSU),universal plastid amplicon(UPA),and partial mitochondrial cytochrome c oxidase subunit I gene(COI). No intraspecific divergence was found in our collection for these markers,except for a 1–3 bp divergence in the COI of Ceramium kondoi,Symphyocladia latiuscula,and Neosiphonia japonica. Because short DNA markers were used,the phylogenetic relationships of higher taxonomic levels were hard to evaluate with poor branch support. More than half species of our collection failed to find their matched sequences owing to shortage information of DNA barcodes for macroalgae in Gen Bank or BOLD(Barcode of Life Data) Systems. Three specimens were presumed as H eterosiphonia crispella by cluster analyses on DNA barcodes assisted by morphological identification,which was the first record in the investigated area,implying that it might be a cryptic or invasive species in the coastal area of northwestern Yellow Sea. In the neighbor-joining trees of all three DNA markers,H eterosiphonia japonica converged with D asya spp. and was distant from the other Heterosiphonia spp.,implying that H. japonica had affinities to the genus Dasya. The LSU and UPA markers amplified and sequenced easier than the COI marker across the Ceramiales species,but the COI had a higher ability to discriminate between species.  相似文献   

盐度胁迫下中肋骨条藻和东海原甲藻的生长及内源多胺含量的变化   总被引：1，自引：1，他引：0  

朱晓文  赵卫红  苗辉 《海洋与湖沼》2015,46(1):50-57

在实验室内不同盐度梯度下培养常见的两种赤潮藻——中肋骨条藻(Skeletonema costatum s.l.)和东海原甲藻(Prorocentrum donghaiense),根据logistic生长模型获得了终止生物量Bf和最大生长速率μmax,并测定了藻体中过氧化物酶(POD)、二胺氧化酶(DAO)、多胺氧化酶(PAO)的活性和丙二醛(MDA)、腐胺(Put)、亚精胺(Spd)、精胺(Spm)的含量。结果表明,高、低盐度胁迫下,两种藻均会积累MDA,活性氧自由基的伤害增强,藻的生长受到了抑制。同时,两种藻都会提升多胺含量,通过多胺的调节作用来缓解胁迫的伤害,促进生长,但是在提升的多胺种类和形态上,两种藻存在着差异。高盐胁迫下,中肋骨条藻会提升多胺尤其是游离态多胺的含量来缓解伤害,东海原甲藻则依靠结合态的亚精胺和游离态的精胺的调节作用。低盐胁迫下,中肋骨条藻会提升游离态腐胺的含量,而东海原甲藻体内各形态的多胺都会上升。  相似文献