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球形棕囊藻(Phaeocystisglobosa)是我国南方沿海近年来主要的赤潮原因种之一,由球形棕囊藻形成的赤潮对海水养殖业发展和海域生态环境构成了严重威胁。棕囊藻通常以囊状群体形式形成赤潮,很难获取其丰度数据,以往研究中多以19′-己酰氧基岩藻黄素(Hex-fuco)或19′-丁酰氧基岩藻黄素(But-fuco)作为其特征色素,利用化学分类软件CHEMTAX计算其生物量。为了解我国近海球形棕囊藻的色素组成特征,本文采用高效液相色谱方法,分析了6株球形棕囊藻的色素组成与含量状况,其中5株分离自我国近海。结果表明, 6株球形棕囊藻均以岩藻黄素和叶绿素a为主要色素,但其特征色素Hex-fuco却存在显著的株系间差异,即便是分离自相同海域的不同球形棕囊藻藻株也存在差别。对比棕囊藻游离细胞和囊状群体的色素组成,可以看出两者在色素组成上基本一致,但囊状群体中捕光色素(Light-harvesting pigment)含量低于游离细胞,而光保护色素(Photoprotective pigment)则高于游离细胞,可能与不同存在形态的棕囊藻对光照的适应特征差异有关。以上研究表明,在以CHEMTAX方法计算球形棕囊藻生物量时,需要充分调查海域棕囊藻的特征色素组成情况,获取其特征色素信息,构建合理色素比例初始矩阵,为球形棕囊藻赤潮监测奠定基础。 相似文献
74.
Satellite-derived phytoplankton pigment absorption(a_(ph)) has been used as a key predictor of phytoplankton photosynthetic efficiency to estimate global ocean net primary production(NPP). In this study, an a_(ph)-based NPP model(Ab PM) with four input parameters including the photosynthetically available radiation(PAR), diffuse attenuation at 490 nm(K_d(490)), euphotic zone depth(Z_(eu)) and the phytoplankton pigment absorption coefficient(a_(ph)) is compared with the chlorophyll-based model and carbon-based model. It is found that the Ab PM has significant advantages on the ocean NPP estimation compared with the chlorophyll-based model and carbonbased model. For example, Ab PM greatly outperformed the other two models at most monitoring sites and had the best accuracy, including the smallest values of RMSD and bias for the NPP estimate, and the best correlation between the observations and the modeled NPPs. In order to ensure the robustness of the model, the uncertainty in NPP estimates of the Ab PM was assessed using a Monte Carlo simulation. At first, the frequency histograms of simple difference(δ), and logarithmic difference(δ~(LOG)) between model estimates and in situ data confirm that the two input parameters(Z_(eu) and PAR) approximate the Normal Distribution, and another two input parameters(a_(ph) and K_d(490)) approximate the logarithmic Normal Distribution. Second, the uncertainty in NPP estimates in the Ab PM was assessed by using the Monte Carlo simulation. Here both the PB(percentage bias), defined as the ratio of ΔNPP to the retrieved NPP, and the CV(coefficient of variation), defined as the ratio of the standard deviation to the mean are used to indicate the uncertainty in the NPP brought by input parameter to Ab PM model. The uncertainty related to magnitude is denoted by PB and the uncertainty related to scatter range is denoted by CV.Our investigations demonstrate that PB of NPP uncertainty brought by all parameters with an annual mean of5.5% covered a range of –5%–15% for the global ocean. The PB uncertainty of Ab PM model was mainly caused by a_(ph); the PB of NPP uncertainty brought by a_(ph) had an annual mean of 4.1% for the global ocean. The CV brought by all the parameters with an annual mean of 105% covered a range of 98%–134% for global ocean. For the coastal zone of Antarctica with higher productivity, the PB and CV of NPP uncertainty brought by all parameters had annual means of 7.1% and 121%, respectively, which are significantly larger than those obtained in the global ocean. This study suggests that the NPPs estimated by Ab PM model are more accurate than others, but the magnitude and scatter range of NPP errors brought by input parameter to Ab PM model could not be neglected,especially in the coastal area with high productivity. So the improving accuracy of satellite retrieval of input parameters should be necessary. The investigation also confirmed that the SST related correction is effective for improving the model accuracy in low temperature condition. 相似文献
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采用传统养殖试验方法研究了日粮中添加叶黄素与角黄素对瓦氏黄颡鱼(Pelteobagrus vachelli Richardson)体色的影响。实验设计了11组等蛋白质(42.6%)、等能量(18.5MJ/kg)的实用试验日粮,在试验日粮中分别添加0、25、50、100、200mg/kg叶黄素和25、50、100mg/kg叶黄素与25、50mg/kg角黄素,对照组为野生瓦氏黄颡鱼。结果表明,实验结束时(60d),试验3、8、9日粮组(添加50mg/kg叶黄素、50mg/kg叶黄素+25mg/kg角黄素、50mg/kg叶黄素+25mg/kg角黄素)鱼体体色与对照组鱼(野生瓦氏黄颡鱼)体色相似,试验3、8、9组鱼皮肤中叶黄素含量与对照组鱼差异不显著(P0.05)。本实验认为,在日粮中添加叶黄素对瓦氏黄颡鱼的着色效果明显较角黄素好,是养殖瓦氏黄颡鱼饲料的适宜添加色素。在瓦氏黄颡鱼的饲料中叶黄素的建议添加量为50mg/kg。 相似文献
77.
为探究珠江口海域自养微微型浮游生物种群时空分布特征及其与环境之间的关系,于2013年5~11月,运用高液相色谱(HPLC)法和流式细胞术对珠江口海域表层水体中微微型浮游生物进行测定。流式细胞计数结果显示,珠江口海域自养微微型浮游生物由聚球藻(Synechococcus, Syn)和微微型真核生物(Picoeukaryotes,PEUK)组成。聚球藻始终占据总细胞丰度的主导地位。光合色素化学分类法(Chemotaxonomy,CHEMTAX)分析表明,自养微微型浮游生物群落结构具有明显的季节性变化,春季和夏季生物量以聚球藻为主,秋季生物量以青绿藻为主。CHEMTAX分析和流式细胞计数结果的相关性分析表明,在春季和夏季Syn细胞丰度与CHEMTAX生物量(即Syn贡献chla)之间呈现极显著正相关(P<0.01),PEUK细胞丰度与CHEMTAX生物量(即PEUK贡献chla)也存在显著正相关(P<0.05);然而,在秋季则无显著性相关关系(P>0.05)。冗余分析表明,温度和营养盐浓度是影响自养微微型浮游生物群落分布与组成的重要因素。另外,盐度、透明度、悬浮颗粒物对自养... 相似文献
78.
Upwelling occurs on the coast of Java between June and October, forced by local alongshore winds associated with the southeasterly monsoon. This causes variations in phytoplankton community composition in the upwelling zone compared with the surrounding offshore area. Based on pigments analysis with subsequent calculations of group contributions to total chlorophyll a(Chl a) using CHEMTAX, we studied the distribution and composition of phytoplankton assemblages in the subsurface chlorophyll maximum along the south coast of Java and the influence of upwelling. Nineteen phytoplankton pigments were identified using high-performance liquid chromatography, and CHEMTAX analysis associated these to ten major phytoplankton groups. The phytoplankton community in the coastal area influenced by upwelling was characterized by high Chl a and fucoxanthin concentrations, indicating the dominance of diatoms. In contrast, in the offshore area, the Chl a and fucoxanthin concentrations declined to very low levels and the community was dominated by haptophytes represented by 19′-Hexanoyloxyfucoxanthin. Accordingly, microphytoplankton was found to be the major size class in the coastal area influenced by upwelling, while nanophytoplankton was most abundant in the offshore area. Low concentrations of other accessory pigments indicated less contribution from dinoflagellates,prasinophytes, chlorophytes and cryptophytes. Photo-pigment indices revealed that photosynthetic carotenoids(PSCs) were the largest component of the pigment pool, exceeding the proportion of Chl a, with the average PSCTP up to 0.62. These distribution trends can mainly be explained by phytoplankton adaption strategies to upwelling and subsurface conditions by changing species composition and adjusting the pigment pool. 相似文献
79.
海洋酸度变化下孔石莼对农药硫丹的生态响应研究 总被引:1,自引:0,他引:1
硫丹作为一种持久性有机氯农药,其对水生生物的毒性已引起广泛关注。本文以大型海藻孔石莼为材料,探究了海洋酸度变化下硫丹对孔石莼的生态毒理学效应。实验结果表明,低浓度硫丹对孔石莼的生长、光合色素及2种抗氧化酶均有明显的促进效应,50μg/L的硫丹促进效应最为显著,然而随着硫丹浓度的升高或暴露时间的延长,抑制作用明显增强。pH=7.9会促进孔石莼的生长,但会降低藻体内光合色素的含量。低pH环境会进一步加剧硫丹对孔石莼的毒性效应,两者的交互作用在不同时间段发挥不同的主效应。 相似文献
80.
吐鲁番盆地侏罗系沉积岩的颜色与铁的赋存状态关系研究 总被引:1,自引:0,他引:1
吐鲁番盆地中-上侏罗统是典型的陆相沉积岩,发育了众多彩色岩层,如浅红色、棕色、灰绿色层等。穆斯鲍尔谱法测试结果显示这些沉积岩多变的颜色受其总铁含量和铁元素的赋存状态(化学种)的控制。检测出的铁化学种主要有反铁磁性赤铁矿铁、顺磁性三价铁和顺磁性亚铁,黄铁矿铁仅在很少样品中存在。总体而言,浅红色岩层含有最高的总铁含量和赤铁矿铁,灰色岩层则以顺磁性的亚铁为主,暗色和绿色岩石仅含有顺磁性的二价铁或者与相对丰度较低的三价铁共存。岩石中的铁元素及其化学种是影响其岩性特征,包括颜色的一个重要因素,并进一步影响遥感技术应用的图像解译和谱段选择。 相似文献