小球藻和铜绿微囊藻的高浓度Chl-a高光谱定量模型

本研究将地物高光谱遥感技术应用于室内实验,从而得到小球藻和铜绿微囊藻的高光谱特征.通过多种半经验方法,如单波段、波段比值和微分法,建立了两藻种最优的Chl-a高光谱定量模型,并与室外情况进行了对比.结果表明:小球藻的最优定量模型为Chl-a=174.6 1138292(R703) 2.3(109[(R703)]2(p＜0.01),相应的方法适宜性为:一阶微分法＞单波段法＞波段比值法;铜绿微囊藻的最优定量模型为Chl-a=5299164(R757)1.9773(p＜0.01),相应的方法适宜性为:单波段法＞波段比值法＞一阶微分法;从高光谱特征来看,小球藻在540 nm和700 nm附近存在明显的特征波峰,其位置随Chl-a浓度增大而向长波方向偏离,铜绿微囊藻在530 nm、660 nm和700 nm附近存在3个较强的特征波峰,在610 nm和680 nm附近存在明显的波谷;与以往室外研究不同的是铜绿微囊藻的反射率在400-500 nm之间的R值并不低,是因为没有非藻类颗粒物的影响,总吸收明显降低.     

南太平洋所罗门群岛海域黄鳍金枪鱼繁殖生物学研究

根据2012年9~12月所罗门群岛海域采集的353尾黄鳍金枪鱼Thunnus albacares样本,分析渔获物个体组成、性别比例、性成熟率和性腺指数等繁殖生物学参数。结果表明,捕获个体中包含大小两个群体;雌性群体个体规格明显小于雄性(p0.001)。春夏季9~12月雌、雄总体性别比为0.67︰1,显著偏离1︰1(p0.01);但性别比例与调查月份和个体大小密切相关,从9月到12月逐渐接近,至12月达到1︰1(p0.05)。性别比例随叉长增长逐步降低,叉长大于110cm个体中以雄性为主(p0.05),雌性比例与叉长呈现线性负相关关系,相关系数为-0.90,(p0.01)。雌、雄个体性成熟率和性腺指数在春末夏初间逐步增长,至11~12月达到最高;Ⅴ~Ⅵ期产卵个体比例增加,这表明所罗门群岛海域黄鳍金枪鱼春夏季存在产卵群体,从10月开始出现产卵个体,调查期间12月产卵个体比例达到相对最高,并且性腺指数与叉长呈现正相关关系;更一步的分析表明,雌、雄个体初次性成熟叉长分别为97.4cm和103.7cm。对该海域黄鳍金枪鱼繁殖生物学的研究有助于了解该种群资源状况,对渔业资源评估具有重要意义。     

长江口及其邻近海域大型底栖动物生物量、丰度和次级生产力的初步研究

为了解长江口及邻近海域大型底栖动物生物量、丰度和次级生产力的分布情况于2004年2月、5月、8月和11月共4个航次分别在长江口40个观测站采集大型底栖动物定量样品并利用Brey的经验公式对大型底栖动物栖息丰度、生物量、次级生产力和P/B值进行了研究计算.该调查海域共采到大型底栖动物202种,其中多毛类102种,软体动物51种,甲壳类27种,棘皮动物7种,其它动物15种.大型底栖动物年平均丰度为394.7 ind/m2;年平均生物量以去灰分干重计,为2.58 g(AFDW)/m2;年平均次级生产力以去灰分干重计,为3.52 g(AFDW)/(m2*a);P/B值平均为1.53.结果表明,长江口大型底栖动物次级生产力自长江入海口向东呈递增趋势.本文分析了长江口及其邻近海域大型底栖动物优势种的组成,主要生态类群的分布特征和次级生产力分布格局与生态环境的关系.通过比较,发现长江口大型底栖动物优势种发生了较大的变化;次级生产力高于东海而低于渤海和胶州湾;P/B值高于南黄海、胶州湾和渤海,也说明了长江口大型底栖动物群落中个体小、生活史短,代谢快的种类所占的比例高于以上海域.     

Biogeochemical Variation in Dimethylsulfide, Phytoplankton Pigments and Heterotrophic Bacterial Production in the Subarctic North Pacific during Summer

Dimethylsulfide (DMS), chlorophyll a (Chl-a), accessory pigments (fucoxanthin, peridinin and 19-hexanoyloxyfucoxanthin), and bacterial production (BP) were measured in the surface layer (0–100 m) of the subarctic North Pacific, including the Bering Sea, during summer (14 July–5 September, 1997). In surface sewater, the concentrations of DMS and Chl-a varied widely from 1.3 to 13.2 nM (5.1 ± 3.0 nM, mean ± S.D., n = 48) and from 0.1 to 2.4 µg L^–1 (0.6 ± 0.6 µg L^–1, n = 24), respectively. In the subarctic North Pacific, DMS to Chl-a ratios (DMS/Chl-a) were higher on the eastern side than the western side (p < 0.0001). Below the euphotic zone, DMS/Chl-a ratios were law and the correlation between DMS and Chl-a was relatively strong (r ² = 0.700, n = 27, p < 0.0001). In the euphotic zone, DMS/Chl-a ratios were higher and the correlation between DMS and Chl-a was weak (r ² = 0.128, n = 50, p = 0.01). The wide variation in DMS/Chl-a ratios would be at least partially explained by the geographic variation in the taxonomic composition of phytoplankton, because of the negative correlation between DMS/Chl-a and fucoxanthin-to-Chl-a ratios (Fuc/Chl-a) (r ² = 0.476, n = 26, p = 0.0001). Furthermore, there was a positive correlation between DMS and BP (r ² = 0.380, n = 19, p = 0.005). This suggests that BP did not represent DMS and dimethylsulfoniopropionate (DMSP) removal by bacterial consumption but rather DMSP degradation to DMS by bacterial enzyme.     

基于多元统计分析的渔山列岛潮间带软体动物功能群和次级生产力比较

渔山列岛于2008年成为国家级海洋生态保护区,为了解渔山列岛保护区内潮间带软体动物次级生产力的时空变化。于1982年和2010年的3个季节(春、夏、冬)在渔山列岛进行潮间带软体动物调查,采用多元统计分析软体动物时空差异,以Brey经验公式计算分析软体动物次级生产力(P值,P/B值)。结果表明,年际间物种食性结构发生了明显的改变,1982年潮间带软体动物对次级生产力贡献率最大的物种有单齿螺(Monodonta labio)、锈凹螺(Chlorostoma rustica),占软体动物总次级生产力的42.88%,2010年潮间带软体动物对次级生产力贡献率最大的物种有覆瓦小蛇螺(Serpulorbis imbricata)、条纹隔贻贝(Septifer virgatus),占软体动物总次级生产力的75.96%。1982年,年均栖息密度为2758ind/m2,年均生物量为2100.26g/m2,年均次级生产力为240.04g/(m2·a),年均P/B值为0.63a–1;2010年,年均栖息密度为699ind/m2,年均生物量为1101.85g/m2,年均次级生产力为94.82g/(m2·a),年均P/B值为0.55a–1。多因素方差分析表明软体动物次级生产力年际间差异显著(F=5.761,P0.05),季节间和潮位间差异都不显著(F=0.135,P0.05;F=2.076,P0.05),P/B的值较低,表明该海域软体动物世代更替速度较慢,2010年的P/B值(0.55a–1)低于1982年的P/B值(0.63a–1),表明近30年来群落结构受到影响。     

营养盐因子对龙须菜和菊花江蓠氮磷吸收速率的影响

本文在实验室条件下,研究了营养盐因子对龙须菜和菊花江蓠N、P吸收速率的 影响,分别对不同氮和磷的浓度、氮磷比及不同化合态氮对这两种藻类氮、磷吸收速 率的影响进行了实验与分析．结果表明:在适宜范围内,两种海藻对氮、磷的吸收速率 随介质中氮、磷浓度的增加而增加;不同氮磷对两种海藻N吸收速率的影响不存在 显著差异,但对磷吸收速率的影响非常显著,最高对磷吸收速率在介质的氮磷比为 10:1时;海藻对NH4-N的吸收速率随着NO3-N／NH4-N比的降低而增加,对PO43-P的 吸收速率与对NH4-N的吸收相似,而对NO3-N的吸收速率与对NH4-N的吸收相反．     

Roles of Biogeochemical Processes in the Oceanic Carbon Cycle Described with a Simple Coupled Physical-Biogeochemical Model

To evaluate the contribution of biogeochemical processes to the oceanic carbon cycle and to calculate the ratio of calcium carbonate to organic carbon downward export, we have incorporated biological and alkalinity pumps in the yoked high-latitude exchange/interior diffusion-advection (YOLDA) model. The biogeochemical processes are represented by four parameters. The values of the parameters are tuned so that the model can reproduce the observed phosphate and alkalinity distributions in each oceanic region. The sensitivity of the model to the biogeochemical parameters shows that biological production rates in the euphotic zone and decomposition depths of particulate matters significantly influence horizontal and vertical distributions of biogeochemical substances. The modeled vertical fluxes of particulate organic phosphorus and calcium carbonate are converted to vertical carbon fluxes by the biological pump and the alkalinity pump, respectively. The downward carbon flux from the surface layer to the deep layer in the entire region is estimated to be 3.36 PgC/yr, which consists of 2.93 PgC/yr from the biological pump and 0.43 PgC/yr from the alkalinity pump, which is consistent with previous studies. The modeled rain ratio is higher with depth and higher in the Pacific and Indian Oceans than in the Atlantic Ocean. The global rain ratio at the surface layer is calculated to be 0.14 to 0.15. This value lies between the lower and higher ends of the previous estimates, which range widely from 0.05 to 0.25. This study indicates that the rain ratio is unlikely to be higher than 0.15, at least in the surface waters.     

2001-2002年天目湖(沙河水库)浮游植物的生态学研究

2001年6月~2002年5月,对天目湖进行的浮游植物周年调查表明,天目湖共有浮游植物7门75属,其中年平均丰度为5026.20×104个/L,以蓝藻为主,占总丰度的54.45%;而年平均生物量为(15.364±9.103)mg/L,其中硅藻居首位,为6.634 mg/L,占浮游植物年平均生物量的43.18%;其周年变化是丰度和生物量最高值均出现在5月,丰度在5月和9月出现2个峰值,而生物量则在5、7、10月出现3个峰值。浮游植物丰度从大坝处1#点到河流入湖口的9#、10#点变化不明显但略有增加,而生物量则呈明显增加。通过对水温、透明度、营养盐与浮游植物丰度和生物量的线性回归分析发现,浮游植物丰度、生物量与水温、TP存在显著的正相关,而与N/P比、透明度存在显著性负相关,与TN相关性不是很明显。     

不同固有频率比条件下圆柱双自由度涡激振动特性的数值研究

采用RANS方法,结合SST k-ω湍流模型,对不同顺流向与横顺流向固有频率的比值(即固有频率比,fnx/fny)条件下低质量比圆柱体的双自由度涡激振动进行了二维数值模拟。圆柱体的质量比为2.6,雷诺数范围为2 500~18 750,相应的约化速度范围为2~15,包括了经典试验中出现的整个锁定范围。通过研究发现,固有频率比是影响振动特性的重要参数,随着固有频率比的增加,响应幅值逐渐降低且向更高的约化速度偏移;在低约化速度范围内,固有频率比对顺流向和横流向振动之间的相位差以及升力频率有较大影响,从而得到各种不同偏向的8字形轨迹;最后对不同固有频率比条件下的尾涡模式进行了讨论,给出了对应不同约化速度时的尾涡模式。     

大菱鲆体重和主要体型比率性状的遗传动态分析

The objective of this study was to estimate genetic parameters of body width(BW)to body length(BL)ratio(BW/BL)and of body weight traits(BWT)in turbot,and to elucidate the genetic mechanism of the two traits during ontogeny by dynamic genetic analysis.From 3 to 27 months,BW,BL and BWT of each communally stocked fish were measured every 3 months.The BW/BL ratio was measured at different sampling ages.A twotrait animal model was used for genetic evaluation of traits.The results showed that the heritability values of BW/BL ratio ranged from 0.2168 to 0.3148,corresponding to moderate heritability.The BWT heritability values ranged from 0.2702 to 0.3479 corresponding to moderate heritability.The heritability of BW/BL ratio was lower than that of BWT,except at 3 months of age.Genetic correlation between BW/BL ratio and BWT decreased throughout the measurement period.Genetic correlations were higher than the phenotypic correlations.The current results for estimating genetic parameters demonstrate that the BW/BL ratio could be used as a phenotypic marker of fast-growing turbot,and the BW/BL ratio and BWT could be improved simultaneously through selective breeding.