营养限制对三种浮游动物的影响

Nutrient imbalance—a mismatch in nutrient ratios between the available food supply and the demands of consumers—has the potential to be transported up food chains,exposing zooplankton to nutrient limitations.In this study,the response of Calanus sinicus(copepod),Moina mongolica(cladocera),and Brachionus plicatilis(rotifer) to nutrient-limited(no-limited,P-limited,and N-limited) food were evaluated from the perspective of growth,reproduction,and stoichiometric homoeostasis.The results indicated that the growth of three species was suppressed under nutrient-limited(especially P-limited) conditions.However,the effect of nutrient limitations on their reproduction was species-specific.For C.sinicus,the dietary UFA(unsaturated fatty acid) as a major phospholipid component affected their egg production and total FA supporting energy promoted the hatchability of eggs.Furthermore,excess carbon in the diet promoted egg production but reduced hatching success.For M.mongolica,nutritional(P and UFA) and energy(total FA) support affected their fecundity.B.plicatilis fecundity exhibited the same pattern of growth(no-limitedN-limitedP-limited).In terms of stoichiometric homeostasis,B.plicatilis' s elemental compositions were less likely to be affected by nutrient limitations than M.mongolica.We suggest that the effects of nutrient imbalances could potentially become an evolutionary force affecting ecosystem structure and stability in eutrophic waters.     

乌苏里白鲑肌肉营养成分与品质评价

【目的】测定乌苏里白鲑(Coregonusussuriensis)肌肉的营养成分,评价其营养品质。【方法】2016年11月2日于黑龙江干流抚远段采集乌苏里白鲑样品,用常规方法测定水分、粗蛋白、粗脂肪、灰分、氨基酸、脂肪酸和矿物质等成分,并分析其营养品质。【结果】乌苏里白鲑肌肉(鲜样)中水分、粗蛋白、粗脂肪和粗灰分的含量分别为76.96%±2.29%、20.44%±1.48%、1.28%±0.23%和1.19%±0.12%。肌肉中含有18种氨基酸,其中8种必需氨基酸(EAA)鲜样中质量分数是7.12%±0.58%,占氨基酸总量的37.39%,符合FAO/WHO推荐的理想蛋白质标准。根据AAS值乌苏里白鲑肌肉中第1限制性氨基酸为苏氨酸,第2限制性氨基酸为色氨酸,必需氨基酸指数(EAAI)为60.36。乌苏里白鲑肌肉中含有丰富的不饱和脂肪酸,脂肪酸中EPA、DHA含量分别为6.31%、13.86%,明显高于其他几种经济鱼类。肌肉中富含K、Na、P、Mg等多种人体所需的矿物质元素。【结论】乌苏里白鲑肌肉是一种高蛋白、低脂肪、脂肪质量较高健康食品。     

淤泥质光滩-盐沼过渡带波浪衰减的观测研究 以长江口崇明东滩为例

1 引言 波浪是海岸环境中最重要的动力条件之一.无论就泥沙起动、搬运和堆积的沉积动力学而言[1],还是从海岸防护的角度考虑[2],波浪都是不可缺少的动力因子.由沉积物组成的潮间带分布在世界海岸的许多岸段[3].由于黄河、长江等大河有大量细颗粒泥沙来源,我国有广泛发育的淤泥质潮间带,其中尤以连绵近千千米的江苏-上海潮间带著称于世.     

沙丘生境沙鞭（Psammochloa villosa）种群空间分布格局

种群空间分布格局是植物种群自身生物学特性与环境因素相互作用的结果,一直是生态学研究的热点。采用群落学调查与点格局分析方法,研究了不同沙丘生境下斑块植被沙鞭（Psammochloa villosa）种群的空间分布格局。结果表明：（1）沙鞭种群在不同沙丘生境下均存在聚集分布格局,聚集尺度表现出先减小后增大趋势;（2）沙鞭种群在半固定沙丘中2—37 cm尺度正向偏离泊松聚块模型,95—168 cm尺度负向偏离泊松聚块模型;（3）沙鞭种群在流动沙丘和固定沙丘符合嵌套双聚块模型,在半流动沙丘0—50 cm尺度负向偏离嵌套双聚块模型,在半固定沙丘0—3、98—105、110—123 cm和130—168 cm尺度负向偏离嵌套双聚块模型。斑块状分布和种内种间竞争是沙鞭种群空间分布格局发生转变的关键,确保斑块内部个体高度聚集,牺牲斑块外围个体是沙鞭种群空间布局和资源占据的生态适应策略之一。     

上海洋山建港后港域夏季水文泥沙状况分析

对2007年9月17-26日在上海洋山港海域固定观测点(平均水深13 m)观测得到的水文泥沙要素,以及悬沙和底质样品分析.分析结果为:1)港域有效波高0.21-1.37 m(风速0.6～14.0 m/s),平均0.61 m(平均风速5.5 m/s).平静天气(平均风速小于5.0 m/s)下,波高随水深变化,两者的相关系数为0.899;而在强风天气下,波高受风况控制.2)最大表层流速超过2.00 m/s.大潮涨潮流占优势,小潮时落潮流占优势;与北岛链汉道封堵前相比,大潮涨、落潮平均流速分别减小15%和30%,小潮涨、落潮平均流速均减小30%～40%.各层余流均为西北方向,与涨潮流方向一致;垂向平均余流速0.11 cm/s,表层达0.25 m/s.3)离底高程1.35 m层和0.35m层最大悬沙浓度均大于3 kg/m3,两层平均悬沙浓度分别为0.89和0.95 kg/m3.无论大潮还是小潮涨潮悬沙浓度均大于落潮,这种现象在大潮时更为显著,潮周期中最大悬沙浓度出现在涨急.与工程前相比悬沙浓度明显降低,大、小潮降低均达20%.4)港区底质平均粒径9.0μm,工程后有变细的趋势.     

温度和饵料对双刺纺锤水蚤产卵率和孵化率的影响

Acartia bifilosa (Copepoda: Calanoida) is a common species in offing of global waters and it often becomes dominant species in some estuaries. This species develops different strategy according to variation of environment. Despite its ecological role, Acartia bifilosa also has been concerned as live feeds in aquaculture, but study on egg production rate of this species in saturated diet in different temperature and different diet is so far not available. In order to interpret the importance of temperature and diet on natural population variation and also on aquaculture as foods of larval fish, the functional response of reproductive success of Acartia bifilosa was quantified in the laboratory using different temperatures and diets. Acartia bifilosa was captured in Jiaozhou Bay and acclimated to corresponding temperature for 3~4 days. In order to reduce the effect of large extent temperature range on organism, we captured Acartia bifilosa from March to June and acclimated them to temperature which is adjacent to natural temperature. Daily egg production rate (EPR, eggs female-1day-1) was detected for 11~15 days at 5 different temperatures ranged from 8.0 to 23 °C and all the females was feed on saturated diet all through the experiments. EPR on first day was not calculated in the mean EPR to eliminate the effect of different diets. This result showed that Acartia bifilosa spawned continuously during the experiment days and no obvious regulation was found. EPR was positively correlated with temperature from 8.0 to 23 °C. The highest mean EPR was observed at 23 °C (7.3 eggs female-1day-1), and the lowest value was found at 8 °C (3.8 eggs female-1day-1). The effect of diets on EPR was evaluated at two different temperatures (8.0 °C and 12.5 °C). Same trends were found at the two temperatures: mean EPR fed on Chaetoceros sp. was higher than that fed on Skeletonema costatum, and during the 14-day experiments, EPR was higher for females fed on Skeletonema costatum than chaetoceros sp. in the first few days (3~5 days), but it changed reversely in the subsequent days until the end of the experiments. Hatched eggs were observed in the two experiments at temperature 8°C and 12.5 °C and no diapause eggs were found. The hatching success rate was low at 8°C but reached 93.2% at 12.5 °C. According to the results in this paper, we detected the comfortable temperature range for EPR, and evaluated the effect of Skeletonema costatum which often brings out red tide in natural waters. These results are beneficial to ecological research for explaining population variation and population recruitment of this species, These data also can be used in Acartia bifilosa aquaculture.     

Distribution patterns of chlorophyll <Emphasis Type="Italic">a</Emphasis> in spring and autumn in association with hydrological features in the southern Yellow Sea and northern East China Sea

Two field studies were conducted to measure pigments in the Southern Yellow Sea (SYS) and the northern East China Sea (NECS) in April (spring) and September (autumn) to evaluate the distribution pattern of phytoplankton stock (Chl a concentration) and the impact of hydrological features such as water mass, mixing and tidal front on these patterns. The results indicated that the Chl a concentration was 2.43±2.64 (Mean ± SD) mg m^?3 in April (range, 0.35 to 17.02 mg m^?3) and 1.75±3.10 mg m^?3 in September (from 0.07 to 36.54 mg m^?3) in 2003. Additionally, four areas with higher Chl a concentrations were observed in the surface water in April, while two were observed in September, and these areas were located within or near the point at which different water masses converged (temperature front area). The distribution pattern of Chl a was generally consistent between onshore and offshore stations at different depths in April and September. Specifically, higher Chl a concentrations were observed along the coastal line in September, which consisted of a mixing area and a tidal front area, although the distributional pattern of Chl a concentrations varied along transects in April. The maximum Chl a concentration at each station was observed in the surface and subsurface layer (0–10 m) for onshore stations and the thermocline layer (10–30 m) for offshore stations in September, while the greatest concentrations were generally observed in surface and subsurface water (0–10 m) in April. The formation of the Chl a distributional pattern in the SYS and NECS and its relationship with possible influencing factors is also discussed. Although physical forces had a close relationship with Chl a distribution, more data are required to clearly and comprehensively elucidate the spatial pattern dynamics of Chl a in the SYS and NECS.     

渔洞水库地区地震活动性和构造应力场分析

统计了渔洞水库的水位变化规律,分析了水库蓄水前后库区及其附近地区的地震活动性和构造应力场特征。结果表明,水库蓄水前后研究区地震活动的图像、强度和频次都没有明显变化;水库蓄水和水位变化对研究区构造应力场没有明显的影响。     

2012年冬季菲律宾海浮游动物丰度和生物量的水平分布

为了解西太平洋菲律宾海浮游动物丰度和生物量的水平分布特征,于2012年11月26日至2012年12月12日对菲律宾海上层海洋(0—200m)的浮游动物进行了调查。调查站位分别位于受赤道逆流(NECC)、棉兰老流(MC)、北赤道流(NEC)和黑潮(KC)影响的海域。通过比较浮游动物的丰度和生物量(分别用干重,灰分,无灰干重和含能量等指标表示),探讨不同海流中浮游动物的分布特征。结果表明:桡足类、毛颚类和水母类是菲律宾海浮游动物的三大主要类群。调查海域浮游动物丰度为11—116ind./m3,NECC区平均丰度最高((96±28)ind./m3),然后依次是MC区和KC区,NEC区最小((26±9)ind./m3)。在浮游动物生物量(干重)方面,同样NECC区最高((3.25±1.11)mg/m3),其次为MC区,但是平均丰度最小的NEC区生物量超过KC区。造成这一差异的主要原因,可能是由于KC区的浮游动物具有更高的含水量以及较小个体所占比例较高。不同水团之间浮游动物灰分、无灰干重和含能量的分布特征与干重相一致。结合环境因子分析显示,上升流、叶绿素a、初级生产力、海流和温度等因素对浮游动物的分布具有一定影响。     

长江口年代际冲淤演变趋势预测与应对策略

受流域来水来沙条件变化及河口大型工程建设的综合影响,长江口呈现新的冲淤格局,为预测未来演变趋势,本研究基于前期研究中建立的长江口年代际冲淤演变预测模型（Delft3D）,未来情景考虑不同来沙量条件和相对海平面上升速率。预测结果表明,到2035年长江口整体以冲刷为主,口内河段主槽和浅滩边缘冲刷较明显,仅高滩局部淤积;到2050年口内河段保持净冲刷状态,拦门沙地区在现状来沙量条件下略有淤积,但在极端低来沙量条件下转变为净冲刷状态,海平面上升对拦门沙地区冲刷具有一定抵消作用,但不会使冲淤状态产生本质改变。本研究分析认为,长江口局部区域未来冲淤趋势可能对河口综合治理与保护产生不利影响,针对新格局条件下的滩槽河势稳定、重要洲滩保护、重大工程安全评估、冲刷致灾研判以及海堤防护标准再评估等方面提出了对策建议,可为新时期长江口综合治理与可持续发展提供参考。