胶州湾北部沿岸浮游植物生态特征的研究

根据1998年4月中旬～10月中旬胶州湾北部的调查结果,共检出浮游植物26属56种,其中硅藻23属50种,甲藻3属6种。浮游植物数量的峰值出现在4月中旬和9月下旬,其均值分别为15115.5×103cell／m3和133315．1×103cell／m3,最低值出现在6～7月。加氏星杆藻、中肋骨条藻和浮动弯角藻曾在该海区形成优势种。     

虾塘水体中浮游植物群落特征及其与营养状况的关系

通过对虾养殖期间的连续监测结果;讨论和阐述了虾塘水体中浮游植物群落特征及其与营养状况的关系。虾塘中浮游植物在生态学上主要表现为群落构成简单、优势种单一且演替速度快,从而决定了该环境中浮游植物群落的不稳定性。无机氮营养盐（IN）是浮游植物繁殖生长的限制性因素,二者之间里较好的幂函数衰减曲线关系（R＝0．76）,且当浮游植物密度降至3．2×103细胞／ml时,水环境中的IN呈跃升趋势,此时所对应的透明度为0．6±0．2m。     

包头南海湖非冰封期浮游植物的时空动态特征

为了解包头南海湖浮游植物群落非冰封期的时空动态特征,2017年5-10月,在南海湖设置了12个监测站位,监测浮游植物时空变化,并同步监测水环境因子。结果表明,南海湖12个站位共鉴定出浮游植物146种(含变种);其中,绿藻门(Chlorophyta)59种,蓝藻门(Cyanophyta)31种,硅藻门(Bacillariophyta)37种,裸藻门(Euglenophyta)9种,金藻门(Chrysophyta)5种,黄藻门(Xanthophyta)3种,隐藻门(Cryptophyta)2种。浮游植物密度为23.35×10~6～115.59×10~6个/L;优势度分析表明,5-6月主要以绿藻占优势,优势种为四尾栅藻(Scenedesmus quadricauda)和螺旋弓形藻(Schroederia spiralis);7-9月主要以蓝藻占优势,优势种为微小平裂藻(Merismopedia tenuissima)和水花束丝藻(Aphanizomenon flosaquae);10月以绿藻和硅藻占优势,优势种为四尾栅藻和近缘针杆藻(Synedra affinis)。空间上呈现出沿进水口向湖心区逐渐递增的趋势,湖心区整体密度较高,而排污口和芦苇区处密度相对较低;冗余分析(RDA)表明,氨氮、化学需氧量、pH、叶绿素-a以及水温是影响浮游植物分布的主要水环境因子,绿藻与总氮关系密切,蓝藻主要受总磷的影响,硅藻受pH影响较大。     

黄海春季浮游植物的调查研究

1998年 5月 16日～ 6月 1日 ,对黄海 ( 33°0 0′～ 39°30′N,12 1°0 0′～ 12 5°30′E)进行了浮游植物调查研究 ,结果显示 :1998年春季黄海已鉴定的浮游植物有 14属 2 9种。其中 ,硅藻门有 10属 2 1种 ,甲藻门 4属 8种。在硅藻门中圆筛藻属的种类最多 ,有 7种 ,其次是根管藻属 ,有 3种。甲藻门中甲藻属的种类最多 ,有 5种。浮游植物的平均数量为 2 .2 3× 10 4 个 / m3,其中 ,硅藻门的平均数量为1.55× 10 4 个 / m3,占浮游植物总量的 69.5% ,甲藻门的平均数量为 0 .68× 10 4 个 / m3,占浮游植物总量的 30 .5%。黄海北部浮游植物的数量高于黄海中、南部。黄海浮游植物分布密集区主要在调查区西、北部。与 1986年同期黄海浮游植物调查资料相比 ,1998年春季黄海浮游植物的种类组成和 1986年春季相似 ,但浮游植物的数量减少 64.6%。     

鲢、鳙对三角帆蚌池塘藻类影响的围隔实验

以浙江金华汤溪威旺养殖基地的三角帆蚌养殖水体为研究对象,通过围隔实验比较研究了单养鲢、鳙和三角帆蚌的池塘浮游植物密度、生物量和优势种(属)组成等的差异,以及养蚌池混养鲢鳙对水体浮游植物密度、生物量以及优势种变化的影响。结果表明,养蚌(10#)围隔的浮游植物平均密度和生物量均显著高于高密度鲢(12#)围隔(P<0.05),其蓝藻数量及生物量显著高于高密度鲢(12#)和低密度鳙(13#)围隔(P<0.05),绿藻数量则显著低于低密度鲢单养(11#)围隔(P<0.05)。在鱼蚌混养的情况下,单养蚌(10#)围隔浮游植物平均数量显著高于鲢-蚌混养(15#,16#)和鳙-蚌混养(17#,18#)围隔(P<0.05),其蓝藻数量及生物量极显著高于鲢-蚌混养(15#,16#)或鳙-蚌(17#,18#)围隔(P<0.01),其绿藻数量显著低于混养高密度鲢(16#)或低密度鳙(17#)的混养围隔(P<0.05)。研究结果充分说明,鲢、鳙和三角帆蚌三者对水体藻类组成的影响有别,三角帆蚌养殖池中适当混养鲢或鳙可以有效控制蓝藻(铜绿微囊藻)的生长,促进绿藻(四尾栅藻)的生长,并最终有利于三角帆蚌的养殖,混养鲢密度的增加有利于控制藻类生长,而鳙密度的增加促进了裸藻等中大型藻类的生长。     

虾蟹混养池塘浮游植物群落结构的变化特征

为摸清锯缘青蟹(Scylla serrata)与斑节对虾(Penaeus monodon)混养池塘浮游植物种群结构的变化特征,于2018年3-11月对广州市番禺区十六涌3个养殖池塘中的浮游植物开展了逐月调查,并通过冗余分析(RDA)探讨了浮游植物与环境因子的相关性。结果表明,养殖池塘中共鉴定出浮游植物29种,主要由硅藻、蓝藻、甲藻、绿藻和裸藻5大门类组成,其中硅藻种类最多(19种),占浮游植物种类数的65.5%;其次是蓝藻,共5种,占浮游植物种类数17.2%;甲藻3种,绿藻和裸藻各1种。共出现优势种16种,主要为直舟形藻(Navicula directa)、奇异菱形藻(Nitzschia paradoxa)、柔弱菱形藻(Nitzschia delicatissima)、尖布纹藻(Gyrosigma acuminatum)、大角角藻(Ceratium macroceros)和小颤藻(Oscillatoria tenuis)等。浮游植物细胞密度介于2.56×103~189.2×103个·m-3,Shannon-Weaver多样性指数介于0.468~2.597。浮游植物与环境因子相关性RDA结果表明,营养盐、盐度和pH是影响养殖塘浮游植物种群结构的主要环境因子。     

博斯腾湖浮游植物季节变化的研究

针对博斯腾湖近几年面临着污染加剧、水体富营养化、渔业捕捞盲目等关键问题,采用《内陆水域渔业自然资源调查手册》有关方法,2004年通过6次有代表性采样,对博斯腾湖浮游植物数量、生物量进行了全面的分析研究。结果显示,博斯腾湖浮游植物数量最低的是4月,最高的是8月;6次采样数量为3．0×10^4～1423．2×10^4个／L,平均为393．7×10^4个／L;生物量为0,064～8,256mg/L,平均为2．969mg/L。全年以飞燕角甲藻（Ceratium hirundinella）为主要的优势种类;微囊藻（Microcystis）是全湖次优势藻,不仅在夏季出现率高,而且在寒冷且水温低的11月也多有出现;钟罩藻（Dinobryon）是喜水温较低的种类,该种类在4月为多个站的绝对优势种。     

Effects of shrimp pond water on phytoplankton: importance of salinity and trophic status of the receiving environment

Aquaculture generates a large load of effluents rich in organic matter and nutrients that may be introduced into the environment. This study aimed to assess in a microcosm experiment, the effect of shrimp pond water mixed with Patos Lagoon estuary water on phytoplankton chlorophyll a and primary production, simulating two salinities. Chlorophyll a, dissolved inorganic nutrients and primary production were measured in two experiments. In Harvest I, salinity of shrimp pond and environment water was similar, and chlorophyll a showed different trends over time, according to the amount of nitrogen available. In Harvest II, with different salinities and high nutrient concentrations in environment water, chlorophyll a levels showed a similar increasing trend over time in all mixtures. Net primary production showed differences among treatments in the first sampling in Harvest I, but not in the second, whereas no differences were observed among treatments in Harvest II. We conclude that shrimp pond effluent can lead to short‐term variations in chlorophyll a and primary production levels, with similar salinities. Salinity differences result in lower chlorophyll a and primary production values than expected according to the nutrient input. Differences in salinity can be an important management strategy to choose the best harvest period.     

铜陵淡水豚国家级自然保护区浮游植物群落特征与水质评价

经济发展改变了铜陵淡水豚国家级自然保护区的水域水生生态环境,为了揭示该保护区浮游植物群落结构特征与水质状况,分别于2011年6月、7月及9月按对4个代表性断面进行浮游植物群落研究,并根据浮游植物群落结构的物种组成,及其结合Shannon-Weaver指数和 Pielou 均匀度指数对水质营养及污染状况进行评价。结果表明：该保护区浮游植物有86种,其中绿藻门最多,34种,占全部浮游植物种类的39.53%;硅藻次之,29种,占总种类的33.73%;蓝藻门14种,占总种类的16.28%。浮游植物总平均密度为9.79×105 ind•L-1,总平均生物量为0.303mg•L-1,调查区域浮游植物平均密度由高到低依次为铜陵沙头南>铜陵沙头北>萝卜洲尾南>萝卜洲尾北;平均生物量由高到低依次为铜陵沙头南>铜陵沙头北>萝卜洲尾北>萝卜洲尾南。铜陵淡水豚自然保护区水质属于富营养型,处于α-中污染状态。     

Mutualism between euryhaline tilapia Sarotherodon melanotheron heudelotii and Chlorella sp.—Implications for nano-algal production in warmwater phytoplankton-based recirculating systems

The West-African euryhaline tilapia, Sarotherodon melanotheron heudelotii shift from visually feeding on zooplankton when juveniles to mostly filter feeding on phytoplankton when adults. When reared using an appropriate ration in intensive aquaculture systems, S. m. heudelotii also consume algal-based detritus, and contribute to sediment mineralization, clean up their environment, and ultimately stimulate and sustain algal growth. We analysed such practical advantages for phytoplankton-based recirculating systems, using S. m. heudelotii and Chlorella sp. as biological material originating from the prototype of such a system operated in Senegal. We performed a 24-h factorial design experiment in 36 tubs, cross-classifying three levels of S. m. heudelotii (fishless control, unfed fish, and fed fish) with four levels of Chlorella initial density.Chlorella overall mean density increased significantly from fishless, to unfed fish, and fed fish treatments, and with Chlorella initial density. S. m. heudelotii did not alter nitrogen nor phosphorus concentrations, only affected by algal initial densities. Most ammonia excreted by fish was probably uptaken by Chlorella. Bacteria-mediated diurnal nitrification was possibly an alternative ammonium loss mechanism at highest oxygen concentrations. Algae were not limited by nitrogen or phosphorus but most likely by low dissolved organic carbon availability. Chlorella differential responses with fed vs. unfed Sarotherodon suggest that CO₂ supplied by heterotrophic S. m. heudelotii respiration played a key role. Observed Chlorella growth rates were similar to the highest rates obtained in algal mass cultures, enriched with CO₂, nitrate and phosphate, under artificial lighting.Our results suggest the existence of a Sarotherodon-Chlorella mutualism in our systems, where S. m. heudelotii provide CO₂, the major limiting factor of Chlorella growth, whereas Chlorella oxygenate and detoxify the water media from ammonia, promoting S. m. heudelotii production. This mutualism could be used to optimize photosynthetic suspended-growth aquaculture systems, particularly in the Tropics where light is abundant and temperature is continuously high.