深圳红树林湿地浮游植物多样性的组成与分布

根据深圳福田红树林湿地的浮游植物周年调查资料,分析浮游植物群落多样性的组成与时空分布特征,并利用浮游植物群落多样性指数对湿地水体的营养状态进行评价。共记录浮游植物5门28属51种,各季度浮游植物数量均超过10.6 ind·L^-1。硅藻分布广泛,在种类和数量上均占主导地位,优势种为微小小环藻（Cyclotella caspia）和诺氏海链藻（Thalassiosira nordenskiöldi）等,耐受污染的藻类,如小颤藻（Oscillatoria minima）、鱼形裸藻（Euglena pisciformis）在夏秋2季成为个别站位的优势种。浮游植物种类组成时空变化明显,而数量的空间变化较大、季节变化不大,优势种的时空变化明显,但种类单一,多样性指数的空间变化较大。群落多样性指数评价结果显示,深圳红树林湿地处于中-富营养化状态,有向富营养化过渡的趋势,应加强对内陆径流和污水排放进入红树林湿地的严格控制和管理。     

基于组合可拓综合分析法的鄱阳湖流域水质富营养化评价

长期跟踪定位评价湖泊的水质营养化程度,对于实现地区水功能具有重要意义。针对评价方法中指标选取的可行性、单一性、权重赋值的主观随意性以及水质变化的模糊性、随机性、动态性和生物指示性等特点,采用了可拓综合评价法和浮游生物调查与室内测定法相结合,构建了组合可拓综合分析法,一方面利用可拓综合分析法对鄱阳湖流域5个代表性观测站点的10年的年均（每2年）观测数据进行评价;另一方面通过浮游生物指示法对该5个站点的水质进行富营养化评价,以生物指示评价法所得等级与可拓综合分析法评定等级吻合的最多次数所对应等级作为组合可拓综合评价法的评价等级。结果表明：（1）自2006年以来鄱阳湖流域水体富营养化水平较为平稳,总体呈好转势态。2010年有4个观测点的水体达到富营养化程度,而在2014年湖区的蛤蟆石和鄱阳水质略有所改善,达到轻富营养化程度,都昌、康山、星子站点的水体为中营养化,改善幅度较大,水质较好;（2）从湖区的地理区位看,鄱阳湖湖区的南部和西部的水质富营养化程度总体上要好于北部、东部和中部湖区,水质富营养化程度表现为区域的不均匀性。     

三种浮游植物指示法在景观性河流水体营养状态评价中的应用

为探求三种浮游植物指示法在景观性河流水体营养状态评价中的应用是否合理, 分别于2014 年3 月(枯水期)和5 月(丰水期)在卫河新乡段进行为期两次的采样。选取3 个采样点, 从上游到下游依次编号①-③号, 分别对3 个采样点的浮游植物和相关理化因子进行分析。基于水体理化因子所得的综合营养状态指数(TSI)评价结果表明, 卫河新乡段水质总体处于贫中-中富营养状态; 丰水期比枯水期水体营养状态较低; 同时下游②、③号位点在两次采样中的TSI值均高于①号样点, 表明其富营养化程度更为严重。应用藻类污染指数、Shannon-Wiener 指数和Q 指数三种方法对水体进行评价, 结果表明在景观性河流水体中, Shannon-Wiener 指数的评价结果与TSI 的评价结果相一致, 适宜用于评价此类水体的营养状态。     

胶州湾湿地海域水体和表层沉积物环境质量评价

基于2009年对胶州湾湿地48个站点的调查数据,采用内梅罗(Nemerow)指数、富营养指数(EI)和Hakanson潜在生态危害指数法对胶州湾湿地水体和表层沉积物环境质量现状进行了评价.结果表明:对参与评价的pH值、溶解氧、无机氮、活性磷酸盐、CODMn、石油类、Cu、Zn、Pb、Cd、Hg、As、六六六、滴滴涕、大肠菌群、粪大肠菌群等16项指标而言,各调查月份大沽河感潮河段水质处于中污染-重污染水平,潮间带区域水质处于轻污染-中污染水平,浅海区域水质处于轻污染水平.胶州湾湿地不同区域富营养化程度差异明显,其中大沽河感潮河段水体EI值在58.13 ～327.89,富营养化程度严重;潮间带区域水体EI值在1.34 ～19.96,富营养化程度较为严重;浅海区域水体EI值在0.65 ～ 2.10,富营养化程度较轻.胶州湾湿地海域表层沉积物质量基本处于轻污染水平,其中大沽河感潮河段处于轻污染水平,潮间带区域处于轻污染-中污染水平,浅海区域处于较清洁-轻污染水平.胶州湾湿地海域表层沉积物中重金属单项污染参数(Cfi)和污染程度指数(Cd)较低,污染程度处于低级水平,Cu、Zn是表层沉积物中的主要污染因子;重金属潜在的生态危害系数(Eir)和潜在生态危害指数(RI)较小,污染程度属于低生态危害范畴.     

基于大型底栖无脊椎动物完整性指数的鄱阳湖湿地生态健康评价

湿地生态健康评价对于掌握湿地的健康状况、理解人类活动干扰对其影响及实施生态预警等有重要意义。鄱阳湖对于维持其流域甚至长江中下游的生态平衡十分重要,目前尚未建立起其较完善的生态健康评价指标体系。大型底栖无脊椎动物完整性指数(benthic macroinvertebrate-based index of biotic integrity, B-IBI)是广泛应用的湿地生态健康评价方法。基于30个采样点(7个参照点,23个受损点)的大型底栖无脊椎动物采样数据,构建鄱阳湖湿地的B-IBI指数,采用自然断点法划分非常健康、健康、一般、差和极差5个健康等级标准,据此评价湿地生态健康状况。研究表明:(1)基于B-IBI指数的鄱阳湖湿地生态健康评价结果为一般;(2)就采样点B-IBI分值而言,呈现出西部健康状况优于东部的格局,其中国家级自然保护区内状况较好,而工业区、城镇、农田及河流入湖口附近状况较差;(3)B-IBI指数与前期构建的景观发展强度指数(LDI)、栖息地环境质量指数(QHEI)以及植被完整性指数(V-IBI)具有显著相关性,表明基于不同指数的评价结果较为一致。本研究构建的B-IBI指数能为鄱阳湖湿地的生态健康评价和监测提供重要方法。     

图们江下游湿地生态系统健康评价

湿地是世界上具有独特结构与功能的生态系统,图们江流域湿地生态系统的健康对该区乃至东北亚地区综合生态系统网络的建设具有重要意义。选择图们江流域下游为研究区,基于压力-状态-响应(PSR)模型,在压力系统、状态系统、响应系统三个层面选取30个指标构建了图们江下游湿地生态系统健康评价指标体系,运用层次分析法和多级模糊综合评判法对研究区湿地生态健康状况进行综合评价,其结果为0.5878,处于亚健康状态。其中,压力系统的健康指数为0.5292,响应系统的健康指数为0.6866,状态系统的健康指数为0.5116,各等级隶属度S=(16.83%, 25.37%, 16.76%, 16.97%,24.07%)。主要表现在研究区域湿地的补水水质差,导致湿地水质污染加重,富营养化现象严重;并且由于人为因素,湿地大面积退化,景观破碎化加剧,功能逐渐丧失,生产力水平下降;急需对本区域湿地进行保护与管理。     

基于湿地植物光谱的水体总氮估测

利用再生水补充城市湿地是目前湿地恢复与重建的主要方向,然而再水中高浓度的氮、磷含量极易导致水体富营养化。遥感技术已成为富营养化监测的重要手段,但对于植被覆盖水域的富营养化直接探测存在一定的局限性。以北京市典型再生水补水湿地奥林匹克公园南园湿地为研究区,利用湿地植物光谱进行水体富营养化主控因子总氮的遥感探测。测定芦苇(Phragmites australis)和香蒲(Typha angustifolia)的叶片光谱及水体总氮含量,在对数据进行预处理的基础上建立二者的关系模型,包括单变量模型(比值光谱指数(SR)模型和归一化差值光谱指数(ND)模型),与多变量模型(逐步多元线性回归(SMLR)模型和偏最小二乘回归(PLSR)模型),并利用交叉验证决定系数(R2cv)和均方根误差(RMSEcv)进行模型精度检验。结果表明,不同回归模型相比,多变量回归模型精度较高;多变量回归模型中,PLSR模型精度较高,R2cv可达0.72,RMSEcv仅为0.24,是建立湿地植物光谱与水体总氮含量关系的最优模型。不同湿地植物类型相比,利用芦苇反射光谱建立的各种预测模型的精度都高于香蒲。其他环境因子(总磷)也是影响TN含量与湿地植物反射光谱关系的重要因素。研究成果可以弥补现有水体富营养化遥感探测的不足,并为再生水利用的城市湿地水质监测与管理提供有力的科学依据。     

RS和GIS支持的洪河地区湿地生态健康评价

洪泛平原淡水自然湿地对于生态多样性保护具有重要意义。当前自然湿地普遍面临气候变化与人类活动干扰和影响,其生态健康的状况令人担忧,结合新的地学信息技术探索自然湿地生态健康评价分析方法具有重要意义。本研究选择位于三江平原东北部的洪河国家级自然保护区湿地及其周边农场湿地为研究区,依据遥感和地理信息系统技术支持,结合野外生态调查与水文气象监测数据,从水文地貌特征、景观特征和人类扰动3方面选取一系列评价指标因子,利用层次分析法和综合指数方法,对研究区湿地进行了定量生态健康分析评价。研究结果表明：（1）洪河自然保护区的湿地生态健康状况是最好的,其周边农场从鸭绿河农场、前锋农场到洪河农场的湿地生态健康状况依次递减。（2）洪河自然保护区功能分区生态健康状况由好到差的顺序为：核心区>缓冲区>实验区,与实际野外调查情况一致。（3）本研究建立的评价指标体系和相应分析方法能够科学的评价湿地生态健康。评价分析结果显示水文地貌要素是影响湿地生态健康的关键性因素。本研究利用RS和GIS技术与传统生态学评价分析方法结合,以栅格为单位基于区域生境特征进行湿地生态健康综合评价具有一定的方法先进性。     

基于植被完整性指数的鄱阳湖湿地生态健康评价

基于鄱阳湖湿地30个采样点的植被调查数据,利用植被完整性指数法(V-IBI)评价鄱阳湖湿地生态健康状况。通过分布范围分析、判别能力分析和相关性分析,从35个候选生物参数中筛选出6个核心参数,利用比值法对核心参数赋值并累加求得各采样点V-IBI分值,以所有采样点95%分位数值为最佳期望值建立评价标准划分健康等级。结果显示:鄱阳湖湿地生态健康状况总体较好,30个采样点中6个为非常健康(V-IBI≥5.01),7个为健康(4.38≤V-IBI5.01),8个为一般(3.74≤V-IBI4.38),7个为差(3.10≤V-IBI3.74),2个为极差(V-IBI3.10),呈现出西部优于东部,北部优于南部的空间差异。V-IBI与景观发展强度指数(LDI)和栖息地环境质量评价指数(QHEI)呈显著相关性,表明V-IBI方法对鄱阳湖湿地生态健康状况评价结果合理有效,可作为鄱阳湖湿地生态监测的重要手段。     

广西刁江流域主要河流水质评价

为研究广西刁江水质污染现状, 从刁江流域上游到下游共设置 9 个水质监测断面。于 2013 年 12 月-2014 年 12月对河流的 pH、溶解氧、高锰酸盐指数、叶绿素 a、总氮、总磷、氨氮、硝酸盐氮、亚硝酸盐氮、正磷酸盐、重金属(砷、铅、镉、汞、铬)水质指标进行监测。采用单因子和综合污染指数对刁江水质进行评价, 同时开展水体富营养化评价。单因子污染指数评价结果表明刁江流域主要污染物为总氮和砷。综合污染指数评价结果表明刁江流域水质整体较好, 但上游的平村河污染较严重。从时间分布来看, 秋季水质最差, 冬季较好。从营养化状态指数来看, 平村河为中度富营养化状态, 其余河流为中营养状态, 富营养化程度呈现春夏高, 冬季低的特点。对评价结果进行主成分分析, 结果表明刁江流域总氮最大的贡献者可能来源于居民的生活污水。     

Current status and future tendency of lake eutrophication in China

Current trophic status and trend of Chinese freshwater lakes were investigated in this study. The results showed that all lakes studied were commonly undergoing the eutrophica-tion process, water quality decreased and lake's ecosystem is being declined. Most of the urban lakes are facing serious eutrophication. Many medium-sized lakes are in metrophic or eutrophic status, some local water are even approaching the hypertrophic level. The famous five freshwater lakes in China have entered into eutrophication in the condition of higher nutrient load. Lake Taihu, Hongze and Caohu are already in eutrophic state. Eutrophic lakes are mainly distributed in the middle and lower reaches of Yangtze River and Yungui plateau. Lake eutrophication developed rapidly. Among the 34 lakes studied in 1970's, most of lakes were in the mesotrophic status, mesotrophic water area accounted for 91.8%. With the nine year of 1978-1987 the area percentage of oligotrophic lakes decreased from 3.2% to 0.53%, and that of eutrophic lakes increased from 5.0% to 55.01%. Recent data showed 57.5% lakes were in eutrophic and hyper trophic status of the 40 surveyed lakes. Eutrophic trend of Lake Taihu, Chaohu and Xuanwu in the region of the middle and lower reaches of Yangtze River was predicated using the ecological stress model. The results showed that in 2008 Lake Taihu, Chaohu and Xuanwu might be of eutrophication, eutrophication and hypertrophication, respectively if no control measurement is taken. Provided the pollution water treatment rate is 60% in 2030, approximately 30 billion ton pollution water would still be discharged directly in the lakes. Therefore, in 2030 the urban lakes in China might be eutrophication or hypertrophication, and most of the medium-sized lakes at the urban-rural fringe might be in eutrophication or hypertrophication. The famous five biggest freshwater lakes in China might be eutrophication if control countermeasures are taken as now. Lake eutrophication has become a serious environmental problem in China. Based on the domestic and foreign experiences of the eutrophic control technologies, both nutrient pollution control and lake ecological restoration should be carried out and this may be the guidance for the eutrophic control of lakes in China.     

Combining multivariate statistical techniques and random forests model to assess and diagnose the trophic status of Poyang Lake in China

Floodplain lakes are valuable to humans because of their various functions. An emerging public concern on lake eutrophication has heightened the need to assess and predict the trophic status in floodplain lakes, particularly for those with high spatial heterogeneity. In this study, combined multivariate statistical techniques and random forests model were used to characterize the water quality and trophic status of Poyang Lake. By classifying and characterizing seasonal water samples comprising 11 water quality parameters collected from 13 sampling sites in Poyang Lake between 2008 and 2014, the dataset was divided into the central and northern lake groups, which corresponded to lentic and lotic regions in Poyang Lake, respectively. The spatial water quality variations and underlying patterns were investigated by performing discriminant analysis and principal component analysis (PCA). Lastly, random forests (RF) were used to predict the chlorophyll a (Chl-a) variations of the central and northern lakes. The PCA results indicated that the water quality of the central and northern areas of the lake was controlled by different environmental variables and underlying pollutant sources. The RF model outperformed the artificial neural network and linear regression and was robust with strong predictive capabilities. It was determined that the most important predictors of the Chl-a variations in the northern lake were water temperature (T) and water level, whereas transparency, T, and water level were the most efficient predictors in the central lake. The RF model can also be applied to trophic prediction in other large lakes with considerable spatial variations. This study will have implications on water quality management and eutrophication prevention in floodplain lakes with high spatial heterogeneity.     

Current status and future tendency of lake eutrophication in China

Current trophic status and trend of Chinese freshwater lakes were investigated in this study. The results showed that all lakes studied were commonly undergoing the eutrophication process, water quality decreased and lake's ecosystem is being declined. Most of the urban lakes are facing serious eutrophication. Many medium-sized lakes are in metrophic or eutrophic status, some local water are even approaching the hypertrophic level. The famous five freshwater lakes in China have entered into eutrophication in the condition of higher nutrient load. Lake Taihu, Hongze and Caohu are already in eutrophic state. Eutrophic lakes are mainly distributed in the middle and lower reaches of Yangtze River and Yungui plateau. Lake eutrophication developed rapidly. Among the 34 lakes studied in 1970's, most of lakes were in the mesotrophic status,mesotrophic water area accounted for 91.8%. With the nine year of 1978-1987 the area percentage of oligotrophic lakes decreased from 3.2% to 0.53%, and that of eutrophic lakes increased from 5.0% to 55.01%. Recent data showed 57.5% lakes were in eutrophic and hypertrophic status of the 40 surveyed lakes.Eutrophic trend of Lake Taihu, Chaohu and Xuanwu in the region of the middle and lower reaches of Yangtze River was predicated using the ecological stress model. The results showed that in 2008 Lake Taihu, Chaohu and Xuanwu might be of eutrophication, eutrophication and hypertrophication, respectively if no control measurement is taken. Provided the pollution water treatment rate is 60% in 2030, approximately 30 billion ton pollution water would still be discharged directly in the lakes. Therefore, in 2030 the urban lakes in China might be eutrophication or hypertrophication, and most of the medium-sized lakes at the urban-rural fringe might be in eutrophication or hypertrophication. The famous five biggest freshwater lakes in China might be eutrophication if control countermeasures are taken as now.Lake eutrophication has become a serious environmental problem in China. Based on the domestic and foreign experiences of the eutrophic control technologies, both nutrient pollution control and lake ecological restoration should be carried out and this may be the guidance for the eutrophic control of lakes in China.     

Current status and future tendency of lake eutrophication in China

Current trophic status and trend of Chinese freshwater lakes were investigated in this study. The results showed that all lakes studied were commonly undergoing the eutrophication process, water quality decreased and lake’s ecosystem is being declined. Most of the urban lakes are facing serious eutrophication. Many medium-sized lakes are in metrophic or eutrophic status, some local water are even approaching the hypertrophic level. The famous five freshwater lakes in China have entered into eutrophication in the condition of higher nutrient load. Lake Taihu, Hongze and Caohu are already in eutrophic state. Eutrophic lakes are mainly distributed in the middle and lower reaches of Yangtze River and Yungui plateau. Lake eutrophication developed rapidly. Among the 34 lakes studied in 1970’s, most of lakes were in the mesotrophic status, mesotrophic water area accounted for 91.8%. With the nine year of 1978–1987 the area percentage of oligotrophic lakes decreased from 3.2% to 0.53%, and that of eutrophic lakes increased from 5.0% to 55.01%. Recent data showed 57.5% lakes were in eutrophic and hypertrophic status of the 40 surveyed lakes.

Eutrophic trend of Lake Taihu, Chaohu and Xuanwu in the region of the middle and lower reaches of Yangtze River was predicated using the ecological stress model. The results showed that in 2008 Lake Taihu, Chaohu and Xuanwu might be of eutrophication, eutrophication and hypertrophication, respectively if no control measurement is taken. Provided the pollution water treatment rate is 60% in 2030, approximately 30 billion ton pollution water would still be discharged directly in the lakes. Therefore, in 2030 the urban lakes in China might be eutrophication or hypertrophication, and most of the medium-sized lakes at the urban-rural fringe might be in eutrophication or hypertrophication. The famous five biggest freshwater lakes in China might be eutrophication if control countermeasures are taken as now.

Lake eutrophication has become a serious environmental problem in China. Based on the domestic and foreign experiences of the eutrophic control technologies, both nutrient pollution control and lake ecological restoration should be carried out and this may be the guidance for the eutrophic control of lakes in China.

     

基于PCA和SOM模型的龙感湖水质时空动态研究

为评估湖泊渔业模式转型阶段水环境的时空动态, 选择长江中下游典型湖泊龙感湖为研究地点, 于2017—2018年对该湖的黄梅水域和宿松水域进行周年季度水质监测, 通过主成分分析(PCA)和自组织特征映射人工神经网络(SOM)模型定量分析了水体理化参数的时空变化特征, 采用综合营养状态指数法(TLI)对水体富营养化状况进行了评价。PCA分析结果表明, 龙感湖宿松水域和黄梅水域的水质差异较小, 季节动态明显。全湖氨氮夏季平均浓度高达0.64 mg/L; 总氮夏季平均浓度为2.30 mg/L, 冬季平均浓度为1.04 mg/L; 叶绿素a夏季平均含量达95.28 μg/L, 秋季平均浓度为28.30 μg/L; pH夏季最高, 达9.27; 总磷冬季最高, 平均为0.22 mg/L; TLI指数表明龙感湖除秋季属于轻度富营养水体外, 其他3个季节均属于中度富营养状态。SOM模型结果具有可视化强的优点, 能够更清晰和直观地反映龙感湖水质的时空分布动态。围栏拆除和禁渔等管理措施有助于湖泊渔业环境修复和资源恢复, 建议对渔业模式转型后的湖泊生态系统变化进行长期跟踪监测评估。     

Characteristics of a landscape water with high salinity in a coastal city of China and measures for eutrophication control

Eutrophication of landscape waters is drawing public concerns in China but few studies have been conducted on the problem associated with high water salinity as what happens at Sino-Singapore Tianjin Eco-city in Tianjin, a coastal metropolis of northern China. In order to find ways for eutrophication control, a comparative study was conducted on three landscape water bodies, namely Qingjing Lake, Jiyun River and Jiyun River Oxbow, which are under varied conditions of salinity, organic, and nutrients intrusion. The spatial and temporal variations of water quality were revealed by water sampling and analyses, and correlative relationships were obtained between water salinity and other parameters related to eutrophication. By utilizing a trophic level index (TLI), the eutrophication status of the three landscape water bodies in different seasons could further be evaluated. As a result, water temperature, as expected, showed the strongest effect on eutrophication because higher TLI together with higher Chl-a concentrations tended to occur in later spring and summer seasons, while nutrient concentration, especially TP, was also the determinative factor to the eutrophication status. Of the three water bodies, the Jiyun River Oxbow showed a salinity as high as 20 g/L or more in contrast with the other two water bodies with salinity as 4–5 g/L. Although its TP concentration was usually very low (about 0.1 mg/L), it was under a moderate eutrophication status almost in all seasons, indicating that high salinity tends to induce alga growth. Dilution of saline inflow and nutrients reduction could thus be proposed as the main measures for eutrophication control of landscape waters in the study area.     

300年来鄱阳湖营养盐演化重建与模拟

水体富营养化已经成为全球性的问题而受到广泛关注,然而其发生的过程和机制尚未完全明了。在湖泊营养演化过程中,水文和生态是两个最基本的制约因素。相对于短期的和试验性的研究,长时间尺度的营养盐变化过程能更全面地揭示营养盐的演化机制。以我国最大的淡水湖——鄱阳湖为例,采用湖泊水体交换周期模型和湖泊生态-营养盐动力耦合模型,重建鄱阳湖营养盐的长期变化,并利用沉积钻孔代用指标加以验证。在此基础上探讨其演化机制,模拟的时间序列中营养盐变化对气候水文与生态系统存在两种不同的响应模式。敏感因子分析显示:典型同步响应期中(1812—1828 AD),气候水文因子的贡献率达79.1%,生态因子为20.9%;典型异步响应期中(1844—1860 AD),两者贡献率分别为36.4%和63.6%。在模拟的营养盐变化时间序列中同步期占62.5%,说明气候因子在营养盐演化过程中起重要的作用;异步期虽只占12.5%,但对湖泊营养盐作用、营养盐反馈生物量同样至关重要。相关分析结果显示,生物量增长与TP含量基本呈线性关系,但存在一个阈值。在没有超过阈值前,生物量对TP具有较好的调节作用;当超过阈值之后,生物量的调节作用减弱。     

Eutrophication of Lakes Leman and Neuchâtel (Switzerland) indicated by oligochaete communities

In 1978–80, oligochaete communities of meso-eutrophic Lake Léman (Lake of Geneva) were compared to those of mesotrophic Lake Neuchâtel. Worm species were classified into three groups corresponding to their increasing tolerance to eutrophication: (1) oligotrophic species, mostly Peloscolex velutinus, Stylodrilus heringianus; (2) mesotrophic species, mostly Potamothrix vejdovskyi, P. bedoti; (3) eutrophic species, mostly Potamothrix hammoniensis, P. heuscheri, Tubifex tubifex. In both lakes, eutrophic species constituted the bulk of the communities in terms of absolute abundance. However, relative abundance of mesotrophic and eutrophic species was higher in Lake Léman; oligotrophic species were more important in Lake Neuchâtel. These data confirmed the trophic classification of lakes based on chemical parameters. The number of zero values, which perturbated statistical analysis, was reduced by using species groupings instead of isolated species. Thus, making the lakes more comparable even if different species were present in each one. Relative density values based on all samples were distributed among 4 density classes for the 3 species groupings. The 12 resulting frequencies described the community structure expressed in terms of eutrophication. Furthermore, these frequencies may be used for comparison of eutrophication levels in several lakes.     

Cyclopoid copepods as bioindicators of eutrophication in reservoirs: Do patterns hold for large spatial extents?

Some species of copepods are sensitive to water quality oscillations from natural or anthropogenic causes. Information on basic ecological attributes such as abundance can be helpful in the context of hydric resources monitoring. Our study analyzed if the abundance of 22 copepod species of the second largest basin of South America was more associated with variables oscillating by natural or anthropic causes, contrasting among oligotrophic, mesotrophic, and eutrophic reservoirs. Our aim was to identify and understand the abundance of species with potential to monitor water quality in large scale assessments. Potential bioindicators would have different abundances in eutrophic, mesotrophic and oligotrophic sites and would not oscillate according to natural characteristics of reservoirs (water temperature, air temperature, and depth). Two species were sensitive to eutrophication and were not related to natural characteristics of reservoirs, that is, they were suitable for biomonitoring the La Plata Basin. Thermocyclops minutus negatively responded to eutrophication, while Acanthocyclops robustus responded positively. Additional exploratory analyses identified that Copepod abundance was related to total phosphorus, chlorophyll-a concentration, water transparency, total suspended matter, and depth. Metacyclops mendocinus, Acanthocyclops robustus, Mesocyclops meridianus, Mesocyclops ogunnus, and Thermocyclops decipiens were abundant in eutrophic reservoirs, and Thermocyclops minutus, and Thermocyclops inversus were associated with higher water transparency, typically oligo/mesotrophic reservoirs. Overall, we found that cyclopoids are highly affected by eutrophication, and species abundance could be used to monitor reservoirs and anticipate potential impacts on water quality in large-scale biomonitoring schemes.