厦门周边水库浮游植物碱性磷酸酶活性研究

从2010年6月初至12月末,对厦门周边九龙江江东水库、厦门大学芙蓉湖和情人湖三个淡水湖库进行两周一次的连续采样,开展水体总碱性磷酸酶活性(APA)的研究。从营养盐和叶绿素a水平看,三个湖库属不同的富营养化程度:芙蓉湖>情人湖>江东水库。群落水平的总碱性磷酸酶活性和溶解性磷酸盐(SRP)浓度的结果表明,三处水体均呈现群落水平上的磷胁迫状态;不同水体的浮游植物群落结构存在显著差异,同时不同浮游植物的磷胁迫亦不同,蓝藻是芙蓉湖的绝对优势类群且标记率较低,绿藻是情人湖和江东水库的优势类群,且标记率较高。群落组成在一定程度上可以反映浮游植物群落的磷胁迫状态。     

北京城市河湖营养状态与蓝藻水华研究

2003-2004年的调研结果显示,北京城市河湖(长河水系)总氮平均含量为1.667 mg/L,总磷平均含量为0.144 mg/L,浮游藻类平均细胞密度为41 150×104/L,其中蓝藻占90.0%.浮游藻类的群落结构为蓝藻(Cyanophyta)-绿藻(Chlorophyta)型,河湖水体中营养盐与初级生产力的关系为浮游藻类响应型,连续两年发生以微囊藻(Microcystis)占优势的蓝藻水华.河湖水体5项指标(SD、TP、TN、CODMn、Chla)的TSIM值在57～87间,水体已达到富营养或重富营养程度.其主要原因是:1)营养盐和有机物的污染;2)北京市淡水资源紧缺,补给城市河湖水量少;3)在河湖水系治理中,底部硬化,两侧(或周围)衬砌,破坏了水体的自然生态系统,使其自净能力大大降低.     

长江中下游浅水湖泊水下辐照度漫射衰减特征研究

基于2007年9月底和10月初在湖北武汉东湖、梁子湖、洪湖以及2010年4月在昆山市傀儡湖进行的水下光场测定数据,分析了4个湖泊漫射衰减系数变化特征及其主导因素.在东湖和傀儡湖各站点水体主要光学因子变化不大,梁子湖和洪湖由于具有草型和藻型湖区,所以各因子在不同点位变化较大.通过对透明度和各光衰减因子的回归分析可知,无机颗粒物是影响东湖和傀儡湖透明度的主要因子,而梁子湖和洪湖透明度则受无机和有机颗粒物的共同制约.4个湖泊的光谱漫射衰减系数最低值均出现在580 nm处,在675 nm处各点均具有相应的叶绿素a的特征吸收峰,在叶绿素a浓度较低站点衰减峰相对不明显.东湖平均真光层深度小于湖体平均深度,在目前的光场条件下沉水植物很难生长,而在梁子湖、洪湖和傀儡湖其真光层深度均超过了水深,为沉水植物的生长提供了良好的水下光环境.对PAR衰减与各衰减因子进行回归分析发现,在东湖、傀儡湖主导PAR衰减的是无机颗粒物,梁子湖和洪湖PAR衰减受到无机颗粒物、有机颗粒物和叶绿素a的共同作用.颗粒物特征波长750 nm处的光束衰减系数与PAR漫射衰减系数存在显著正相关,说明颗粒物散射显著贡献水下光辐射漫射衰减.研究结果有助于指导浅水湖泊水下光场条件改善和沉水植物恢复.     

菹草残体厌氧分解过程中上覆水的硫酸盐还原特征

在富营养化淡水湖泊中,微生物对水生植物的厌氧分解会导致局部水域泛黑发臭,产生草源性"湖泛"现象,但是当前对上覆水中硫酸盐还原细菌(SRB)在水生植物残体分解中的作用还不甚了解.本研究通过室内模拟实验,分别向湖水(本底硫酸根浓度为40 mg·L~(-1))中添加不同浓度的硫酸根,研究了硫酸根浓度升高对上覆水中SRB参与水生植物菹草(P.crispus)残体分解的影响.结果表明,硫酸根浓度升高显著促进了上覆水中硫酸盐还原作用,实验第50 d时,添加了40 mg·L~(-1)硫酸根实验组(40S)中可溶性硫化物(∑H_2S)为(100.11±5.08) mg·L~(-1),远高于未添加硫酸根对照组(CK)的(46.83±3.79) mg·L~(-1).硫还原细菌如脱硫化弧菌属(Desulfovibrio)、脱硫肠状菌属(Desulfotomaculum)和脱硫微菌属(Desulfomicrobium)在40S中的相对丰度显著高于CK(p0.05),而脱硫化孢弯菌属(Desulfosporosinus)则在CK中的相对丰度更高,这说明硫酸根浓度升高促进了菹草残体厌氧分解过程中某些特定种属SRB的生长繁殖.此外,硫酸根浓度升高也影响了菹草厌氧分解过程中有色溶解有机物(CDOM)组分含量的变化,类腐殖质组分在第63 d的荧光强度显著高于第10 d(p0.05),这说明硫酸根浓度升高促进了菹草厌氧分解过程中类腐殖质的产生.本研究对于进一步认识淡水水体中硫酸盐还原的环境效应及生物学机制具有重要意义,也为富营养化水体生态系统修复提供理论依据.     

Development and evaluation of the Lake Macroinvertebrate Integrity Index (LMII) for New Jersey lakes and reservoirs

In response to the recent focus by the U.S. EnvironmentalProtection Agency on bioassessment of lakes, a multimetric index was developed for New Jersey lakes and reservoirs using benthicmacroinvertebrates. Benthic samples were collected fromreference and impaired lakes with muck and intermediate sedimentsin central and northern New Jersey during summer 1997. We used astepwise process to evaluate properties of candidate metrics andselected five for the Lake Macroinvertebrate Integrity Index(LMII): Hilsenhoff Biotic Index (HBI), percent chironomidindividuals, percent collector-gatherer taxa, percentoligochaetes/leeches, and number of Diptera taxa. We scoredmetrics as the fraction of the best expected value (based on allsites) achieved at a site and summed them into the LMII. Evaluation of the LMII showed that it discriminated well betweenreference and impaired lakes and was strongly related to severalpotential stressors. Chemical and physical gradients distinguished between reference and impaired lakes, and the LMIIsummarized these gradients well. The LMII corresponded stronglywith land use, but some lakes with more urban land use stillachieved high scores. Based on a power analysis, the ability ofthe LMII to detect differences in condition was sensitive to thenumber of samples from each lake.     

长江中下游湖区浮游植物初级生产力估算

长江中下游是我国淡水湖泊最集中的区域,也是富营养化较为严重的地区。作为湖泊系统初级生产力的主要影响因子氮、磷等营养元素增加,会显著影响湖泊系统的初级生产力。近几十年来越来越多的学者运用模型来模拟湖泊等水体的初级生产力。而VGPM模型和Talling模型综合考虑了水温、光合有效辐射、湖泊叶绿素浓度和真光层深度等因素,能较准确地模拟水柱初级生产力。1987~1991年、2001～2005年长江中下游湖区湖水中TP浓度分别为0059～0105和0070~0167 mg/L,湖泊TP浓度升高,导致湖泊藻类初级生产力增大。15 a间湖区的初级生产力由0139～0381 gC/(m2〖DK〗·d)上升到0128～0504 gC/(m2〖DK〗·d)。在VGPM模型1987～1991年、2001～2005年湖区固碳量由3 32125 tC/d上升到3 76502 tC/d,增加1336%;在Talling模型中湖区固碳量由2 39964 tC/d上升到3 27242 tC/d,增加3637%     

Levels and congener profiles of polybrominated diphenyl ethers (PBDEs) in Zebra mussels (D. polymorpha) from Lake Maggiore (Italy)

Several congeners of polybrominated diphenyl ethers (PBDEs) were monitored in 14 different sampling stations of Lake Maggiore, the second largest Italian lake in regard to surface, volume and average depth, using the sentinel-organism Zebra mussel (Dreissena polymorpha). Results revealed a moderate contamination with summation operatorPBDE levels (BDE-17, -28, -47, -66, -71, -85, -99, -100, -138, -153, -154, -183, -190 and -209) ranging from 40 to 447ngg(-1) lipid weight which are similar to those found in environments polluted by deposition or atmospheric transport. The general order of decreasing congener contribution to the total load was BDE-47>-99>-100>-209, which closely reflected patterns observed in mussels collected in freshwater ecosystems worldwide.     

Human-mediated dispersal of aquatic invertebrates with waterproof footwear

Human-mediated dispersal has rarely been considered in wetland conservation strategies at regional scales, yet high concern exists about this aspect for (inter-)national management considering invasive species in other aquatic systems. In this context, we aim at understanding the role of human-mediated dispersal by footwear in protected wetlands with high conservation value. Zooplankton and zoobenthos were sampled in 13 shallow lakes in central Spain and, at the same time, mud attached to waders was collected and later cultured in deionized water under laboratory conditions for 4 weeks. Two-hundred and four individuals belonging to 19 invertebrate taxa were recovered after hatching; Ostracoda (84 %), Cladocera (53 %), Copepoda (30 %), Anostraca (30 %), and Notostraca (7 %) were the most frequent groups among the hatched crustaceans. NMDS and PERMANOVA analyses showed significant differences between the dispersed (via footwear) and the source active metacommunity, suggesting different dispersal abilities among the species found. Human vectors facilitate dispersal among protected lakes, which could eventuality lead to biotic homogenization and faster spread of non-indigenous species. Preservation strategies and education campaigns associated to target humans in close contact with water bodies should be imperative in conservation management of protected lakes.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-015-0689-x) contains supplementary material, which is available to authorized users.     

江汉平原四湖地区生态环境综合评价

四湖地区是江汉平原的中心地带,也是国家和湖北省重要农业生产基地。这里自然资源丰富,地理条件复杂,生态问题众多,生态环境问题已经成为这一地区农业发展的制约因素。通过对四湖地区生态环境进行综合评价,遵循自然和经济的发展规律,提出了调整四湖地区的生态结构和进行环境整治的途径。     

基于湖北省12个中小型湖泊的水环境遥感监测应用示范

以《湖北省水环境遥感监测示范系统》为数据处理平台,对2012—2014年湖北省大东湖水网、梁子湖水系和汤逊湖水系共计12个湖泊的水质类别以及营养状态级别进行遥感监测,并对比实测数据进行精度评价。结果表明:遥感监测的梁子湖、豹澥湖和严西湖水质相对较好,杨春湖、北湖和南湖水质相对较差且富营养化状况较为严重。该系统能很好地实现对水质优良达标湖泊以及富营养化湖泊的识别。对示范区域各湖泊水质类别和营养状态级别的遥感监测,基本上能满足业务化运行的需求。个别湖泊遥感监测精度较低,主要表现为遥感监测的湖泊水质类别和营养状态级别均要优于实测的结果。系统对于面积相对较大的湖泊遥感监测精度更高。