蠡湖——无锡生态文明建设的一张靓丽名片

蠡湖位于江苏省无锡市西南部,是太湖伸入无锡的内湖,原名五里湖,又名漆湖,亦称小五湖。明代,人们因范蠡偕西施来此隐居而改称蠡湖。因此无锡人对于蠡湖的这份情缘最早可上溯到春秋战国时期。这位2400多年前的越国大夫,给蠡湖涂抹上一段梦幻般的浪漫色彩。     

五里湖的枝角类

1951和1952两年,中国科学院水生生物研究所进行了江苏无锡五里湖的集体调查工作,经常每隔半月在湖内采集水梯、浮游生物标本及湖底动物标本。     

太湖五里湖富营养化的碳同位素记录

通过太湖五里湖表层沉积物柱样中总有机碳、总氮、总磷的变化,探讨了五里湖营养盐磷输入的历史记录,结合总有机碳碳同位素的分析,揭示了该湖富营养化和初级生产力的演化过程.总有机碳碳同位素值为-27.0‰～-26.3‰,平均-26,6‰,从底部向上波动变化,在深度12 cm处最大,然后向上逐渐减小,5 cm处降至最小,随之向上逐渐增大,反映了随着人为活动强度的加大,该湖水体富营养化程度逐渐加剧的特点,并且总有机碳碳同位素与有机碳、氮原子比值记录了湖泊水生植物群落由水草为主-草藻结合-藻类为主的演替过程.

Abstract：

Through the analysis of total organic carbon, total nitrogen, and total phosphorus con-centrations in surface sediment cores from Wuli Bay of Taihu Lake, the historical record of phos-phate input in the Bay was studied, and in combining with the analysis of carbon isotope value of bulk sedimentary organic matter, the evolution process of the primary productivity and eutrophi-cation in the Bay was revealed. The carbon isotope value of the sediment total organic C was -26. 6‰ on average, with a variation between-27.0‰ and-26. 3‰. It was decreased with depth up to the lowest value at 5 cm, subsequently increased gradually up to the highest value at 12 cm, and then fluctuated downward with the depth, which suggested that the evolvement of eu-trophication, productivity, and primary producer was associated with the increasing phosphorus input from human activities. Moreover, the concentrations of total phosphorus and the C/N atom-ic ratios of total organic carbon to total nitrogen recorded the succession process of aquatic plant community from float grass to float grass + algae to algae.     

太湖五里湖仔稚鱼时空分布特征

为探究五里湖仔稚鱼群落结构及分布特征，于2016年4—10月对五里湖仔稚鱼进行系统调查。期间共采集仔稚鱼70678尾，共鉴定出鱼类20种(属)，隶属于7目8科18属。五里湖仔稚鱼密度均值为3825尾/100 m3，主要优势种为?属(Hemiculter sp.)，其数量占比为68.76%。五里湖仔稚鱼主要采集于4—8月，密度高峰期为6月，各物种密度高峰期存在差异，最早的为鲤(Cyprinus carpio)、鲫(Carassius auratus，4月)，最晚的为短吻银鱼属(Salangichthys sp.，8—9月)。五里湖仔稚鱼分布具有显著的空间差异，沿岸带仔稚鱼密度显著高于(P<0.05)敞水区，密度分别为5650和310尾/100 m3。西五里湖仔稚鱼的密度高于东五里湖，密度分别为4482和3600尾/100 m3。典范对应分析结果显示，水温、溶解氧、浮游植物和浮游动物密度是与仔稚鱼分布显著相关的环境因子(P<0.05)。研究结果显示，五里湖鱼类主要繁殖期为4—8月，主要产卵和育幼水域为沿岸带，其中西五里湖的育幼功能优于东五里湖，因此进一步维持对西五里湖的生境保护，加强东五里湖沿岸带植被恢复及入湖支流水质监控，控制外源污染物，对促进五里湖生境优化及鱼类资源自然增殖具有积极意义。