三峡水库典型库湾生态渔业综合效益评估——以重庆市忠县甘井河水域牧场为例

THE COMPREHENSIVE EVALUATION OF THE BENEFITS ON THE ECOLOGICAL FISHERY IN THE TYPICAL BAYS OF THE THREE GORGES RESERVOIR——AN EXAMPLE OF THE GANJING RIVER WATER RANCH IN ZHONGXIAN COUNTY OF CHONGQING

以三峡库区忠县甘井河水域牧场示范区为例,在水域牧场内、外设置采样点,调查水质、浮游生物及土著鱼类组成现状,同时监测水域牧场内放养鲢(Hypophthalmichthys molitrix)、鳙(Aristichthys nobilis)的起捕规格及生长情况,旨在评估三峡水库典型库湾生态渔业的综合效益。忠县甘井河水域牧场水域面积为0.08 km2,按"零投喂"的放养模式经营,放养的鲢、鳙起捕规格分别为(2436±486)和(2769±496)g,年龄均为3—4龄。生态效益方面,水域牧场内、外调查到的土著鱼类数量均为10种,优势种均为贝氏Hemiculter bleekeri和似鳊Pseudobrama simoni。在6月、9月和12月,水域牧场内总氮(TN)、总磷(TP)比水域牧场外低或相近,水域牧场内溶氧(DO)比水域牧场外高或相近;在3月、9月和12月,水域牧场内、外水质总体无差异;而在鱼类生长旺季的6月份,水域牧场内的水质优于水域牧场外,说明生态渔业在一定程度上改善了水质。经济效益方面,甘井河水域牧场年均效益202.6万元;社会效益方面,共转产渔民111人,提供就业岗位45个,人均年收入36610元。

This paper takes Ganjing River water ranching in Zhong Xian county of Chongqing for example to evaluate the comprehensive benefits of ecological fishery in typical bay of the Three Gorges Reservoir. Ganjing River water ranching wa- ter area is 8 hm2, the operation mode is ＂zero＂ feeding and ＂grazing＂ extensive farming, the harvesting size of Hypophthal- michthys molitrix and Aristichthys nobilis in water ranching were （2436.2 ± 486.6） g and （2769.4 ±496.5） g, respectively, the age class of them were 3 and 4 years. In ecological benefits, the number of native fish inside and outside water ranching was 10, and the dominant species inside and outside water ranching were HemicuIter bleekeri and Pseudobrama simoni. In June, September and December, total nitrogen （TN） and total phosphorus （TP） inside the waters ranching were all lower than that of the water ranching outside or equivalent, indissolved oxygen （DO） inside the waters ranching was higher than that of water ranching outside or equivalent. In March, September and December, there was no difference in water quality between outside and inside water ranching. But in the fast growing season of fish in June, water quality inside waters ranching was better than outside water ranching, indicating that ecological fishery improved water quality. In economic benefit, the average annual benefit of Ganjing River water ranching was 2026000 RMB. In social benefit, because the construction and operation of Gan- jing River water ranching, 111 fishermen changes the line of production, and it also provided 45 jobs and the average annual income of one person was 36610 RMB. It should be summed up the ecological fishery of Zhong Xian county water ranching, to extend the industrial chain, and to be popularized and applied in other bay of Three Gorges Reservoir.