摘要
通过2003-2004年对太湖鱼类组成、优势鱼类鲚鱼的年龄结构及食物组成分析,结合鱼类渔获量统计和环境检测资料,研究了太湖鱼类渔获量、组成比例和优势鱼类湖鲚种群年龄结构的变化规律、机制以及相应变化对环境产生的下行效应.结果表明,太湖鱼类总渔获量已从1952年的4 060.7 t上升到2002年的30 516.5 t;鲚鱼已成为绝对优势种,从1952年的640.5 t,占15.8%,上升到2002年的19 571 t、占64.1%;鲚鱼种群年龄组成的低龄化趋势明显,种群中0+个体占(99.04±2.21)%(2003年)、(99.08±0.80)%(2004年);而0+鲚鱼主要以浮游动物为食,其中枝角类占食物总个数的(89.77±13.69)%;鲤鲫鱼1952-1998年期间相对稳定在(1 010.1±367.2) t,占总量的(8.89%±5.33)%,1999年达到2 547.4 t,占11.7%,2000-2002年达到(3 500～3 700) t,占总量的11.8%～14.7%,已成为太湖的主要鱼类之一;太湖的主要肉食性鱼类鮊鱼由最高年份(1987年)的1 090.8 t、占鱼类总量7.7%降至近8年(1995-2002年)的100～150 t、仅占0.4%～0.5%.分析认为:太湖鱼类总渔获量升高主要是鲚鱼的快速增加所引起;而鲚鱼快速增加的原因是富营养化引起的浮游生物数量快速增加及对其有抑制作用的鮊鱼数量不断减少所导致.鲚鱼数量升高又消耗了大量浮游动物,这可能成为太湖浮游植物失去抑制从而暴发的主要生物因素之一.
Based on the catches composition from 1952 to 2002, the investigation of age structure of dominant fish population and the analysis of the food composition of lake anchovy （Coilia ectenes taihuensis Yen et Lin） in 2004, changes of fish catches and population age structure of dominant species and the changes＇ top-down effects on environment in Lake Taihu were studied. The results showed that： the total fish catches increased to 30516.5 ton in 2002; lake anchovy became the dominant fish in the lake and its catches increased only 4060.7 ton in 1952 to 19571 ton, accounting for 64.1% of the total fish catches in 2002 from 640.5 ton, accounting for 15.8% in 1952; its age structure showed the trend of low age; The catches and the percentage of catches of common carp （Cyprinus carpio Linnaeus） and crucian carp （Carassius auratus Linnaeus） increased quickly and become one of the main fishes since 2000 after keeping rather stable for 47 years; topmouth cuher （Erythroculter ilishaeformis Bleeker and Erythroculte rmongolian Basilewsky） decreased from 1090.8 ton, accounting for 7.7% in 1987 to only 100-150 ton, accounting for only 0.4%-0.5% of the total fish catches during recent eight years. The analysis showed that the increase of total fish catches was mainly caused by the lake anchovy quickly increasing, which resulted from factors such as eutrophication, the obstruction between Changjiang River and Lake Taihu and the decrease of topmouth cuher caused by over-fishing; The increase of the lake anchovy catches led to the decrease of the zooplankton stock during recent years, so that the large amount of phytoplankton in Lake Taihu could not be eaten by zooplankton. This probably was one of the main biologic reasons that phytoplankton in Lake Taihu proliferated quickly during recent years.
出处
《安徽农业大学学报》
CAS
CSCD
北大核心
2005年第4期471-477,共7页
Journal of Anhui Agricultural University
基金
中科院知识创新工程重大项目(KZCX1-SW-12-IV)
国家"863"项目(2002AA60101和2002AA601013)资助
关键词
太湖
鱼类渔获量
优势种
年龄组成
下行效应
Lake Taihu
fish catches
dominant fish
population age structure
top-down effects
