秦岭西段鱼类多样性现状初报

对秦岭西段汉江水系和嘉陵江水系的鱼类和环境调查显示，人类活动对鱼类多样性产生了较大的影响。本文试图对该地区鱼类多样性丧失的现状加以报道并对原因进行分析。以前该地区鱼类共有142种，本次调查的渔获物中只有34种。鱼类物种资源的减少是多种因素造成的：水坝的修建使得鱼类栖息地环境改变从而导致鱼类的种类和种群数量变化，水污染、过度捕捞和非法渔业也在一定程度上破坏了鱼类物种多样性。

A preliminary investigation on fish species diversity in western region of Qinli ng Mountains

The investigation on fish and their habitats in Hanjiang River system and Jialingjiang River system in west region of Qinling Mountains indicated that human activities had a great impact on fish diversity. This paper intended to give a general report and analysed the causes of the descent of fish diversity in this area. There were 142 species of fish recorded in these two river systems in Qinling Mountains,but only 34 species were collected in this expedition to west region of Qinling. It was discovered that decrease of the number of fish species was caused by a lot of factors, including water conservancy facilities construction,water pollution,over_fishing and illegal fishery.