论文部分内容阅读
1985年8月—1986年10月(2,9月除外),在长江口海区进行了鱼卵、仔鱼调查。结果表明,该海区系由淡水鱼类、半咸水鱼类和沿岸、近海鱼类四种生态类型组成的鱼类生态结构,具有特殊复杂的生态特点;其种类组成和数量分布,皆受长江径流、台湾暖流及黄海冷水团等水系的相互消长、交换而形成的错综复杂的海况条件所制约。目前该海区的鱼类种间数量对比关系发生变化。历史上的重要经济鱼类数量极少,而作为它们的主要饵料之一的鳀鱼数量却占绝对优势。这与渔业上的过度捕捞和滥捕有很大关系。因此,以发展增、养殖事业来转化和降低捕捞强度,对保护鱼类资源具有重大意义。
From August 1985 to October 1986 (except in February and September), fish eggs and larvae were surveyed in the Yangtze Estuary. The results showed that the sea area is a kind of fish ecological structure consisting of freshwater fish, brackish water fish and four types of coastal and offshore fish, with special and complex ecological characteristics. The species composition and quantity distribution are all affected by the Yangtze River Runoff, Taiwan’s warm current and the Yellow Sea cold water regiment and other water systems to each other growth, exchange and the formation of the complex sea conditions constraints. At present, the number of fish species in the sea contrasts with each other. Historically, the number of important economic fish is very small, while the quantity of anchovy as one of their main bait has the absolute advantage. This has a lot to do with overfishing and over-fishing in fisheries. Therefore, it is of great significance for the protection of fish resources to transform and reduce fishing intensity in order to develop and raise aquaculture.