A Study of the Characteristics of Fish Shoals in Coastal Waters of Northeast Taiwan Using an Echo-Signal Image Processing System

Abstract

淡水地區之流袋網漁業由來已久，但有關其仔稚魚群之分布特性研究則十分缺乏。本研究以魚探調查及海洋斷面觀測，並透過相關法與空間型態分析法，解析仔稚魚群之單群規模、空間分布型態及其與溫鹽變動特性關係。結果顯示當水域中因不同溫鹽性質之海水交衝而形成鋒面時，魚群之斷面分布大多集中於鋒面外緣收斂速度小於6 cm/sec之區域，而水域中沒有形成鋒面時，魚群則零星分布於整個水層。Four hydroacoustic surveys were conducted to study the distribution of larval fish schoolsand their relation to pycnocline in coastal waters of Northwestern Taiwan,July to October1992.The convergence speed of pycnocline was as a reliable environmental factor indeterming the distribution of the larvae.When the convergence speed was greater than 6cm/sec,the density of fish larvae was low.Most of the fish schools inhabited in the areaswhere the convergence speed was less than 6 cm/sec.