economic over fishing的意思|示意

Over centuries, Manchurian ancestors lived in Northeast China of short frost-free season with fishing and hunting being their main economic sources instead of planting.

满族先祖长期生活在无霜期短的东北，初以少种植、多渔猎为主要经济来源。

For protecting the resources and gaining better economic efficiency, the harvesting strength should not be higher than 0.6 and the first fishing age should not be over 3 years old.

建议为了保护资源并获得较好的经济效益，应使捕捞强度不超过06起捕年龄不超过3龄。