Answer:
Electronic sonar and Global Positioning Systems are used to locate the fish. Ships cross the area, dragging huge nets at the right depth to catch them. The usable catch is often cut, packaged, and frozen right on board. Ships can remain on the ocean for several weeks before returning to home port.
Stock assessments are scientific processes that analyze available data using statistical models to produce management advice. That management advice estimates sustainable harvest levels maximizing fishery removals while protecting stocks’ long-term health.