RV Corella Fisheries Laboratory cooperated with the Admiralty Research Laboratory to identify fish detected by long-range sonar equipment installed at the Admiralty Experimental Station, Perranporth. The RV "Corella" was directed from the shore to an area some 65 km distant, that was returning a strong and extended echo. The "Corella" was able to correlate this target with shoals detected on a conventional echo sounder, and substantial catches of sprats were taken in the area using a midwater trawl. The RV "Corella" was used throughout the 1970s for pioneering studies on fish migration. Individual plaice ("Pleuronectes platessa") fitted with 300 kHz acoustic transponding
Reddish egret reddish head and neck with shaggy plumes. The adult white morph has completely white body plumage. Young birds have a brown body, head, and neck. During mating, the males plumage stands out in a ruff on its head, neck and back. The reddish egret is considered one of the most active herons, and is often seen on the move. It stalks its prey visually in shallow water far more actively than other herons and egrets, frequently running energetically and using the shadow of its wings to reduce glare on the water once it is in position to spear a fish;