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
Flatfish …bony fish as a rule have a marked tendency to be flattened in a vertical direction…. It was natural, therefore, that when the ancestors of [flatfish] took to the sea bottom, they should have lain on one "side"…. But this raised the problem that one eye was always looking down into the sand and was effectively useless. In evolution this problem was solved by the lower eye ‘moving’ round to the upper side. Flatfish is considered a Whitefish because of the high concentration of oils within its liver. Its lean flesh makes for a unique flavor that differs from species