RV Platessa tagged plaice were released off the Cumberland coast, using the RV "Platessa" during 1949 and 1950. In August 1951 echo-sounder traces were obtained over a wide area off Whitby by the RV 'Platessa', using a Marconi sounder. They were found to occur at a depth corresponding to that of a sharp thermocline, and small whiting about 3 in. in length, large Medusae, herring and sandeel larvæ were caught with a pelagic trawl at the depth of the trace. This work was reported in a ‘letter’ to the journal Nature in 1952. In 1950 the RV "Platessa" was involved in comparative
American smooth flounder American smooth flounder The American smooth flounder ("Pleuronectes putnami") is a flatfish of the family Pleuronectidae. It is a demersal fish that inhabits shallow inshore salt and brackish waters at depths of up to . Its native habitat is the temperate waters of the northwestern Atlantic, from Ungava Bay in Quebec, Canada to Rhode Island, United States. It can grow up to in length. The American smooth flounder is a right-eyed flatfish, resembling the winter flounder in shape and appearance. Its upper side, including the fins, ranges in colour from dark grey to brown or almost black, and may be