RV Platessa the central basin. The RV "Platessa" (LT205) was in service with Ministry of Agriculture, Fisheries and Food (United Kingdom) from April 1946 until June 1967, during which time she participated in more than 473 separate research campaigns. She was primarily confined to the southern North Sea, but with occasional forays into the Irish Sea and English Channel, especially in the 1960s. The RV "Platessa" (LT205) was overwhelmingly dedicated to research on North Sea herring and North Sea Plaice. This work included the tagging of more than 12,000 plaice during the 1950s, 7000 during the 1960s. In addition, large numbers of
Demersal fish is pointed downwards; this is beneficial as their food is often below them in the substrate. Those bottom feeders with upward-pointing mouths, such as stargazers, tend to seize swimming prey. Benthic fish, sometimes called groundfish, are denser than water, so they can rest on the sea floor. They either lie-and-wait as ambush predators, maybe covering themselves with sand or otherwise camouflaging themselves, or move actively over the bottom in search for food. Benthic fish which can bury themselves include dragonets, flatfish and stingrays. Flatfish are an order of ray-finned benthic fishes which lie flat on the ocean floor. Examples are