Danube bleak by the building of dams across many of the rivers. Landlocked populations survive in small rivers and reservoirs, breeding in the small streams above the dams. The main Caspian Sea population has found ways of spawning below the dams. Overfishing and pollution in the Caspian Sea could impact on the Danube bleak but in 2008 the IUCN Red List of Threatened Species listed it as being of "Least concern". The Danube bleak feeds on small crustaceans, worms, molluscs, insect larvae, insects and small fish. Male Danube bleaks assemble in May to July at spawning sites in fast flowing streams with
Crab meat and the animal is then returned to the water. The practice is defended because some crabs can naturally autotomise (shed) limbs and then about a year later after a series of moults, regenerate these limbs. In Western Europe crab meat is derived primarily from the species "Cancer pagurus". "C. pagurus" is a large crab noted for the sweet, delicate flavour of its meat. It is also known as the "Brown Crab", the "Common Crab" or the "Edible Crab". The United Kingdom is the largest fishery for "C. pagurus" with large fisheries in Scotland and a smaller but substantial fishery in