This weather fluctuation can alter the recruitment of sand eel. Fisheries of sand eel can also be harmful to seabird colonies. The impacts of intense Raitt's sand eel fishing has been debated. Four other species of sand eel are also distributed in this part of the Atlantic. Raitt's sand eel have very specific habitat requirements. The great sand eel ("Hyperoplus lanceolatus") is the greater species of sand eel. Common guillemots feed exclusively on Raitt's sand eel during the breeding season. Seabirds in particular rely heavily on the Raitt's sand eel to feed their chicks. The Raitt's sand eel is a keystone species in the North Sea food web. The Raitt's sand eel is known from fishing records to have regular population fluctuations.