Specieswatch: basking sharks still a mystery despite being largest fish in British waters

More research is needed to help conserve the poorly-understood basking sharkSurprisingly little is known about the largest fish in British waters, the basking shark, Cetorhinus maximus; for example, where does it go in winter? Even its name is misleading. When this 10-metre (33ft) giant is on the surface, it is not sunbathing but swimming gently along with its metre-wide mouth open, filtering tons of water to harvest the plankton.These sharks used to be hunted for their large oil-filled livers, a quarter of their body weight, which kept them buoyant. The oil was used to fuel Victorian lamps. Shark numbers are much reduced and efforts are being made to track them, identify individuals and conserve them. Continue reading...