Published online by Cambridge University Press: 24 May 2004
Interannual and spatial differences in the abundance of Metridia lucens are reported from the Irish Sea from 1996 to 2001. In most years the abundance in spring is very low (<50 m2), however in 2001 the abundance was high and this enabled a rare study of the vertical distribution of M. lucens in coastal waters. The vertical distribution differs with time of day and water column structure. Abundances were always higher in stratified deeper waters compared with mixed or coastal waters.