The basking shark is the largest fish in the Atlantic Ocean, and the second largest living fish in the world after the whale shark. Despite its large size, it is completely harmless for humans. It is a filter feeder which feeds on plankton, and it can frequently be seen swimming slowly, close to the surface of the sea, with its mouth wide open, following plankton concentrations in the water column.
The basking shark is a highly mobile species, traveling great distances across oceans and through a wide variety of oceanic habitats. Breeding sites are currently unknown, as is the global population size and trend.
They are most often encountered on the surface in North Eastern Atlantic coastal waters during calm, sunny conditions between April and October, but exact months vary with the areas: for example, around Cork County waters they can be found from April to July, but they do not appear in the West coasts of Scotland until July and August.