Fish larvae were collected by the continuous plankton recorder (CPR, operated by SAHFOS) all year long between 1951 and 2005 along transects in the Celtic Sea and English Channel. The CPR is towed by ships of opportunity at speeds of 15 to 20 knots, at an approximate depth of 10 m. Water enters the recorder through an aperture of 1.27 cm2, and is filtered through a continuously moving band of silk with an average mesh size of 270 µm.