Mesozooplankton biomass in the Celtic Sea: a first approach to comparing and combining CPR and LHPR data

Zooplankton biomass varies on temporal, horizontal and vertical scales. How ever, data sets which incorporate all these dimensions at high resolution a re very rare. Two devices which measure all these aspects have recently bee n simultaneously deployed in the Celtic Sea, the continuous plankton record er (CPR) and the Longhurst-Hardy plankton recorder (LHPR). This demonstrate s that integrated biomass derived from the LHPR are plot significantly diff erent from those derived using the CPR, Values have, therefore, been combin ed for the first time to describe the vertical distribution of mesozooplank ton biomass at the Celtic Sea shelf edge through an annual cycle. This sugg ests that the surface biomass peak is broader at the shelf break than in th e open ocean and in the autumn the main biomass peak may be below the depth sampled by the CPR.