BUSCADOR RECOLECTA

PERFILMED-II Cruise (29GD20090627) carried out on the Research Vessel García del Cid in 2009, In most of the plankton production models, space is not taken into consideration, as if the pelagic trophic relations took place in an evenly distributed universe. Food or predators are parametrised as average concentration values, although spatial heterogeneity and time variability (patchiness) at all scales is a constant characteristic for marine physical and chemical variables, as well as for plankton communities. The vertical structure of plankton in patches or layers has been described since long , but their effects on the coupling between the different trophic components and the oceanographic singularities that control the matter and energy transfer have been poorly studied. In order to allow us to explain some paradoxical features of consumers production under conditions of low average resource availability, in the Framework of the PERFIL-MED cruise we studied the time-changes on the vertical pattern distribution of meso- and microplankton in relation to physical heterogeneities during the summer stratification period.The study took place on board the R/V García del Cid, from the 27/06/09 to the 01/07/09 in the Catalan Sea, NW Mediterranean, at a fixed station (40.45 ºN, 2.39 ºE). Profiles of physical (T, S), chemical (O ) and biological (fluorescence) data were made with a CTD SBE 911plus. The high-resolution vertical distribution of the rate of turbulent mechanical energy dissipation, epsilon, was obtained with a MST micro-structure profiler®. The vertical distribution of organisms ranging from 50 µm to 2 mm ESR was obtained with a TAPS® (high resolution acoustics, 6 frequency channels from 265 to 3000 KHz). For depthstratified plankton hauls (15-level, from 0 to 200 m depth) we used a LHPR® fitted with 200 and 50 µm-mesh gauzes, and the on-board analysis of microplankton was made with a FlowCam® on depth-selected water samples. All the profiles were obtained in the 0-200 m depth water column. The analysis of zooplankton biovolume, the organic C contents (from biovolume and a conversion factor), individual numbers and the identification of taxonomic groups, was made using the free software ZooImage® , which uses ImageJ® for the step of image analysis, and R for classification and data analysis