CTD, chlorophyll, and phytoplankton data collected in the seasonally stratified waters of the Western English Channel during the summer of 2013.

This dataset contains CTD, chlorophyll, and phytoplankton abundance and biomass data gathered through analysis of discrete water samples collected from multiple sailings of the RV Callista. The data were collected offshore of Falmouth, UK to explore the seasonally stratified waters of the Western English Channel in June and July 2013. Discrete water samples were taken with CTD profiles to examine the phytoplankton communities of subsurface chlorophyll maxima. Phytoplankton taxa/groups were identified, counted, and converted to a measure of biomass to analyse phytoplankton communities to determine if subsurface chlorophyll maximum thin layers (<5m thick) have a distinct phytoplankton community structure to that of broader maxima. The data were collected by Michelle Barnett as part of her PhD study funded by the Graduate School of the National Oceanography Centre, Southampton. A SeaBird SBE19+ CTD was used with a Wet Labs ECO FLNTU fluorometer to take temperature, fluroescence, density, conductivity, and salinity profiles with 5 litre Niskin bottles attached to the CTD rosette. Chlorophyll measurements were taken using a Turner Designs 10AU fluorometer after 50 ml subsamples were passed through 25 mm Whatman GF/F filters and kept at -20 degrees C in darkness. Phytoplankton were examined under a Brunel SP951 inverted trinocular light microscope after 50 ml subsamples were collected and preserved in Lugols iodine to a final concentration of 1%. The data also contains sample date, time, position, and depth.