Figure A-2: CA-DA fluorescence in seawater from North Sea spring bloom

Top: Garret screen sample, day of sampling, Middle: Garret screen sample, analysed next day

Bottom: Subsurface sample, analysed next day

Red: no DA added, Green +100nM DA, Blue +1000nM DA

Left: CA-DA peak 285/460nm, Middle:Tryptophan peak 285/340nm, Right: DA peak 325/520nm

Fluorimeter sensitivity 10. Error bars indicate range of rapid variation