Distribution of cholorophylls and phaeopigments in the Northwestern Atlantic Ocean

Abstract

During a cruise in the Northwestern Atlantic the distributions of chlorophylls and phaeopigments were investigated in relation to mesoscale features by high-performance liquid chromatography. Samples were collected from hydrographic Stations and from two Continuous underway sampling systems fished simultaneously at the surface (2 m) and at deeper (30–90 m) depths. Highest pigment concentrations were associated with the transitional zones between Slope Water, the Gulf Stream and Northern Sargasso Sea. Chlorophyll b occurred in 47% of the samples analyzed and the dominant chlorophyll a degradation product was phaeophorbide a. Chlorophyllide a was usually found at low concentrations and phaeophytin a levels were undetectable. Concentrations of the various chlorophylls and their degradation products were used to infer Changes in taxonomic composition, phytoplankton biomass and zooplankton grazing pressure across several frontal zones.