The relationships between beam attenuation, absorption, suspended particle concentration, size distribution and pigment content are examined for a region where the particle concentration and pigment maxima are widely separated. Mie scattering analyses are performed on this data to predict the profiles of backscattering. It was found that absorption and scattering are not and have no theoretical reason to be well correlated in a vertical section even if the particle concentration is perfectly correlated with phytoplankton biomass. Due to the rapid change in irradiane with depth, pigment concentration and therefore particulate absorption are not expected to be correlated with biomass or productivity as calculated from published laboratory results and theoretical models of phytoplankton pigment content. The beam attenuation is a good indicator of particle concentration and its vertical distribution relative to the pigment distribution is consistent with models of phytoplankton growth. An examination of data from a meridional transect of the North Pacific and from the Northeast Pacific coastal upwelling region suggested the universality of these findings. The remote-sensing algorithms that predict backscattering from chlorophyll concentration were developed using near-surface data. Use of these algorithms for the prediction of vertical structure of backscattering is discouraged. ¿ American Geophysical Union 1990