Concentration and distribution of chlorophyll in fertilized plots in a Massachusetts salt marsh

Abstract

The amount of algal chlorophyll on the mud surface of a salt marsh was not affected directly by additions of urea or sewage sludge fertilizer but was proportional to light reaching the surface. Fertilization affected the algae by increasing the standing crop of grass and theregy reducing the light underneath. Vertical distribution of total chlorophyll depended on the species and biomass of grass present. Algal chlorophyll was concentrated at the mud surface and horizontally was very patchy. Locally the quantity exceeded the amount found in other productive marine ecosystems.