The fucoid brown algaAscophyllum nodosum (L.) Le Jolis annually produces lateral reproductive branches (i.e. receptacles) approximately equal in weight to its vegetative thalli. The receptacles are shed within a single month during the spring. The estimated total input of receptacles to the detrital pool within the Great Bay Estuary System of New Hampshire-Maine, U.S.A., is 445 g dry wt·m−2·yr−1. Decomposition rates were rapid with only 50% or less of the original litter remaining after 50 days. Nitrogen and phosphorus flux from the litter bags varied with environmental conditions and habitats.