Nutrient input by seabirds to the forest on a coral island of the Great Barrier Reef

The rate of deposition of droppings from White-Capped Noddies Anous minutus Boie, the principal seabird nesting and roosting in the trees of Pisonia grandis R. Br. on Heron Island, Great Barrier Reef, was measured 3 times during 1983.Deposition at ground level was extremely variable, partly because much of the material was intercepted by foliage.An average rate of deposition was about 2 g m-2 d-' (dry matter), equivalent to a total input of about 45 tonnes yr-' to the soil under the P. grandis canopy of the island.This represents the transfer of about 1.4 tonnes yr-' of phosphorus from the surrounding waters to the island's soil where P may become stabilised in insoluble form.