Production Ecology of a Sandy Beach

The vertical distribution of pigments and organic matter and the yearly cycle of production in a sandy beach are described for positions at low water and to a sublittoral depth of 13 m. The chlorophyll and carbon content of the populations attached to the sand grains increases with increasing depth of overlying water. At low‐water mark, viable diatom populations are found to 20 cm deep in the sand. The effects of wave action, however, keep these populations at a relatively low level so that the yearly primary production of the benthic flora is in the range 4–9 g C m −2 .