Animal abundance and food availability: some comments

We challenge a conclusion reached by Barnes & de Villiers in a paper that was recently published in this Journal, viz that certain benthic invertebrates occur in lower abundances in lagoons than in intertidal soft-bottom areas and that this difference is due to lower food supply at lagoon bottoms. Our experience in the Wadden Sea shows that food does not limit the abundance of primary consumers in areas where environmental conditions are harsh. Such conditions prevail in most of the upper half of the intertidal which is characterized by low abundance of zoobenthos despite a high food supply.