COMPARTMENTS AND PREDATION IN AN ESTUARINE FOOD WEB

1. The proposition that strong functional predator-prey links are associated wit compartments in food webs (Paine 1980) is examined for a large, well-documented web, the Ythan estuary. 2. A simple method for the detection and description of infrastructure within binary food webs is described and this is applied to 12 webs previously analysed by Pimm & Lawton (1980) and to the Ythan web. 3. There was evidence for significant compartmentation in several real webs, all of which are reasonably well documented, aquatic and benthic. However, there was no evidence of compartments in the Ythan web. 4. Manipulative field experiments on a range of avian, fish and invertebrate predators provided no evidence for strong functional interactions in the Ythan web. 5. It is concluded that the lack of both compartments and strong linkage is consistent with Paine's hypothesis, but that the proposition needs further testing for other well-described systems.