The tidal coastline presents a fascinating ecological world. Rocky shores with their recurrent zonation of algae and sessile invertebrates demonstrate the orderliness of nature, apparently obeying general explan­ atory principles. The niche theory could just as well have hatched out of the tight species-packing on the coral reef flats. Fluxes of carbon and nitrogen are best studied in mangroves and salt marshes with their outstanding primary productivity; the bare mud and sands of the tidal flats are different. Their ecological treasures are well concealed, and perhaps not to everybody's taste. Pick up a piece of tidal sediment and see how it resembles a large, rotten cheese! It smells, is slimy and sticky, is punched with holes and crowded with various worms. Tidal flats receive detritus from both the land and the sea. They sup­ port a rich benthic community which attracts birds from far distant breeding grounds, and serves as a nursery for crabs, shrimp and fish. Tidal flats are a busy ecological turntable. They import low valued organic matter, and they export well-fed birds to the land and grown-up fish to the sea. They offer ideal opportunities for aquaculture but are also used as dumping grounds for industrial wastes. All this may call for a marine ecologist to investigate the basic processes involved. Yet there is still another reason.

Inhalt

1. Introduction.- 1.1 The Beginnings of Research in Tidal Flat Ecology.- 1.2 Field Experiments on Tidal Flats.- The Tidal Flat Ecotone.- 2. Tides, Sediments, and the Distribution of Organisms.- 2.1 Tides and Sediments.- 2.2 The Distribution of Organisms.- 3. Biogeochemistry of Tidal Sediments.- 3.1 The Vertical Chemocline.- 3.2 Burrows and Pellets.- 4. Living in Tidal Sediments.- 4.1 Low Tide Endurance, Avoidance, and Peference.- 4.2 Production and Consumption of Biomass.- 5. The Tidal Flats of Königshafen.- 5.1 The Environment.- 5.2 The Biotic Community.- Experiments on Tidal Flats.- 6. Some Problems of Methodology.- 6.1 General Considerations.- 6.2 The Methodology of Caging.- 7. Exclusion of Large Fish and Birds.- 7.1 Effects on Macrofauna.- 7.2 Effects of Grazing.- 7.3 Moderate Effects on the Benthos.- 8. Predation by Crabs, Shrimp, and Small Fish.- 8.1 Predator Additions.- 8.2 Associated Predators.- 8.3 Predator Removals.- 8.4 Predation in the Tidal Nurseries.- 9. Endobenthic Predation.- 9.1 Carnivores Within the Tidal Sediments.- 9.2 Predator Additions and Removals.- 9.3 Multiple Predation on Tidal Flats.- 10. Prey Dynamics and Predator Impact.- 10.1 Cockles.- 10.2 Lugworms.- 11. Macrofauna Promotes Meiofauna.- 11.1 Promotive Bivalves.- 11.2 Meiofauna at Lugworm Burrows.- 11.3 Removal of Lugworms.- 12. Interactions in the Biotic Assemblage.- 12.1 A Conceptual Hierarchy of Ecological Processes.- 12.2 Promotor Effects.- 12.3 Consumer Effects.- 12.4 Competition.- 13. The Open Community on Tidal Flats.- 13.1 An Ecological Turntable.- 13.2 Low Connection Between Species.- 13.3 The Prevalence of Predation.- References.