Ecology of Sandy Shores

Abstract

1. Introduction. 2. The Physical Environment. Sand. Porosity and permeability. Penetrability. Waves. Types of waves. Wave energy. Refraction. Shoaling and breaking. Wave-driven longshore currents and rip currents. Bound and infragravity waves - surf beat. Edge waves. Tides. Internal waves. Wind. Sand movement. Interaction between beach slope, waves and particle size. Beach types. Circulation cells and mixing. Water filtration by the sand. Exposure rating. Conclusion. 3. Beach and Surf-zone Flora. Benthic microflora. Surf-zone phytoplankton. Conclusions. 4. Sandy-beach Invertebrates, with special reference to the Macrofaunal Genera. Phylum:Porifera. Phylum:Cnidaria. Phylum:Platyhelminths. Phylum:Nemertea. Phylum:Nematoda. Phylum:Rotifera. Phylum:Gastrotricha. Phylum:Kinorhyncha. Phylum:Loricifera. Phylum:Annelida. Phylum:Echiurida. Phylum:Sipunculoidea. Phylum:Brachiopoda. Phylum:Mollusca. Phylum:Tardigrada. Phylum:Arthropoda. Phylum:Ectoprocta. Phylum:Echinodermata. Phylum:Hemichordata. 5. Adaptations to Sandy-beach Life. Locomotion:burrowing. Locomotion:surfing. Rhythms of activity. Sensory responses and orientation. Choice of habitat. Nutrition. Respiration. Environmental tolerances. Reproduction. Aggregations and gregariousness. Responses to and avoidance of predators. Conclusions. 6. The Macrobenthic Communities. Sampling methods. Diversity and abundance. Distribution and zonation. Migrations and spatial and temporal changes. Competition, disturbance and predation. Trophic relationships. Conclusions. 7. Interstitial Ecology. The interstitial climate. The biota. Distribution of the interstitial fauna. Temporal changes. Meiofaunal communities. Trophic relationships. Biological interactions. Conclusions. 8. Surf-zone Fauna. Zooplankton:composition. Adaptations of surf-zone zooplankton. Zooplankton:migrations. Zooplankton:distribution. Zooplankton:biomass and abundance. Food and feeding relationships. Surf-zone fishes. Juveniles and nursery areas. Surf-zone fish communities. Fishes:temporal variability. Ichthyofaunal trophic relationships. Other groups. Conclusions. 9. Birds and other Terrestrial Vertebrates. 10. Sandy Beach Ecosystems. Food sources. Macroscopic food chains. Examples of macroscopic food chains. The interstitial food chain. The microbial loop. Energy flow in beach and surf-zone ecosystems. The sandy beaches of the Eastern Cape. Nutrient cycling. Conclusions. 11. Sandy Beaches and Pollution. Crude oil pollution. Oil dispersants. Sewage and organic enrichment. Factory effluents. Thermal pollution. Indicators of pollution. Toxicity studies. Conclusions. 12. The Dune Ecosystem and Dune/Beach Exchanges. The physical environment - wind and sand transport. Coastal dune formation by vegetation. Dune types. Edaphic features. Water. The gradient across coastal dunefields. Dune vegetation. The fauna. Food chains of the dune ecosystem. Dune/beach exchanges. A case study of dune/beach exchanges. Conclusions. 13. Conservation and Management.