Microbial, microalgal and planktonic reef life
Microbes, including bacteria, archaea, viruses, fungi, protozoans and microalgae, are the most abundant and arguably the most important members of coral reef communities. They occur in the water column and sediment, and in association with other reef organisms. This chapter describes the abundance, diversity, function and productivity of microbes, with an emphasis on free-living types. They are key to recycling and retention of organic matter via the ‘microbial loop’, and are an important food source for larger reef organisms. The metazoan zooplankton are also described, including larvae of most reef invertebrates and fish. They are described in terms of their duration in the plankton, their settlement behaviour (e.g. that of coral larvae), their daily migration patterns and their role as a food source for larger organisms. Their importance for inter-reef connectivity is discussed.