Studies on blue-green algae photosynthetic bacteria in the lagoon of Aldabra Atoll

This thesis reports a study of the dominant communities of photosynthetic prokaryotes, growing in the intertidal zone of the lagoon of Aldabra Atoll, Indian Ocean. The work was carried out from November 197A- to June 1975. Physico-chemical and descriptive data collected from standard transects of the intertidal zone are presented, together with the Eh-pH ranges of various communities associated with lagoon sediments. A taxonomic checklist is given of species from marine and brackish habitats, with descriptions and notes on distribution and abundance. More detailed studies were made on various communities of blue-green algae and photosynthetic bacteria. These included estimations of standing crop, the monitoring of physico-chemical parameters over 24 hour periods, and studies on the ability to fix nitrogen in situ as indicated by the acetylene reduction assay technique.