It is experimentally proved that turf algae in combination with sediment prevents the settlement of coral larvae. My field observations are contradictory to it. I observed lot of new recruits on hard substrate which has been covered with turf algae and sediment. Is there any other factor which could aid the settlement of coral larvae on a turf algal substrate?
There's some pretty good review papers on this topic. Here's a good summary with references to reviews of the impacts of coral - macroalgae phase shift.
www.researchgate.net/publication/231183154_Alternative_states_on_coral_reefs_beyond_coral-macroalgal_phase_shifts/file/d912f5065859f490f7.pdf
Norstrom et al. 2009. Alternative states on coral reefs: Beyond coral-macroalgae phase shifts. Marine Ecology Progress Series 376:295-306.
Article Norstrom AV, Nystrom M, Lokrantz J, Folke C.. Alternative st...
Coral spat can not settle on turf or sediment however they can settle on 'open' space next to turf and sediment. However they later run the risk of getting out-competed once the turf grows.
Kenneth M Leber @ Thank you Sir. The review article you suggested was informative.
Charlotte L Johansson@ Thanks for your response. your comments support my observations. My observations showed that a coral new recruit and turf exist together on a hard substrate. But I could not judge which one settles first. Im also thinking of what contributes to the success of coral larvae over the turf.
The spat also run the risk of being consumed when herbivores target the adjacent turf. Perhaps the success of the spat is only determined by luck..
Please also see the following RG links.
Article Effects of algal turfs and sediment on coral settlement
Article Sediment associated with algal turfs inhibits the settlement...
Article Macroalgae Inhibits Larval Settlement and Increases Recruit ...