Evidence against a mechanism of allelopathy in the green alga Chlorodesmis fastigiata

Allelopathic macroalgae have been shown to have significant negative effects on corals via the transfer of toxic compounds. The interaction that takes place between allelopathic macroalgae and other algae, however, has not been studied in detail. Here, the effects of the allelopathic Chlorodesmis fastigiata on other macroalgae were analyzed. These effects were first tested on complete coral and macroalgal individuals over several days, then on small samples of the macroalgal species when exposed to isolated toxins. However, neither experiment found significant negative effects on either Sargassum mangarevense or Boodlea kaeneana due to the interaction between these algae and the toxin produced by C. fastigiata . Distribution and abundance of C. fastigiata was also assessed around the island of Moorea in French Polynesia.