Succession and pattern of tropical intertidal seagrasses in Cockle Bay, Queensland, Australia: A decade of observations

Abstract

After cyclonic devastation, the course of recolonisation by seagrasses was followed. Halophila ovata Gaud. and Halophila ovalis (R. Br.) Hook. f. were the pioneer species, and if present in quantity are evidence of past disturbance. Halodule uninervis (Forsk.) Aschers. colonised quickly on thin or thick sediments, where it is then out-competed by Cymodocea serrulata. (R. Br.) Aschers. & Magnus. Ten years after disturbance, the Halophilae has reached a steady state, unlike Halodule uninervis whose frequency was still increasing. Cymodocea serrulata recolonised the thicker sediments only slowly before being outcompeted by Halimeda opuntia (L.) Lamouroux. Although Thalassia hemprichii (Ehrenb.) Aschers. survived the cyclone better than other species, it was never, and it never became, an important component of the meadows. The seagrasses were objectively classified into pioneer, competitor or tolerator classes, and a largely deterministic model of their patterns and processes is suggested.