The subtidal fouling organisms of the Calliope River and Auckland Creek, Central Queensland

The fouling organisms of Calliope River and Auckland Creek have been investigated to determine the most abundant and recurrent macrofouling species, and their succession on newly exposed surfacts. Short- and long-term test plates have been used at three localities since May 1975, and data to May 1977 are analysed here. Forty-seven species were found on the short-term plates. Thirteen were sessile and used in numerical analyses. Sites 2 and 3 (Calliope River) differed from Site 1 (Auckland Creek) by: the number of species; paired t-tests of species occurrence; and the mean number of individuals of each species. These differences are presumed to reflect physical disturbance at Site 1. Only three species (Balanus, Ficopomatus and Electra) occurred consistently on the short-term plates. Optimal wavelengths of the 5 species which showed significant periodicity in settlement were determined and compared with periodicities in temperature, chlorinity and rainfall. All had significant relationships with temperature, 3 with chlorinity and 0 with rainfall. Algal biomass also showed a much closer relationship to temperature than to chlorinity. The long-term plates indicated that a ‘pioneer’ phase is gradually (after 3-11 months) replaced by a ‘climax’ phase, characterized by Crassostrea, Modiolus, Balanus and Ficopomatus. A mosaic of the ‘pioneer’ and ‘climax’ phases is the common condition found on old plates and on naturally occurring substrates in the study area.