SEASONAL AND TEMPORAL ASPECTS OF RECRUITMENT AND SUCCESSION IN AN INTERTIDAL ESTUARINE FOULING ASSEMBLAGE

The recruitment and succession of fouling organisms was examined on fo ur substrata (concrete, plywood, fibreglass and aluminium) in Quibray Bay of Botany Bay in New South Wales, Australia. Eighteen 10x10 cm pan els of each substratum were submersed in each of four seasons: January (summer), March (autumn), May (winter) and October (spring) 1992. Six of each substratum were retrieved after 1 month, 2 months and 4-5 mon ths. Thus in this study, as a methodological improvement over many oth er studies of succession, samples were taken independently with regard to time. Seasonal recruitment was important in determining the patter n of succession and the composition of the assemblage. Sydney Rock oys ters, Saccostrea commercialis (Iredale & Roughley), recruited in large numbers on panels submersed in January and, by their rapid growth, do minated the available space after 4-5 months. The greatest recruitment of the barnacle Hexaminius sp. and the greatest percentage cover of a lgae (six species) occurred on panels submersed from October to March. While panels submersed in January for a period of 4-5 months resulted in a single outcome, an oyster-dominated-assemblage, panels submersed in October for the same period of time resulted in a set of alternati ve outcomes depending on the relative abundance of barnacles and algae . The results of this study suggested that models and mechanisms of su ccession in the marine environment should be based on the traits of in dividual species (including seasonal recruitment, growth and ability t o resist invasion) with respect to the limiting resource(s) in the sys tem, which for many sessile marine species is the available space.