No effect of naturally-occurring rock types on settlement or survival in the intertidal barnacle, Tesseropora rosea (Krauss)

The settlement and early survival of young barnacles, Tesseropora rosea (Krauss), on four different, naturally-occurring rock substrata were investigated in a four-factor experiment. Three factors assessed variation on three spatial scales: among shores on the New South Wales coast in eastern Australia i.e., 10 to 600 km apart; among sites within these shores i.e., 20 to 50 m apart; within these sites, i.e., < 3 m². Variation on these scales was usually significant for settlement density and proportional survival 30–60 days post-settlement. The fourth factor, different rock types, showed no consistent trends for settlement density or proportional survival. Previously observed differences in these phenomena among shores cannot, therefore, be ascribed to differences in rock substrata.