A STAGE-STRUCTURED FINITE ELEMENT MODEL FOR THE POPULATION DYNAMICS OF TWO INTERTIDAL BARNACLES WITH INTERSPECIFIC COMPETITION

Marine life cycles commonly include a planktonic larvae phase that is transported by ocean currents. In this work, to assess the relationship between the physical processes that disperse larvae and the intensity of species interaction in the benthic habitat, we use a two dimensional stage-structured finite element model that introduces an interspecific competition for space among adults of the barnacles Balanus glandula (dominant species) and Chthamalus (Chthamalus dalli and Chthamalus fissus - subordinate species) which inhabit the rocky intertidal zone of North American Pacific coast. The main objective of this work is to characterize the effect of some idealized current patterns combined with hierarchical competition for space among adults on their relative abundances. A four stage-structured representation of the species life cycle is used. Numerical simulations showed that coastal flows may affect the adult distribution and the population interaction strength of the dominant on the subordinate species, that decreases as the velocity speed of the flow field increases. This behavior yields different population distribution patterns at the coast depending on the current pattern.