Description
Characterizing the relationship between the abundance and composition of species and the structural complexity of their habitats is a common goal of ecological studies. Temperate rocky reefs in southern California largely support Macrocystis pyrifera (giant kelp) forests, and extensive research has been conducted on the role of M. pyrifera as an important habitat-forming species. Virtually no research, however, has been directed towards another prominent, shallow-water macroalga, Egregia menziesii (feather boa kelp) and the organisms associated with these kelp forests. Here, I conducted a series of field surveys aimed at identifying and enumerating fish and invertebrate species associated with E. menziesii in comparison to the faunal assemblages associated with nearby M. pyrifera forests in standardizing for water depth and other environmental conditions. I observed differences in fish and invertebrate numerical densities, with higher densities in M. pyrifera than in E. menziesii but with no differences in fish biomass density. There was also a difference in maroinvertebrate numerical density, as well as a difference in macroinvertebrate diversity, with higher diversity in M. pyrifera. However, there was no significant difference in fish biomass between kelp species. PERMANOVA revealed that fish and invertebrate assemblages differed between regions. There was a marginal difference in fish assemblages, and a significant difference in macroinvertebrate assemblages, between kelps. Finally, I examined habitat factors within each kelp species that could be driving differences in assemblages. Interestingly, the most common factor in models predicting M. pryifera communities had to do with the kelp itself, whereas factors in models predicting E. menziesii assemblages pointed to other abiotic factors.
