Informing Kelp Forest Restoration Site Selection With The California Spiny Lobster (Panulirus interruptus)

Abstract

Kelp forest communities in Southern California provide ecosystem services that support biodiversity, tourism, recreation, and fisheries, yet their extent has declined by up to 80% over the last century. Contributing to the decline is the extraction of predators controlling sea urchin populations, which are kelp herbivores. This can result in the formation of persistent “urchin barrens” that may become the subject of kelp forest restoration efforts. This project models and predicts preferable habitat for the California Spiny Lobster (an urchin predator) as a means of improving the efficiency of kelp forest restoration projects. To this end, a GIS tool was developed to analyze lobster abundances recorded as part of the Channel Islands National Park Service’s long term Kelp Forest Monitoring dataset. Habitat predictions suggest that urchin barrens around the northern-most Palos Verdes peninsula may have the most preferential lobster habitat, thereby enhancing restoration longevity through normal lobster foraging behavior. Results also suggest that lobster may be especially attracted to features that maximize their associational defense, such as continuous ledges that form topographically-concave ridgelines.