Seeking Sponges: Distribution of Exposed Porifera in Mo’oera, French Polynesia

Sponges constitute an important part of marine and aquatic ecosystems, however compared to other benthic groups little is known about sponges. Knowledge of sponge species and distribution is extremely limited on Mo’orea, French Polynesia. The purpose of this research was to describe the distribution of sponges using Rapid Habitat Assessment surveys at different locations around the island and to investigate distributional influences that cause zonation via a transplant experiment. Sponge species were given arbitrary species names and identified based on basic morphological characteristics. RHA’s were conducted at five sites around Mo’orea sampling the sub habitats present on the reef in terms of % cover of substrate types and ecological benthic attributes as well as taxon abundance for coral, fish and, sponges. To examine influences on distribution one sponge species was transplanted from the fringing to the barrier reef and caged against various factors then evaluated based on weight change. A one way ANOVA revealed certain species have significant differences in distribution with respect to location on the reef. Experimental results did not show a significant difference between weight loss based on the cage treatments, but overall every treatment lost weight. Based on the factors examined by the RHA no habitat types or distributional information specific to any one species could be attained. Analysis of the experiment data indicated that predation may limit some species to specific habitats