Sponge richness on algae-dominated rocky reefs in the western Antarctic Peninsula and the Magellan Strait

Abstract

Sponges are important components of high-latitude benthic communities, but their diversity and abundance in algal-dominated rocky reefs has been underestimated because of the difficulty of in situ identification. Further, the influence of canopy-forming algae on sponge richness has been poorly studied in southern high-latitude rocky reefs compared to other latitudes. Here, we quantified taxon richness of sponges in algae-dominated rocky reefs at three sites in the western Antarctic Peninsula (62–64° S) and two sites in the Magellan region (53° S). We found higher sponge richness at sites in Antarctica (15) than in Magallanes (8), with Antarctic sponge richness higher than that reported for Arctic algal beds and similar to that reported for temperate regions. Estimated sponge richness at our Antarctic sites highlights diverse sponge assemblages (16–26 taxa) between 5 and 20 m that are typically dominated by macroalgae. Our results suggest that sponge assemblages associated with canopy-forming macroalgae on southern high-latitude reefs are more diverse than previously thought.

• Porifera
• sponge–algae interactions
• Antarctica
• sub-Antarctic
• southern high-latitudes.

Acknowledgements

We thank the Chilean Antarctic Institute personnel and volunteers at Professor Julio Escudero and Yelcho research stations for field and logistical support, and the Brazilian National Council for Scientific and Technological Development, Brazil. We also thank J.B. McClintock and an anonymous reviewer for their constructive comments. This research was partially funded by projects INACH:T2-08, FIC-R 2008 (Gobierno Regional de Magallanes y Antártica Chilena), FAPERJ (Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Brasil) and CONICYT/FONDECYT/INACH/INICIACION/#11150129.