Invertebrate settlement and diversity on a glass sponge reef

Glass sponge reefs are an ecosystem unique to the continental shelf of the northeast Pacific Ocean. Due to their vulnerability and limited distribution, several sponge reef protection initiatives exist within Canadian waters with the common goal of conserving biodiversity. To date, the biodiversity associated with sponge reefs has largely been assessed using remote video methods that allow us to describe large fauna associated with the reefs. However, small organisms are typically missed, resulting in an underestimate of reef-associated biodiversity. In this study we aimed to further describe invertebrate biodiversity associated with sponge reefs. Sponge reefs recently discovered in Howe Sound, British Columbia are within safe recreational SCUBA diving limits allowing us to examine macrofaunal settlement timing and community structure using diver-deployed settlement plates. We examined the effect of settlement plate material and elevation above the benthos within the reef on invertebrate community structure. A total of 70 taxa settled on the plates representing 10 phyla, including two phyla not previously described on sponge reefs: Nemertea (ribbon worms) and Platyhelminthes (flatworms). There were no significant differences in taxa richness, diversity, or community structure associated with settlement plate material or height above the benthos. Ours is the first report of invertebrate settlement on a sponge reef in the Salish Sea and the first description of larval settlement timing for nine invertebrate species in the northeast Pacific.

Improving monitoring by understanding the patterns and drivers of biodiversity on Canada’s Glass Sponge Reefs

Glass sponge reefs, built by up to three species of dictyonine hexactinellid sponges, are hotspots of biodiversity that are unique to the waters of the Pacific continental shelf. Since 2012 we have surveyed the biological community on 21 sponge reefs from the Strait of Georgia to Chatham Sound, British Columbia. Here we present patterns of biodiversity found on glass sponge reefs and associations between common reef-dwelling organisms and sponge reef habitat categories: no visible reef, dead reef, mixed reef, live reef, and dense live reef. Further we share our findings regarding energy flow through the reef community and the implications for the maintenance of biodiversity in this system. We discuss how our findings inform monitoring in the new Hecate Strait and Queen Charlotte Sound Glass Sponge Reefs Marine Protected Areas and the many other conservation-based fishing closures centered on sponge reefs. Finally, we show how this research has led to the development of novel monitoring methods, namely the application of passive acoustic monitoring on the sponge reef ecosystem.

Improving monitoring by understanding the patterns and drivers of biodiversity on Canada’s Glass Sponge Reefs

Glass sponge reefs, built by up to three species of dictyonine hexactinellid sponges, are hotspots of biodiversity that are unique to the waters of the Pacific continental shelf. Since 2012 we have surveyed the biological community on 21 sponge reefs from the Strait of Georgia to Chatham Sound, British Columbia. Here we present patterns of biodiversity found on glass sponge reefs and associations between common reef-dwelling organisms and sponge reef habitat categories: no visible reef, dead reef, mixed reef, live reef, and dense live reef. Further we share our findings regarding energy flow through the reef community and the implications for the maintenance of biodiversity in this system. We discuss how our findings inform monitoring in the new Hecate Strait and Queen Charlotte Sound Glass Sponge Reefs Marine Protected Areas and the many other conservation-based fishing closures centered on sponge reefs. Finally, we show how this research has led to the development of novel monitoring methods, namely the application of passive acoustic monitoring on the sponge reef ecosystem.