Bentho-pelagic coupling: Does quality and diversity of  food supply influence infaunal biodiversity?

Regulation of sedimentary biodiversity patterns is a topic of heated debate that has generated considerable theoretical discussion in the absence of much experimental data. Using an in situ experimental approach, we are investigating the role of food supply in establishing infaunal patterns and maintaining biodiversity in sub-arctic sedimentary ecosystems. Natural sediment was enriched artificially in situ by divers at a depth of 20 m, creating patches containing no enrichment, enrichment with a monoculture of concentrated algae, or enrichment with an algal mixture. The patches were sampled 1 week and 5 weeks after enrichment and sorted for macrofauna. We hypothesized that a mixed enrichment would affect a broader diversity of colonizers and that different enrichments would attract different colonizers. Results indicate that quality and diversity are not major contributors to benthic pattern. Sub-arctic benthic communities do undergo changes from spring to summer with polychaetes, bivalves, cumaceans and amphipods contributing to pattern early in the year while polychaetes tend to be the major players in driving pattern as summer progresses.