Data from: Epibenthic predators control mobile macrofauna associated with a foundation species in a sub-arctic subtidal community

Foundation species (‘FS’) are strong facilitators providing habitat for
numerous dependent organisms. The communities shaped by FS are commonly
structured by interplay of facilitation and consumer control. Predators or
grazers often indirectly determine community structure eliminating either
FS or their principal competitors. Alternatively, they can prey on the
dependent taxa directly, which is generally buffered by FS via forming
complex habitats with numerous refuges. The latter case has been never
investigated at high latitudes, where consumer control is widely
considered weak. We manipulated the presence of common epibenthic
crustacean predators to assess their effect on mobile macrofauna of the
clusters developed by a FS (barnacle Balanus crenatus and its empty tests)
in the White Sea shallow subtidal (65° N). While predation pressure on the
FS itself here is low, the direct effects of a spider crab Hyas araneus
and a shrimp Spirontocaris phippsii on the associated assemblages were
unexpectedly strong. Removing the predators did not change species
diversity, but tripled total abundance and altered multivariate communtity
structure specifically increasing the numbers of amphipods, isopods (only
affected by shrimp) and bivalves. Consumer control in the communities
shaped by FS may not strictly follow the latitudinal predation gradient
rule.