Table 1 Definitions of the components of primary question a

Native seaweed and herbivore assemblages

Introduction, establishment and spread of exotic seaweeds

Species/taxa diversity (e.g richness, Simpson/Shannon/Berger-Parker diversity indices), species/taxa evenness (e.g. Pielou evenness index), total community cover, total community biomass, total biomass, mortality, density, single species/taxa cover, single species/taxa biomass, individual growth, individual size, community productivity, per capita reproductive output

Invaded vs non-invaded units Unit: organisms/individual/plots/ treatments/areas/sites/locations/regions Invaded unit vs Invader removal unit Unit: organisms/individual/plots/ treatments/areas/sites/locations/regions Control unit (no Invader) vs Invader transplanted unit Unit: organisms/individual/plots/ treatments/areas/sites/locations/regions