Inter-annual variations in biomass of loose lying algae Furcellaria–Coccotylus community: The relative importance of local versus regional environmental factors in the West Estonian Archipelago

The effects of local nutrient loading, harvesting, regional temperature patterns and weather induced light conditions were assessed on the interannual dynamics of the commercially important loose-lying red algal community of Furcellaria lumbricalis and Coccotylus truncatus. Higher algal biomasses were due to higher temperatures and number of calm days (i.e. clear water phases) during the active growing season in spring and summer. In addition, higher biomasses were associated with a higher number of stormy days in November–February, which is linked to a reduced ice cover and longer growing season. Commercial harvesting and nutrient load did not appear to drive the interannual dynamics of these red algae. Thus, the dynamics of the loose-lying red algal community is constrained by regional rather than local environmental factors.

► We estimated relative contribution of local and large-scale environmental variables to the interannual dynamics of the loose-lying red algal community.
► The dynamics of the loose-lying red algal community is constrained by regional rather than local environmental factors.
► Commercial harvesting and nutrient load did not appear to drive the interannual dynamics of the community.