Table 4.

Area–depth–volume-weighted seasonal and yearly mean values of benthic and pelagic gross primary production (GPP in mg C m⁻² day⁻¹ and g C m⁻² year⁻¹, respectively) in the Öre estuary and Bothnian Bay for 2012. The benthic share of total primary production (benthic + pelagic) is shown by “% benthic”. The area between the shoreline and 10 m depths defines the coastal area, and the coastal volume is the volume related to this area (Supplementary material A). The difference in benthic contribution between the estuary and the Bothnian Bay mainly depends on bathymetric differences

Site	Average summer GPP (mg C m−2 day−1)				Yearly GPP (g C m−2 year−1)
	Coastal		Whole system		Coastal		Whole system
	Benthic	Pelagic	Benthic	Pelagic	Benthic	Pelagic	Benthic	Pelagic
Öre estuary	133.2	136.0	45.4	163.8	23.6	31.9	8.0	38.6
% benthic	49		22		43		17
Bothnian Bay	196.5	107.2	52.9	123.1	36.9	25.1	9.4	21.3
% benthic	65		30		59		31