Figure 4
From: Biogeochemical feedbacks to ocean acidification in a cohesive photosynthetic sediment
Diel oscillations in porewater (a) [H+] (Δ[H+]D-L, nmol L−1) and (b) [O2] (Δ[O2]L-D, µmol L−1) as a function of depth in the surface layer of intact cores of subtidal silt sediment submerged in ambient (circles) and CO2-enriched (triangles) seawater. A 1 mm surface layer of either sterile sand (filled symbols, Control) or calcite (open symbols, +Calcite) was added to the sediment cores. The horizontal line at 0 mm depth indicates the position of the sediment surface.
