Figure 3
From: Biogeochemical feedbacks to ocean acidification in a cohesive photosynthetic sediment
Average (n = 6) vertical microprofiles of porewater [O2] measured in intact cores of subtidal silt submerged in (a, b) ambient seawater and (c, d) CO2-enriched seawater under conditions of (a, c) light and (b, d) darkness. A 1 mm surface layer of either sterile sand (blue symbols, Control) or calcite (open symbols, +Calcite) was added to the sediment cores at the start of the experiment. The horizontal lines at 0 mm depth indicate the position of the sediment surface. Black horizontal lines extending to the right or left of the symbols indicate 1 SD. The dashed horizontal line indicates the average O2 penetration depth in Control (long dash) and +Calcite (short dash).
