Fig. 4
From: Late Neoproterozoic seawater oxygenation by siliceous sponges
Couplings in the Late Neoproterozoic to Cambrian marine ecosystem and their effects on the oxygen concentration in the water column. a Effects resulting from the expansion of sponges. Processes a–h are denoted by arrows and are detailed in the text. Arrows denote positive couplings (enhancing mechanisms) and circles negative couplings (inhibiting mechanisms). b With expansion of sponges the oxygen minimum zone shifted towards greater water depth, increasing the benthic oxygen inventory at the continental slope
