Fig. 2.

2-D distribution of oxygen and sulphide in the rhizosphere of Zostera muelleri during full light (250 µmol photons m−² s⁻¹). a Oxygen (left) and corresponding reduction in sulphides (right) around the leaking root tips (overlain with bw image of roots and marked with white squares where oxidation has occurred). b Lack of oxygen loss around older roots (left) and corresponding increase in sediment sulphides (right) along the length of the root (overlain with bw image of roots). Scale bar is 5 mm