Temperature sensitivity of detrital photosynthesis.

T opt of kelp detritus is ≥3 °C colder than that of the intact plant. Given that E. radiata is one of the most temperature-tolerant kelps, this suggests that photosynthesis is generally more thermosensitive in the detrital phase, which partly explains the enhancing effect of temperature on remineralisation. In contrast to darkness, even subcompensating irradiance maintains detrital viability, elucidating the accelerating effect of depth and its concomitant light reduction on remineralisation to some extent. Detrital photosynthesis is a meaningful mechanism underlying at least two drivers of remineralisation, even below the photoenvironment inhabited by the attached alga.