Activities by Hediste diversicolor under different light regimes: Experimental quantification of particle reworking using time-resolved imaging

All measured reworking proxies demonstrated a general decrease in transport of luminophores in darkness compared to light/dark cycles. The difference was significant for proxies determined from sectioning. Imaging of particle transport demonstrated that rates were ~ 30% higher during light/dark cycles, with ~ constant amount of particles transported on a daily basis. The effect of light was consistent in the two microcosm types. However, there was a significant difference in Db, while r and MPD were not significantly different between the cores and aquaria. Overall, these results suggest a light-triggered surface feeding by H. diversicolor. Our study highlights the importance of experimental settings for quantification of particle transport by fauna, and that light conditions and types of experimental microcosms need to be carefully considered during investigations of bioturbation in illuminated environments.