Accumulation and fate of phytodetritus on the sea floor

Phytoplankton blooms sometimes result in the mass sinking of phytodetritus through the water column to the sea floor. The accumulation of a phytodetrital fluff layer on the sea floor is an episodic or seasonal event in some marine environments. This review provides a comprehensive list of locations in the world where the accumulation of phytodetritus has been observed on the sea floor. The microscopic and chemical composition of phytodetritus sampled from the sea floor at shallow to abyssal depths is also summarised. In addition, this review provides an overview of the mechanisms leading to mass sinking events, rates of accumulation of fluff layers, the impact of phytodetritus on fluxes of dissolved and particulate matter at the sediment/water interface, and the fate of phytodetritus on the sea floor. More studies are needed to understand the importance of these ephemeral phenomena for the ecology of benthic organisms, benthic-pelagic coupling in the carbon cycle, and the geological record in marine sediments.