Time-lapse photography indicates that biological activity and reworking acted as a catalyst for sediment erosion by bottom currents during a two-day period at a depth of 360 meters in the Hudson submarine canyon. Decapod Crustacea were responsible for the major tracks and burrows. Deep, sharp tracks made by the crab Cancer borealis were smoothed by currents within three hours, but a large burrow was maintained with intermittent excavation by a smaller burrowing decapod crustacean. The asteroid (seastar) Henricia did not track but smoothed the bottom. A polychaete worm appeared to forage in the Cancer tracks. Bottom water turbidity varied abruptly at intervals of less than one hour.