Swift currents crossing the intertidal reef often carry rocks, broken off coral colonies, and clumps of sponges and algae all the way from the seaward reef groove and spur system. As it reaches the lagoon side of the reef, it begins to lose some of its force, and much of the debris builds a rocky berm edged by a kind of talus slope where the rocks and coral pile up. The berm in the upper photo stands about 2 meters tall. The second photo shows piles of rocks and coral at the base of the talus slope. A number of slugs have been found in this pile, in particular Berthellina citrina and Glossodoris rufomarginata.
