Apo Reef two lagoon systems, the north and south lagoons which are bounded by narrow reef platforms. It is a almost triangular northern and southern atoll-like reefs separated by a deep channel that is open to the west. The channel runs east to west from deep with a fine white sand bottom, numerous mounds and patches of branching corals under the deep blue water. The north lagoon is an enclosed triangular coral reef platform partly exposed during low tide. It is relatively shallow with depths of about . While the south lagoon is an inverted triangular coral platform enclosed on two sides
Deep-water coral extended to . Scientists recently deployed concrete reef balls in an attempt to provide habitat for fish and coral. Scientists estimate that trawling has damaged or destroyed 30 to 50 percent of the Norwegian shelf coral area. The International Council for the Exploration of the Sea, the European Commission’s main scientific advisor on fisheries and environmental issues in the northeast Atlantic, recommend mapping and closing Europe’s deep corals to fishing trawlers. In 1999, the Norwegian Ministry of Fisheries closed an area of containing the large Sula Reef to bottom trawling. In 2000, an additional area closed, covering about . An