Rhodoliths were observed and collected from two different sites near Baradal Island, Tobago Cays. Site 1 (Figure 1) is located south-east of Baradal Island and lies within the back reef zone. The back reef is between 50 and 75 metres wide and is characterised by average water depths of 2 meters and strong westward flowing currents. In this zone, rhodoliths are preferentially concentrated in 2 to 3 metres wide, 2 to 5 metres deep sandy depressions that lie between patch reefs. The rhodoliths are commonly partially buried in coarse calcareous sands. This is believed to be a result of sand being deposited over and around the nodules by wave action.
Site 2 (Figure 1) is an area that spans across the north-eastern to northern part of Baradal Island. This area is located between 10 and 20 meters seaward from the island and lies within the lagoon. Current velocities are reported to be stronger in this area because of longshore currents flowing along the east coast of the island. Rhodoliths observed at Site 2 are evenly distributed across the sandy bottom. Representative samples were collected in approximately 2 meters water depth.