Wild Caribbean reef fish anywhere in the Caribbean. The final island to be featured is Trinidad, cut off from South America by rising sea levels 2,000 years ago. Its island fauna include many mainland species such as red howler monkeys, capuchins and scarlet ibis. Coral reefs, which thrive in the warm, shallow waters around Caribbean Islands, are the subject of the second programme. Hard corals are the reef-builders, and grow their tough external skeletons by extracting nutrients from algae growing within them. Time-lapse footage shows coral polyps emerging at night to trap drifting plankton. Marine life featured includes Caribbean reef squid, octopus
Sully Island Sully Island Sully Island (Welsh: Ynys Sili) is a small tidal island and Site of Special Scientific Interest at the hamlet of Swanbridge, Vale of Glamorgan, 400 yards off the northern coast of the Bristol Channel, midway between the towns of Penarth and Barry and 7 miles (11 kilometres) south of the Welsh capital city of Cardiff. Access to the island is on foot at low tide from the car park of the "Captain's Wife" public house. It is 14 and a half acres in extent and is one of 43 (unbridged) tidal islands which can be reached on foot