Located on the South American Continental Shelf, Tobago is washed from the south by the turbulent Guyana Current and from the open Atlantic to the east by the North Equatorial Current. The mixing of these currents, combined with periodic pulses of nutrient-rich water from the Orinoco River in the rainy season (June-December), generates an abundance of plankton. This plankton is the base for the unusually abundant and varied life found on Tobago’s reefs.
The numerous fringing coral reefs surrounding Tobago are characteristically rich in filter-feeding animals, such as sponges and soft corals. The abundance of plankton also explains the massive size of some of the hard corals such as the giant boulder brain coral off Speyside, which is over 6 meters wide, and the huge barrel sponges that can be seen in the Columbus passage south of Tobago.
Above the reefs, Tobago is noted for enormous shoals of planktivorous fish that in turn attract schools of predatory fish such as jacks, barracuda, wahoo, tarpon and tuna. Other large animals frequently seen are sea turtles, reef sharks, hammerhead sharks, groupers, eagle rays and manta rays. These members of Tobago’s marine megafauna are not only ecologically essential to the health and integrity of the reef’s ecosystems; they are also some of the most valuable eco-tourism assets in the region. Tragically, some of these large animals are also some of the most vulnerable.
Not surprisingly, diving is a rapidly expanding activity on the island. Surface temperatures average between 26 and 31 degrees C throughout the year, with excellent water clarity from January to May. From June to December large volumes of fresh silt-laden water from the Orinoco River pass between Trinidad and Tobago, occasionally lowering inshore salinities to below the normal 36 ppt. These plumes of green fresh water create noticeable temperature and salinity gradients in the surface waters that add another level of intrigue to the already other-worldly atmosphere of the reef.
Here is a quick summary of some of the best known reefs and dive sites around Tobago.
Diver’s Dream, Diver’s Thirst, Flying Reef, Cove Reef are some of the dive sites located in the Columbus Passage, one of the top drift-diving locations in the Caribbean. These sites have strong currents that flow in a westerly direction, which sweep past the island’s at speeds ranging from a leisurely half-knot to a blistering 4 knots. This constant water movement sculpts sea fans and giant barrel sponges into strange shapes. Turtles, eagle rays and reef sharks are usually seen on these exhilarating dives.
The reefs and dive sites along Tobago’s Caribbean coast are some of the most beautiful on the island. The currents are less strong than in the Columbus passage, and the hard coral reefs at Arnos Vale and Culloden are some of the best to be seen. The Wreck of the Maverick, sunk in 1997 off Mt. Irvine, is invariably abundant in fish life, with schools of barracuda, grunts, triggerfish and jacks. Close encounters with giant jewfish are not uncommon, and always unforgettable. The Sister’s Rocks is a spectacular dive that consists of a cluster of rock pinnacles which breaks the surface and drops to a depth of 140 feet. This area is the home for large pelagics and a residential population of hammerhead sharks that are usually seen against the open blue waters, while lobsters and moray eels stay close to the reef.
Japanese Gardens, Black Jack Hole, Kelleston Drain, Bookend, and St. Giles are some of the varied and beautiful dives off the northeastern coast of Tobago. These dives are mainly for advanced divers, where conflicting currents create a playground for mantas, barracuda, and tarpon. Other current patterns offer more gentle drifts along sloping reef covered with hard corals, sponges, sea fans and sea plumes. Multitudes of damselfish, blue chromis, creole wrasse, angelfish, butterfly fish, and parrotfish add infinite colour, under the permanent gaze of roaming jacks, snappers and barracuda. Manta rays are frequent visitors.
Buccoo Reef is a largest coral reef in Tobago and was designated as a marine park in 1973. Its massive proportions contain a reef system of five reef flats that are separated by deep channels. An associated lagoon, the Bon Accord Lagoon, is almost completely enclosed by Sheerbird’s Point and a dense mangrove belt.
The succession of fauna and flora, from the dense mangrove to the outer reef, is a biologist’s delight. This reef complex is also more accessible to the non-diver, as snorkeling and glass-bottom boats offer an easy way to observe the many habitats and species it contains. The reef flats have wave-resistant species adapted to turbulent waters, such as elkhorn coral, while the reef crests are dominated by the star coral. At greater depths in the Coral Gardens the benthic fauna changes and is made up of large colonies of brain coral, starlet coral and star coral, with many waving soft corals.
This is one of the best examples of a reef complex in the region, but tragically, the Buccoo Reef is a shadow of what it once was. A combination of pollution from land run-off and physical damage from reef walking and anchors has degraded much of this once magnificent reef. There is hope to restore this magnificent reef and a concerted effort from the community, the private sector and government can make it happen. The Buccoo Reef Trust is playing an active role in this process and is initiating a Restoration Program with the relevant agencies. A film called “Buccoo Reef: To Rescue and to Restore” has recently been produced by the Buccoo Reef Trust in collaboration with the Tobago House of Assembly which explains some of the approaches that are being taken.