Caring for Tobago Reefs
Anjani Ganase, Trinbagonian marine biologist, continues her exploration of marine Tobago. This week, she takes another look at Tobago’s iconic Buccoo Reef, comparing what was seen on the reef almost 50 years ago with what’s there today. Follow Anjani Ganase on twitter: @AnjGanase
|Anjani Ganase, photo by Amanda Ford|
In April 1967, Dr. Thomas F. Goreau, a marine biologist at the University of the West Indies, Mona, Jamaica, visited Tobago’s Buccoo Reef to assess the composition and health of the reef and advise on recommended steps for its preservation. Dr. Goreau was an expert in coral reefs carrying out crucial research on Caribbean coral reefs at Discovery Bay, Jamaica, over ten years. This was his account of the Eastern and Outer reefs of the Buccoo system:
“As seen from the air, the best living coral framework by far occurs on the north-eastern windward side of the reef facing Buccoo Bay. Here the outer slope is steep and is covered with dense somewhat buttressed stands of Elkhorn coral that form the living rampart on which the surf breaks.”
Based on Goreau’s description in the report, here’s what we would expect to see. The surf zone of this reef was made up of Elkhorn coral, a branching species, whose thick branches span out to resemble a tree canopy with light sifting through to the reef creatures streaming below. Very dense interlocking thickets of these corals extend to the surface at low tide and break up the strong forces of the waves, giving shelter to the fragile fire coral and smaller colonies of other coral growing in between these corals. Moving farther down the reef slope and extending beyond 30 feet in depth, the shape of the corals change, consisting of highly diverse and abundant massive and boulder shaped corals. These corals included large brain corals, up to six feet in diameter, and other massive growth forms, such as the boulder star coral, whose shape resembles a long draping skirt. In between these large coral mounds there were finer branching forms – finger coral and staghorn coral, as well as an abundance of fire coral and patches of calcareous macroalgae, which is a major source of sand being produced for the Buccoo area. This colourful and richly diverse reef was home to many fish species including groupers, snappers and parrotfish.
This assessment of Buccoo reef – high coral cover and diversity, low algae and little disease - was similar to many Caribbean reefs throughout the 1960s up to the 1970s. However, in the late 1970s, there was widespread mortality of the Elkhorn corals throughout the Caribbean, as a result of the white band disease. This was followed in the 1980s by the regional death of the sea urchin, a crucial grazer. Sea urchins prevented reefs from being overgrown by macroalgae, and their loss shifted many reefs from coral dominance to algae-dominated reef. The degradation of Caribbean coral reefs continues to this day compounded by declining water quality, unregulated fishing and global warming which further limits recovery of the reefs.
Back in 1967, the strong recommendation made by Dr. Goreau was to protect the Buccoo Reef, not just the coral reef habitat but also the neighbouring lagoon, seagrass beds and mangroves, since the health of one habitat greatly affects the health of the other. Furthermore, he advocated maintaining water quality by implementing sewage treatment on shore, since poor water conditions harbour pathogens that can infect the corals. In retrospect, if Dr. Goreau’s recommendations were implemented earlier, it may have allowed for quicker recovery of the reef community following these disturbances and buffered the damages done to the coral from coral bleaching events.
|Underwater view of Buccoo reef in 2012, Photo by Jahson Alemu|
WHAT THE REEF LOOKS LIKE IN 2016
Here is an account from Jahson Alemu, the coral reef ecologist who carried out assessments, while working at the Institute of Marine Affairs in March 2014:
The surf zones of the Eastern reef and the Outer reef consist of the skeletons of Elkhorn coral, colonised by sea fans and fire coral. Small massive corals are present, but overall this area is very sparse of coral life and the vibrant community that used to live among these corals. Moving farther down the reef slope, coral cover increased but there are no large colonies of living brain and boulder corals. Most living corals are smaller in size, and are more encrusting and plating in shape. The boulder star corals predominate below 15 feet, but most colonies have evidence of partial mortality and suffer from yellow band disease. We do find small colonies of Elkhorn corals at 25 feet with the largest colony being about three feet in diameter, a fraction of the size seen in the 1960s. At this depth, the reef is a mixture of hard and soft coral but the more delicate branching corals are absent. Fish life are mainly juvenile parrotfish communities, with adults more common during spawning sessions. Small reef fish are abundant, such as the damselfish, snappers and grunts but more ecologically important fish and top predators are rare. Some fish still utilise the reef structure provided by the coral skeletons as areas to seek refuge. Macro-algae and turf algae are abundant on the reef; they are the main competitors of corals denying them space to settle or grow on.
Following Goreau’s guidelines, the Buccoo reef area was declared an area for restricted use in 1973; the marine park management plan was established in 1995. Forty-nine years since Goreau’s recommendations were made, progress has been too slow when considering the increasing frequency at which coral bleaching events are occurring as the earth climate continues to warm.
More importantly today, the protection of the reef is about understanding how innately the reef is connected to lives and livelihoods for the well-being of communities in Tobago, as well as Trinidad. Buccoo Reef is our living heritage. Jahson is hopeful and so we should all be; science has shown that if you give nature a chance, it will reward you in ways you could never imagine.
Goreau, T. F. (1967), Observations and recommendations concerning the preservation of the reef and its lagoon in relation to urb
FOR THE PROTECTION OF BUCCOO REEF
Some of the recommendations made to the Economic Planning Unit of the Prime Minister’s Office in Trinidad and Tobago in 1967 by Dr T F Goreau.
(Review of Goreau’s paper was facilitated by the Institute of Marine Affairs)
The Buccoo Reef – Bon Accord Lagoon complex is a single ecosystem which is unique in the eastern Caribbean for its biological richness, beauty and accessibility. This area is therefore to be regarded as a national asset, the development of which must take into consideration the long term economic and educational value of this reef for the nation as a whole. … It is up to Government to preserve and hold in perpetual trust for the people of Trinidad and Tobago this priceless national resource.
IMMEDIATE AND ON-GOING IMPLEMENTATION
· Removal of mangrove from the designated area to be forbidden.
· All insect control measures with residual insecticides to be stopped.
· Dumping of garbage, sewage, petroleum waste into the reef, lagoon from shore as far as Stonehaven to be forbidden.
· All interference with the bottom of the sea to be forbidden in the preserve.
· Capture of fish, turtles, shrimp or other creatures by any means within the preserve to be forbidden.
· Collection of specimens for scientific research to be allowed with permission from relevant authorities.
· On-going programmes of research and monitoring to be initiated by Government with relevant university.
· Create a national preserve or park with appropriate legislation.
· Government should acquire at fair value all lands bordering the Bon Accord Lagoon including Pigeon Point, Sheerbird Point, the mangrove forests and swamps in the area.
· Create a national marine park, for educational and tourism purposes, with an aquarium and museum. Train guides and park rangers to conduct tours for school children students, and other visitors to the reef and lagoon
· No marinas should be allowed in the confines of the park, but mooring facilities and jetties for the small boats required in the preserve on the western side of Pigeon Point and northern side of Sheerbird Point.
· All boats and tourist operators using the preserve to be registered and licensed.