- Views 2854
A Strategy for Restoration of Damaged Coral Reefs and Fisheries
at Ashton Harbour, Union Island, the Grenadines
Dr. Thomas J. Goreau
President, Global Coral Reef Alliance
I recently had a chance to quickly check the health of coral reefs around Union Island and nearby islands including Mayreau, Petit Saint Vincent, Palm Island, and the Tobago Keys, and to talk extensively to local fishermen, divers, environmentalists, and hotels about long term changes in the coral reefs of these islands. It is clear that catastrophic damage was done to Ashton Harbour by a failed marine development in a protected area. This has destroyed coral reefs, seagrasses, and the fish, lobster, and conch (lambi) resources of the largest fishing village on the island. An active program of marine environmental restoration is urgently needed. The following provides a brief outline towards possible restoration strategies.
Ashton Harbour is the largest Bay in the Saint Vincent Grenadines, and had the greatest range of environmental habitats. They included the largest mangroves in the Grenadines, seagrass beds rich in lobster and lambi, coral reefs of fringing, patch, and barrier reef types, and an offshore island (Frigate) that was an important bird habitat (W. S. Price. & P. G. Price, 1994, A survey of the nearshore marine environment of Union Island, St. Vincent & the Grenadines, Union Island Association for Ecological Protection). Because of its environmental importance, Ashton Harbour was selected to be a Conservation Area under Schedule 11, Regulation 20, The Fisheries Act, 1986, and was formally designated as such on January 5th, 1987 (W. S. Price. & P. G. Price, 1994, Ashton Marina project, potential ecological impact on Union Island, St. Vincent & the Grenadines, Union Island Association for Ecological Protection). Despite this official designation as a protected area, a 300 boat marina project was proposed in the bay by developers.
An environmental impact study of the proposed project before its implementation pointed out that if the development were to be carried out the causeways would cut off water circulation to the bay, causing catastrophic damage to reefs, seagrasses, and fisheries (W. S. Price. & P. G. Price, 1994, Ashton Marina project, potential ecological impact on Union Island, St. Vincent & the Grenadines, Union Island Association cheap oakleys for Ecological Protection). Many citizens of the fishing village of Ashton opposed the project, on grounds that it would cause irreparable environmental and social harm to their community (M. Harvey, 1991, A 17 point article on the social, cultural, and economical disadvantage of the Ashton Marina complex, Union Island Ecotourism Movement).
Nevertheless the project proceeded, with the exactly the results that had been predicted. After dredging causeways that completely blocked circulation of water through the bay the “developers” vanished, stealing a large loan negotiated from European sources, which they had tricked the St. Vincent Government into guaranteeing financially. Al though the project then collapsed, preventing further pollution of the bay by marine fuel and sewage, causeway blockage of the bay’s circulation caused the western half of the bay to become stagnant. This killed coral reefs, seagrasses, lobster, fish, and lambi in this half of the bay. At the same time, blockage of circulation caused sand to accumulate in the eastern half of the bay, smothering coral reefs and seagrasses, and wiping out their fish, lobster, and lambi populations as well. The resources of the largest fishing community on the island have been destroyed, without compensation (W. S. Price & P. G. Price, 1997, Paradise lost: Post mortem of the Ashton Marina project ecological impact on Ashton Lagoon, Union Island, St. Vincent & the Grenadines, Union Island Association for Ecological Protection.).
An independent survey of the reefs of Ashton Harbour was carried out in February 2003 by Dr. Thomas Goreau and Nicholas Sammons of the Global Coral Reef Alliance. We found that the western half of Aston Harbour was stagnant and the water was green with chlorophyll due to excessive nutrient buildup, causing turbidity that prevented light needed to support seagrasses and fisheries. The mangroves had been severely stunted in most of their area due to interference with natural seawater circulation caused by the construction of causeways. Reefs on the western side of Frigate Island were in poor condition with low live coral cover. Corals inside the lagoon in the eastern side of the bay were almost all dead and overgrown with weedy algae, as the result of nutrient buildup due to poor circulation. Only the outer reef barrier reef slope was free of weedy algae. Despite lack of pollution, the reefs of even the fore-reef area were not in good condition. The reef crest had formerly been composed of massive growths of Elkhorn coral (Acropora palmata) but these were almost everywhere dead. It is certain that these shallow reefs were killed by white band coral disease epidemic which destroyed this species throughout the eastern Caribbean around 1980, and there has been very little recovery. Many head corals had also suffered mortality on their tops around 5 years ago, almost certainly as the result of a bleaching event caused by global warming in 1998, Although there were a few small patches of young live Elkhorn coral, these made up no more than a percent or so of the dead coral of the same species. The predominant live corals seen in shallow water are weedy species of Porites astreoides, and Porites porites, and of fire corals, Millepora squarrosa, Millepora complanata, and Millepora alcicornis, which overgrow dead reef framework but do not themselves build it. The deeper reef is almost entirely dominated by large colonies of star corals, Montastrea annularis. However about half of the surface of these corals were dead. Active signs of Black Band Disease, Yellow Band Disease, Dark Spot Disease, and Rapid Wasting Disease were seen on them. It appeared that large amounts of this coral had been infected by fungi and attacked by parrotfish, probably in 1997 as happened in Bonaire and other sites around the Caribbean (T. J. Goreau, J. Cervino, M. Goreau, R. Hayes, M. Hayes, L. Richardson, G. Smith, K. DeMeyer, I. Nagelkerken, J. Garzon-Ferrera, D. Gil, G. Garrison, E. H. Williams, L. Bunkley-Williams, C. Quirolo, K. Patterson, J. Porter, & K. Porter, 1998, Rapid spread of diseases in Caribbean coral reefs, REVISTA BIOLOGIA TROPICAL 46 Supl. 5: 157-171). The effects here appear to have been as severe as in Bonaire, formerly regarded as the worst known area affected in the Caribbean. So intensive were the effects that many star coral heads were observed to have had their tops destroyed to the point that they were concave rather than convex! In addition no young corals of this species were seen. All small colonies seen were clearly surviving portions of larger colonies, not young ones. So although this species is dominant in the reef, it appears to have suffered complete reproductive failure, and young corals are not replacing those that are dying from diseases. No lobster and conch were seen anywhere, although these had formerly been extremely abundant according to local fishermen. Studies of temperature, salinity, oxygen, and chlorophyll should be carried out in both sides of the bay to document the impacts of poor circulation.
There is no doubt that the only mitigation for this disaster is to remove the causeways and reopen circulation to the bay (W. S. Price & P. G. Price, 1997, Paradise lost: Post mortem of the Ashton Marina project ecological impact on Ashton Lagoon, Union Island, St. Vincent & the Grenadines, Union Island Association for Ecological Protection.). A proposal to do so has been submitted to the European Union by the Union Island Association for Ecological Protection and the Union Island Ecotourism Movement, and approved for funding, but has foundered over the issue of control of the land involved (Jacques Daudin and Matthew Harvey, personal communication, 2003). Apparently http://www.troakley.com/ the failed project is in receivership by the bank, which still hopes a developer will come in with the money to complete the project. This would only compound the ecological damage, and is most unlikely given that nearby Clifton Harbour already has adequate facilities, making those proposed un-needed and not financially viable, especially in the currently depressed tourism economy. The best solution to this problem would seem to be for the Government to turn over the lands in question to the local non-profit organizations to manage the designated protected area, so that they can receive the European Union funds allocated for the restoration of the bay and its fisheries.
In our view active restoration and community based management is essential to reverse the ecological damage to reefs and fisheries, once circulation is restored. Use of the Biorock® method, which is easily taught to fishermen, is recommended to restore coral growth, reproduction, resistance to environmental stress, and to create habitat to restore fish and lobster populations. A conch and lobster hatchery should be established using some of the enclosures that do not block circulation of the bay. Seaweed mariculture should be established, both as a form of alternative income for fishermen, but also to increase recruitment of juvenile lobster and lambi. Studies in Jamaica by A. H. Macfarlane and T. Goreau found that large numbers of young lambi and lobster, as well as fish, were attracted to algal mariculture projects, helping increase their populations in nearby seagrasses and reefs. These methods should be applied to Ashton Bay to increase lobster and conch reproduction, recruitment, and densities at all phases of their life cycles. It is also recommended that a survey be made of the physical circulation patterns of the bay under various scenarios of re-opening circulation in order to determine the most cost-effective method of doing so. David Harris, a Trinidad-based coastal zone engineer, is recommended for such a study due to his experience with computer modeling of circulation patterns based on studies of waves, currents, and bathymetry throughout the Eastern Caribbean.
The Global Coral Reef Alliance is ready to assist Union Island Fishermen’s Cooperatives, the Union Island Association for Ecological Protection, the Union Island Ecotourism Movement, and the Ministry of Agriculture and Fisheries in restoring damaged coral reefs and fisheries by training local participants in the design, construction, maintenance, and repair of such projects. The first step would be to establish a small pilot cheap oakley sunglasses project to demonstrate and assess the benefits of such projects in terms of increased growth of corals and fish populations. A suitable site has been identified in east Richmond Bay (appended). We are requesting permission to conduct a pilot project there.
Dr. Thomas J. Goreau
1) Bigsands reef restoration pilot project proposal
2) Summary of the advantages, disadvantages, and safety of Biorock® coral reef and fisheries restoration technology
3) Results of microscopic examination of electrically grown and normal corals for tissue and skeletal abnormalities
Biorock® is a trademark of Biorock, Inc. The Biorock® Process is owned by Biorock®, Inc.