Tobago Cays Marine Park

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Chapter 3. SITE DESCRIPTION

f - Impacts and threats affecting the area

Impacts and threats within the area


Impact and threats level Evolution In the short term Evolution In the long term Species affected Habitats affected Description / comments
Exploitation of natural ressources: Fishing limited unknown unknown There is very limited fishing within the TCMP – it is only permitted in the management zone to the west of Mayreau, far from the centre of the park. Occasionally people are caught illegally fishing within the area, it is not known how large illegal fishing is, but it is likely to be limited. At Saline Bay (Mayreau), 0.2 tons of fish is landed each year (although this is quite an old figure).
Exploitation of natural ressources: Agriculture limited unknown unknown There is very small scale agriculture on Mayreau, however this is unlikely to increase, given the topography, limited water sources and fragile soils.
Exploitation of natural ressources: Tourism very important increase unknown All listed coral and fish species are threatened by both physical damage to coral (boats, snorkelers, anchors) and water pollution. All listed fish species as well as lobster (Panulirus argus) are threatened by illegal fishing. Water pollution and physical damage are the two main threats to the biodiversity of the park. Surveys have shown that many reefs are in decline and are threatened by algal growth and disease, both of which can develop as reefs are degraded by pollution and physical damage. All turtle species and Queen Conch (Strombus gigas) are threatened by damage to sea grass beds, disturbance from tourists when resting, feeding and nesting, and hunting by locals for merchandise (although this may not occur in the park). As mentioned above, all coral reefs are threatened by a variety of impacts – water pollution and physical damage being the most serious. Sea grass beds are threatened by anchor damage, as well as pollution. Terrestrial habitats (mangroves, beaches, wetlands) may be threatened by waste dumping, overcrowding, fires, physical damage from hiking and proposed tourism development. Tourism is a significant threat to the biodiversity of the TCMP. There are many tourist activities which have an impact: •water pollution (discussed more in the pollution section) •physical damage to the reef from snorkelling, diving, paragliding, boats and anchors •turtle disturbance •illegal fishing •dumping and fires on beaches •purchasing endangered merchandise •tourist development on Mayreau A large amount of tourists visit the park each year, there are often up to 100 yachts moored in the park in the high season, although a the carrying capacity is estimated at only 50 yachts. Without some consideration of overcrowding, many of these impacts will be more difficult to tackle. The main impact is water pollution from yachts – dumping sewage and other waste into the waters of the park. This causes nutrient overload and eutrophication and algal growth. This is a key threat to the health of the reefs. Physical damage includes anchor damage to reefs and sea grass beds, although the main sea grass bed near Baradal is now off limits to yachts. Unsupervised snorkelers often damage the reef by accidentally or deliberately touching coral, and stirring up sediments. Boats and dinghies may accidentally run into coral reef, and paragliding (and other water sports) may also damage the reef. A popular area for snorkelers is the sea grass beds around Baradal because of the presence of turtles, however snorkelers often disturb turtle feeding and resting. Additionally some snorklers feed turtles, which may encourage them to congregate and make them more vulnerable to predation. The presence of people on the beach may discourage and impact on turtle nesting. There is only one small toilet in the TCMP, and there are no rubbish bins. Visitors are expected to take their rubbish with them, but dumping still occurs. Vendors in the TCMP may also improperly dispose of rubbish. Fires are frequently lit (sometimes to burn waste) and this may impact on terrestrial vegetation. Some vendors sell merchandise made from CITES listed species (such as turtle or conch) – it is not illegal to sell it, but it is illegal to transport it across national borders – although most tourists do not realise this and take the souvenir back home. This encourages further hunting of threatened species. Illegal fishing is also a problem, although the extent is not know. Both locals and tourists have been caught fishing and using spear guns – these are both prohibited in the main areas of the park. There are some proposed tourist developments on Mayreau, including a marina (on the salt pond) and a new resort on the west coast. These developments may impact on threatened wetlands, pollute marine resources and clear other terrestrial vegetation.
Exploitation of natural ressources: Industry limited not specified not specified There is no industry in the park
Exploitation of natural ressources: Forest products limited not specified not specified There may be very small use of forest products on Mayreau.
Increased population limited increase increase The population of Mayreau is growing slowly, but any new tourism development may increase this more rapidly.
Invasive alien species significant increase increase Lionfish threaten coral reefs through predation of fish species which are essential to keep the reef healthy There are two alien species within the park – goats and lionfish. The goats still remain on Petit Rameau in small numbers - The introduction of goats to the islands is also believed to have had a negative influence on the vegetation cover and composition. The goats are reportedly still present on Petit Rameau in small numbers, although occasional culling by the police and the rangers has reduced the population. Lionfish have rapidly spread across the Caribbean and are a huge threat to marine fish species. They are present in the park. They are very aggressive predatory fish who eat small and juvenile fish, and they breed and spread very rapidly.
Pollution very important increase increase All coral species Coral reefs Water pollution is one of the most significant threat to the biodiversity of the TCMP. Within the last 20 years several formal and informal reports have suggested that there has been a slow degradation of the coral reef ecosystems in the Tobago Cays. Water pollution from yachts, mainly sewage, threatens corals refs because it leads to eutrophication, may disturb breeding and fish movement, and encourages algal growth. The centre of the park, where the most yachts moor, is most threatened by pollution. Surveys ave noted high levels of faecal coliforms across the park. Solid waste is often left on the islands by visitors as well, sometimes including faeces since there are inadequate toilet facilities.
Other significant unknown unknown All coral species, particularly Acropora palmate Coral reefs Recent hurricanes and storms have done considerable damage to coral reefs, particularly World’s End reef where corals were destroyed due to wave action. White-band disease and black-band disease has impacted coral species, and soft corals have been affected by Aspergiliosis. Elkhorn coral (Acropora palmate) has been especially impacted by white-band disease. Damage to reefs by other impacts (especially water pollution) makes them more vulnerable to disease. Bleaching has occurred across Horseshoe reef, caused by ocean warming, perhaps linked to climate change.

Impacts and threats around the area


Impact and threats Level Evolution In the short term Evolution In the long term Species affected Habitats affected Description / comments
Exploitation of natural ressources: Fishing limited unknown unknown Fishing occurs outside the park boundaries, and may be a mix of local fishers and larger boats from other nations (Grenada, Trinidad etc.). Fishing of large species may affect the biodiversity within the park, however it is probable that the park helps fishing stocks outside its boundaries by providing a safe nursery for juvenile fish.
Exploitation of natural ressources: Agriculture limited not specified not specified The park is far away from surrounding islands
Exploitation of natural ressources: Tourism very important increase increase Increase in tourism in the region may bring more tourists to the park, increasing visitor impacts.
Exploitation of natural ressources: Industry limited not specified not specified The park is far away from surrounding islands
Exploitation of natural ressources: Forest products limited not specified not specified The park is far away from surrounding islands, and there is unlikely to be any forestry on Mayreau.
Increased population limited increase unknown Increase in the population of surrounding islands may indirectly place greater pressure on TCMP by hampering efforts to establish carrying capacity limits, and through increased vendor competition.
Invasive alien species significant increase increase Unless lionfish are controlled across the Southern Grenadines, any efforts within the park will be futile, since the species spreads very quickly.
Pollution limited not specified not specified Water pollution and sediments from surrounding islands may have a small impact on the park.
Other limited not specified not specified Any disease in surrounding areas may make it into the park.