Impact assessment

Feral goats (Capra hircus) are introduced but very successful herbivores found in areas all over the Caribbean island Bonaire. Within the Washington-Slagbaai national park, STINAPA is currently taking measures in order to control the goat population. Research was requested to provide a scientific background on the impact of feral goats in the park. This field experiment included the analysis of 13 areas where goats had been excluded for a period of 8 years. This study revealed the negative impact of feral goats on the vegetation of the Washington-Slagbaai national park. Recovery of the vegetation in the exclosures was found to be significantly higher in comparison with areas accessible for goats. Vegetation rejuvenation within the exclosures increased dramatically for tree species such as Capparis odoratissima, Randia aculeata and Guaiacum officinale. Direct and indirect positive relations with goat presence were observed for Opuntia wentiana and Croton flavens.

The presence of feral goats (Capra hircus) can have detrimental effects to island ecosystems where native plants have evolved in the absence of these animals. Feral goats are implicated in habitat destruction and alteration of species composition on sensitive island ecosystems. In the absence of population control, goats have become the ecologically dominant species on many islands, with the results that numerous endemic or native plant species have been extirpated, or are threatened by excessive grazing. It is demonstrated that the removal of goats can lead to rapid recovery of suppressed vegetation.
Nine excluders and nine controls were established randomly in three areas of the Quill. Data is collected annually every April. The size of each excluder and control is approximately 3m2. Overall a slight difference is apparent between the Quill control and excluder sites in 2014, with more plants present in the excluder plots than in the control plots.
 
Retrieved from STENAPA

Abstract:

On October 14 and 15, 2008 Tropical Storm Omar reached Bonaire. Wind speed averaging 18 to 20 knots from SW started at 3 am on October 14 and lasted for 48 hours. The minimum distance between the center of the storm and Bonaire was 200 km in a NW direction and the maximum wind speed at that moment was 32 to 33 knots. 

A total of 27 sites were surveyed. In the West, from Karpata to Vista Blue on the leeward side of Bonaire (20 sites) and around Klein Bonaire (7 sites). 

Abstract:

St. Eustatius National Parks Foundation (STENAPA) is the only active environmental non-government organization on St. Eustatius, and was legislated in 1996 with a mandate from the Island Government to protect and manage the island’s marine resources. St. Eustatius Marine Park was established in 1996 and became actively managed in 1997 to conserve and protect the marine environment surrounding the island from the high water line up to and including the 30 meter (100 feet) depth contour. The marine environment of St. Eustatius supports 27.5 km2 of biologically diverse coral reef, seagrass, sandy seabed and open ocean communities. The Marine Park is one of the top 5 sites in the Caribbean to see healthy coral and fish populations. The 2 reserves have 43% hard coral cover and the Protected Area is a home, migratory stop over or breeding site for 14 IUCN Red List species, 10 CITES Appendix I species and 98 Appendix II species.

St Eustatius Marine Park attracts around 500 yacht visitors and 2500 diving/snorkeling visitors per year contributing to income for the 70% of the islands population employed in restaurants, hotels and other services1. Other uses of St Eustatius Marine Park are for Fisheries (25 fishermen use the waters of St Eustatius) and in excess of 1000 tankers a year using the oil storage facility at Statia Terminals NV. Anchoring is the main threat to the marine resources caused by the operations of Statia Terminals NV, although pollution is also an important issue with sewage and other wastes including ballast waters entering St Eustatius Marine Park waters from vessels.

Field work carried out involving survey dives, stakeholder consultation and photographic records found that significant damage has been done to the reefs within and beyond the designated anchoring zones for the vessels using Statia Terminals NV. The main impacts of the damage are:

Direct impacts:

• Broken individual coral colonies
• Structural damage to the reefs
• Sedimentation

Secondary impacts:

• Decreased fisheries production for subsistence, commercial and sport fishing.
• Decrease in dive tourism, and related activities.
• Change in community structure
• Ciguatoxic (poisonous) fish
• Decreased recruitment and coral larvae survivorship

Management Recommendations:

Recommendations to manage the anchoring issues are:

• Install a Vessel Monitoring System with alerts to unsustainable practices.
• Monitor the current status, ongoing damage and recovery of the coral reefs
• Establish a protocol for response and restoration after damage has occurred.