Assessment of Ramsar site Lac Bonaire – June 2010

Findings

The main issues that Lac Bay faces were identified as follows:

1. Filling-in of Lac and reduced water circulation. Over-grazing by extensive livestock husbandry as well as non-sustainable land-use practices (e.g. barren fields) has resulted in an accelerated infilling of the bay with sediment, which hampers water circulation and causes mangrove die-off. This has lead to a gradual reduction of the effective nursery and habitat surface of the bay over the last decades.
2. Increase in uncontrolled recreational pressure. The Lac ecosystem has been modified or altered by construction of roads, the building of hotels, subterraneous nutrient enrichment by untreated sewage and more. Trampling is causing an important decrease in sea grass bed coverage in the bay. Endangered species such as turtles and nesting birds are vulnerable to human disturbance (Lac is intensively used for various kinds of recreation).
3. Litter contamination. Marine litter washed in from the open ocean and abandoned fishing lines in the deeper parts of Lac are big issues.
4. Algal blooms. While the outer reef is in very good health, many of the inner reef’s corals, gorgonians and sponges are being overgrown by the crustose calcareous alga Ramicrusta sp. This may cause a serious decline in living corals inside the bay.

Management Recommendations:

The highest priority is to start habitat restoration.

Direct enforcement of existing and new legislation is crucial as well as a permanent presence of one or more officials.

Filling-in of Lac and reduced water circulation

• Tackle the livestock overgrazing problem in the whole watershed.
• Regularly open up the former channels to the rear areas of the mangroves and re-establish circulation and water quality.
• Remove filled-in sediments and reforest with red mangroves in the rear stagnant areas of Lac so as to re-establish mangrove and fish nursery habitat.

Address increase in uncontrolled recreational pressure

• Set upper limits for the various users.
• Strictly limit public access to seagrass areas using a combination of zoning, demarcation and enforcement.
• Upgrade the visitor facilities designed to limit or steer user impact towards low sensitivity areas.
• Monitor the human use of the bay.
• Assess Lac’s current bird use and their vulnerability to disturbance.

Litter contamination

• Conduct regular cleanups with volunteers and monitor litter densities.
• Limit and regulate fishing inside of Lac.
• Conduct PAH  (polyaromatic hydrocarbon) studies of the water in Lac.

Algal blooms

• Periodic annual monitoring of enteric bacterial presence at high risk locations.
• Install a monitoring program to assess the nutrient situation in Lac at several locations.
• Continue monitoring of coral overgrowth by Ramicrusta sp.