Salient Features of a Possible Marine Protected Area (MPA) for Shacks Beach in Isabela, PR by Steve Tamar, Kathy Hall, and Joel Cordero

Possible Physical Boundaries:

• Western terrestrial limit could very likely be the outflow mouth of the Quebrada Los Cedros.
• Eastern terrestrial limit could possibly be the “Dead End Road,” Calle Pedro Albizu Campos.
  
• These limits demark approximately 2 km of coastline.
• The marine limit could very well be the 45 foot depth contour, which would enclose most of the healthy and active reef ecosystem. There is no definite visual reference to be followed beyond the large sand covered bottom patch located offshore in approximately the middle of the proposed reach of coastline. However, buoys can serve as markers indicating the boundary.

Unique or protected marine life and geological features of this proposed MPA: Using the small rocky point that has been traditionally used as a boat launching site as a reference point.

• Elkhorn coral (Acropora palmata) to the NW of this site, and also to the NE further offshore, outside of the reef break.
• Staghorn coral (Acropora cervicornis) to the NE of this site, outside the reef break.
• Fused staghorn coral (Acropora prolifera), a hybrid between elkhorn and staghorn corals. Can be seen on the inside reef, near the dead end road.
  
• Hawksbill turtles (Eretmochelys imbricata) and green turtles (Chelonia mydas) forage in the area. Hawksbills nest on the beach in front of the reef system.
• West Indian manatees (Trichechus manatus manatus) frequent the area. They probably drink fresh water that bubbles up from the ocean floor and use the "blue holes" for protection in giving birth. Manatees with new born calves have been sited, and groups of up to four manatees have been seen at a time.
• Atlantic bottlenose dolphins (Tursiops truncatus) and humpback whales (Megaptera novaeangliae) visit the offshore area.
• Manta rays (Manta sp.) have been sited here.
• Submarine caverns exist in various places along the reef system, principally in the "holes" located 20-30 m offshore to the NE of this site. These caverns have specialized vertebrate and invertebrate species associated with low light situations. This is the only place in Puerto Rico where an extensive cavern system can be accessed from a shore dive, to the delight of national and international divers.
  
• The coral reefs outside the "blue holes" have a spur and groove formation. They are healthy and have a high percentage of hard corals in relation to algae. The hard corals have undergone extensive bleaching episodes in the past, with remarkable recovery. There is an area of soft corals or sea fans (Gorgonia sp.) to the west of the boat-launching area that is very healthy compared to sea fans in many other parts of the Caribbean, where they are succumbing to disease.
• There are some small patches of sea grass (Thalassia testudinum) in the inner reef area.
• Black Mangrove trees along the Quebrada Los Cedros provide habitat for many species including a large variety of birds.
• Moderately high sand dunes exist along the undeveloped part of the shoreline. These dunes are well-vegetated and act as a barrier to light pollution that can affect nesting and hatchling sea turtles.
• Petroglyphs can be found carved into the beach rock on the shoreline.
• These are the features that need a higher level of protection than is currently being provided by land use planning to date and public education.