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ABSTRACT1. Acropora cervicornis (staghorn coral) and Acropora palmata (elkhorn coral), once common features of shallow Caribbean reefs observed growing as large stands or thickets, are now found mainly as remnant pockets or isolated colonies at a fraction of their historical areal extent.2. In February 2010, a large, surviving population of A. cervicornis was surveyed at Cabezos del Cayo, Punta Rusia, Dominican Republic to document its present condition and potential threats to its persistence.3. The A. cervicornis surveyed at Cabezos del Cayo provides a rare glimpse of the habitat structure that these keystone components of coral reefs once provided. The staghorn population covers an area of 2 ha and is formed by interlocking skeletons of unusually large and thick A. cervicornis colonies.4. The large size of its colonies (maximum branch length 250 cm; average linear length of live tissue 471 cm; maximum number of branch tips 141 per colony; maximum branch diameter 5 cm) and the complex open canopy of these colonies, have not been described, to our knowledge, in the recent literature.5. The site is within Montecristi National Park but there is no active protection in this area and signs of overfishing are evident based on low fish abundance and complete lack of fish 420 cm in length.6. The stressors associated with this population include significant predation by gastropods and fireworms, overgrowth by macroalgae, damselfish 'gardening' activities, and white band disease.7. The management priority for the staghorn population at Cabezos del Cayo, Dominican Republic, should be to enforce the legal framework that is already in place for the protection of Montecristi National Park, limiting unsustainable and damaging fishing practices, and limiting land-based sources of pollution associated with increasing population numbers and future coastal development.

The coastal bays of South Florida are located downstream of the Florida Everglades, where a comprehensive restoration plan will strongly impact the hydrology of the region. Submerged aquatic vegetation communities are common components of benthic habitats of Biscayne Bay, and will be directly affected by changes in water quality. This study explores community structure, spatio-temporal dynamics, and tissue nutrient content of macroalgae to detect and describe relationships with water quality. The macroalgal community responded to strong variability in salinity; three distinctive macroalgal assemblages were correlated with salinity as follows: (1) low-salinity, dominated by Chara hornemannii and a mix of filamentous algae; (2) brackish, dominated by Penicillus capitatus, Batophora oerstedii, and Acetabularia schenckii; and (3) marine, dominated by Halimeda incrassata and Anadyomene stellata. Tissue-nutrient content was variable in space and time but tissues at all sites had high nitrogen and N:P values, demonstrating high nitrogen availability and phosphorus limitation in this region. This study clearly shows that distinct macroalgal assemblages are related to specific water quality conditions, and that macroalgal assemblages can be used as community-level indicators within an adaptive management framework to evaluate performance and restoration impacts in Biscayne Bay and other regions where both freshwater and nutrient inputs are modified by water management decisions.

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