The CARICOMP monitoring network gathered standardized data from 52 seagrass sampling stations at 22 sites (mostly Thalassia testudinum-dominated beds in reef systems) across the Wider Caribbean twice a year over the period 1993 to 2007 (and in some cases up to 2012). Wide variations in community total biomass (285 to .2000 g dry m22) and annual foliar productivity of the dominant seagrass T. testudinum (,200 and .2000 g dry m22) were found among sites. Solar-cycle related intra-annual variations in T. testudinum leaf productivity were detected at latitudes . 16uN. Hurricanes had little to no long-term effects on these well-developed seagrass communities, except for 1 station, where the vegetation was lost by burial below ,1 m sand. At two sites (5 stations), the seagrass beds collapsed due to excessive grazing by turtles or sea- urchins (the latter in combination with human impact and storms). The low-cost methods of this regional-scale monitoring program were sufficient to detect long-term shifts in the communities, and fifteen (43%) out of 35 long-term monitoring stations (at 17 sites) showed trends in seagrass communities consistent with expected changes under environmental deterioration.
Queen conch, Strombus gigas (Linnaeus, 1758), is a species of significant economic importance in the Caribbean Sea, exploited mainly for consumption by a ravenous export market in the USA and French West Indies. Because populations have been depleted throughout the Caribbean region by over shing, present conservation efforts are focused on regional harmonization of conch management to improve its sustainability. In the present study, we compare the reproductive cycle of S. gigas from eight sites (Florida Keys, Alacranes Reef, Chinchorro Bank, San Pedro, San Andrés Archipelago, Guadeloupe, Martinique, and Barbados) to consider the biological rationale for a harmonized closed shing season. A framework recognizing four reproductive stages for males and females is proposed for use in future studies. Signi cant di erences were found in the timing and intensity of reproductively active stages between conch from western and eastern sites in the wider Caribbean region. Two distinct reproductive strategies were observed: (1) continuous and low level of reproduction throughout the year (Alacranes Reef, San Pedro, and San Andrés Archipelago); and (2) a discrete and intense reproductive period with rapid gametogenesis (Guadeloupe, Martinique, and Barbados). Queen conch required a temperature of ≥27.7 °C to initiate gametogenesis; and were found in the resting stage below 27.5 °C. Based on a comparison of spawning seasons across the reproductive strategies observed, we suggest that the most “biologically meaningful” period for a closed season for the entire western central Atlantic would need to incorporate the months of June to September, at a minimum, to over regional protection for spawners.
This study sought to quantify the potential effects of changes in Caribbean reef fish populations on recreational divers' consumer surplus. Over five hundred tourist SCUBA divers were interviewed at seven sites across three Caribbean countries representing a diversity of individuals within the Caribbean dive market. A choice experi- ment was used to assess willingness to pay as a function of the abundance and size of reef fishes, the presence of fishing activity/gear, and dive price. Despite some preference heterogeneity both between and within sites, the results indicate that future declines in the abundance of reef fishes, and particularly in the number of large fishes observed on recreational dives, will result in significant reductions in diver consumer surplus. On the other hand, improvements in fish populations and reduced fishing gear encounters are likely to result in signif- icant economic gains. These results can be used to justify investment in pre-emptive management strategies targeted at improving reef fish stocks (namely reducing unsustainable fishing activities and land-based reef im- pacts), managing conflicting uses, as well as to indicate a possible source of financing for such conservation activities.
Halophila stipulacea (Hydrocharitaceae) is reported for the first time from Aruba, Curaçao, Grenadines (Grenada), St. Eustatius, St. John (US Virgin Islands), St. Martin (France), and St. Vincent and the Grenadines, bringing the total number of known occurrences from eastern Caribbean islands to 19. Native to the Red Sea and western Indian Ocean, H. stipulacea spread to the Mediterranean Sea in the late 1800s and became established in the eastern Caribbean in 2002. The species has dispersed north and south of its first sighting in Grenada and now spans a latitudinal distance of 6° (>700 km), most likely facilitated by a combination of commercial and recreational boat traffic. The continuing range expansion of H. stipulacea indicates the species has successfully acclimated to surviving in the Caribbean environment, warranting further investigation into its ecological interactions with the indigenous seagrasses.
The white sea urchin, Tripneustes ventricosus, is common in shallow coastal waters of the tropical Atlantic Ocean, and is widely distributed in the Caribbean Sea. The species supports small-scale, commercially important, seasonal fisheries in several islands in the eastern Caribbean including Barbados, Martinique (France) and Saint Lucia, and minor subsistence fisheries in Grenada and Saint Vincent and the Grenadines. However, despite significant management and conservation efforts by some countries, white sea urchin population abundance has declined locally. Understanding the large fluctuations in local population size and implementing sound management practices in the white sea urchin fisheries is critical to the sustainable use of this resource in the future, and would benefit considerably from a sharing of information and management experiences. To this end, this circular has attempted to collate both published and unpublished information on the white sea urchin and its fisheries in the eastern Caribbean and perspectives on past and current management of these fisheries.