RESUMO

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 m(-2)) and annual foliar productivity of the dominant seagrass T. testudinum (<200 and >2000 g dry m(-2)) were found among sites. Solar-cycle related intra-annual variations in T. testudinum leaf productivity were detected at latitudes > 16°N. 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.

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RESUMO

Discovery Bay is one of nine sites around Jamaica’s coastline, soon to gain the legislative protection of Fish Sanctuary (and Scientific Reserve) status. Cumulative natural and anthropogenic impacts drove the 1980’s coral to algae phase shift. Discovery Bay CARICOMP data (1994 to 2007) showed an increase in coral cover from less than 5% reported in the mid 1980’s to 11.7±0.31% (mean±SE) despite chronically high algal cover (61.4±2.2%) at 9m. Coral cover has been sustained despite low urchin densities (0.99±0.91 urchins m-2), low juvenile coral abundance (2.15±0.19 corals m-2) and coral mortality from repeated bleaching events. Community metrics from the CARICOMP site were compared to an adjacent reef habitat which was found to have higher coral cover (16.36±3.1%), as well as higher urchin (13.7±0.84m-2) and juvenile coral (9.7±1.7m-2) densities. Large branching coral species were absent along the CARICOMP transects and sparse at the nearby shallow reef. Both sites continue to be heavily overfished. Local history records the use of spatially and temporally isolated management strategies which have attempt to rehabilitate various aspects of this area. This unique temporal data set (based on the CARICOMP Methods Manual 2000) provides a baseline for evaluating Government (in)action and is used to justify proposals for ecosystem management which could facilitate phase shift reversal in a coral dominated system. An ecosystem approach that implements several concurrent strategies within and adjacent to the Reserve could accelerate the recovery process. The long term viability and benefit of both old and new marine protected or reserve areas could be enhanced through coral gardening on artificial reef structures with a view to restoring the reefs’ three-dimensional complexity. Such actions could heoretically accelerate phase reversal to coral dominated reefs common in the area prior to the devastating impacts of the 1980s. Rev. Biol. Trop. 58 (Suppl. 3): 63-69. Epub 2010 October 01.

Discovery Bay es uno de los nueve sitios alrededor de Jamaica, pronta a obtener la protección legislativa como Santuario de Pesca (y Reserva Científica). Los impactos naturales y antropogénicos acumulativos de la década de 1980 condujo a cambio de fase de coral a algas. Los datos CARICOMP de Discovery Bay (1994 a 2007) mostraron un aumento en la cobertura de coral de menos del 5% informada a mediados de 1980 a 11.7±0.31% (media±ES) a pesar la alta cobertura crónica de algas (61.4±2,2%) a 9m de profundidad. La cobertura de coral se ha mantenido a pesar de las densidades bajas de erizo de mar (0.99±0.91 erizos m-2), baja abundancia de juveniles de coral (2.15±0.19 m corales-2) y mortalidad de corales debido a fenómenos de blanqueo repetitivos. Estadísticas de la comunidad del sitio CARICOMP contrasta con un hábitat de arrecife adyacente que tienen mayor obertura de coral (16.36±3.1%), de erizos (13.7±0.84 m-2) y de juveniles de coral (9.7±1.7 m-2). Especies de coral de grandes ramas estaban ausentes de los transectos CARICOMP y eran pocos en los arrecifes poco profundos cercanos. Ambos sitios siguen siendo, en gran medida, objeto de sobrepesca. La historia local registra el uso de estrategias de gestión espacial y temporalmente aisladas que se implementaron en el pasado para intentar rehabilitar a diversos aspectos de esta área degradada. Los datos temporales de CARICOMP establecen una base única base para la evaluación "en" acción del Gobierno y se utiliza para justificar las propuestas de gestión de los ecosistemas que podrían facilitar la reversión de fase a un sistema dominado por corales. Un enfoque de ecosistemas que implementa varias estrategias simultáneas dentro y adyacente a la Reserva podría acelerar el proceso de recuperación. La viabilidad a largo plazo y el beneficio de viejas y nuevas áreas marinas protegidas o reservas podría ser mejorada a través de cultivo de coral en arrecifes artificiales con el fin de restablecer la complejidad tridimensional de los arrecifes coralinos. Tales acciones podrían, teóricamente, acelerar la reversión de fase a coral como era común en el área antes de los impactos devastadores de la década de 1980.

Assuntos

RESUMO

Discovery Bay is one of nine sites around Jamaica's coastline, soon to gain the legislative protection of Fish Sanctuary (and Scientific Reserve) status. Cumulative natural and anthropogenic impacts drove the 1980's coral to algae phase shift. Discovery Bay CARICOMP data (1994 to 2007) showed an increase in coral cover from less than 5% reported in the mid 1980's to 11.7 +/- 0.31% (mean +/- SE) despite chronically high a lgal cover (61.4 +/- 2.2%) at 9 m. Coral cover has been sustained despite low urchin densities (0.99 +/- 0.91 urchins m(-2)), low juvenile coral abundance (2.15 +/- 0.19 corals m(-2)) and coral mortality from repeated bleaching events. Community metrics from the CARICOMP site were compared to an adjacent reef habitat which was found to have higher coral cover (16.36 +/- 3.1%), as well as higher urchin (13.7 +/- 0.84 m(-2)) and juvenile coral (9.7 +/- 1.7 m(-2)) densities. Large branching coral species were absent along the CARICOMP transects and sparse at the nearby shallow reef. Both sites continue to be heavily overfished. Local history records the use of spatially and temporally isolated management strategies which have attempt to rehabilitate various aspects of this area. This unique temporal data set (based on the CARICOMP Methods Manual 2000) provides a baseline for evaluating Government (in)action and is used to justify proposals for ecosystem management which could facilitate phase shift reversal in a coral dominated system. An ecosystem approach that implements several concurrent strategies within and adjacent to the Reserve could accelerate the recovery process. The long term viability and benefit of both old and new marine protected or reserve areas could be enhanced through coral gardening on artificial reef structures with a view to restoring the reefs' three-dimensional complexity. Such actions could theoretically accelerate phase reversal to coral dominated reefs common in the area prior to the devastating impacts of the 1980s.

Assuntos

RESUMO

Maintaining regional competitiveness and economic viability for Port Bustamante - Kingston Harbour, Jamaica, required improved accessibility to "Post Panamax" (too large to pass through the Panama Canal) container vessels. Removal of the northern portion of the shallow coral reef at Rackham's Cay, which was partially obstructing the western end of the east ship channel, was proposed. This aesthetically valuable reef was used by local fishermen and comprises part of the declared Palisadoes - Port Royal Protected Area. The proposal to transplant certain of the benthic species was advanced to mitigate loss of viable reef components. Between December 2001 and February 2002, sixty thousand items, consisting of reef building massive and branching corals; gorgonians; urchins (Diadema and Tripneustes spp.) and Thalassia meristems were relocated. During dredging, sedimentation rates from suspended solids in the water column were 0.003 g/cm(2)/day at the control site and 0.008 g/cm(2)/day at the dredge site. Coral cover in the relocation area increased from 15% to 20% while bare substrate decreased from 27% to 21%. This paper documents the mitigation required; some factors controlling the ecology of Rackham's Cay reef, the methodology of the relocation process; and the level of post-dredging survivorship of relocated corals. Political and economic realities of some proposed developments often override ecological considerations. Transplantation of important marine benthic species although time consuming, technically challenging, and expensive, may be one way for developers and ecologists to achieve sometimes disparate goals. This project cost US$1.7 million. The "items" moved were neither unique nor endemic and remain vulnerable to natural and anthropogenic impacts. This project increased public awareness and interest regarding the ecological and economic importance of reef ecosystems. It is anticipated that future coastal and inland developments will benefit from the lessons taught by these mitigative interventions.

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