Status of Caribbean coral reefs after bleaching and hurricanes in 2005

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Status of Caribbean Coral Reefs after Bleaching and Hurricanes in 2005GuatemalaGuatemala has limited reef development along the Caribbean coast, with the best known beingthe carbonated banks of Punta Manabique, which are dominated by sediment resistant coralsspecies such as Siderastrea siderea, and the isolated coral communities and diminutive patchreefs of the Gulf of Honduras.Status of coral reefs prior to 2005: There has been significant degradation of Guatemalanreefs because of the combined effects of hurricanes, flooding and associated sedimentation,and increases in sea surface temperature. The major threat to the reefs of Punta Manabiqueis sedimentation resulting from deforestation and soil erosion, which bring elevated sedimentloads and contaminants onto reefs, causing increased coral mortality and algal proliferation. Astudy conducted in 2000, recorded live coral cover of less than 9% and non-coralline macroalgalcover of 65%.Effects of the 2005 Bleaching Event: The only monitoring data on the bleaching in 2005 wereobtained in late November at Punta Manabique with 16% of 31 colonies being affected (datafrom the Mesoamerican Barrier Reef System Project, Synoptic Monitoring Program).Impacts of Hurricanes in 2005: Like Belize, the reefs of Guatemala were not directly affectedby the storms or hurricanes of 2005. However, increased sediment runoff associated with thetorrential rains generated during the passage of Hurricane Beta near Honduras is likely to havehad an impact.Status of reefs in 2006: Based on a rapid assessment of 5 reef sites (145 colonies) in August2006, the 2005 bleaching event did not appear to have made a significant impact on Guatemala’sbank reefs. Recent mortality was less than 1%, while disease infestation was somewhat higherat 11%. Mean live coral cover was low overall, averaging 8.5% and similar to that found in2000. Mean fleshy macroalgae cover was recorded at 7.3% and turf at 23.4%.Socioeconomic impacts and management responses: River inputs of nutrients and sedimentsresulting from land erosion impede reef growth. Those reefs that do exist are subjected tointense fishing pressure and currently have minimal fish populations. Guatemalan fishermenare increasing fishing pressures on the southern reefs of Belize.HondurasWhile only small coral reef communities occur on the Caribbean coast of Honduras (PuertoCortes, La Ceiba and Tujillo), there are well developed reefs on the outer Bay Islands (Utila,Morat, Barbareta, Roatàn, and Guanaja) and Cayos Cochinos. Well developed fringing andpatch reefs are also found eastward (Misquitu Cays and Banks) and further northeast of themainland (Swan Island). The edge of the Honduran continental shelf is almost vertical and hashigh coral cover.Status of coral reefs prior to 2005: The Global Coral Reef Atlas reports average coral coverof 28% on the fore-reefs of the Bay Islands in the early 1990s. A 2001 WWF survey foundaverage fore-reef live coral cover in Roatan/Barbaretta of 12%, with 8% in Cayos Cochinos,somewhat lower than the MAR-wide average of 15%. This same study found the prevalence of56
Status of the Mesoamerican Reef after the 2005 Coral Bleaching Eventcoral disease in Honduras was slightly higher than the MAR-wide average (4.4% versus 3.4%)as was recent partial mortality (1.8% versus 1.6%). The reefs of the Bay Islands were consideredto be relatively healthy prior to the 1998 mass bleaching event and Hurricane Mitch. Theseevents resulted in 18% coral mortality on shallow reefs and 14% on deep reefs, along with ahigh prevalence of coral diseases. Hurricane Mitch contributed to this damage via mechanicaldamage from waves and coral smothering from sediment-laden runoff. Hurricane Iris in 2001also affected Honduran reefs through increased river runoff and sedimentation.Effects of the 2005 Bleaching Event: No data on the extent of the 2005 bleaching event(during the event) were available to the authors. The MBRS Synoptic Monitoring Programreports data from one site (Utila) collected in February 2005 (before the bleaching season). Thereef status indicators for 2006 show some signs of elevated disease and bleaching. However,without any data on the extent of bleaching during the 2005 bleaching season, no potentialrelationships can be considered.Impacts of Hurricanes in 2005: The 2005 tropical storms probably reduced the temperatureof overlying reef waters and decreased the severity of bleaching and associated mortality.However, some reefs may have been smothered by sediment plumes from runoff and mudslidesoriginating from torrential rains, especially from those generated during the passage ofHurricane Beta.Status of reefs in 2006: An assessment of 61 reef sites (1363 colonies) from early June to mid-August 2006 revealed some bleaching, but less than 11%. The prevalence of coral disease wasrather high among the reef flat and patch reef sites, but recent mortality was less than 5%. Livecoral cover was relatively low, averaging between 10% and 15%. Mean fleshy macroalgae coverwas recorded at 15% on fore-reefs, 16% on patch reefs and 19% on reef flats.There were moderate levels of coral bleaching, disease and mortality on the reefs ofHonduras, predominantly resulting from the effects of hurricanes and to a lesser extent toincreased water temperatures.Reef Habitat assessed(n = number of colonies)Colonies Affectedby Bleaching (%)Colonies Affectedby Disease (%)Recent ColonyMortality (%)Reef flat (n = 373 colonies) 11 14 4Fore-reef (n = 868 colonies) 4 9 2Patch reef (n = 122 colonies) 8 18 2Socioeconomic impacts and management responses: The Bay Islands’ reefs are the centerfor both tourism and fishing activities. Fringing reefs have been heavily exploited and thecontinued high demand for fish products has resulted in a relocation of fishing efforts tothe more remote offshore reef banks. The Reefs at Risk project has estimated that 34% ofHonduran reefs are threatened by anthropogenic stress, with the most pervasive being overfishing(30%), coastal developments (25%), sedimentation from agricultural practices (10%)and marine based activities (6%). Enforcement of regulations aimed at protecting coral reefsand resource management is generally weak. Twelve MPAs have been developed, although anumber of these are not legally declared or fully managed.57
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Dedication: This book is dedicated
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Status of Caribbean Coral Reefs aft
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Managing for Mass Coral Bleaching:
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Status of Caribbean coral reefs after bleaching and hurricanes in 2005

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