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 2005In t r o d u c t i o nThe Southern Tropical America (STA) Node of the GCRMN includes Costa Rica, Panama,Colombia, Venezuela, and Brazil, with reefs in Pacific, Caribbean and Atlantic waters. TheNode is coordinated by the ‘Instituto de Investigaciones Marinas y Costeras’ (INVEMAR) inColombia, with support from UNEP-CAR/RCU in Jamaica; the Node has been developing coralreef monitoring in this region since 1999.Most coral reefs in the region have undergone major changes in the last 30 years, particularlyduring the 1980s, with considerable loss of live coral cover on many reefs and increasingdominance of algae. Nevertheless, high coral cover can still be found on many reefs on boththe Caribbean coast (means between 20-40%) and the Pacific coast (means above 40%).Some changes were caused by ‘natural’ agents (ENSO events, bleaching, disease outbreaks,phytoplankton blooms), but others are clearly related directly to human activities (deforestation,increased sedimentation, coastal development, sewage pollution, over-fishing). The 1997-98El Niño events had little effect on reefs in the region. Monitoring data from the 5 countriesindicate that reefs of the STA region did not change significantly between 2000 and 2004. Masscoral bleaching was recorded in the region during 2005 although some reefs were not affected(e.g. Costa Rica). Thus, this report focuses on the effects of coral bleaching events in Brazil,Colombia, and Venezuela.13° N 80° W70° W CuracaoBonaire60° W50° W40° W13° NSanta MartaLos Isla Margarita TobagoRoquesPANA MASan BlasGulf ofChiriquiCOLOMBIAVENEZUELAGUYANASURINAMEAtla n t i cOcea nFRENCH GUYAN AGorgona3° N # #3° NLEGENDCoral ReefsEC UADO RP E R U7° S 7° SAtoll deRocasNatalB R A Z I LMaceioPa c ifi cOcea n17° S 17° SKi lo me te rs0 250500 1, 000AbrolhosCHILEArch80° W70° WBOLIVIA60° WPARAGUAY50° WItacolomis40° WMap of the Southern Tropical America region.106
The Effects of Coral Bleaching in Southern Tropical America: Brazil, Colombia, and VenezuelaBrazilIn t r o d u c t i o nThe coral reefs of Brazil have low coral diversity (18 species with 6 endemic) and arediscontinuously distributed in 5 major areas along the 2500 km western Atlantic coastline:Touros-Natal has extensive coastal knoll and patch reefs; Pirangi-Maceió has linear coastalreefs and higher species diversity; Todos os Santos Bay-Camamu; Porto Seguro-Cabrália; andthe Abrolhos Region to the east and south. The National Marine Park of Abrolhos covers 900km 2 and contains the richest coral reefs in Brazil, including the Timbebas Reefs (isolatedcoastal bank reefs), fringing reefs on offshore volcanic islands of the Abrolhos Archipelago, andthe ‘chapeirões’, which are giant mushroom-shaped coral pinnacles 70 km offshore.Stat u s o f Co r a l Reefs Pr i o r to 2005The first record of coral bleaching was in the Abrolhos area of Eastern Brazil in 1994. In 1998,bleaching was observed in Bahia, north of Salvador City and in the Abrolhos, when sea surfacetemperatures (SSTs) increased in mid January and peaked between mid March and April, beforedeclining in late May. The SSTs ranged between 29.5°C and 30.5°C; or 1-2°C higher than thelong-term average summer maximum of 28.5°C. In 2003, two ‘hot spots’ occurred in EasternBrazil (Tinharé and Abrolhos) when SSTs rose in mid February and were 1°C above the longterm average in mid March; the hot spots dissipated in late April with up to 20% of coralcolonies bleached in Tinharé, and 17% in Abrolhos (SST anomalies are based on ‘HotSpot’charts in www.osdpd.noaa.gov/PSB/EPS/SST/climahot.html).Effects o f t h e 2005 Bl e a c h i n g Ev e n tTwo reefs in Southern Bahia, Itacolomis and Abrolhos, were affected by increased SSTs inmid-March 2005 with a maximum rise of 0.75°C above the long-term average. The ‘HotSpots’dissipated by the end of April, however, coral bleaching was observed on the Itacolomis Reefsduring April, with up to 17% of colonies affected. About 28% of coral colonies were bleachedon the Abrolhos reefs in early May. The coincidence of mass coral bleaching events in EasternBrazil and high SSTs during the last 8 years strongly indicates that these temperature increasesare the primary cause of bleaching in the region. Bleaching was mild in Bahia in 2006 withonly 6.2±7.1% of colonies bleached on the Abrolhos fringing reefs, compared with 28.3±4.9%in 2005. Live coral cover increased from 11.4 ±5.0% (2005) to 13.5 ±3.5% (2006), with no risein recent mortality. The amount of dead coral declined from 20.5% (2005) to 17.5% (2006).Percentage of bleached coral colonies observed on Brazilian reefs in 2005 and 2006 fromassessments performed using the AGRRA protocol.ReefsTime ofobservationNumber reef sitesNo. coloniesobservedPercentagebleached coloniesItacolomis April 2005 3 280 4.7 – 17.0Abrolhos May 2005 3 399 23.5 – 33.3Abrolhos March 2006 6 553 2.0 – 17.0107
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Stat u s o fCa r i b b e a nCo r a
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Dedication: This book is dedicated
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Status of Caribbean Coral Reefs aft
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Status of Coral Reefs in the Caribb
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3. Hu r r i ca n e s a n d t h e i
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Hurricanes and their Effect on Cora
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Hurricanes and their Effect on Cora
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4. Th e 2005 Bl e a c h i n g Ev e
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The 2005 Bleaching Event: Coral-Lis
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5. Stat u s o f t h e Mesoamerican
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Status of Caribbean coral reefs after bleaching and hurricanes in 2005

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