<strong>Status</strong> <strong>of</strong> Coral Reefs <strong>of</strong> the Lesser Antilles <strong>after</strong> the <strong>2005</strong> Coral Bleach<strong>in</strong>g Event%9080706050403020100GuadeloupeMar – Jul 05 Nov – Dec 05 Apr – May 06 Nov – Dec 06Survey Date%%6050403020100706050403020100Mart<strong>in</strong>iqueJul – 05 Dec – 05 Jul – 06 Dec – 06Sa<strong>in</strong>t Barthélemy Survey DateFeb – 05 Aug – 05 May – 06 Nov – 06Survey Date% Species bleached% Colonies bleached% Cover bleached% Mortality (% cover lost)The effects <strong>of</strong> <strong>in</strong>creased sea temperatures on the <strong>coral</strong> <strong>reefs</strong> <strong>of</strong> the French West Indies are presented<strong>in</strong> these 3 figures. There was no apparent <strong>bleach<strong>in</strong>g</strong> by July <strong>2005</strong>; but between August <strong>and</strong> December,there was clear evidence <strong>of</strong> a major <strong>bleach<strong>in</strong>g</strong> event with about half <strong>of</strong> all <strong>coral</strong>s bleached, but fewsigns <strong>of</strong> mortality. However, by mid-2006, 30% to 40% <strong>of</strong> the <strong>coral</strong> cover had died, <strong>and</strong> more than10% <strong>of</strong> the rema<strong>in</strong><strong>in</strong>g <strong>coral</strong>s were bleached.91
<strong>Status</strong> <strong>of</strong> <strong>Caribbean</strong> Coral Reefs <strong>after</strong> Bleach<strong>in</strong>g <strong>and</strong> Hurricanes <strong>in</strong> <strong>2005</strong>Observations <strong>in</strong> June 2007 showed that many <strong>coral</strong>s rema<strong>in</strong>ed pale or partially bleached <strong>and</strong>had not fully recovered their stock <strong>of</strong> zooxanthellae, despite normal seawater temperatures.The three-dimensional structure <strong>of</strong> the <strong>reefs</strong> was apparently not affected by the <strong>bleach<strong>in</strong>g</strong>; forexample, <strong>in</strong> 2004, the average number <strong>of</strong> fish species per 600 m 2 was 45 <strong>and</strong> the average fishbiomass was 807 kg.ha -1 <strong>and</strong> by the end <strong>of</strong> 2006, comparable measures were 48 species <strong>and</strong> 994kg.ha -1 .Mart<strong>in</strong>ique: Bleach<strong>in</strong>g started <strong>in</strong> August <strong>2005</strong> <strong>and</strong> the first surveys <strong>in</strong> December showed that<strong>bleach<strong>in</strong>g</strong> affected 51% <strong>of</strong> <strong>coral</strong> species, 49% <strong>of</strong> all <strong>coral</strong> colonies, <strong>and</strong> an average <strong>of</strong> 50% <strong>of</strong> thesurface area <strong>of</strong> each colony. Coral mortality was moderate <strong>in</strong> December with a loss <strong>of</strong> 11% <strong>in</strong><strong>coral</strong> cover. The number <strong>of</strong> <strong>coral</strong> recruits decreased from an average <strong>of</strong> 49 recruits per 10 m 2 <strong>in</strong>July <strong>2005</strong> to 28 recruits per 10 m 2 <strong>in</strong> December <strong>2005</strong>, even though <strong>coral</strong> recruitment is usuallygreater <strong>in</strong> December. Juvenile recruitment was still low <strong>in</strong> 2006 (32 recruits per 10 m 2 ).Bleach<strong>in</strong>g persisted dur<strong>in</strong>g 2006 <strong>and</strong> by the end <strong>of</strong> the year, 27% <strong>of</strong> all <strong>coral</strong> species showedsigns <strong>of</strong> <strong>bleach<strong>in</strong>g</strong> <strong>and</strong> 18% <strong>of</strong> <strong>coral</strong> colonies were affected. The average bleached surface area<strong>of</strong> <strong>coral</strong>s was 26%. As a consequence <strong>of</strong> the delayed <strong>coral</strong> mortality, the average <strong>coral</strong> cover haddecl<strong>in</strong>ed from 28% to 19%. Most <strong>of</strong> the recently dead <strong>coral</strong>s were colonized by algae, which<strong>in</strong>creased cover by 15%. The health <strong>of</strong> surviv<strong>in</strong>g <strong>coral</strong> colonies was threatened by <strong>coral</strong> disease,with 49% <strong>of</strong> colonies show<strong>in</strong>g tissue necrosis <strong>and</strong> 48% <strong>of</strong> the colony surface area affected.The fish communities did not appear to be affected: <strong>in</strong> the <strong>2005</strong> <strong>bleach<strong>in</strong>g</strong> there was an average<strong>of</strong> 46 species per 600 m 2 <strong>and</strong> fish biomass <strong>of</strong> 788 kg.ha -1 ; whereas <strong>in</strong> 2006 there were 44 specieson average <strong>and</strong> the biomass was 1207 kg.ha -1 .Sa<strong>in</strong>t-Barthélemy: Bleach<strong>in</strong>g was recorded first <strong>in</strong> August <strong>2005</strong> <strong>and</strong> affected 63% <strong>of</strong> <strong>coral</strong>species, 48% <strong>of</strong> colonies, <strong>and</strong> an average <strong>of</strong> 54% <strong>of</strong> the <strong>coral</strong> cover. No immediate <strong>coral</strong>mortality was seen. Coral recruit density was the lowest noted dur<strong>in</strong>g this season, decl<strong>in</strong><strong>in</strong>gfrom 50 recruits per 10 m 2 to 35 recruits per 10 m 2 . Recruitment <strong>of</strong> juveniles rema<strong>in</strong>ed low<strong>in</strong> 2006. Throughout 2006, there was delayed <strong>coral</strong> mortality <strong>and</strong> by the end <strong>of</strong> the year <strong>coral</strong>communities showed no signs <strong>of</strong> recovery, with 40% <strong>of</strong> <strong>coral</strong> species, 14% <strong>of</strong> colonies <strong>and</strong> anaverage <strong>of</strong> 20% <strong>of</strong> the surface <strong>of</strong> <strong>in</strong>dividual colonies still be<strong>in</strong>g bleached. By November, the live<strong>coral</strong> cover had decl<strong>in</strong>ed by 40%, from 20% before <strong>bleach<strong>in</strong>g</strong> to 12% <strong>after</strong>wards <strong>and</strong> the dead<strong>coral</strong>s were ma<strong>in</strong>ly colonized by algae, with cover <strong>in</strong>creas<strong>in</strong>g by 12%.The surviv<strong>in</strong>g colonies deteriorated significantly throughout 2006; early <strong>in</strong> the year, tissuenecrosis on colonies rose from 18% to 23%, <strong>and</strong> the colony surface area affected <strong>in</strong>creasedfrom 30% to 48%. The number <strong>of</strong> <strong>in</strong>fected colonies was still high although many had died from<strong>coral</strong> disease. By mid-2007, many <strong>coral</strong>s rema<strong>in</strong>ed pale or partially bleached <strong>and</strong> had not totallyrecovered from <strong>bleach<strong>in</strong>g</strong>, despite normal sea surface temperatures.The average fish species richness on <strong>reefs</strong> was 48 species per 600 m2 <strong>and</strong> the fish biomass751 kg.ha -1 before <strong>2005</strong>; <strong>and</strong> 57 species per 600 m 2 <strong>and</strong> a similar fish biomass <strong>of</strong> 742 kg.ha -1 <strong>in</strong>200692