<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>ASSESSING RECOVERY OF REEFS IN BELIZEThe recovery <strong>of</strong> Belize’s <strong>reefs</strong> from the comb<strong>in</strong>ed impacts <strong>of</strong> mass <strong>bleach<strong>in</strong>g</strong> <strong>and</strong>Hurricane Mitch <strong>in</strong> 1998 were <strong>in</strong>vestigated <strong>in</strong> early <strong>2005</strong> to determ<strong>in</strong>e whether no-takeprotection status could accelerate potential recovery (i.e. <strong>in</strong>crease resilience as def<strong>in</strong>edby 4 <strong>in</strong>dices: the abundance/diversity <strong>of</strong> benthic functional groups; hard <strong>coral</strong> diversity;<strong>coral</strong> recruitment; <strong>and</strong> herbivore abundance). Data were collected <strong>in</strong> <strong>2005</strong> at 3 highlyprotected sites <strong>and</strong> 3 reference sites <strong>and</strong> compared with data collected prior to orimmediately <strong>after</strong> the 1998 event. There has been little recovery s<strong>in</strong>ce 1998, with live<strong>coral</strong> cover at the 6 sites rema<strong>in</strong><strong>in</strong>g less than 15%.Because <strong>of</strong> the high level protection, it was predicted that the no-take <strong>reefs</strong> would exhibitsignificantly greater live <strong>coral</strong> cover <strong>and</strong> juvenile <strong>coral</strong> densities, <strong>and</strong> lower macroalgalcover than the fished <strong>reefs</strong>. However, there was no significant difference <strong>in</strong> mean live<strong>coral</strong> cover <strong>and</strong> <strong>coral</strong> diversity between fished <strong>and</strong> no-take <strong>reefs</strong>. Moreover, the density <strong>of</strong>juvenile <strong>coral</strong>s was greater on fished <strong>reefs</strong> <strong>and</strong> the cover <strong>of</strong> macroalgae was significantlygreater on unfished <strong>reefs</strong>.From: Nadia Bood (nbood@wwfca.org), Melanie McField (mcfield@healthy<strong>reefs</strong>.org) <strong>and</strong>Rich Aronson (raronson@disl.org).2Percent <strong>coral</strong> cover (300m )4030201001997 1999 <strong>2005</strong>2Percent macroalgae cover (300m )353025201510501997 1999 <strong>2005</strong>YearYearCoral species diversity (H')1.81.61.41.21.00.80.60.40.20.01997 1999 <strong>2005</strong>2Juvenile <strong>coral</strong>s per m10864202001 <strong>2005</strong>YearMean UnfishedYearMean Fished50
<strong>Status</strong> <strong>of</strong> the Mesoamerican Reef <strong>after</strong> the <strong>2005</strong> Coral Bleach<strong>in</strong>g EventBelize was attributed to this <strong>2005</strong> <strong>bleach<strong>in</strong>g</strong> event, possibly because <strong>of</strong> the relatively late onset,the cool<strong>in</strong>g effects <strong>of</strong> numerous tropical storms <strong>and</strong> <strong>hurricanes</strong>, <strong>and</strong> possibly because many <strong>of</strong>the <strong>coral</strong>s susceptible to <strong>bleach<strong>in</strong>g</strong> had died dur<strong>in</strong>g earlier events. Despite the lack <strong>of</strong> apparent<strong>bleach<strong>in</strong>g</strong> related mortality <strong>in</strong> <strong>2005</strong>, <strong>coral</strong> <strong>bleach<strong>in</strong>g</strong> rema<strong>in</strong>s the major threat to all <strong>reefs</strong> <strong>in</strong>Belize; <strong>in</strong>clud<strong>in</strong>g the most remote <strong>and</strong> most well-protected (<strong>in</strong> terms <strong>of</strong> MPA management).While all nearshore <strong>and</strong> some <strong>of</strong>fshore <strong>reefs</strong> are threatened by a variety <strong>of</strong> chronic local stresses,mass <strong>coral</strong> <strong>bleach<strong>in</strong>g</strong> events threaten all <strong>reefs</strong> <strong>and</strong> may <strong>in</strong>hibit the natural ability <strong>of</strong> <strong>bleach<strong>in</strong>g</strong>damaged<strong>reefs</strong> to recover from repeated <strong>bleach<strong>in</strong>g</strong> events.Data from the Mesoamerican Barrier Reef System (MBRS) Project between early July <strong>and</strong> lateSeptember <strong>2005</strong> showed the first <strong>bleach<strong>in</strong>g</strong> on the Belize <strong>reefs</strong> <strong>in</strong> mid July with 25% <strong>of</strong> coloniesaffected. The proportion <strong>of</strong> bleached colonies <strong>in</strong>creased through August <strong>and</strong> September.Although no data are available for Belize <strong>after</strong> September, <strong>bleach<strong>in</strong>g</strong> was observed <strong>in</strong> Belize(Turneffe, Ambergris Caye, Glovers Reef, among others) through to mid-November. Not all<strong>coral</strong>s bleached <strong>and</strong> most that did were only partially bleached. Bleach<strong>in</strong>g occurred primarily<strong>in</strong> colonies <strong>of</strong> Siderastrea siderea, Montastraea spp., Diploria spp. <strong>and</strong> Agaricia spp.The extent <strong>of</strong> <strong>bleach<strong>in</strong>g</strong> <strong>in</strong> Belize <strong>in</strong> <strong>2005</strong> is seen as the number <strong>of</strong> <strong>coral</strong> colonies affected <strong>in</strong> theNorthern Summer. Data provided by MBRS Synoptic Monitor<strong>in</strong>g Program (www.mbrs.org.bz)LocationMonth assessed(n = number <strong>of</strong> colonies)Colonies Affected byBleach<strong>in</strong>g (%)Belize July (n = 488) 25August (n = 505) 19September (n = 221) 39It may not be co<strong>in</strong>cidental that <strong>2005</strong> was the most active storm season <strong>in</strong> the Western Atlantic<strong>in</strong> the past century. There were repetitive decreases <strong>in</strong> sea surface temperatures, which appearto co<strong>in</strong>cide with the passage <strong>of</strong> <strong>in</strong>tense storms that probably <strong>in</strong>creased mix<strong>in</strong>g <strong>and</strong> reducedSSTs. Thus, these storms may have contributed to the relatively low level <strong>of</strong> mortality <strong>of</strong> <strong>coral</strong>s<strong>in</strong> Belize <strong>in</strong> <strong>2005</strong>. A similar, but less dramatic, hurricane caused similar cool<strong>in</strong>g dur<strong>in</strong>g the1995 <strong>bleach<strong>in</strong>g</strong> event.For four <strong>in</strong>tervals between early July <strong>and</strong> mid November <strong>2005</strong>, the average weekly SST <strong>in</strong>Belize exceeded the 30°C <strong>bleach<strong>in</strong>g</strong> threshold for <strong>coral</strong>s <strong>in</strong> the region, result<strong>in</strong>g <strong>in</strong> between 1.5<strong>and</strong> 3 ‘Degree Heat<strong>in</strong>g Weeks’ <strong>of</strong> temperature stress. On each occasion the stress was quicklyreduced by rapid drops <strong>in</strong> temperature <strong>and</strong> co<strong>in</strong>cident storm activity. By late November theregular cool w<strong>in</strong>ds, the ‘northers’, lowered sea temperatures.Impacts <strong>of</strong> Hurricanes <strong>in</strong> <strong>2005</strong>: Hurricanes have had a relatively regular impact on the <strong>reefs</strong><strong>of</strong> Belize, but <strong>hurricanes</strong> Hattie (1961) <strong>and</strong> Mitch (1998) were exceptional. Hurricane Hattiereduced live <strong>coral</strong> cover on many <strong>reefs</strong> by 80%; however <strong>reefs</strong> subsequently recovered, at leastto some extent. Hurricane Mitch <strong>in</strong> 1998 did not make l<strong>and</strong>fall <strong>in</strong> Belize, but the pound<strong>in</strong>gwaves resulted <strong>in</strong> extensive physical damage throughout Belize, particularly on the Southern<strong>reefs</strong>. The heavy ra<strong>in</strong>fall associated with this slow-mov<strong>in</strong>g storm also resulted <strong>in</strong> major flood<strong>in</strong>gthat damaged both <strong>in</strong>shore <strong>and</strong> <strong>of</strong>fshore <strong>reefs</strong> <strong>of</strong> Belize <strong>and</strong> Honduras.51