ATOLL RESEARCH BULLETIN NO. 131 POST-HURRICANE CHANGES ON THE BRITISH HONDURAS REEFS AND CAYS: RE-SURVEY OF 1965 by D. R. Stoddart Issued by THE SMITHSONIAN INSTITUTION Washington, D. C., U. S. A. August 15, 1969 Contents Introduction Recovery of coral reefs Cays of the Barrier Reef Cays of Turneffe Cays of Lighthouse Reef Geomorphic changes on the cays Vegetation changes on the cays References Figures (following p. 25) 1 Pattern of hurricane damage to sand cays (from ARB 95, Fig. 62) 2 Status of coral reefs 1965 3 St. George's Cay 1965 4 Sergeant's Cay 1965 5 Goff's Cay 1965 6 English Cay 1965 7 Rendezvous Cay 1965 8 Tobacco Cay 1965 9 Scipio Cay 1962 and 1965 10 Colson Cay 1962 and 1965 11 Pelican Cay 1965 12 Little Calabash Cay 1965 13 Sandbore Cay 1965 14 Northern Cay north point 1960, 1962, 1965 15 Mangrove mortality and recovery 1965 Page POST-HURRICANE CHANGES ON THE BRITISH HONDURAS REEFS AND CAYS: RE-SURVEY OF 1965 by D . R . Stoddart INTRODUCTION On 30-31 October 1961, Hurricane H a t t i e crossed t h e coas t a l co ra l r e e f a rea of B r i t i s h Honduras, s h o r t l y a f t e r an extens ive survey of the geomorphology of t h e r e e f s and r e e f i s l a n d s , c a r r i e d out during 1959-1961 (Stoddart 1962, h e r e a f t e r c i t e d as ARB 87). Ear ly i n 1962 t h e r e e f a rea was re-surveyed, and re-photographed from the a i r , and many of t h e i s l a n d s were re-mapped by ground survey. This re-survey formed t h e b a s i s of a d e t a i l e d r e p o r t on t h e immediate e f f e c t s of ca t a s t roph ic storms on co ra l r e e f s and i s l a n d s (Stoddart 1963, h e r e a f t e r c i t e d as ARB 95) . With Moorhouse's observat ions a t Low I s l e s , Great Bar r i e r Reef, t h e work of t h e P a c i f i c Science Board expedi t ion t o J a l u i t A t o l l , Marshall I s lands (Blumenstock, e d i t o r , 1961), and the l a t e r work of Sauer (1962) and McIntire and Sauer (1965) i n Maur i t ius , t h i s r epor t formed t h e bas i s f o r an understanding of the e f f e c t s of inf requent events of considerable magnitude on t h e co ra l i s l a n d ecosystem. I t is necessary, however, not only t o s tudy immediate e f f e c t s of such storms, but a l s o t o eva lua te t h e i r long-term impl i ca t ions . How long does i t take a c o r a l r e e f co rega in i t s pre-hurr icane s t a t e ? How permanent a r e changes i n r e e f and i s l a n d morphology caused by exceptional storms? What i s t h e sequence o f vegeta t ion development o r recovery on storm-damaged i s l a n d s ? Do i s l a n d s destroyed by t h e storm rap id ly re-form? Only a t Low I s l e s , Great B a r r i e r Reef, do we have observat ions over s e v e r a l decades beraing on these problems (T. A. Stephenson and o the r s 1936, Moorehouse 1936, W . Stephenson and o thers 1958, Fa i rbr idge and Teicher t 1948), but t h e storm e f f e c t s t h e r e have been comparatively minor. The only s tudy of t h e l o n g - t e n e f f e c t s of a major storm has been a t J a l u i t A t o l l , where t h e e f f e c t s of Typhoon Ophelia, f i r s t s tud ied i n 1958, were re -assessed t h r e e years l a t e r (Blumenstock and o the r s 1961). I n t e r e s t i n these problems, and t h e need t o add d a t a from t h e Caribbean t o compare with those from J a l u i t , l ed t o a f u r t h e r expedi t ion t o t h e B r i t i s h Honduras r e e f s i n March and Apri l 1965. This expedi t ion has been only b r i e f l y repor ted (Stoddart 1965), and t h e p resen t paper p re sen t s t h e main conclusions i n g r e a t e r d e t a i l , and documents t h e pos t - hur r icane changes on t h e ind iv idua l i s l a n d s s tud ied . No attempt i s made i n t h i s paper t o draw general conclusions on t h e long-term s ign i f i cance of c a t a s t r o p h i c storms on r e e f s : re-surveys of t h e B r i t i s h Honduras coas t must continue u n t i l equi l ibr ium condi t ions a r e again e s t ab l i shed be fo re t h i s w i l l be poss ib l e . The B r i t i s h Honduras da ta have been compared with those from o t h e r a reas and some pre l iminary conclusions on t h e r o l e of major storms have been drawn i n a sepa ra t e paper (Stoddart 1969). Hurricane H a t t i e crossed t h e B r i t i s h Honduras coast from the e a s t on t h e n igh t of 30-31 October 1961. Eas t e r ly and nor the r ly winds t o t h e no r th of t h e storm t r a c k and south and southwest winds t o t h e south gusted t o 200 m.p.h., and a storm surge r a i s e d s e a l eve l up t o 15 f e e t above normal l e v e l s within a zone 20-40 miles wide nor th and south of t h e storm t r a c k , e s p e c i a l l y on the b a r r i e r r e e f . The t r a c k and t h e sequence of events assoc ia ted with t h e passage of t h e hurr icane have been recons t ruc ted i n some d e t a i l (ARB 95, 7-20). Damage t o both r e e f s and cays r e s u l t i n g from t h e abnormal wind and s e a condit ions during t h e storm was d i s t i n c t i v e l y zoned both no r th and south of t h e storm t r a c k , as described i n d e t a i l i n ARB 95 and summarized i n Figure 1. The p resen t paper should be read i n conjunction with t h i s e a r l i e r work: no attempt i s made h e r e t o summarize e a r l i e r d a t a , but only t o present t h e new da ta gained i n 1965. The r epor t dea l s f i rs t with r e e f s ; then with changes on t h e cays of t h e b a r r i e r r e e f , of Turneffe, and of Lighthouse Reef, r e spec t ive ly ; and f i n a l l y summarizes t h e morphologic and vegeta- t i o n a l changes on t h e cays between 1961 and 1965. The 1965 i n v e s t i g a t i o n was made poss ib l e by generous f i n a n c i a l a s s i s t ance from Cambridge Travel l ing Expenses Fund, from t h e Royal Geographical Socie ty , and from the Cambridge Phi losophica l Socie ty . I thank these bodies f o r t h e i r a i d , and a l s o M r . and Mrs. N . B. S t a l k e r , of Bel ize, f o r t h e i r g r e a t kindness and h o s p i t a l i t y , and Miss Evelyn L . P r u i t t , Head, Geography Branch, Off ice of Naval Research, f o r t r a n s - a t l a n t i c t r a n s p o r t a t i o n . D r . F. R . Fosberg and D r . M.-H. Sachet again determined my p l a n t c o l l e c t i o n s , and helped i n many o the r ways. I thank a l s o P h i l i p and Ronnie Young who ably took me from cay t o cay i n t h e Sunshine and t h e Ramrod. S i r Pe ter S t a l l a r d , then Governor, and t h e Ministry of Natural Resources, Bel ize , showed much i n t e r e s t i n t h i s p r o j e c t . RECOVERY OF CORAL REEFS General Survey Damage t o r e e f s caused by Hurricane H a t t i e was concentrated on t h e b a r r i e r r e e f between English Cay and Rendezvous Cay, where almost a l l l i v i n g c o r a l s were destroyed. Damage was a l s o heavy northwards t o a t l e a s t S t . George's Cay and south t o Cay Glory, and a l s o on t h e eas t e rn s i d e of Turneffe. Moderate damage was noted on t h e b a r r i e r r e e f from Cay Glory t o Curlew Cay. In the a r e a of heavy damage almost a l l t r a c e of reef -s lope groove-spur systems disappeared, leaving a ba re s lope; whereas i n t h e zone of moderate damage remnants of spurs survived t h e storm, though f l o u r i s h i n g co ra l co lonies had disappeared (ARB 95, 21-29, Fig. 14) . I n 1965 r e e f s were observed from t h e a i r along the b a r r i e r r e e f from S t . George's Cay t o Curlew Cay, a d i s t ance of 55 miles , and along the e a s t s i d e of Turneffe. Only a b r i e f observat ion of the r e e f s near Half Moon Cay on Lighthouse Reef was poss ib l e . No l i v i n g co ra l could be seen on Gallow's Point Reef, formerly t h e most no r the r ly f l o u r i s h i n g l i n e a r r e e f of t h e b a r r i e r r e e f system. The sea was except ional ly c l e a r and calm, and it was poss ib l e t o s e e a ver- t i c a l c l i f f - l i n e a t t h e foo t of t h e gent ly s lop ing r e e f f a c e , i t s e l f now devoid of c o r a l s and with no groove-spur development. A t Sergeant ' s Cay t h e r e was some l i v i n g co ra l on t h e south s i d e of t h e r e e f pa tch , but l i t t l e o r none a t Paunch, Goff 's and English Cays. The numerous pa tches between English and Rendezvous Cays, once t h i c k l y coated with orange Acropora, were ba re , with only occasional s c a t t e r e d patches of c o r a l . Between Rendezvous and Cay Glory no growing c o r a l was seen on t h e b a r r i e r , and no t r a c e of groove-spur formation. Groove-spur i s first seen imme- d i a t e l y south o f Cay Glory, and l i v i n g c o r a l i s found on t h e spurs where t h e b a r r i e r t u rns southwestwards south of Cay Glory. Most o f t h e spurs a re fragmentary and l i v i n g co ra l i s absent o r r a r e as f a r south as Tobacco Cay. Living c o r a l approaching pre-hurr icane luxuriance i s seen on t h e shal lower p a r t of spurs a t South Water Cay and Car r i e Bow Cay, though t h e deeper spurs a r e bare . Rich c o r a l growth i s seen a t Curlew Cay and southwards. In t h i s a r e a , south of the storm t r a c k , dominant storm waves were from t h e south and sou theas t , from t h e lagoon r a t h e r than t h e open s e a ; and a t both Car r i e Bow and Curlew Cays t h e southern s i d e s of t h e r e e f patches a r e bare of c o r a l s . On the e a s t s i d e of Turneffe, condi t ions i n 1965 were s i m i l a r t o those on t h e b a r r i e r r e e f . Living c o r a l s seem almost non-exis ten t , and although t r a c e s of r ee f - f ace l i n e a t i o n can be seen nor th of Sold ier Cay t h e r e was no s i g n of growing c o r a l s . These d a t a , admit tedly incomplete, suggest t h e fol lowing zones of r ee f damage and recovery: (1) To ta l des t ruc t ion of l i v i n g c o r a l s and absence of regenera t ion: extending a t l e a s t 15 miles nor th of t h e storm t r a c k and 12 miles south; t h i s includes t h e whole of Turneffe, except f o r a reas of l o c a l p ro tec t ion . (2) Survival of t r a c e s of r e e f - f r o n t l i n e a t i o n , but death of c o r a l s and almost no regenera t ion: extending from 12 t o 20 miles south of t h e hurr icane t r a c k . There a r e no comparable da ta t o t h e north of t h e storm t r a c k , where pre-hurr icane r e e f growth was f e e b l e . ( 3 ) Reef-l ineat ion more o r l e s s i n t a c t , bu t patchy su rv iva l of c o r a l s , passing i n t o r i c h c o r a l growth a t a d i s t ance of 25 miles south of t h e storm t r a c k . (4) Damage minor o r r a p i d l y r epa i r ed : a t d i s t ances g r e a t e r than 25 miles from t h e storm t r a c k . This p a t t e r n of zonation i s s i m i l a r t o t h a t described immediately a f t e r Hurricane Ha t t i e , and suggests t h a t l i t t l e r ee f recovery had taken p lace by 1965. Underwater observat ions t o confirm t h i s conclusion were made a t Sergeant ' s Cay and Rendezvous Cay r e e f s . Se rgean t ' s Cay Reef Sergeant ' s Cay s t ands on a small patch r e e f on t h e edge of the c o a s t a l s h e l f . Damape i n 1961 was considerably l e s s than on some of In 1965 t h e su r face of t h e patch was covered with s l a b s and s t i c k s of dead c o r a l , covered with pink encrus t ing a lgae , with some Halimeda, and, on t h e l e e s i d e , meadows of Padina and Turbinar ia . The boulders o f S i d e r a s t r e a and Dip lo r i a on t h e seaward s i d e which survived t h e storm appeared hea l thy , though l i t t l e l i v i n g Montastrea was seen . New growth of c o r a l s i s r a t h e r s p a r s e . Acropora palmata forms s c a t t e r e d colonies uo t o 1 foot t a l l and 1-2 f e e t i n diameter . bu t only a s i n g l e colonv of - Acropora ce rv ico rn i s was seen . There a r e many small co lonies of Por i t e s a s t r e o i d e s a few inches i n diameter , small clumps of Agar ic ia , and l a r g e r patches of Mil lepora. Nevertheless t h e a reas of l i v i n g co ra l a r e sva r se . and sevara ted bv wide areas of rubble and a lgae . Most of t h e new co ra l s a re minor r e e f - b u i l d e r s , with the exception o f A. palmata. No l a r g e r sponges were seen , and ha rd ly any Gorgonians, i n con t ra s t t o t h e i r abundance before t h e storm. Rendezvous Reef Rendezvous Reef was s tud ied i n d e t a i l before Hurricane Ha t t i e , and again af terwards (ARB 95, 23-25, Fig. 1 5 ) , and it was poss ib l e t o desc r ibe the hurr icane damage i n some d e t a i l using underwater observa- t i o n s and a sequence of low-a l t i tude co lo r a i r photographs. The a i r photograph cover was repea ted , with underwater observa t ion , i n 1965. Immediate post-hurr icane changes were summarized i n 1962 as fol lows: "Montastrea annular i s has survived a l l round the r e e f patch with moderate success , toge ther with Mil lepora, which may, a t l e a s t i n p a r t , have grown s ince the storm. More massive specimens of - A . palmata have a l s o survived i n p l aces . On t h e su r face of the patch, S i d e r a s t r e a rad ians can s t i l l be found i n t h e t u r t l e g ra s s , but not Cladocora o r Manicina. The deeper s lopes round t h e whole patch seem t o be bare . . . . As rough es t imates of the amount of damage, t h e t o t a l r e e f damage may be placed a t 75-80 pe r cent ; d e s t r u c t i o n of A. ce rv icorn is 100 p e r cen t ; A. palmata 80 pe r cen t ; and M . annu la r i s 50 per c e n t . The extens ive r u b b l e banks along t h e e a s t e r n r e e f c r e s t a r e now t h i c k l y coated with purple algae." (ARB 95, 25) . Comparison of t h e 1962 and 1965 a i r pllotographs shows no major changes i n the a reas of growing c o r a l . Montastrea annu la r i s has survived on t h e southwest, e a s t and nor th s i d e s of the r e e f , t oge the r with a few l a rge Acropora palmata on t h e e a s t and nor theas t s i d e s . Some of t h e Montastrea co lonies a r e p a r t l y dead, some a re overturned but s t i l l a l i v e , but none seems vigorous. No Acropora c e r v i c o r n i s , once abundant, was seen except on t h e r e e f s lope a t t h e nor th po in t . Small new colonies of Agar ic ia , Mil lepora, and Por i t e s a s t r e o i d e s were seen, t oge the r with co lonies of such unimportant spec ie s as Manicina a e r o l a t a , Eusmilia f a s t i g i a t a and Mycetophyllia lamarckana. Sponges and Gorgonians a r e f a i r l y numerous. The carpe t of dead c o r a l rubble on t h e r e e f c r e s t and f l a t i s t h i c k l y coated with a lgae , c h i e f l y Padina, and Thalass ia i s growing p r o l i f i c a l l y on t h e su r face of t h e patch. The a rea south of t h e cay, and t h e northwest s i d e of t h e r e e f , both s t r i p p e d of c o r a l s by t h e storm, a re s t i l l ba re . The only reef -bui ld ing c o r a l s found i n 1965 were those which survived t h e storm; a l l new growth has been o f non- frame-building forms. Comment The slow r a t e of r e e f recovery r equ i re s explanat ion , i n view o f t h e known r a p i d i t y of growth o f co ra l co lonies , e s p e c i a l l y of branching forms such as Acropora ce rv ico rn i s . Following t h e 1950 cyclone a t Low I s l e s , Great Bar r i e r Reef, Stephenson and o the r s (1958, 304) suggested t h a t t h e l a rge q u a n t i t y of mobile debr is produced by t h e storm would i n h i b i t co ra l co loniza t ion and thus delay r e e f growth. They a l s o suggested t h a t a more severe storm might sweep debr i s o f f r e e f s com- p l e t e l y , and t h a t as a r e s u l t recovery could then be more r ap id . In addi t ion , t h e r e may be a c t i v e competition f o r a v a i l a b l e s u b s t r a t e s between c o r a l s and more r ap id ly growing a lgae , p a r t i c u l a r l y Padina. I t i s a l s o poss ib l e t h a t increased water t u r b i d i t y may i n h i b i t co ra l co loniza t ion; and, f i n a l l y , t h e r e a re no d a t a on how long a spec ie s such as A. c e r v i c o r n i s , which su f fe red major damage, t akes t o spread from a "Teservoir" such a s t h a t of t h e southern b a r r i e r r e e f t o s i t e s 50-100 miles away. I t i s thus not poss ib l e t o p red ic t how long r e e f regenera t ion may take i n t h e badly damaged a r e a s . Stephenson and o t h e r s ' es t imate (1958, 261) of 10-20 years i n t h e case of Low I s l e s i s probably too low i n t h e B r i t i s h Honduras case . Applying a l t e r n a t i v e reasoning, t h e Rendezvous Cay r e e f , which was f l o u r i s h i n g when s tud ied i n 1959-1960, must have been severe ly damaged by t h e major hurr icane of 1931, suggest ing a recovery period of perhaps 20-25 years . Continued observat ion of r e e f recovery i s c l e a r l y needed before conclusions can be drawn. CAYS OF THE BARRIER REEF Ambergris Cay (ARB 95, 31-33, Fig. 16) Ambergris Cay i s t h e l a r g e s t mangrove-sand cay on t h e B r i t i s h Honduras b a r r i e r r e e f , cons i s t ing of a seaward sand r idge , with coconuts and l i t t o r a l woodland, and a leeward a rea of mangroves and drying sand f l a t s . Hurricane damage was confined t o minor shore l ine r e t r e a t , near- shore sand-s t r ipping , and t h e f e l l i n g of nearshore coconuts. Damage was g r e a t e s t a t San Pedro v i l l a g e , where t h e seaward sand r idge is h ighes t and wides t , and where considerable damage was caused t o bu i ld ings . During t h e hurr icane , beach r e t r e a t f u r t h e r exposed low a reas of cay sandstone which had been p a r t l y v i s i b l e before the storm. In 1965 t h i s rock was s t i l l very f r i a b l e , though darker i n co lo r , near San Pedro i t s e l f . Far ther north it had been eroded t o small r e s idua l mounds, more s t rongly l i t h i f i e d , and c lose t o Boca Bacalar Chico these mounds formed small headlands 10 yards long between sandy bays 30-50 yards across . The zone of sur face sand s t r i p p i n g i s here about 50 yards wide along t h e shore, and terminates in land i n an i r r e g u l a r c l i f f 1-2 f e e t high. Above t h i s c l i f f t h e r e i s a 100 pe r cent vegeta t ion cover, s ca rce ly a f f e c t e d by t h e storm. Most of t h e coconuts survived, though a number lack crowns. Over the s t r i p p e d zone the sur face vegeta t ion cover i s not more than 25 p e r cen t , dominated by Tournefort ia up t o one foo t high (compare three f e e t above the c l i f f ) and Euphorbia, with Ambrosia, Suriana, Sporobolus, Ipomoea and Flaver ia l i n e a r i s . Other p l a n t s seen a t San Pedro include Hymenocallis, Cordia, Ipomoea - tuba , Sophora and Suriana. The l i t t o r a l woodland not p lanted with coconuts includes Borrichia arborescens, Hamelia pa tens , and a Solanum 10-12 f e e t t a l l . Buildings have been repa i red a t San Pedro, and a la rge new j e t t y b u i l t on t h e seaward s i d e . Cay Caulker (ARB 95, 33-35, Fig. 17) Post-hurricane changes a t Cay Caulker have been minor. This i s a mangrove-sand cay with windward sand r idge , i n places f ron ted by Rhizophora and h a l f t h e leeward mangrove i s dead, and c o n t r a s t s with the greenness of the sand-area veee ta t ion . Trees and shrubs i d e n t i f i e d - - on t h e sand a r e a i n 1965 included Cordia sebestena, Casuarina e q u i s e t i - f o l i a ( i n t h e v i l l a g e ) , Coccoloba u v i f e r a , a species of Reynosia, W c h i a arborescens, Suriana maritima, Tournefort ia gnaphalodes, Lantana involucra ta , Turnera u lmi fo l i a , and a Solanum. There has been some recovery i n s t r ivved a reas of g ras ses , sedges, herbs and v ines , - - . which a r e deksest sou% of t h e v i l l a g e where hurr icane e f f e c t s were - - minor. Those i d e n t i f i e d i n 1965 were Cyperus l i g u f a r ~ , , F i m b r i s t y l i s cymosa subsp. spathacea, Chloris p e t r a e a , Eragros t l s omlnguensis, Wedelia t r i l o b a t a , Cro ta l a r i a verrucosa, Stachytarpheta mutabi l i s v , maxonii, -- Sida acuta , Ageratum maritimwn, Ageratum l i t t o r a l e , Philoxerus vermicular i s , Euphorbia b l o d g e t t i i , Euphorbia mesembrianthe- mi fo l i a , Pithecellobium s p . , Spermacoce suaveolens, Ernodea l i t t o r a l i s , and Vigna lu teo la . New j e t t i e s have been b u i l t on both t h e seaward and lagoon shores a t Cay Caulker v i l l a g e . Cay Chapel (ARB 95, 35-36, Fig. 17) Cay Chapel i s a l a rge ly sandy i s l a n d with a narrow leeward mangrove f r i n g e . About h a l f t he sand-area vegeta t ion was c leared , except f o r some coconuts, s h o r t l y before Hurricane H a t t i e , i n order t o e s t a b l i s h t o u r i s t f a c i l i t i e s . The hurr icane caused considerable shore l ine r e t r e a t , s t r i p p i n g of sur face sand near t h e seaward shore, and f e l l i n g of coconuts. On the northern, c leared , p a r t of the i s l a n d the re i s a zone 15-20 yards wide, along the seaward shore , of roo t s exposed by sand-s t r ipping , separa ted by a low c l i f f from the main i s l a n d surface . A t t h e foo t of t h e s t r i p p e d slope a bank of Tha las s i a had accumulated i n 1965, followed immediately landward by a continuous zone of colonizing Tournefort ia gnaphalodes 5 yards wide and 1-2 f e e t high. In p laces t h e Tournefort ia i $ replaced by Suriana up t o 6 f e e t h igh , Conocarpus up t o 8 f e e t high, o r low Borrichia; t he cover on t h i s lower s lope i s about 80 p e r cent . Between t h i s shrubby zone and t h e eroded c l i f f l i n e , t he vegeta t ion i s much l e s s dense, with l a rge b a r e areas between patches of Ernodea, Cassytha, some Wedelia, and low Conocarpus. The coconut r o o t s forming a network over the su r face a r e r o t t e n and can e a s i l y be pu l l ed a p a r t . The c l i f f l e t i s l ined with coconuts and dwarf Coccoloba, with an i n t e r - mi t t en t f r inge of Conocarpus and some Tournefort ia . The main cay su r face , previously c leared , i s now q u i t e densely covered with grasses , Ernodea, and clumps of Conocarpus and Suriana. A b e l t of Rhizophora a t t he north end of the cay i s dead. The creeper Merremia d i s s e c t a and the shrub Rivina humil is were co l l ec ted i n 1965. Far ther south, shore r e t r e a t during the hurr icane revealed an exposure of cay sandstone well above high water on the seaward shore (ARB 95, 35-36). This i s now separa ted from the s e a by a b e l t of Tournefort ia 1-2 f e e t high, with some Borrichia 6 f e e t t a l l , Suriana, grasses and Wedelia. The a rea o f outcropping sandstone i s s c a t t e r e d with seedlings of Tournefort ia and Suriana. The rock i s b e t t e r cemented than i n 1962, bu t s t i l l f r i a b l e . The undisturbed cay vegeta t ion in land c o n s i s t s of ~ o c c o l o b a , coconuts, Suriana and ~ o u r n e f o r t i a , with grasses and Ageratum. A rapid t r ave r se was made along t h e west s i d e of the cay about 100 yards from the l e e shore. The vegetat ion cover i n t h e former c l ea red area i s low, with a 60 p e r cent cover of Ernodea, Cakile and Conocarpus. S a l t eff lorescence o r a l g a l binding gives a c r u s t y su r face t o t h e s i l t y sand. S t . George's Cay (ARB 95, 37-40, Fig. 19) Figure 3 S t . George's Cay cons i s t s o f an arcuate mangrove i s l a n d with a sandy a rea a t i ts northern end. Long c leared f o r use as a hol iday r e s o r t , t h e low sandy a rea , only 50-100 yards wide, was cu t by f i v e deep channels when overtopped by t h e storm surge during Hurricane Ha t t i e and almost a l l man-made s t r u c t u r e s were swept away. The northernmost po in t escaped extreme damage, and re t a ined a t u r f of g ras ses , with Euphorbia, Wedelia, Hymenocallis and many coconuts. Elsewhere only patches of pre-storm ground vegeta t ion survived, with Ageratum, Cakile , Euphorbia, Cyperus, Wedelia, and Hymenocallis, though most coconuts disappeared. By 1965, two of t h e channels (B and C) had been closed by a r t i f i c i a l f i l l , and the o thers were not iceably shallower and l e s s sharply defined. Channel A was the deepest . The cones of submarine sand on t h e seaward s i d e had a l t e r e d i n shape and t h e i r o u t l i n e s were no longer c l e a r , and s i m i l a r deposi t ion had taken p lace on the lagoon s i d e s of D and E . Most o f the mangroves a r e dead, except a t t h e northern end. Ground vegeta t ion is luxur iant except i n i l l - d r a i n e d a reas . Thus i n the o ld cemetery, no r th of Channel D , t h e r e a r e broken Coccoloba and Conocarpus, with Ageratum, Ipomoea, Wedelia, S tachytarpheta , Hymenocallis, Euphorbia and g ras ses . Far ther nor th , outs ide t h e cemetery, t h e ground cover c o n s i s t s of Sesuvium, Ageratum, Cyperus, Ba t i s maritima, Euphorbia and g ras ses . Between Channels B and C, both f i l l e d , t h e ground i s lower and water- logged, with Sesuvium, Ba t i s , g ra s ses , and even Rhizophora seed l ings . Several l a rge houses and s u b s t a n t i a l j e t t i e s have been b u i l t s i n c e 1962, and some coconuts have been p lan ted . C lea r ly it i s intended t o make t h e cay a hol iday r e s o r t aga in , b u t , l acking t r e e s , it i s s t i l l an u n a t t r a c t i v e p l ace . Sergeant ' s Cay (ARB 95, 41-42, Fig. 22) Figure 4 Sergeant ' s Cay almost completely disappeared during Hurricane H a t t i e , and reformed as a smal le r sandbore, which i n 1962 was beginning t o be colonized by p l a n t s . Four months a f t e r t h e storm t h e main colo- n i z e r on t h e f r e s h sand su r face was Por tu laca o l e racea , i n patches 1-2 f e e t i n diameter , with small a reas of Sesuvium portulacastrum and Euphorbia mesembrianthemifolia, and a s i n g l e Rhizophora seedl ing . The 1962 i s l a n d was two- f i f th s t h e a r e a o f t h e pre-storm cay, and lay t o t h e west of t h e o l d i s l a n d s i t e . Aggradation and eros ion of t h e shores was t ak ing p lace , and t h e i s l a n d was c l e a r l y not s t a b l e . By 1965 t h e cay had s h i f t e d back towards i t s o r i g i n a l p o s i t i o n , though i t s a r e a continued t o dec l ine , from 4500 square yards t o 2600 square yards i n 1962 and 2200 square yards i n 1965. The vegeta t ion had developed considerably. On a small c e n t r a l a r ea , where p a r t of t h e pre-storm su r face can s t i l l be seen (560 square yards , o r 25 pe r cent of t h e 1965 a r e a ) , t h e r e i s a continuous herb mat of Ipomoea ( I . - tuba and I . pes-caprae) , Wedelia t r i l o b a t a , and Euphorbia (E. mesemFrianthe- mi fo i i a , E . b l o d g e t t i i ) . Both Por tu laca and Sesuvium a r e absent . Shrubs, absent in-1962, a r e represented- Conocarpus up t o 10 f e e t t a l l , s i x Suriana maritima up t o 5 f e e t t a l l , and t h r e e Tournefor t ia gnaphalodes l e s s than 3 f e e t t a l l . There i s a s i n g l e seedl ing of Coccoloba uv i f e ra 2 f e e t high. Both Euphorbia and Ipomoea a r e beginning t o colonize t h e ba re sand surrounding t h e vegeta ted a rea , and a t t h e eas t e rn end t h e r e i s a consuicuous white-flowered clumu of Eustoma e x a l t a t a . Other herbs co l l ec t ed included Cakile l anceo la t a , Batis maritima and Philoxerus vermicular i s . I n t h r e e yea r s , t h e r e f o r e , t h e number of spec ie s on t h e cay increased from 4 t o 13. The i s l a n d i s s t i l l mobilk, however, and f u r t h e r changes can be expected. Goff ' s Cay(ARB 95, 43-44, Fig. 23) Figure 5 Before t h e hu r r i cane , Goff 's Cay was a small coconut-covered sandy i s l a n d , with a t h i n ground vegeta t ion of herbs , v ines and g ras ses . During t h e storm it was severe ly eroded, and t h e vegetated a rea reduced from 2100 t o 950 square yards. By 1962 much f r e s h sand had accumulated around t h i s remnant t o give a t o t a l a r e a of 2650 square yards . In 1965 s l i g h t recess ion of t h e southern shore had been balanced by cons iderable aggradat ion of new beach r idges on t h e no r th s i d e , g iv ing a t o t a l a r e a of 3250 square yards , very s l i g h t l y l e s s than t h e pre-storm a rea . The rubbly shores of 1962 a re now covered with sand, and t h e beachrock seen i n 1962 has been covered with rubble and cobbles. The immediate pos t -hurr icane vegeta t ion cons is ted of dead coconuts, a broken Coccoloba, and patches of Por tu laca o l e racea , t h e only co lon ize r . By 1965 t h e core-area was covered with a mat of Euphorbia, Sesuvium, Ipomoea, and Ernodea l i t t o r a l i s . Ipomoea vines a re spreading out on t o t h e f r e s h sand. Eighteen coconuts p lanted s ince t h e storm have grown up t o 3 f e e t t a l l . The number o f p l a n t spec ies had thus increased from 1 i n 1962 t o 5 i n 1965. A s i n 1962 t h e r e i s an unvegetated sandbore no r th of t h e cay, apparent ly migrat ing i n pos i t i on with weather changes. English Cay (ARB 95, 44-45, Fig. 24) Figure 6 Before Hurricane H a t t i e , English Cay was a s e t t l e d , coconut-covered i s l a n d with l i t t l e ground vege ta t ion and a r e s i d e n t populat ion of p i l o t s and l ighthouse keepers. In t h e storm t h e a rea of t h e cay decreased from 5750 t o 3150 square yards by shore r e t r e a t on a l l s i d e s . Eight out of 98 coconuts remained, toge ther with a s i n g l e broken Coccoloba and an anc ient Rhizophora. By 1965 t h e r e had been l i t t l e change i n t h e morphol- ogy of t h e i s l a n d , except f o r t h e leeward sandsp i t . Eighteen coconuts had been p lan ted , and t h e r e i s a patchy ground cover of Sesuvium, Euphorbia, and Portulaca o l e racea . The o ld Rhizophora and t h e Coccoloba a r e dead; but a surv iv ing pawpaw t r e e (Carica papaya) was found. With t h e reoccupat ion of t h e cay by people it i s c l e a r t h a t n a t u r a l regenera- t i o n of t h e vegeta t ion is not t ak ing p l ace . Rendezvous Cay (ARB 95, 47-49, F ig . 28) Figure 7 Like English Cay, Rendezvous before t h e storm was inhabi ted , covered with coconuts, and sub jec t t o p e r i o d i c c l ea r ing of ground vege ta t ion . I t s gross morphology was l a r g e l y man-induced, with a l a rge dry-land a r e a of dumped conch s h e l l s . The a r e a of t h e cay changed l i t t l e during t h e storm, though much su r face sand was s t r i p p e d and deposi ted along t h e west shore , p a r t l y burying the conch accumulations. A l l t h e coconuts disappeared, but t h e o r i g i n a l root-bound su r face remained p a r t l y i n t a c t . Within f i v e months many pioneers had colonized t h i s su r face . Por tu laca o l e racea was most widespread, with t h e sedge Cyperus p l a n i f o l i u s and grasses such as Sporobolus. Other c o n s t i t u e n t s of the ground vege ta t ion i n 1962 were Sesuvium portulacastrum, Euphorbia mesembrianthemifolia, Ipomoea pes-caprae, Cakile l anceo la t a , ~ i m b r i s t ~ ~ x e r u s - vermicular i s . Solanum lycopersicum was c o l l e c t e d , and seedl ings of Rhizophora and Tournefor t ia were seen. Forty young coconuts were p lanted a t t h i s t ime. By 1965 t h e vegeta t ion had changed considerably i n p a t t e r n and i n dens i ty . Most of the ground su r face was covered with a mat o f Ipomoea and Euphorbia, with smal le r a reas of Wedelia t r i l o b a t a and Sesuvium. Cyperus, Ageratum, Cakile and Sporobolus were present i n pa tches , bu t Por tu laca was r a r e . The coconuts had grown up t o 10 f e e t t a l l , with t h e b igger t r e e s i n t h e cen te r of t h e i s l a n d . A t the northern end of t h e cay t h e r e were low bushes of Tournefor t ia and Suriana, with a lone Casuarina r ap id ly being undermined by the sea . One of the broken Coccoloba s t i l l l ived , toge the r with Rhizophora seedl ings . The number of species i n 1962 was 12, and i n 1965 not l e s s than 16. Active eros ion was continuing i n 1965, when the whole of t h e eas t e rn shore had r e t r e a t e d 10-15 yards from i t s 1962 p o s i t i o n . Many of the newly-established shrubs and coconuts a re being undermined by t h i s r e t r e a t , which i s considerably reducing the width of the northern end of the i s l a n d . There i s a small hut on t h e i s l a n d , i n t e r m i t t e n t l y occupied. Tobacco Cay (ARB 95, 53-55, Fig. 31) Tobacco Cay i s a t r i a n g u l a r i s l a n d 300 yards long and up t o 150 yards wide i n the south, covered with coconuts and permanently inhabi ted . I t was mapped i n 1960 and again i n 1961, when the main changes were i n t h e s i z e of seasonal sand r idges along the south shore and i n the p a t t e r n of ground vkgeta t ion . In 1960 t h i s was dominated by dense Stachytarpheta up t o 3 f e e t t a l l , Wedelia t r i l o b a t a , Hymenocallis, and Ipomoea (I. pes-caprae, I . s t o l o n i f e r a ) . Smaller and apparently more r ecen t ly c leared areas h a z a t h i n cover of Euphorbia, Canavalia and Vigna lu t eo la . Sesuvium was found around the shores. Changes between 1960 and 1961 showed t h a t t h e p a t t e r n of vegeta t ion was l a rge ly a funct ion of repeated c l ea r ing by t h e inhab i t an t s . Hurricane winds i n 1961, from the southwest, blew down many coconuts, and deposi ted t h i n ca rpe t s of f r e s h sand up t o 15 yards wide along the south and west shores. The e a s t shore r e t r e a t e d up t o 14 yards. After the hurr icane t h e su r face was covered with f a l l e n coconut t runks , e spec ia l ly i n t h e south. Terminalia survived, even along the south shore. Wedelia was much less widespread i n e a r l y 1962, when t h e dom- . inant ground cover cons is ted of Ipomoea and Stachytarpheta , with some Sesuvium, Vigna l u t e o l a , Portulaca o leracea , Euphorbia and grasses . Bv 1965 manv of t h e f a l l e n coconuts had been c l ea red . and o ther l i v i n g t r e e s seen included Coccoloba, Cordia, Terminal ia , a small Carica, and Bumelia r e t u s a . Wedelia had expanded g r e a t l y i n the cen te r of t h e i s l a n d , except where very r ecen t ly c l ea red ; and the r e s t of the su r face was coveredAwith ~ t a c h y t a r ~ h e t a , . Ipomoea, Hymenocallis and Euphorbia. The changes i n d i s t r i b u t i o n of these p l a n t s s ince 1962 were very not iceable . Ipomoea and Sesuvium a re the chief beach-crest co lonizers , t oge the r with small a reas of Tournefor t ia gnaphalodes (not previously seen) . The southern sandsp i t , s l i g h t l y reduced i n s i z e , is being colonized by Sporobolus, ~ u ~ h o r b i a , ~es;vium, Ipomoea, seve ra l Tournefort ia seedl ings , and a s i n g l e Sophora tomentosa 2-1/2 f e e t t a l l . Other p l a n t s seen on Tobacco Cay included Canavalia, Portulaca, Cyperus, Rhizophora, Avicennia and Conocarpus. Apart from the thinned coconut canopy and the number of broken t runks , t he e f f e c t s of the hurr icane a re no longer obvious. The f r e sh sand carpet had already'been colonized by Ipomoea i n 1962, and even where su r face sand was s t r i p p e d i n 1961 t h e r e has been coloniza t ion by Ipomoea, Euphorbia and o the r p l a n t s . South Water Cay (ARB 95, 55-57, Fig. 3 2 ) Post-hurr icane changes a t South Water Cay have been small . The leeward beaches have accre ted s l i g h t l y , and t h e eas t e rn shore has r e t r e a t e d . There has been s l i g h t e ros ion a l s o a t t h e south po in t . The northern p a r t of t h e i s l a n d , with a t h i c k e t of coconuts, su f fe red l i t t l e change i n 1961 a p a r t from shore r e t r e a t . Coconuts, Thrinax and Coccoloba were t h r i v i n g he re i n 1965, with Wedelia, Ipomoea, Bat is maritima, Euphorbia, and Sesuvium. In t h e cen te r of t h e cay, where l a rge houses and pa ths f lanked wi th Hibiscus were formerly maintained, t h e su r face i s now covered with Euphorbia, Ipomoea, S tachytarpheta , Ambrosia and Cassytha, with a few Coccoloba t r e e s and some Hymenocallis. Along t h e eroding e a s t e r n shore t h e r e i s some bushy Bor r i ch ia with much Cassytha, a few Tournefor t ia s eed l ings , and a ground cover of Sesuvium, Ipomoea, Euphorbia and Sporobolus. On t h e southern p a r t of t h e i s l a n d , many young coconuts were p lanted a f t e r the hu r r i cane , and i n 1965 some were 10-15 f e e t t a l l . Two small Casuarina survived on t h e lagoon shore . One o r two Rhizophora a re a l i v e on the e a s t shore but t h e r e a re very few seed l ings . E f f e c t s of t h e hurr icane a r e no longer obvious. Though many houses were damaged i n 1961, new ones have been b u i l t , inc luding two a t t h e no r th p o i n t , and a s u b s t a n t i a l bu i ld ing has been e rec t ed nea r t h e south end by a Belize nunnery. A new j e t t y has been b u i l t f o r t h i s i n t h e west bay. Carr ie Bow Cay (ARB 95, 57-58, Fig. 3 3 ) This i s l a n d , used as a p r i v a t e hol iday r e s o r t , was covered with coconuts i n 1960. Morphologic changes were s l i g h t during t h e storm, many coconuts s t i l l s tood, and Euphorbia formed a patchy su r face cover i n 1962. By 1965 a number of small coconuts had been p lanted t o r ep lace those destroyed, and low Tournefor t ia bushes were growing along t h e northern h a l f of t h e seaward shore . Ground cover included Euphorbia. Ipomoea, Sesuvium and g ras ses , but i s c l e a r l y o f t e n modified by man. Bugle Cay (ARB 95, 67-68, Fig. 43) Bugle Cay i s a mangrove i s l a n d with a small low sandy a rea a t i t s west end, c l ea red and p lanted with coconuts. This sandy a rea s u f f e r e d considerable marginal e ros ion and su r face sand s t r i p p i n g during t h e hurr icane; many coconuts s tood, bu t t h e ad jacent mangrove was much broken and d e f o l i a t e d . Coconuts p lanted s i n c e t h e storm were 2 - 3 f e e t t a l l i n 1965. The a rea between t h e sand r idge and t h e mangrove, c l ea red by man before t h e storm, i s now being colonized by Sesuvium and Bat i s maritima. There i s a small patch of Sesuvium a t t h e northern en- t h e sand r idge , with Ba t i s , Euphorbia and Cyperus, but t h e r e s t of t h e su r face i s kept a r t i f i c i a l l y c l ea red . A s u b s t a n t i a l hurr icane-proof concrete house has been b u i l t f o r t h e l ighthouse keeper s i n c e t h e storm. Sc ip io Cay (ARB 95, 66-67, Fig. 42) Figure 9 Sc ip io Cay i s a low-lying, sandy i s l a n d , covered with coconuts, with a l a rge c e n t r a l Avicennia swamp. Beach r idges on t h e e a s t and southeast s i d e s a r e covered with Thrinax. The hurr icane caused cons iderable beach eros ion and c l i f f i n g along t h e e a s t shore , followed by t h e depos i t ion of a r idge of f r e s h sh ingle up t o 20 yards wide and 2 f e e t t h i c k on the scoured s u r f a c e , with a r idge of sh ing le and rubble 10 yards wide and genera l ly l e s s than 3 f e e t high forming a new s h o r e l i n e . This outermost r idge i n 1962 was discontinuous and a l s o enclosed a l a rge pool a t t h e south po in t ; it was unvegetated. By 1965 t h i s f r e s h sh ingle r idge had been pushed landward and undergone minor changes i n o u t l i n e . Near t h e e a s t po in t 50 yards of t h e o u t e r r idge have disappeared, bu t f a r t h e r south gaps have been i n f i l l e d . The main colonizer o f t h e bare sh ing le i s Sesuvium, followed by Sporobolus and Euphorbia. Shrubs a re represented by a s i n g l e Sophora seed l ing . I t seems l i k e l y t h a t t h e r idges w i l l continue t o migrate towards t h e old cay shore , and thus u l t i m a t e l y rep lace t h e zone eroded i n 1961. The wedge of perched sh ing le on t h e o ld cay su r face i s now being colonized by neighboring vege ta t ion . Colson Cay (ARB 95, 67, Fig. 42) Figure 10 Colson Cay i s very s i m i l a r t o Sc ip io , being formed of a pe r iphe ra l coconut-covered sandy a rea and c e n t r a l Avicennia marsh. Much of the southeas tern shore i s covered by Thrinax. As a t Sc ip io , beach r e t r e a t and c l i f f i n g i n 1961 were followed by depos i t ion of a sh ing le wedge, e s p e c i a l l y on t h e e a s t s i d e , and formation of a sh ing le r i d g e of fshore . The r idge i t s e l f was 2 - 2-1/2 f e e t high, and separa ted from t h e under- cu t shore by a low carpe t of s h i n g l e 15-20 yards wide, by c losed pools , o r by open water . Par t of t h e r i d g e , on t h e southeas t shore , was eroding i n 1962. Considerable changes had taken p lace by 1965 i n t h e r idge morphology. The long s p i t a t t h e e a s t poin t had been welded t o t h e shore , enclosing a pool 6-12 inches deep f i l l e d with a lgae . Southwards from t h e e a s t po in t , where e ros ion was noted i n 1962, t h e sh ing le shore- l i n e has r e t r e a t e d 5-10 yards , and i s now c l i f f e d and s t i l l r e t r e a t i n g . North of t h e e a s t p o i n t , however, a new low r idge of f r e s h white sh ing le has been b u i l t aga ins t t h e grey hurr icane r idge of 1961, s o t h a t t h e r e has been a general advance of t h e shore of about 5 yards . Sesuvium i s again t h e main colonizer of t h e s h i n g l e , with some patches of Euphorbia, Sporobolus and Cassytha, and two small Tournefort ia bushes. L i t t l e change was noted i n t h e main cay vegeta t ion; though broken Cordia sebes tena t r e e s were i n f lower. CAYS OF TURNEFFE Pel ican Cay (ARB 95, 72-73, Fig. 44) Figure 11 Pel ican Cay i s a sandy i s l a n d with a t h i c k e t of Cordia sebes tena , Bursera simaruba and Thrinax, and a b e l t of Rhizophora t o leeward. The vegeta t ion was badly damaged dur ing t h e hu r r i cane , when much of t h e su r face sand on the seward s i d e o f t h e cay was eroded ( l eav ing remnants of cemented sh ingle s tanding above t h e new beach l e v e l ) , and f r e s h rubble and sh ing le was deposi ted along t h e margin of the vege ta t ion t h i c k e t . The Rhizophora was completely d e f o l i a t e d during t h e s torm. No morphologic changes were noted i n 1965. The most s t r i k i n g change was t h e co loniza t ion of t h e sh ingle-carpe t a reas by Tournefor t ia gnaphalodes, and t o a l e s s e r ex ten t by Sesuvium. Much of t h e broken Cordia was i n f lower, some of i t being found i n the Bursera a rea . - Ipomoea tuba was conspicuous, climbing on the broken t r e e s and extending out over t h e sh ing le c a r p e t . A s i n g l e seedl ing of Sophora was seen. The osprey nes t seen i n 1962 s t i l l ex i s t ed , and a newly hatched green t u r t l e was seen c lose t o t h e shore i n 1965. Cockroach Cay (ARB 87, 46, Fig. 25; ARB 95, 73-74, Fig. 45) Cockroach Cay i s a sandy i s l a n d , densely covered with coconuts before t h e 1961 hur r i cane . During t h e storm a l l t h e coconuts were removed by overtopping waves, which eroded much of the su r face sand. In e a r l y 1962, t h e su r face on t h e seaward s i d e was formed of bare coconut r o o t s , and t h a t t o leeward of coarse rubble and r o o t s . One o r two Cordia survived, much broken, toge ther with patches of t h e o r i g i n a l t u r f cover; but immediately a f t e r t h e storm t h e only vegeta t ion cons is ted of spa r se Euphorbia, Cyperus and Sesuvium, and one o r two Rhizophora seed l ings . The seaward shore was c l i f f e d , exposing a s o f t i n c i p i e n t sandstone a t t h e northwest end. In 1965 morphologic changes had been minor, though t h e degree of cementation of t h e outcropping rock had increased t o f o n a hard rock ledge 4-6 inches above low water . The densest vegeta t ion i s a t t h e nor th end of t h e cay, with a continuous cover of Ipomoea, Canavalia and Sesuvium. Along the seaward shore t h e r e i s a f r i n g e of Tournefor t ia , Sophora and Suriana bushes, with Sesuvium and Ipomoea, b u t most of t h e cay su r face s t i l l has but a sparse cover of Cyperus, Euphorbia, Ageratum and Canavalia. Broken Cordia stumps a re i n f lower, e s p e c i a l l y along the lagoon shore. On t h e ad jacent Cay V of t h e Cockroach Group, t h e pre-hurr icane vegeta t ion of bushes was l a r g e l y k i l l e d and p a r t l y blanketed by storm sh ing le i n 1961; leeward mangrove was d e f o l i a t e d . In 1965 t h e f r e s h sh ing le was colonized only by a small patch of Sesuvium. In t h e vegeta t ion t h i c k e t Tournefor t ia was most l uxur i an t , forming patches up t o 4 f e e t high and 10 yards i n diameter . Sur iana , Conocarpus and Coccoloba a r e a l s o p r e s e n t , wi th a ground cover of Euphorbia and Cyperus. About h a l f of t h e leeward Rhizophora i s a l i v e . S o l d i e r Cay (ARB 87, 43-44, Fig. 21-23; ARB 95, 74-76, Fig. 46) The coconut-covered sandy i s l a n d of S o l d i e r Cay was s t r i p p e d of a l l vegeta t ion by Hurricane H a t t i e and transformed i n t o an eroded su r face , with exposed coconut r o o t s , f lanked by a wide sh ing le carpe t on t h e l e e s i d e and a narrow r i d g e on the seaward s i d e . Four coconuts only survived t h e storm, and i n 1962 t h e r e was a sparse and patchy growth of Sporobolus, Cyperus, Ageratum and Por tu laca . In 1965 vegeta- t i o n on t h e o ld cay su r face was s t i l l spa r se . Much was s t i l l ba re , with patches of Ipomoea, a g ra s s (probably Sporobolus), Cyperus and Ageratum. Along t h e seaward margin of the o ld cay, overlooking t h e hurr icane sh ing le , t h e r e i s a shrub zone dominated by ~ o u r n e f o r t i a , t o g e t h e r w i t l l Suriana l e s s than 3 f e e t h igh , and a g r o ; n d e s u v i u m sureadinn out onto t h e s h i n e l e . Veeetation is more extens ive on t h e - " - leeward sh ingle a rea , with a 50 per cent cover of Sesuvium, Euphorbia, Cyperus, Ipomoea and Wedelia, two clumps of Tournefor t ia and two of Suriana, and a s i n g l e Sophora i n f lower, 3 f e e t t a l l . There i s a l s o a small patch of very f leshy Sesuvium on the sh ingle bar o r i s l e t e a s t of the cay. Conocarpus, Avicennia and Coccoloba survived on t h e main i s l a n d from before the storm. Morphologic changes s ince 1962 have been l imi t ed t o s l i g h t shore l ine r e t r e a t around the leeward sh ing le a r e a and some changes i n the shape of detached sh ingle i s l e t s . L i t t l e Calabash Cay (ARB 87, 44, Fig. 19; ARB 95, 76-77, Fig. 47) Figure 12 L i t t l e Calabash Cay was formerly the cen te r of the Turneffe copra indus t ry , with houses, a j e t t y , and coconut palms. A l l human i n s t a l - l a t i o n s were destroyed during the hur r i cane , and so were a l l t h e coconuts. Considerable sur face and marginal erosion reduced t h e s i z e of t h e i s l a n d , and i n 1962 the su r face was low-lying, with exposed r o o t s and two brackish pools . A la rge f r e s h sandspi t b u i l t up a t t h e north- e a s t end of the cay following t h e storm. In 1962 the only vegeta t ion was a s c a t t e r of Ageratum, Wedelia, Cakile and grasses over the o ld land area . By 1965 minor shore l ine adjustments had taken p lace , with some sediment acc re t ion a t t he southern end. The pools had disappeared, and t h e sur face was covered with patches o f grasses and herbs. Two areas of Sesuvium, an a rea of g ras s , and a l a rge area of Batis maritima on t h e s i t e of the l a r g e s t pool were d i s t i n c t i v e . In addi t ion t h e r e i s a mixed a rea of Ageratum, Euphorbia and Wedelia. Shrubs a re represented by two bushes of Borrichia arborescens, seedlings of Tournefort ia and Suriana, and low Conocarpus. The number of species present has thus increased from not l e s s than 4 t o not l e s s than 10 i n t h r e e years . A small hut has been b u i l t on the i s l a n d , and na tu ra l regenerat ion of the vegeta t ion w i l l thus not take p lace . Big Calabash Cay (ARB 87, 42, Fig. 20; ARB 95, 77-78, Fig. 48) Before the hurr icane the vegeta t ion of Big Calabash resembled t h a t of L i t t l e Calabash, being dominated by coconuts with a ground cover of grasses and herbs, but the i s l a n d was much l a rge r and hurr icane damage was t h e r e f o r e l e s s in t ense . Though the shore l ine r e t r e a t e d and t h e r e was some scouring and channel-cut t ing by overtopping water , much of the o r i g i n a l t u r f e d surface survived, though almost a l l t he coconuts, and t h e Rhizophora seedl ings between it and the adjacent small i s l a n d , were swept away. In 1965 t h e r e was a 90 pe r cent ground cover of coarse g ras ses , a l l s t e r i l e , together with Ageratum, Batis maritima and Euphorbia. The southern end of t h e i s l a n d has a f r inge of shore l ine Borr ichia , some Conocarpus, and a mat of Sporobolus, and elsewhere t h e r e a r e some Borrichia and young newly-planted coconuts. On t h e seaward shore a new Rhizophora has grown t o a height of 3 f e e t . A small house has been b u i l t on t h e cay by a r e s iden t fisherman. On the adjaccnt i s l a n d (East Cay I) t h e r e is a ground cover of Sesuvium and Euphorbia and a number of Borrichia bushes. The pre- hurr icane Rhizophora i s a l l dead. East Cay I1 now cons i s t s only of dead shrubs and rubble. Deadman I (ARB 87, 37-38, Fig. 16; ARB 95, 79-80, Fig. 49) The post-hurr icane su r face of Deadman I cons is ted of bare r o o t s and f r e s h sh ingle , and an i n c i p i e n t "promenade" of cay sandstone was exposed by beach r e t r e a t on t h e south and e a s t shores. A few sp ide r - l i l i e s (Hymenocallis) survived a t t h e eas t e rn end, with some Borr ich ia bushes, a patch of Sesuvium, and sparse Euphorbia, Ageratum and Cyperus. By 1965 t h e inc ipent promenade a t t h e e a s t end had disappeared through e ros ion , but t h a t along t h e south shore was more s t rong ly l i t h i f i e d . The northern r idge of hurr icane sh ing le had been eroded s l i g h t l y , but otherwise t h e r e were no morphologic changes. In t h e a rea of s t r i p p e d r o o t s , ground vegeta t ion cover was s t i l l patchy: spec ie s p re sen t included Ageratum, Euphorbia, Sesuvium, Ernodea, Wedelia, Cyperus, and Echi tes umbellata. Much of t h e sh ing le was ba re , except f o r a few small pp Borr ich ia and Tournefort ia bushes and some Hymenocallis. Two coconuts P a r e s t i l l a l i v e , and two Thrinax; t h e o l d Avicennia a t t h e e a s t end s t i l l has some leaves . A s i n g l e seed l ing of Sophora was noted. Deadman I1 (ARB 87, 38, Fig. 16; ARB 95, 80, Fig. 50) A t Deadman I1 t h e hurr icane k i l l e d most of t h e vegeta t ion t h i c k e t and deoosi ted a c a r ~ e t of s h i n e l e over t h e seaward s i d e of t h e cay. - Beach r e t r e a t a l s o exposed an i n c i p i e n t promenade. Borr ich ia , Hymenocallis, Ageratum, Sesuvium and Sporobolus were noted i n 1962. In 1965 much of the i n c i p i e n t promenade had gone, p a r t i c u l a r l y i n t h e south, though t h e rock which-remained was more strongl; l i t h i f i e d . . On t h e f r e s h sh ing le a rea the re a r e pa tches of Tournefort ia , Conocarpus, Borr ich ia , Hymenocallis, Euphorbia and Sesuvium. In the t h i c k e t area t h e r e i s a 100 per cent ground cover of Ageratum and Euphorbia, with Conocarpus along t h e west shore , and some Thrinax 3-4 f e e t t a l l . O f four coconuts which survived t h e storm, one was f r u i t i n g . Deadman IV (ARB 87, 39, Fig. 17; ARB 95, 81, Fig. 51) Deadman IV c lose ly resembles Deadman I 1 i n both pre- and pos t -hurr icane c h a r a c t e r i s t i c s . The f r e sh sh ingle had i n 1965 been colonized by a b e l t of Tournefor t ia , with a s i n g l e Suriana, and a ground cover of Sporobolus, Euphorbia and Ipomoea. New Thrinax had reached h e i ~ h t s of 2-4 f e e t . In t h e t h i c k e t a rea t h e r e i s a cover of grasses , ~ u i h o r b i a and Ageratum, with some Borrichia, and small Rhizophora along t h e west shore . Four of n ine coconuts which survived t h e storm were f r u i t i n g . Deadman V (ARB 87, 39-40, Fig. 18; ARB 95, 81, Fig. 52) Af t e r the hurr icane , Deadman V cons is ted of a western s e c t o r of d e f o l i a t e d mangrove, and an e a s t e r n s e c t o r of sand formerly covered with coconuts, and i n 1962 p a r t l y covered with Euphorbia and Sporobolus and p a r t l y ba re . By 1965 t h e Euphorbia and Sporobolus had colonized much of t h e bare a rea , and s e v e r a l patches of Sesuvium had appeared. There a r e s i n g l e bushes of Borr ich ia and Suriana. Four coconuts were s t i l l a l i v e . Most of the mangrove i s dead, but seedl ings of Rhizophora a r e numerous i n shoal water south of t h e cay. CAYS OF LIGHTHOUSE REEF Sandbore Cay (ARB 87, 56-58, Fig. 28; ARB 95, 89-91, Fig. 56) Figure 13 Sandbore Cay a t t h e nor th end of Lighthouse Reef i s an i s l a n d of complex geometry much a l t e r e d by I-lurricane H a t t i e . Before t h e hurr icane i t cons is ted of t h r e e s p i t s of unequal s i z e extending leeward from a sandy seaward beach, which had i t s e l f been r e t r e a t i n g westwards (lagoon- ward) f o r some decades. The i s l a n d had a dense vegeta t ion of coconuts, shrubs, herbs and g ras ses . During t h e hurr icane t h e two nor thern s p i t s were cu t o f f from t h e r e s t of the cay by a channel 65 yards wide, and the southern s p i t was cu t i n t o two p a r t s by a channel 50 yards wide. The f i rst channel had f i l l e d with f r e s h sediment by e a r l y 1962, bu t t h e o the r remained open, t h e former shore l ines being marked by l i n e s of beachrock. The scoured cay su r face r e t a ined only a few patches of grasses and Euphorbia a t t h e e a s t e r n end; but on t h e l a r g e r nor thern s p i t coconuts, Coccoloba and Conocarpus s t i l l s tood . Most o f t h e shore l ine Tournefor t ia and Suriana had been swept away, but t h e ground su r face in land was p a t c h i l y covered with Sporobolus, Cakile , Euphorbia and Ambrosia. Ipomoea appeared t o have dec l ined i n abundance, Cenchrus t o have increased . Tournefor t ia s eed l ings were noted along the northwest shore i n May 1962. Considerable changes had taken p lace i n morphology and vegeta t ion by 1965. The leeward sandsp i t s had a l t e r e d p o s i t i o n ; the no r theas t shore had continued t o r e t r e a t , exposing f r e s h beachrock; but the main change was t h e growth of a sandbar across t h e narrow ent rance t o t h e bay between t h e nor thern and southern s p i t s . This b a r i s 1 foot high and 35 yards wide, s t i l l unvegetated i n i t s c e n t r a l p a r t . The body of water thus enclosed i s orange-brown i n c o l o r and s t agnan t , with fou l - smell ing margins. The main p a r t of Sandbore i s thus e f f e c t i v e l y a s i n g l e i s l a n d with an i n t e r i o r pool . The gap between t h i s main i s l a n d and t h e r e l i c of t h e southern s p i t i s s t i l l 2-3 f e e t deep and kept open by vigorous water movement; t h e beachrock i n t h e gap is densely covered with Diadema. On t h e main i s l a n d it i s convenient t o d iscuss vege ta t ion changes i n terms of (a) t h e southern s p i t and eas t e rn end, and (b) t h e l a rge northern s p i t . In 1962 t h e southern s p i t and e a s t end of Sandbore had a su r face of bare r o o t s , t h i n l y covered with rubble , and with l i t t l e vegeta t ion except f o r grasses and Euphorbia. I t i s now covered with a dense growth of Ipomoea, Euphorbia and g ras ses , with a t t h e e a s t end areas of Ambrosia and Sesuviwn. There a r e seve ra l Tournefor t ia bushes up t o 3 f e e t t a l l , and Sophora tomentosa 18 inches t a l l . The neck of sand f i l l i n g the nor thern channel has been colonized by g ras ses , Ipomoea, Suriana and Cassytha, with some small Tournefor t ia . The dens i ty of vegeta t ion on t h e nor thern s p i t v a r i e s cons iderably . Patches of Coccoloba and Conocarpus which survived the storm on t h e margins of t h e i n t e r i o r pool a r e now t h r i v i n g . Over t h e r e s t of t h e a rea , vege ta t ion is s t i l l sparse where sand was s t r i p p e d and coconut r o o t s were exposed, bu t i s more luxur ian t where o r i g i n a l pre-hurr icane vege ta t ion maintained a ground cover and s o i l was not l o s t . S u p e r f i c i a l scour channels a r e s t i l l v i s i b l e i n t h e s tr iowed a r e a s . Most of the northern s n i t i s L . covered with an assemblage of Ambrosia h i sp ida , Ernodea l i t t o r a l i s , Ageratum maritimum, Euphorbia s p . , and grasses ( including Sporobolus). There a r e s e v e r a l Borr ichia bushes, and, along the northwest shore , patches of Tournefor t ia up t o 6 f e e t i n diameter and 18 inches t a l l . The sandspi t a t t h e west end i s being colonized by Ipomoea, Euphorbia, Cenchrus t r i b u l o i d e s , Sporobolus and Tournefor t ia . The remnant of t h e southern s p i t has a dense vegeta t ion of Borr ich ia , Suriana, Tournefor t ia and Sophora, with a ground l aye r of Ipomoea, Wedelia, Canavalia, Ambrosia and Ernodea. A new l ighthouse has been b u i l t on t h e nor th s p i t t o rep lace t h a t destroyed i n Hurricane H a t t i e , t oge the r with a j e t t y on the l ee s i d e . The l i g h t i s automatic , and t h e r e i s no provision f o r a r e s i d e n t keeper . 'The remains of t h e "hurricane-proof" house destroyed i n 1961 s t i l l s t and near t h e e a s t p o i n t . Northern Cay (ARB 87, 58-62, Fig. 29; ARB 95, 92-94, Fig. 57) Figure 14 Post-hurr icane changes a t Northern Cay a r e only considerable a t t h e nor theas t p o i n t . This was cu t back 120 yards by t h e storm, but by 1965 had b u i l t out again a t l e a s t 80 yards . The su r face of t h i s new s p i t , t oge the r with t h e bare a rea formed by t h e storm, i s a source of blowing sand which has accumulated a t t h e edge of the vegeta t ion cover, around bushes and g r a s s tussocks , t o form dunes seve ra l f e e t high. The bare nearshore a reas a re being colonized by Suriana, ~ o u r n e f o k i a and Borr ich ia , with Sporobolus and Euphorbia. Along t h e e a s t coas t , much b a t t e r e d Coccoloba i s s t i l l a l i v e , and Pithecellobium i s d i s t i n c t i v e . In land , t h e r e has been no in t e r f e rence with vece ta t ion s ince t h e storm. as t h e cay i s no longer inhabi ted , and t h e r e Ts a dense growth of shrubby vegeta t ion , with Conocarpus up t o 10 f e e t t a l l , Thrinax, Coccoloba, and some new coconuts. Ernodea l i t t o r a l i s i s p r o l i f i c on the ground. Half Moon Cay (ARB 87, 64-77, F igs . 30-34; ARB 95, 94-98, Figs. 58-59) A t Half Moon Cay the t h r e e main vegeta t ion types a re (a) Cordia-Bursera woodland, (b) coconuts with ground vegeta t ion , and (c) coconuts with no ground vege ta t ion . During the hurr icane t h e Cordia- Bursera woodland along the southeas t s i d e of t h e cay was much damaged, e s p e c i a l l y near t h e shore . To t h e nor th of t h i s , in t h e a rea of uncleared ground vege ta t ion , many coconuts were f e l l e d by t h e storm. On t h e e a s t e r n p a r t of t h e cay, with no ground vegeta t ion , few coconuts were f e l l e d , but a Tournefort ia hedge disappeared a t the e a s t po in t . Since t h e hu r r i cane , f a l l e n t runks have been c l ea red from t h e e a s t end of t h e cay and young coconuts p lanted t h e r e and a t t h e south po in t . Shrubs have colonized much of the shore a t t h e e a s t point and on t h e western h a l f of t h e cay. A t the e a s t e r n end t h e r e a re seve ra l Tournefor t ia l e s s than 1 foot h igh , with a l i t t o r a l f r inge of Wedelia, Euphorbia, Sesuvium and grasses . Tournefor t ia , with Sporobolus and Euphorbia, i s found pa tch i ly along t h e southeas t shore and forms a t a l l hedge a t the south po in t . Along t h e nor th shore Sesuvium forms a carpe t 1 -2 yards wide, with some Euphorbia and g ras ses ; immediately in land t h e r e is a s t r i p p e d zone with spa r se r vegeta t ion , and then t h e o ld cay su r face , with a dense growth of Hymenocallis, Wedelia, S tachytarpheta , Euphorbia, Cyperus and g ras ses . Near t h e shore t h e r e a re a few Tournefor t ia bushes up t o 3 f e e t t a l l . Sesuvium and Canavalia, with Tournefor t ia bushes, blanket t h e low ground a t t h e e a s t end of t h e i s l a n d . Along t h e south shore , where r e t r e a t of t h e Cordia-Bursera t h i c k e t was g r e a t e s t , changes have been considerable. Bursera broken by the storm is genera l ly dead, but Cordia has usual ly surv ived , even when phys ica l ly badly damaged, and t h e f r i g a t e s and boobies were nes t ing normally i n t h i s woodland i n Apr i l 1965. The ou te r margin of t h e wood- land i s i r r e g u l a r , and a f t e r the hurr icane the re was a zone of f r e s h sand, sh ingle and rubble 20-30 yards wide along t h e whole shore. Curiously t h i s zone i n 1965 was almost bare of grasses and o the r ground- l a y e r p l a n t s , except f o r a l i t t l e Cyperus and Sporobolus and occasional I r e s i n e d i f f u s a with ho r i zon ta l r o o t s up t o 5 f e e t long, bu t t h e r e i s an approximately 50 per cent cover of Tournefor t ia gnaphalodes, i n patches 2-3 f e e t high and 10 yards i n diameter. This i s t h e most luxu- r i a n t growth of pioneer Tournefor t ia seen on these r e e f s . The damaged l ighthouse was r epa i r ed i n 1963, and a new hurr icane-proof house e rec t ed nearby. Long Cay (ARB 87, 77-81, Fig. 35; ARB 95, 98-99) No morphologic changes were noted a t Long Cay i n 1965. On t h e e a s t e r n r idge no new coconuts had been p lanted , though t h e r e had been some n a t u r a l regenera t ion . There i s a patchy cover of Euphorbia, Wedelia, sedges, and grasses (Sporobolus v i r g i n i c u s , E rag ros t i s dominguensis), with much Ernodea l i t t o r a l i s . Conyza canadensis v. p u s i l l a was c o l l e c t e d he re f o r t h e f i r s t t ime. Tournefor t ia i s found occas ional ly along t h e shore , with some Suriana. There i s su r - p r i s i n g l y l i t t l e Borr ich ia , and only occasional Sophora tomentosa. Lantana invo luc ra t a was a l s o c o l l e c t e d . In t h e nor thern sandy a r e a , vegeta t ion i s dense and tangled with many f a l l e n t runks . Wedelia, Stachytarpheta, Suriana and Ernodea a r e conspicuous; and o t h e r p l a n t s seen include Sophora, Borr ich ia , Tournefor t ia , Euphorbia, Cassytha, Ageratum, Ambrosia and Cordia. The i s l a n d i s again permanently occupi and i n 1965 a l i g h t a i rp l ane s t r i p was being c l ea red with power-saws near t h e southern margin of t h e nor thern sand a rea . GEOMORPHIC CHANGES ON THE CAYS Following the 1962 survey, four zones of hurr icane damage on cays were d i s t ingu i shed (Figure 1 ) : (1) a zone of maximum damage 15-20 miles nor th and south o f t h e storm t r a c k , with most i n t ense winds and maximum storm surge, i n which small cays disappeared, o the r s were s t r i p p e d of vegeta t ion and underwent su r face sand-s t r ipping , beach- re t r ea t and channel-cut t ing, and mangroves were completely d e f o l i a t e d ; (2) a second zone 15 miles wide, nor th and south of zone 1, s u b j e c t t o considerable wave and wind ac t ion but without a pronounced storm surge , i n which t h e main physiographic changes were l imi t ed t o beach r e t r e a t and rlearshore eros ion and depos i t ion , and i n which vegeta t ion changes were small a p a r t from d e f o l i a t i o n of mangroves i n more exposed loca t ions and f e l l i n g of coconuts by wind; (3) a zone i n t h e b a r r i e r r e e f lagoon 30-40 miles south of t h e storm t r a c k , where vegeta t ion changes and eros ional e f f e c t s were small , bu t where ba r s of sand and sh ingle were deposi ted on t h e south and e a s t s i d e s of cays; (4) t h e zone of no damage, which on t h e south s i d e l i e s not l e s s than 40 miles from t h e storm t r a c k . Changes i n t h e per iod 1962-1965 a r e b e s t summarized i n terms of morphologic types i d e n t i f i e d i n 1962, which roughly correspond t o these zones, arranged from t h e zone of maximum t o t h a t of l e a s t damage. Types of adjustment 1. None of the sand cays which disappeared during Hurricane H a t t i e (S t . George's Eas t , Paunch, Glory, Bokel, Saddle) had reappeared i n 1965. 2 . The vegetated sand cays reduced t o sandbores (Sergeant ' s , Gof f ' s ) continue t o change i n form and loca t ion , p a r t l y s t a b i l i z e d by t h e remains of pre-storm root-bound su r faces . The new i s l a n d s a r e genera l ly s l i g h t l y smal le r than those before t h e storm. 3. Vegetated sand cays i n Zone I s t r i p p e d of vegeta t ion and s u b j e c t t o marginal and s u p e r f i c i a l e ros ion (Big and L i t t l e Calabash, Sandbore, Cockroach, English, Rendezvous) genera l ly show only minor geomorphic changes, though i n most cases t h e r e t r e a t of windward shores is cont in- uing, p a r t i c u l a r l y a t Rendezvous. Features above high water a r e unchanged, though channels cu t through former land su r faces have i n some cases shoaled o r f i l l e d (S t . George's, Sandbore). 4. Vegetated sand cays i n Zones I and I1 with major vege ta t iona l but minor geomorphic damage i n 1961 (Half Moon, Tobacco, South Water) have undergone only s l i g h t sho re l ine readjustments , e i t h e r of beach r e t r e a t o r of s p i t aggradat ion. A t Northern Cay small dunes have been formed by t h e Trades blowing over a r ecen t ly developed and unvegetated sandsp i t . 5 . Cays of Zone I11 with pe r iphe ra l sh ing le depos i t s have undergone adjustments i n form of the hurr icane-deposi ted sh ingle ba r s and s p i t s , which have migrated landward (Scipio, Colson). No morpho- log ic changes have taken p lace on t h e s t r i p p e d marginal su r faces of t h e cays themselves. 6 . On t h e l a r g e r mangrove-sand cays of Zones I and I1 (Caulker, Chapel, Big Cay Bokel, Northern Cay), where damage was l imi t ed i n 1961 by t h e s i z e of t h e i s l a n d , the changes r e s u l t i n g from t h e hurr icane , such as nearshore su r face scouring and channel-cut t ing, above high water , have remained una l t e red . Shorel ine changes a r e l e s s marked than on simple sand cays. Comment I t i s c l e a r from t h e 1965 survey t h a t pos t -hurr icane changes have been neg l ig ib l e above high water mark on the cays: on s t r i p p e d su r faces , of ten s c a t t e r e d with hurr icane rubble , no subsequent accumulation of sand has taken p lace , and no marked s o i l formation on newly exposed s u r f a c e s , while accumulations of hurr icane-deposi ted sand and sh ing le beyond t h e l i m i t of wave a c t i o n remain unal te red . On cay margins changes have been more marked, though gene ra l ly minor. The evidence of continued r e t r e a t of windward beaches, reaching a maximum r a t e o f 9-15 f ee t /yea r a t Rendezvous Cay, and of t h e f a i l u r e of cays destroyed t o reappear , suggests t h a t t h e d e s t r u c t i o n of r e e f c o r a l s i n Zones I and I1 e f f e c t i v e l y allows l a r g e r waves access t o r ee f f l a t s and beaches. Increased eros ion may thus continue u n t i l the r e e f s recover , and i n t h e case of narrow i s l ands such as Rendezvous t h i s could lead t o t h e delayed disappearance of cays as a secondary r e s u l t of t h e hu r r i cane . Shingle b a r s on r ee f f l a t s , while not widespread, have been pushed landward, and i n some cases combed out t o form sh ing le f l a t s ; s i m i l a r adjustments of r e e f f l a t sh ingle b a r s have been noted i n pos t -hurr icane surveys a t J a l u i t Atol l (Blumenstock and o the r s 1961). Exposures of p a r t l y l i t h i f i e d rocks revealed by Hurricane H a t t i e i n most cases survived i n 1965. These include beachrock, promenades of cay sandstone, fragments of a probably phosphat ic conglomerate well above s e a l e v e l on Half Moon Cay and Pel ican Cay, and a high-standing cay sandstone on Cay Chapel. In a l l cases t h e degree of l i t h i f i c a t i o n i s g r e a t e r than i n 1962, e s p e c i a l l y on t h e su r face , suggest ing t h a t t h e i n c i p i e n t bonding below t h e ground which leads t o t h e su rv iva l o f t h e bonded ma te r i a l t o form topographic f e a t u r e s has been followed by a secondary subae r i a l o r i n some cases i n t e r t i d a l cementation process . The ledges of cay sandstone a t Big Cay Bokel a r e of s p e c i a l i n t e r e s t , f o r t h e f r i a b l e r o o t - f i l l e d s o f t sandstone of 1962 i s now a compact rock s i m i l a r t o t h a t long exposed elsewhere on t h e Turneffe e a s t e r n sand r i d g e ; t h e coconut roo t s pene t r a t ing t h e rock i n 1962 have now r o t t e d and a r e disappearing. These exposures c l e a r l y demonstrate t h a t l i t h i f i - ca t ion i s a contemporary process capable of forming rock ledges above p resen t s ea - l eve l without any n e c e s s i t y f o r s ea - l eve l change. VEGETATION CHANGES ON THE CAYS The minor na ture 3i geomorphic changes on t h e cays and of r e e f growth i s i n con t ra s t with t h e cons iderable and rapid vegeta t ion changes which have taken p lace i n t h e 3-1/2 yea r s s ince Hurricane H a t t i e . These vege ta t ion changes have not , however, been uniform i n na ture o r r a t e , and may be conveniently d iscussed i n terms of t h e co loniza t ion of d i f - f e r e n t s u b s t r a t e s prepared by t h e hurr icane , and t h e recovery of d i f f e r e n t vege ta t ion types following the storm. Colonizat ion 1. Primary coloniza t ion o f bare i s l a n d s . The four cays of Se rgean t ' s , Gof f ' s , English and Rendezvous on t h e nor thern b a r r i e r r e e f l o s t a l l vegetat ion. a p a r t from broken t r e e stumps during Hurricane Ha t t i e . By e a r l y 1962 Por tu laca o leracea was t h e ch ie f co lon ize r of t h e i r bare s u r f a c e s , i n p laces s t i l l p a r t l y bound by r o o t s , and Euphorbia mesembrianthemifolia and Sesuvium portulacastrum were a l s o p resen t . The t h r e e most damaged cays had 4, 1 and 2 spec ie s o f p l a n t s growing on them f i v e months a f t e r t h e storm; 3-1/2 years af terwards t h e numbers had increased t o 13, 5 and 5, r e spec t ive ly . A t Rendezvous, where more o f t h e o r i g i n a l bound su r face survived, t h e number of spec ie s increased from 13 t o 16 i n the same per iod . Of these colonizing spec ie s , t h r e e were common t o a t l e a s t t h r e e of t h e fou r i s l a n d s i n 1965: Sesuvium, Euphorbia and Ipomoea; Cocos was found on t h r e e i s l a n d s but had been a r t i f i c i a l l y p lanted . The formerly dominant Por tu laca was found on two i s l a n d s but was not conspicuous. Other spec ie s found on two out of fou r i s l a n d s were Wedelia, Cakile , seedl ings of Tournefor t ia and Suriana, and r e l i c t Coccoloba. A t l e a s t 11 o the r soec ie s occurred on onlv one of t h e i s l a n d s : t h i s d ive r se erouo includes " . Ageratum, Euphorbia b l o d g e t t i i , Ernodea l i t t o r a l i s , Bat i s maritima, Philoxerus vermicular i s , Cyperus s p . , Sporobolus s p . , Eustoma e x a l t a t a , Conocarpus e r e c t a , and Casuarina e q u i s e t i f o l i a . On t h e more badly damaged i s l ands t h e pioneers of 1962 were of ten absent i n 1965: thus a t Se rgean t ' s Cay thEee spec ie s out of four i n 1962 were absent i n 1965 (Portulaca o l e racea , Sesu\ri~un portulacastrum, Rhizophora mangle); and - -- - a t Goff ' s Cay t h e s i n g l e spec ie s present i n 1962 (Por tu laca - oleracea) was not seen i n 1965. The g r e a t e r s t a b i l i t y of su-~endezvous Cay, which was s t r ipped of vege ta t ion and heavi ly eroded without being destroyed, i s r e f l e c t e d both i n t h e l a r g e r number of spec ie s present i n 1962 and i n t h e small changes and low r a t e of e x t i n c t i o n between 1962 and 1965. 2 . Colonization of sandy shores and sand r idges . Fresh sand r idges were lodged on the windward shores of s e v e r a l cays during 'iurricane H a t t i e , p a r t i c u l a r l y on Tobacco and South Water Cays, and f r e s h sand beaches were prepared f o r p l an t co loniza t ion a t Sandbore and Half Moon Cays. A t Tobacco Cay t h e new sand r idge had been colonized within f i v e months by an almost complete cover o f Ipomoea. In 1965 Tournefor t ia , Sporobolus and ~ u ~ h o r b i a were found i n a l l four cases mentioned; Ipomoea and Sesuvium i n t h r e e . The bushes . - of Tournefor t ia var ied up t o 3 f e e t i n height and 6 f e e t i n diameter . Other p l a n t s l e s s t y p i c a l of t h i s h a b i t a t but found i n a t l e a s t one of th? :as.ie.i wcrc iophori to:iientosa, U o r r i ~ l ~ i a 3 r b ~ r ~ ~ s : e n s , icedelia - - -- -- . t i 1 .- C.1.i.iytl1.i f i l i fo r~: i i s and Cenchrus t r i h u l o i d c s . -- - ---- 3. Colonizat ion of sh ingle ba r s . Shingle ba r s b u i l t by t h e hu r r i cane a re r a r e except on t h e cays of t h e c e n t r a l b a r r i e r r e e f lagoon, such as Sc ip io and Colson; small ba r s a r e found c lose t o some l a r g e r i s l ands , such as t h a t near So ld ie r Cay. In 1965 t h e main co lon ize r i n each of these t h r e e cases was Sesuvium portulacastrum, with sma l l e r patches of Sporobolus and Euphorbia i n two cases . Seedlings of Sophora and Tournefort ia were each found on one of t h e i s l a n d s , and Cassytha was seen on t h e Colson r idge . The amount of growth on sh ing le ba r s has been much l e s s than on sand r i d g e s . - - probably as a r e s u l t of the g r e a t e r permeabil i ty and a l s o mobi l i ty of t h e former. Ipomoea was not found i n t h i s h a b i t a t , nor were t h e herbs c h a r a c t e r i s t i c of cay su r faces under woodland. 4. Colonization of rubble and sh ing le spreads . Carpets of coarse sediments deposi ted by t h e hu r r i cane were formed on seve ra l of t h e Turneffe cays (Pe l ican , Cockroach V , So ld ie r , Deadman 11, Deadman IV) and a t Half Moon Cay, e i t h e r banked aga ins t vegeta t ion o r i n leeward l o c a t i o n s . Tournefor t ia gnaphalodes was found i n 1965 colonizine t h i s h a b i t a t on a l l t h e i s l a n d s l i s t e d , forming bushes 2-4 - - f e e t high and up t o 30 f e e t i n diameter . Sesuvium portulacastrum was found i n four cases , Euphorbia i n t h r e e , and Sophora, Ipomoea, Cyperus, Sporobolus and Suriana i n two. S ix o t h e r spec ie s were a l s o seen, none of them common, and some, such as Hymenocallis, surv iv ing from t h e pre-hurr icane vege ta t ion under a t h i n carpe t of rubble . 5 . Colonization of s t r i p p e d su r faces . The most common pioneer h a b i t a t prepared by Hurricane H a t t i e was t h e sur face s t r i p p e d of vegeta t ion and s u p e r f i c i a l sediments, covered with exposed r o o t s , p a r t i c u l a r l y of coconuts, and l i g h t l y s c a t t e r e d with co ra l rubble . Because of the l o s s of s o i l , co loniza t ion of these s t r i p p e d su r faces has been much slower than on cons t ruc t iona l su r faces , and i n 1965 many were s t i l l conspicuously b a r e . Regrowth was g r e a t e s t where s t r i p p i n g had been l e a s t severe and where some of t h e pre-storm su r face and vege ta t ion surv ived . S t r ipp ing and coloniza t ion were noted on twelve sandy i s l a n d s (Ambergris, Caulker, Chapel, S t . George's, Big and L i t t l e Calabash, East I , Deadman I , Deadman V , Sandbore, Northern and Long Cays) and t h r e e sh ing le i s l a n d s (Cockroach, So ld ie r , Half Moon). Direct comparison i s d i f f i c u l t because of t h e d i f f e rences i n exposure and degree of s t r i p p i n g (varying from complete t o narrow marginal s t r i p p i n g ) , bu t t h e colonizing spec ie s a re d i s t i n c t from those of o t h e r h a b i t a t s . The most widespread colonizers i n 1965 were Euphorbia (2. mesembrianthemifolia, a l s o E . b l o d g e t t i i ) , seen on 12 of t h e 15 i s l a n d s o u r n e f o F t i a gnaphalodes , found on 10. The bushes of Tournefor t ia vary i n he ight from 1-3 f e e t and i n diameter up t o 30 f e e t . wi th t h e i r g r e a t e s t develooment on Half Moon Cay. Other - shrubs present were Borr ich ia arborescens, up t o 6 f e e t t a l l , on 8 cays; Suriana maritima, up t o 6 f e e t t a l l , on 7 cays; and Conocarpus e r e c t a and Sophora tomentosa, each on th ree cays but only as s c a t t e r e d i n d i - v idua l s . Borr ich ia i s most c h a r a c t e r i s t i c of sandy i s l a n d s on t h e a t o l l s r a t h e r than t h e b a r r i e r r e e f . Ground-laver soec ie s o re sen t on s i x o r more of the f i f t e e n cases s tud ied a re Sesuvium, Wedelia, Ageratum, Ipomoea, Sporobolus, Cyperus and Ernodea; and a t l e a s t 18 o the r colo- n i z ing spec ie s have been noted. The pioneer vege ta t ion of s t r i p p e d - . su r faces i s t h e r e f o r e a d ive r se assemblage dominated by Tournefor t ia and Euphorbia, with Borr ich ia and Ageratum, and conta in ing many of the elements of mature cay vege ta t ion . The importance of Tournefort ia by comparison with Sur iana i s s t r i k i n g ; Tournefor t ia c l e a r l y occupies t h e niche f i l l e d i n t h e Indo-Pacif ic by Scaevola. Tournefor t ia i s mainly a sho re l ine p l a n t , though on s t r i p p e d cays found a l l over t h e su r face , whereas Borr ich ia is gene ra l ly found away from shores . 6 . I n t e r t i d a l and s u b t i d a l h a b i t a t s . L i t t l e a t t e n t i o n could be pa id t o t h e vege ta t ion of marine h a b i t a t s i n 1965. No change was apparent i n the Thalass ia meadows, where ho le s and channels eroded i n 1961 s t i l l su rv ive , c l e a r l y ou t l ined by the absence of t u r t l e g ra s s . I n t e r t i d a l beachrock, which l o s t i t s profuse growth of Turbinar ia t u r b i n a t a and o t h e r spec ie s during t h e storm i s s t i l l bare of l a r e e r a l eae . Subt ida l broken co ra l and rubble have been - - colonized by Padina and o the r a lgae , and encrus t ing pink a lgae a r e widespread. Recovery 1. Recovery of l i t t o r a l woodland The l i t t o r a l woodland of Cordia sebestena and Bursera simaruba a t Half Moon Cay and Pel ican Cay was badly damaged i n 1961, with t r e e s d e f o l i a t e d and broken but often not uprooted: In e a r l y 1962 it was o f t en d i f f i c u l t t o t e l l whether these t r e e s were dead o r a l i v e , though ind iv idua l s of Cordia were seen i n flower even when much broken. In 1965 v i r t u a l l y a l l t h e damaged Bursera was dead, while Cordia had made a remarkable recovery. ?'he sea-grape Coccoloba uv i f e ra a l s o showed a s i m i l a r a b i l i t y t o su rv ive massive physical damage. I t i s too e a r l y t o p red ic t what w i l l happen i n the dead Bursera s t ands , which i n 1965 were being overgrown a t Pel ican Cay by Ipomoea tuba . Trees such as Thrinax and Terminalia which survived the s t o r n ~ i n n e a r s h o r e s i t u a t i o n s were s t i l l a l i v e i n 1965. 2 . Recovery of coconut t h i c k e t . The dominant cay vegeta t ion of neglected o r n a t u r a l l y regenerated coconut woodland with a dense undergrowth of shrubs and ground-layer vegeta t ion has changed (a) because of f e l l i n g o r decapi ta t ing of niany coconuts and (b) because of a t l e a s t temporary ces sa t ion of d i r e c t human in t e r f e rence and c l ea r ing of undergrowth. Thus t h i c k e t s on many cays a re much denser , with s t rong growths of Borr ich ia , Tournefor t ia , and t o a l e s s e r ex ten t Suriana and Sophora. The ground cover of Wedelia, S tachytarpheta , Canavalia and o the r p l a n t s under c l ea red coconut woodland i s commonly reduced by t h i s expansion of shrubby growth. Coconuts p lanted o r n a t u r a l l y germinating a f t e r t h e hurr icane were i n 1965 commonly 3-5 and except ional ly up t o 10 f e e t t a l l . 3. Recovery of mangrove. Mangrove damage i n 1961 was g r e a t e s t i n the a rea of maximum storm surge and wave a c t i o n , and was much l e s s severe i n a reas a f f ec t ed only by wind. On small mangrove i s l a n d s d e f o l i a t i o n was t o t a l i n a zone 25 miles wide centered on the storm t r a c k , and r a r e a t d i s t ances of 30-40 miles from t h e storm t r a c k . S ize of i s l a n d a f f ec t ed t h e degree of damage: l i v i n g ~nangroves were seen i n 1962 on t h e l ee s i d e s of l a rge i s l ands such as Cross Cay, only 1 2 miles from t h e storm cen te r , and de fo l i a t ion was l e s s complete i n t h e i n t e r i o r of the Turneffe lagoon mangroves. Whether t h e mangroves de fo l i a t ed by the storm were dead i n 1962 was not apparent a t t h a t t ime. In 1965 t h e de fo l i a t ed mangroves i n the zone of g r e a t e s t damage were c l e a r l y dead (Figure 15) . On the b a r r i e r r e e f i t s e l f , t h e f i r s t r e l a t i v e l y undamaged mangrove i s l a n d north of t h e storm t r ack i s Cangrejo Cay, south of Ambergris Cay, about 27 miles north of the storm c e n t e r ; and the f i r s t undamaged i s l a n d t o the south i s Crawl Cay, 25 miles south of t h e storm t r a c k . Local exposure i s , of course, important i n d e t e r - mining d e t a i l s of mangrove damage: f o r example, damage was more i n t e n s e a t Bugle Cay, fou r miles f a r t h e r from t h e storm cen te r , than a t Crawl Cay. The t r a n s i t i o n between r e l a t i v e l y l i t t l e and r e l a t i v e l y complete d e f o l i a t i o n i s sharp: the zone of mangrove death s o enclosed has a width of 50-60 mi les . Within the l i m i t of major d e f o l i a t i o n a d i s t i n c t i o n can be made between areas with l i v i n g mangroves i n she l t e red loca t ions and areas where des t ruc t ion was complete. Large patches of l i v i n g mangrove a r e found on t h e west s i d e of Cay Chapel and Cay Caulker, 20 miles no r th of t h e storm t r a c k , and a t Tobacco Range, the same d i s t ance t o t h e south . Within 20 miles of the storm t r a c k , however, damage t o b a r r i e r r e e f man- groves was t o t a l except f o r very small leeward patches on t h e l a r g e s t i s l a n d s . No mangroves a t a l l survived within a mile o r two of t h e storm cen te r (Middle Long Cay, Stake Bank). On Turneffe a l l mangroves were k i l l e d on the small e a s t e r n sand cays, such as t h e Cockroach Cays, and a l l died along t h e e a s t coast of t h e "main" except i n s h e l t e r e d p l a c e s , f o r example near Calabash Cays. Patches a l s o surv ive along t h e s i d e s of some of t h e western en t rances t o Northern and Southern Lagoons. From the a i r t h e r e i s a marked c o n t r a s t between the dead mangrove and t h e green sandy a reas where recovery of g ra s ses , herbs and shrubs has been r ap id . In t h e i n t e r i o r of t h e wider land areas surrounding t h e lagoons damage was l e s s severe , and i n p laces these a reas a r e q u i t e green. These in land loca t ions have not been s tud ied on t h e ground but from t h e a i r they appear t o have a dry-land vegeta t ion with Thrinax r a t h e r than mature mangrove woodland. On Lighthouse Reef patches of mangrove surv ive i n s h e l t e r e d p laces on Northern Cay and Long Cay, but otherwise a l l mangroves a r e dead. The zones of mangrove damage thus defined a re shown i n Figure 15. Both Rhizophora and Avicennia, when dead, r e t a i n tenacious root holds , and t h e i r hard roo t s and branches a r e d i f f i c u l t t o c l e a r . Recolonization of t h e s e a reas i s thus d i f f i c u l t , and t h e drabness of t h e dead mangrove c o n t r a s t s markedly with t h e green of sand and sh ingle cays i n t h e damaged a reas . Lack of seedl ings f o r regenera t ion a l s o delays redevelop- ment: few seedl ings were seen i n 1965 anywhere i n the damaged a r e a , where previous ly they had been abundant. Regrowth may a l s o be delayed by f i r e : considerable a reas were burning on the e a s t s i d e of Turneffe i n Apr i l 1965, though by des t roying t h e dead woody vege ta t ion t h i s may c l e a r t h e ground f o r co loniza t ion by o t h e r p l a n t s . Craighead and Gi lbe r t (1962), d iscuss ing the e f f e c t s of Hurricane Donna i n southern Flor ida i n 1960, have a l s o described widespread d e s t r u c t i o n of mangroves, averaging 25-75 per cent over l a rge areas and l o c a l l y reaching 90 pe r cent . They s t a t e t h a t d e f o l i a t i o n alone i s not a s u f f i c i e n t cause of death, s ince some t r e e s put f o r t h new leaves and suggest mechanical damage, roo t damage, and oxygen def ic iency r e s u l t i n g from marl depos i t ion as add i t iona l causes. They found, as on Turneffe, t h a t on s l i g h t l y h igher a reas covered with buttonwood hammock, damage was very much l e s s than on coas t a l mangroves. The Mauri t ius cyclones apparent ly caused l i t t l e damage t o mangroves (Sauer 1962), but damage comparable t o t h a t seen i n B r i t i s h Honduras was repor ted by Gleghorn (1947) from the northern Great B a r r i e r Reef, following a cyclone i n December 1943. There i s l i t t l e information on mangrove recovery i n r e e f a reas following storm damage. The 1934 cyclone a t Low I s l e s caused mechanical damage t o l a r g e r t r e e s and d e f o l i a t i o n of small ones (Moorhouse 1936); but a decade l a t e r no s i g n of t h e damage could be seen (Fairbridge and Teicher t 1947). In B r i t i s h Honduras the f l o u r i s h i n g mangroves of 1959-1961 had probably developed s i n c e 1931. Near Punta Gorda, where mangroves a re lower than elsewhere, they may have developed l a r g e l y s i n c e t h e major hurr icane of 1945. REFERENCES Blumenstock, D . I . , e d i t o r . 1961. A r epor t on typhoon e f f e c t s upon J a l u i t Ato l l . A to l l Research B u l l e t i n , 75: 1-105. Blumenstock, D . I . , Fosberg, F. R . , and Johnson, C . G . 1961. The re-survey of typhoon e f f e c t s on J a l u i t A to l l i n t h e Marshall I s l ands . Nature, 189: 618-620. Craighead, F. C . and G i l b e r t , V . C . 1962. 'fie e f f e c t s of Hurricane Donna on t h e vegeta t ion o f southern Flor ida . Quar ter ly Journal of t h e F lor ida Academy of Sc iences , 25: 1-28. Fa i rbr idge , R. W . and Te iche r t , C . 1947. The rampart system a t Low I s l e s , 1928-1945. Reports of the Great Barr ie r Reef Committee, 6 : l -16 . Fa i rbr idge , R . W . and Te iche r t , C . 1948. The Low I s l e s of t h e Great B a r r i e r Reef: a new a n a l y s i s . Geographical Journa l , 111: 67-88. Gleghorn, R . J . 1947. Cyclone damage on t h e Great Bar r i e r Reef. Reports of the Great Bar r i e r Reef Committee, 6 : 17-19. McInt ire , W . G . and Walker, H . J . 1964. Tropical cyclones and coas t a l morphology i n Mauri t ius . Annals of the Association of American Geographers, 54: 582-596. Moorhouse, F. W . 1936. The cyclone of 1934 and i t s e f f e c t s on Low I s l e s , with s p e c i a l observa t ions on Por i t e s . Reports of t h e Great Bar r i e r Reef Committee, 4 : 37-44. Sauer , J . D . 1962. E f fec t s o f recent t r o p i c a l cyclones on t h e coas t a l vegeta t ion of Mauri t ius . Jou rna l of Ecology, 50: 275-290. Stephenson, T. A . , Stephenson, A , , Tandy, G . , and Spender, M . A. 1931. The s t r u c t u r e and ecology of Low I s l e s and o the r r e e f s . S c i e n t i f i c Reports of t h e Great B a r r i e r Reef Expedition 1928-9, 3: 17-112. Stephenson, W . , Endean, R . , and Bennett , I . 1958. An eco log ica l survey of the marine fauna of Low I s l e s , Queensland. Aust ra l ian Journal of Marine and Freshwater Research, 9 : 261-318. S todda r t , D . R . 1962. Three Caribbean A t o l l s : Turneffe I s l ands , Lighthouse Reef, and Glover 's Reef, B r i t i s h Honduras. A t o l l Research Bu l l e t in , 87: 1-151. S toddar t , D . R . 1963. E f fec t s of Hurricane Ha t t i e on t h e B r i t i s h Honduras r e e f s and cays, October 30-31, 1961. A to l l Research Bu l l e t in , 95: 1-142. S toddar t , D . R . 1965. Re-survey of hurr icane e f f e c t s on t h e B r i t i s h Honduras r e e f s a n d cays. Nature, 207: 589-592. S todda r t , D . R . 1969. Coral r e e f s and i s l a n d s and c a t a s t r o p h i c storms. Coastal physiography, ed. J. A. S t e e r s , i n t h e p r e s s . 1 Pa t t e rn of hurr icane damage t o sand cays (from ARB 9 5 , F i g . 6 2 ) 2 Status of coral reefs 1965 CHANNEL A ST. GEORGE'S CAY 1965 (CHANNEL C) CHANNEL D L iv ing Rhizophora Dead Rhizophora Submarine Sand Cones Ar t i f i c ia l F i l l Yards 200 Scoured Channel N- 3 St. George's Cay 1965 Pioneer Ipornoea SERGEANT'S CAY. 1965 m] Pioneer Euphorbia Conocarpus ', Tournefortia , , , , : suriana \ \ \ Eustorna \ \ \ Herb Mat(1pornaea. \ Euphorbia,Wedelia) \ \ \ \ \ \ \ \ , \ \ I \ \ I I \ \ \ \ \ \ \ \ i I \ \ 1 JETTY POSTS I , 4 Sergeant's Cay 1965 I ' GOFF'S C A Y 1965 /' , /' / / , / / I 5 G o f f ' s Cay 1965 O Coccolobo ... . . . . .... ENGLISH CAY 1965 6 Engl i sh Cay 1965 7 Rendezvous Cay 1965 8 Tobacco Cay 1965 @ Eupnorbio with Ipornoeo. Sporobolus. Cyperus ond Ageroturn --. ,' ' * , @ sesuvium ioomoeo RENDEZVOUS CAY 1965 1 TOBACCO CAY. 1965 Euphorba Mixea ipornoeo and Euphorbia ipornoea fj sesuvium Wedelia a Hymenocclli is S tachy tarpheta Coccolobo Tournefor t ia Conocarpus Sophoro Terminol ia Cordio i 0 Y A R D S I SCiPlO CAY 9 S c i p i o Cay 1962 and 1965 10 Colson Cay 1962 and 1965 COLSON CAY P E L I C A N C A Y . 1965 \ \ \ \ I \ \ \" - - - - \* \* \* \ \ \ \ \ \ \ \ - - - \ - - - \ \ - - - - - - - - Live Cordlo sebestena Tournefort~u gnaphalodes - - - sesuvlum - - - Thrinox sn rng ie ~ o c k ~e--/-------- E] Fresh Hurr i cune Shingle 0 Feet 100 - 11 Pelican Cay 1965 LITTLE C A L A B A S H CAY 1965 Sesuviurn [I] Bat15 rnar i t i rna Euphorbio.Wedel8a Grasses B o r r ~ c h i a Sur lona T o u r n e f o r t ~ a Q Conocorpus Nc-+------- 1 2 L i t t l e Calabash Cay 1965 SANDBORE C A Y * ... Ground Yegetaf#on EuPh010#(1. Sporobolus, ageroturn. Ipornoea. Sesu, ~ rnbros in . Wedella. Cossytha S ~ T Y D S ~ o , n i y ~ovrnefort ia wltn s u r ~ o n o . Sopnora. Conocarpus 1 i.:..2 I d 13 Sandbore Cay 1965 NORTHERN CAY- NORTH POINT 1 I 14 N o r t h e r n Cay n o r t h p o i n t 1960, 1962, 1965 / MANGROVE MORTALITY B RECOVERY I / / 1965 I 15 Mangrove mortality and recovery 1965