recorded on Tridacna Islet by Clapp & Sibley (1971a) for sooty 

 tern eggs and chicks and by Reese (1987) and Helfman ( 1979) 

 on Enewetak, Micronesia. 



Size : Living in a rich environment free of predators, 

 coconut crabs attain huge sizes on Caroline. The bodies of the 

 largest males were as wide as a full-sized, unhusked coconut 

 (Subchapter 1.1, PI. 56), giving them weights of at least 4 k 

 (Helfman. personal observation). Thorax widths for 10 crabs 

 (2 females with eggs. 8 males) averaged 129 mm. The thorax 

 of the largest male measured 200 mm across, making it. along 

 with many measured on Flint in 1990, one of the largest 

 recorded coconut crabs in the world (the previous record was 

 178 mm, Helfman. 1977a), with an age estimated to exceed 

 40 years (E. Reese, personal communication). 



Conservation: Attributes of International Significance 



When Bennett (1840) stated that "no reefs we had seen 

 could compete with those of Caroline for novelty and beauty," 

 he was seeing an essentially pristine ecosystem through the 

 eyes of a well-traveled naturalist. Caroline is stunning, but its 

 value in today's shrinking world goes well beyond its physical 

 beauty. Caroline' s exceptional attributes need to be elucidated, 

 for the atoll has remained essentially unknown, even to some 

 who have evaluated its worth (King, 1973; Garnett, 1983, 

 1984). Man's presence anywhere, especially on pristine or 

 near-pristine islands, generally brings rapid, often irreversible, 

 changes. There are few, if any, islands remaining in the Pacific 

 that can claim the impressive array of natural features exhibited 

 by Caroline (Nicholson & Douglas, 1969). We believe that it 

 is imperative that this atoll, which has managed to escape large- 

 scale human disturbance, should remain undeveloped. 



Caroline was inhabited from 1988 to 1991 by a single 

 family who lived a spartan, ecologically sound lifestyle. There 

 are no roads, vehicles, stores, jetties, or services (water, sewage, 

 or food), and no communication. There is no passage into the 

 lagoon or safe sea anchorage. 



One of the most important of Caroline's attributes is its 

 relative lack of disturbance. Aside from obvious human 

 impacts on South. Nake. and Ana-Ana, the majority of its 

 motus are dominated by indigenous vegetation and its reefs are 

 basically pristine. There is no obvious pollution to alter the 

 chemistry of the lagoon, beyond the flotsam and jetsam that 

 spatter the windward beaches. It is thus an exceptionally clear 

 and clean ecological laboratory that presents a picture of 

 lagoon ecosystems "before" extensive disturbance by man. and 

 one that provides the marine biologist with an unparalleled 

 opportunity to study undisturbed natural communities. The 

 atoll is rich in marine vertebrates and invertebrates; the maze 

 of reefs and coral heads in the lower half of the lagoon has the 

 highest recorded density of living Tridacna (20/. 25 m 2 ) ever 

 recorded ( Sirenko & Koltun. Subchapter 1 .4. this volume), one 

 of the few undisturbed world populations of this species 

 (Subchapter 1.1. PI. 26). 



Caroline's many islets of different sizes provide excellent 

 examples of soil and vegetation development, accompanied by 

 variations in the diversity of bird life (Fig. 17). Many of its 



disturbed islets have recovered so remarkably they are almost 

 indistinguishable from those which have remained pristine. 

 The changing shapes of the islets, bearing emerging and mature 

 plant communities, graphically portray a natural terrestrial 

 atoll ecosystem. Caroline's concentric pattern of plant 

 community development and the relationships of these 

 communities to islet size, shape, and location on the atoll rim 

 will continue to provide insight into evolutionary processes on 

 atolls if they are left undisturbed. 



Caroline's insular flora, typical of central equatorial islands 

 in their natural state and covering 70% of the atoll's land area, 

 is of both national and international importance. The 27 extant 

 plant species are 85% indigenous (possibly up to 93%), an 

 extremely high figure for anywhere in the world. Six of the 

 seven plant communities are natural. Lushly wooded, Caroline 

 possesses some of the largest and grandest Pisonia (Pisonia 

 grandis) forests known (Subchapter 1.1, PI. 43), occurring on 

 29 islets. Although not as majestic as the prime forests on 

 Washington and Fanning (Northern Line Group), which enjoy 

 a heavier rainfall, those on Caroline are some of the finest 

 representatives of this forest community in the entire Pacific. 

 The 62 ha of Pisonia forest may well cover a larger area than 

 on any other Pacific atoll. 



Caroline possesses significant stands of the hardwood kou 

 (Cordia subcordata), a tree that is now rare in the Pacific. 

 Caroline's groves (Subchapter 1.1, PI. 27), though small and 

 often occurring in mixed native woodlands, total 26 ha. possibly 

 the greatest area on any Pacific atoll. Its extensive coverage of 

 tree heliotrope (Tournefortia argentea) is also notable: scrub 

 and forests of this species form 40% of the atoll woodlands 

 (Subchapter 1.1. PI. 47). Caroline's groves are some of the 

 most unmodified in the Pacific: elsewhere Tournefortia is 

 typically restricted to coastal fringes surrounding anthropogenic 

 plantations (R. Fosberg. personal communication). 



Caroline offers many opportunities for ecological research 

 under reasonably pristine conditions. Valuable clues as to the 

 nature of underground water supplies may lead to a better 

 understanding of the regulation of water supplies on inhabited 

 islands. Marine biological and biomedical research could 

 unearth clues as to the causes and treatment of ciguatoxicity of 

 fishes and crabs. Such topics are increasingly important as 

 more islands are subjected to disturbance and pollution. For 

 example, the abundant red snapper (Lutjanus vaigiensis) and 

 red spotted crab (Carpilius maculatus), both of which are 

 notorious for their potent poisons, are safe to eat on Caroline. 

 Associated with Caroline's plant communities are 

 1 1 species of breeding seabirds numbering well in excess of 

 1,000,000 individuals. The populations of most of these 

 species are of national importance (Table 9). Caroline has the 

 fifth largest red-footed booby colony (Subchapter 1.1, PI. 51) 

 in the world. Its black noddy and white tern (PI. 3) populations 

 are the largest in Kiribati. Under the 1975 Republic of Kiribati 

 Wildlife Conservation Ordinance (amended in 1979). all 

 known seabirds, migrant shorebirds. and endemic land birds 

 are "fully protected throughout the Gilbert Islands" (Garnett, 

 1983, p. 128). However, their protected status is in doubt on 

 Caroline, due to attempts to lease the island for development. 



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