Protected Areas and World Heritage Programme

NAME Malden Island Wildlife Sanctuary and Reserve

LOCATION 4^o03'S, 155^o01'W; in the southern Line Islands, 676 km south-southeast of Kiritimati.

AREA 3,930 ha.

ALTITUDE Sea level to 8 m at the beach crest.

OVERVIEW A dry, low-lying coral island with sparse scrub and a shallow, enclosed lagoon connected to the sea by underground fissures. Malden Island is a Wildlife Sanctuary and a Closed Area with significant populations of several species of seabirds. The island was extensively mined for phosphates between 1860 and 1927.

PHYSICAL FEATURES Malden Island is a low, flat, coral limestone island roughly triangular in shape with a fringing reef. The island measures about 8 km from east to west and 6 km from north to south. A series of wave-like ridges of sand and coral boulders forms a circumferential beach crest. The island contains an enclosed and highly saline lagoon covering approximately 1,300 ha and occupying about one third of the total land area. The lagoon is connected to the sea by underground channels, and has numerous small islets comprised of coral rocks and slabs. The floor of the lagoon is covered in brown mud, and there are some mudflats along the shore. The soil is composed of coarse coral gravel around the margin of the island, but is finer in the interior, with more sand and mud. There is no standing fresh water on the island, but there may be a freshwater lens. The fringing reef is about 100 m wide and extends 300-400 m at its northwestern and southeastern points. Malden is an arid island, with a mean annual rainfall of 726 mm. The annual rainfall is, however, very variable, ranging from as little as 100 mm to 2,400 mm. The mean annual temperature is 29.3^oC (minimum 23.8^oC, maximum 37.2^oC). The prevailing winds are easterly trades, and severe storms are extremely rare.

ECOLOGICAL FEATURES The general aspect of the island is that of moorland, being sparsely vegetated with stunted Sida fallax scrub, low herbs and grasses. Pisonia grandis forest formerly covered much of the island, but this was greatly reduced by indiscriminate felling and grazing during the 19th century, and only one or two clumps of Pisonia survive near the northeast corner of the island. Introduced weeds are particularly common around the old settlement areas. The introduced low-growing woody vine Tribulus cistoides now dominates extensive open areas where it provides increased cover for young Sooty Terns. Parts of the lagoon flat are completely devoid of vegetation. Sixteen species of vascular plants have been recorded, nine of which are indigenous (Garnett, 1983).

LAND TENURE State owned (Government of the Republic of Kiribati).

CONSERVATION MEASURES TAKEN Malden Island was gazetted as a Wildlife Sanctuary and Closed Area in May 1975 under the 1975 Wildlife Conservation Ordinance. Practical enforcement of the regulations is, however, difficult as the Wardens are stationed on Kiritimati, some 670 km away.

CONSERVATION MEASURES PROPOSED Malden Island was selected by the International Biological Program as one of the "Pacific Ocean Islands Recommended for Designation as Islands for Science" (Elliott, 1973).

LAND USE Early Polynesian settlements were abandoned when the island was discovered by Europeans in 1825. Malden was bonded in 1860 under the 1856 American Guano Act, and heavily exploited for guano and phosphate deposits from 1860 until 1927. This was the most commercially successful of the Central Pacific guano islands. The island was occupied between 1956 and 1959 by British servicemen to monitor the Christmas Island atmospheric nuclear bomb test programme, and was itself used as a target for some of the larger detonations (Garnett, 1983). An airstrip was constructed in 1958 and was in regular use until July 1979. Since then, the island has been uninhabited and unused except as a Wildlife Sanctuary. There is no anchorage, and landing is difficult and dangerous.

POSSIBLE CHANGE IN LAND USE The U.S. mineral exploration company GEOMAREX surveyed the island in 1980, and found substantial gypsum deposits which might be worth exploiting commercially in the future (Garnett, 1983).

DISTURBANCES AND THREATS Extensive exploitation of guano and phosphate deposits between 1860 and 1927 resulted in the disappearance of the Phoenix Petrel (Pterodroma alba), at least two other procellarids and Red-tailed Tropicbird (Phaethon rubricauda) as nesting species, although the tropicbird has since returned (Perry, 1980). Potholes and trenches dating back to the phosphate mining days still mar the interior of the island. Cats, pigs, goats and House Mice were introduced by the phosphate company. The last small herd of five feral pigs was eradicated by the Smithsonian Institution's Pacific Ocean Biological Survey Program in 1964, and the goats have also disappeared. Feral cats and House Mice are still present on the island. However, in 1978, the cats appeared to be present in very low numbers and were having little impact on the seabird colonies (Perry, 1980). The original vegetation cover was severely damaged by the phosphate workings, indiscriminate felling and feral pigs and goats. Most of the Pisonia grandis forest was destroyed, and this led to the extirpation of the Black Noddy (Anous minutus) as a breeding species and disappearance of many of the nesting White Terns (Perry, 1980). Fires are a potential hazard; a fire in 1977 threatened breeding seabirds (Perry, 1980). Malden Island is occasionally visited by foreign yachtsmen and fishermen, and these visits cannot be monitored from Kiritimati.

HYDROLOGICAL AND BIOPHYSICAL VALUES None known.

SOCIAL AND CULTURAL VALUE Malden Island is of considerable historical importance. Twenty-one archaeological sites with a total of over 70 ruined buildings and other stoneworks have been found, indicating that the island was settled by early Polynesian for several generations.

NOTEWORTHY FAUNA Malden is a very important breeding site for seabirds. Nineteen species have been recorded and 11 or 12 have been found breeding in recent years. Populations have been estimated as follows 40 Red-tailed Tropicbirds (Phaethon rubricauda), 3,000 Masked Boobies (Sula dactylatra), 2,000 Brown Boobies (S. leucogaster), 5,000 Red-footed Boobies (S. sula), 3,000 Great Frigatebirds (Fregata minor), 7,000 Lesser Frigatebirds (F. ariel), 10,000 Sooty Terns (Sterna fuscata), 2,500 Grey-backed Terns (S. lunata), 200 Blue-grey Noddies (Procelsterna cerulea), 500 Brown Noddies (Anous stolidus) and 50 White Terns (Gygis alba) (Perry, 1980). The island supports the largest concentrations of Lesser Frigatebirds, Grey-backed Terns and probably also Masked and Brown Boobies in the Line Islands. Tidal mudflats bordering the lagoon are frequented seasonally by large numbers of Pacific Golden Plovers (Pluvialis fulva), Bristle-thighed Curlews (Numenius tahitiensis) and Wandering Tattlers (Heteroscelus incanus). The only mammals still present on the island are feral cats and House Mice (Mus musculus). Polynesian Rats (Rattus exulans) are known to have occurred in the past, but are now locally extinct. Small numbers of Green Turtles (Chelonia mydas) nest on the beaches. Two species of lizard, the Mourning Gecko (Lepidodactylus lugubris) and Snake-eyed Skink (Ablepharus boutonii) have been recorded. Invertebrates include hermit crabs (Ceonobita spp.) and a brown libellulid dragonfly (Garnett, 1983).

NOTEWORTHY FLORA None known.

SCIENTIFIC RESEARCH AND FACILITY The island was visited by the Smithsonian Institution's Pacific Ocean Biological Survey Program on several occasions in the 1960s, and by the Line Islands Expedition in 1974. In recent years, staff of the Wildlife Conservation Unit have visited the island almost annually. No detailed research has, however, been undertaken, and there are no research facilities on the island.

MANAGEMENT AUTHORITY AND JURISDICTION Wildlife Conservation Unit, Ministry of Line and Phoenix Development.

REFERENCES Dahl (1980, 1986); Elliott (1973); Garnett (1983, 1984); IUCN (1991); Perry (1980); TCSP (1990).

REASONS FOR INCLUSION 1a, 2c. Malden is valued for its large breeding populations of seabirds and interesting saline lagoon.

SOURCE Mr Aobure Teataata.