Search the SPREP Catalogue

Ten caves in the makatea limestone of Mangaia, Cook Islands were explored and mapped, totalling over 3.7 km of passage. Of these, there was an apparent grouping by elevation that corresponds with previously described sea-level terraces in the makatea. Four caves have major level sections 10-20 m above sea-level, corresponding with a 14.5 m Pleistocene terrace. The high dimensions of these caves indicate downcutting during slow uplift, or multiple reoccupations by highstands of Pleistocene sea-levels. One major cave has level passage 20-30 m above sea-level, corresponding with a 26-27.5 m terrace. Three caves have level passage 40m above sea-level, corresponding with a 34-39 m terrace. Active conduit caves are developed at the present sea-level, but are closed with heavy clay deposits from recent soil erosion.

The Republic of the Marshall Islands requested a natural and cultural biodiversity survey of 6 northern atolls (Bok-ak, Pikaar, Toke, Wotto, Rondik, Adkup) and one reef island (Jemo) which was accomplished over 17 days in September 1988. This report covers the results of the survey of the reefs and corals during the expedition. Ninety-five marine sites were snorkeled and the shorelines of all island were surveyed during the expedition. A total of 168 species and 55 genera and subgenera of stony corals were reported including several new species and one new genus recorded (Polyphyllia) for the Marshalls.

The recorded flora of the raised phosphatic limestone island of Nauru in the equatorial Pacific Ocean consists of approximately 493 species. Only 59 are possibly indigenous, none of which are endemic. The balance is composed of ornamentals, weedy exotics, food plants, and a limited number of other useful cultigens. Twelve of the recorded species are either extinct or were never successfully established on Nauru. Long human settlement, expansion of coconut monoculture during the colonial period, widespread destruction during World War II, and almost a century of open-cast phosphate mining, have led to serious vegetation degradation, disturbance, and displacement

This paper lists the vascular flora of the three atolls (Canton, Gardner, Hull) and five small islands (Birnie, Enderbury, McKean, Phoenix, Sydney) of the Phoenix Group, located in the arid equatorial belt of the Central Pacific, based on extensive collections made in 1973 and 1975 and on previous records and collections. The flora includes 87 species in 36 families. Only 28 of the species (32%) are considered native. A further 60 species have been recorded in the literature, many of them deliberate introductions which have not persisted. These are mentioned but not described.

This paper describes the channels known as hoa which are characteristic of atoll land rims and of some islands on barrier reefs, where they often dissect previously more continuous reef-top sediment accumulations and conglomerate platforms. They are especially common in the central Pacific, and are particularly well developed in some atolls of the Tuamotu Archipelago and on some of the Society Islands. Published hypotheses accounting for the origin and development of hoa of different kinds are outlined. Contemporary hoa on the north side of Hull Atoll in the Phoenix Islands are described and surveyed, as are older, probably Holocene hoa, here termed 'paleohoa', on the same atoll. Regional and local distributions of hoa and paleohoa and differences in hoa morphology are used to assess theories of hoa formation. Both hoa and paleohoa are attributed to hurricane activity, and the presence of paleohoa may thus give an indication of the distribution of hurricanes in the Holocene.

The colonization of the lagoon by coral reef fish larvae was compared between two islands of French Polynesia, the atoll of Rangiroa and the high volcanic island of Moorea. In both cases the larval flux coming into the lagoon followed a daily cycle. Larvae were mainly caught at dusk and during the night, and on both islands the colonization was higher during moonless than moonlit periods. The larval flux did not appear to be dependent on the waterflow in the lagoons. A comparison of larval abundance and taxonomic lists indicates that Scarids and Labrids were dominant in Rangiroa while Gobiidae was the major family on Moorea. This difference could be in part related to the different sampling periods, but other environmental and biological factors could also be important.