The mangrove ecosystem of the Purari Delta

Outlines the climate, water movement pattern, salinity regime, deposition and erosion of this ecosystem (south coast of Papua New Guinea), then describes the mangrove plant species (including Avicennia, Bruguiera and Rhizophora spp.), mangrove distribution and zonation, determinants of zonation (mainly tidal regime, but also wave action and salinity) and succession. The fauna is discussed in terms of 4 broad categories: species which are permanent residents in the mangrove system (eg. mudskipper Periophthalmus, mud lobster Thalassina anomala, mud crab Scylla serrata and fiddler crabs Uca spp.); animals which also occur in swamp forest or rain forest (moving into the mangrove zone as tides recede); marine and estuarine animals (moving into the zone as the tide rises); and fishes and crustacea which spend the early part of their lives in the mangrove zone). The food chains of the mangrove zone are mainly detritus-based. Deposit-feeding prawns and fish are numerous. Ecological interactions are noted: litter breakdown and nutrient fluxes are identified. Utilization of delta mangal resources is shown, and development options indicated. Possible effects of the proposed Wabo HEP scheme are mooted. -P.J.Jarvis