The Freshwater Ichthyofauna of Bougainville Island, Papua New Guinea

Abstract

Tailings disposal from the Bougainville Copper Limited open-cut porphyry copper mine on Bougainville Island, Papua New Guinea (1972-1989) impacted the ichthyofauna of the Jaba River, one of the largest rivers on the island. To assess the 'extent of this impact, comparative freshwater ichthyological surveys were conducted in five rivers on the island during the period 19751988. Fifty-eight fish species were recorded, including one introduction, Oreochromis mossambicus. The icthyofauna is dominated by euryhaline marine species consistent with that of the Australian region, but more depauperate. There are more than 100 species present on mainland New Guinea that are absent from Bougainville streams. Oreochromis mossambicus was the most abundant species in the sampled streams, accounting for 45% of the catch. The most abundant native fishes were the mainly small Gobiidae and Eleotridae. There were few native fish of potential value as food and these were restricted to an eleotrid gudgeon (Ophieleotris aporos), tarpon (Megalops cyprinoides), eel (Anguilla marmorata), and snappers (Lutjanus argentimaculatus and Lutjanus fuscescens). Fish production in the rivers is limited by the morphology of the streams and the depauperate ichthyofauna. Fish yield from the Jaba River in its premining state is estimated to have ranged from 7 to 12 t/yr. The population living in the Jaba ,catchment in 1988 (approximately 4,600 persons) shared this resource, resulting in an extremely low per-capita fish consumption rate of less than 3 kg/yr.