The Demographics of Bumphead Parrotfish (Bolbometopon Muricatum) in Lightly and Heavily Fished Regions of the Western Solomon Islands: A Thesis Submitted in Fulfillment for the Degree of Doctor of Philosophy at the University of Otago, Dunedin, New Zealand

摘要: In this research the ecology of the Bumphead Parrotfish (Bolbometopon muricatum) and the status of the Bumphead Parrotfish fishery in the New Georgia Archipelago is investigated. The Bumphead Parrotfish, or Topa as it is known in New Georgia, is the largest herbivore on coral reefs and it is a species that is vulnerable to overfishing. Despite growing concern over its global status, the factors that make this species vulnerable to overfishing are not well understood. The fishers of Roviana Lagoon (New Georgia, Solomon Islands) have targeted Topa for subsistence purposes for centuries, utilising a detailed body of Indigenous Ecological Knowledge (IEK) to capture Topa from known nocturnal aggregation sites. In recent decades burgeoning human populations, mounting dependence on cash societies and the adoption of new harvesting technologies have dramatically altered the dynamics of the Roviana Topa fishery, with this fishery now being artisanal in nature.A cross-disciplinary approach towards this research was adopted. In the initial stages of this study anthropological methods were used to: Firstly, gain an historical perspective of ecological and social changes that have occurred in the Topa fishery and secondly, gather local knowledge on Topa ecology. Marine biology methods including creel surveys, Underwater Visual Census (UVC), telemetry, ageing and reproductive studies were then employed to quantitatively assess the status of Topa stocks in Roviana Lagoon and provide the demographic data on this species that is required in order to make biologically based management recommendations for this fishery.