This study examines traditional fisheries?related resource management through a case in which local communities, from a basis of customary, ‘common property’ control over the sea and its resources, handle a multitude of development issues. Presenting first some important issues relating to people's role in fisheries management and to the ‘common property’ debate, the article then describes a traditional system for management of land and sea resources in a Pacific Islands society; that of Marovo Lagoon, Solomon Islands. Emphasis is given to fisheries resources, with a view to explaining in practical terms how a system of customary marine tenure operates under the wider social, political, economic and ecological circumstances of change arising from development pressures. Against this background, assessments are made of the viability of this traditional fisheries management system under present conditions of state control and of both external and internal pressures for large?scale resource development enterprises.