Fishery-independent surveys and stock assessment of Panulirus ornatus in Torres Strait

Abstract

The Torres Strait lobster fishery differs culturally and ecologically from other Australian lobster fisheries. Ornate rock lobsters (Panulirus ornatus) have been fished by the inhabitants of Torres Strait for centuries, and commercial fishing began in the late 1960s. The fishery is a major source of income for Torres Strait Islanders, and the aim of management is to balance the needs of traditional and commercial users under a treaty between Australia and Papua New Guinea. In 1989, the absolute abundance of lobsters in the main fishing grounds was estimated by a visual census and a simple assessment was made. Since then, annual fishery-independent surveys of the relative stock abundance, and catch sampling, have contributed to the development of a simple cohort dynamics model of the fishery; for a range of fishing mortalities, it estimates the potential yield and percentage escapement and has provided annual assessments of the status of the stock and potential yield one year in advance— information valuable for managers considering development options and negotiating catch-sharing agreements and access rights. Future research will develop the model by incorporating information from ongoing surveys, catch recording, and logbook data from the Australian and Papua New Guinean fisheries.