Fisheries long term monitoring program : summary of spotted mackerel (Scomberomorus munroi) survey results : 2004-2005

Abstract

Spotted mackerel (Scomberomorus munroi) is an important species to recreational and commercial fishers along the east coast of Queensland. Previous research, and patterns in the catches of the fishery, indicate that there is a single stock between Cairns and northern New South Wales. The single stock undertakes seasonal migration associated with spawning and feeding.

Peak fishing activity occurs where and when favourable weather coincides with the migration pattern of the species. A trend of increasing commercial catches between the late 1990s and the 2000-01 financial year, followed by a sharp decline during the 2001-02 financial year, led to concerns being raised about the long-term sustainability of the fishery. Some major changes were made to regulations relating to management of spotted mackerel in 2002 and 2003. These changes included:

increasing the minimum legal size from 500 to 600 mm total length
reducing the recreational bag limit from 30 to 5
placing an annual cap on the commercial catch
prohibiting the use of nets to target spotted mackerel.
Previous surveys of spotted mackerel have included an extensive Fisheries Research and Development Corporation funded project in the mid 1990s and a small-scale survey under the Department of Primary Industries and Fisheries Long Term Monitoring Program between December 2001 and January 2003.

The present survey represents the start of a long-term, comprehensive monitoring program for spotted mackerel between Cairns and the Queensland - New South Wales border. The objectives of the new monitoring program are to provide annual estimates of the length, age and sex structure of the commercial and recreational catch. This report presents a summary of the length and sex data for the first year of the monitoring program.