The white steenbras (Lithognathus lithognathus), one of South Africa’s most sought after and threatened endemic coastal fishery species, has traditionally been targeted by recreational, subsistence and commercial seine net fishers, and as a result stocks of this species are in a collapsed state. Catch, size and gear restrictions have failed to decrease exploitation or restore spawner biomass levels. Although much is known about its biology, a lack of intimate knowledge on the movement patterns, habitat use and stock integrity, has resulted in difficulties in effective management of this species. The study aims to describe the life-history characteristics, habitat use, movement patterns and genetic diversity of the white steenbras, in South Africa, to provide sound knowledge on which management decisions should be based.
The study will include an assessment of the status of white steenbras stocks in South Africa, using current and historical data, to show trends in catch and effort over the past two decades. Such information will provide insight into the effectiveness of current and historical management measures for the protection of this species. Acoustic telemetry will be used to describe the movement patterns and determine habitat use of juvenile white steenbras within selected South African estuaries, and determine the periodicity and duration of the fishes’ movements between estuarine and marine environments. Such information is essential for estuarine and marine management decisions, and for understanding effects of habitat alteration, degradation or loss and environmental change on the species. Tag-recapture data will be used to determine longshore movement patterns of white steenbras, as well as dispersal from the estuarine environment, along the coastline. Such an understanding of the longshore movement of white steenbras is essential to provide guidelines for management of the species. DNA sequencing will be used to adopt a phylogeographic approach to identify the spatial distribution of genetic diversity within this species.
This study will make use of innovative techniques to investigate the movement patterns, habitat use and habitat connectivity of white steenbras, and the research findings will provide information necessary to assist the corrective management of this over-exploited estuarine-dependent fishery species.
