Summary of Abstract Submission

Abstract Submission No. IO50-03-0046PresentationPoster

UNEXPECTED HIGH MOVEMENT PATTERNS OF AN ESTUARINE DEPENDANT FISH, ACANTHOPAGRUS VAGUS, WITHIN THE KOSI BAY LAKES SYSTEM, SOUTH AFRICA - IMPLICATIONS FOR EXPLOITATION

Carel J Oosthuizen*1

1 University of Pretoria, South Africa

ABSTRACT :

Estuaries serve as core habitat for many estuarine fish species by providing food and protection from predators. Estuaries are also important in serving as nursery areas for numerous marine fish species. Many rural communities entirely rely on estuarine associated fish species as their only source of protein. Here we used acoustic telemetry to determine the movement patterns of the estuarine-dependent riverbream Acanthopagrus vagus (Peters 1852) within the Kosi Bay lakes system in South Africa. The number and mean duration of trips to the mouth area showed to vary greatly among individuals. Most fish moved into the mouth area multiple times following a monthly cycle during spawning months, April to August, which coincided with specific moon phases. Exploitation of A. vagus within this system is extremely high and resulted in a 33.33 % recapture rate of tagged individuals. The high level of movement of A. vagus within the Kosi lakes system together with the current level of exploitation exemplifies the need for immediate implementation of conservation interventions in order to prevent further deterioration of this unique estuarine system.