Fisheries long term monitoring program : Preliminary Assessment of Juvenile Mangrove Jack around Weipa, May 2004

Abstract

This report is a summary of the data collected in the Fisheries Long Term Monitoring Program freshwater fish surveys from 2000 to 2005.
Queensland’s freshwater reaches contain a diverse array of freshwater fish fauna. Over 130 native species are recognised in north eastern Australia which is approximately half of the freshwater fish fauna of the Australian continent (Pusey et al. 2004).
The sustainability of freshwater fish is highly dependent on suitable riverine habitat as species diversity and populations are closely linked to habitat conditions. Exotic fish species including carp (Cyprinus carpio), tilapia (Tilapia, Oreochromis spp.) and mosquitofish (Gambusia spp.) may compete with, or prey on, the eggs and juveniles of native species.
The Department of Primary Industries and Fisheries (DPI&F) Long Term Monitoring Program (LTMP) has monitored the freshwater fish of 10 river systems in Queensland since 2000. The program uses electrofishing sampling techniques to collect annual information on populations of key recreational, commercial and exotic fish species. The program also collects ancillary information on water quality and habitat conditions that may help to correlate changes in fish community structure.
Species diversity in most rivers has remained fairly stable throughout the period of the study. Six exotic fish species have been encountered, with goldfish, European carp and tilapia being of major concern to state agencies.
The six years of sampling has been successful in obtaining a baseline dataset of the fish resources for the ten rivers monitored under the freshwater component of the LTMP.