Concern has been expressed over the future of eastern freshwater cod stocks in the Clarence River system after the NSW Fisheries department allowed a stocking of Australian bass fingerlings from a completely different bioregion to proceed. The fingerlings were contaminated with and introduced the banded grunter ("Amniataba percoides"), an aggressive small native fish, to the lower reaches of the river. It is feared that banded grunter may yet invade the main freshwater reaches of the Clarence River system, with possibly devastating impacts on eastern freshwater cod.