Australian Centre for Tropical Freshwater Research, TOWNSVILLE, AUSTRALIA
Exotic fishes are readily accepted as environmentally harmful in many situations, and certainly unwelcome in protected areas. However, native fishes translocated outside their natural range are commonly considered to be environmentally benign, even though many examples show this to be untrue. Differences between exotic and translocated native fishes reflect geopolitical, not ecological criteria. Because of the failure to recognise potential impacts, private individuals and fisheries agencies have widely translocated native fishes for recreational fishing, without scrutiny by environmental management agencies. Nearly 30 million hatchery-reared fish have been stocked in Queensland, and the number is rapidly increasing. The impact of this program has not been evaluated and little planning has been used to protect conservation areas. The Wet Tropics World Heritage Area (WTWHA) includes a large number of some of the highest conservation-value streams in Australia, many of which occur above waterfalls that act as fish passage barriers. Despite overall high diversity, most WTWHA streams contain only a few small, non-angling species. Thus, stocking of large, aggressive, predatory fish has occurred in many areas. Six of the nine major catchments of the WTWHA and up to 15 National Parks in North Queensland have populations of translocated native fishes. At least 28 translocated native fish species and one translocated native crayfish species have established populations, or are regularly stocked, outside their natural range. Protecting conservation areas from undesirable translocations requires education programs similar to those for exotic fishes, and appropriate planning and co-ordination between environmental and fisheries management agencies.