Fauna of the Annan River System, far North Queensland, with reference to the Impact of Tin Mining. I. Fishes

Abstract

Fish were sampled at a range of sites in the Annan River system in tropical northern Queensland, using a variety of methods. In all, 25 species were recorded, including 14 principal freshwater forms. Species richness increased in a downstream direction and was directly related to stream size, the best measures of which were catchment area and stream length. When adjusted for stream size, the fish fauna of the Annan River system is relatively rich, compared with temperate Australian systems and streams on other continents. Analyses of gut contents of the species found in fresh water showed that six species were carnivorous, four were omnivorous, three were algivorous or detritivorous, and one was piscivorous. Mining impacts were evident at three sites and were associated with a reduced number of species; those eliminated were apparently less tolerant of sediment.