A description of freshwater turtle habitat destruction by feral pigs in tropical north-eastern Australia.

Feral pigs cause major disturbance to wetland habitats that are frequented by freshwater turtles, although the effects have not been quantified. We assessed how feral pig (Sus scrofa) foraging activities affect turtle (Chelidae) habitat in a pair of fenced and unfenced ephemeral floodplain lagoons at Lakefield National Park on Cape York Peninsula, Australia. Feral pigs caused major changes to aquatic macrophyte communities and as a consequence, to the proportional amounts of open water and bare ground. The destruction of macrophyte communities and upheaved wetland sediments significantly affected wetland water clarity and caused prolonged anoxia and pH imbalances in the unfenced lagoon. The combined effects of vegetation destruction and the subsequent excretion of pig wastes also resulted in high nutrient enrichment. Clearly, exclusion fencing will protect freshwater turtle habitats from feral pig foraging activities, however, the choice of which lagoons to fence should only be made with an understanding of their seasonal usage by freshwater turtles.