The protozoan parasites, Cryptosporidium and Giardia represent a major public health concern of water utilities in developed nations. In Australia, marsupials, cattle and sheep are the dominant animals inhabiting water catchment areas and contribute a large volume of manure to catchments. Cryptosporidium fayeri, one of the main species identified in marsupials, was identified in a 29-year-old woman in Sydney in 2009 with identical subtypes found in marsupials in the area. There have also been reports of C. parvum and C. hominis (the most common species found in humans), in kangaroos, a wallaby, possums and bandicoots by independent groups, as well as high prevalence’s of zoonotic genotypes of Giardia in marsupials.

This project conducted a comprehensive study of genotypes of Cryptosporidium and Giardia present in marsupials, pre-weaned cattle and sheep and STP sites, over a three-year period to gain a more thorough understanding of the zoonotic risk these parasites pose to humans. In addition to cataloguing the genotypes present using next generation sequencing technologies, researchers also enumerated the numbers of Cryptosporidium and Giardia (oo)cysts present in samples and conducted a survey of farming practices to determine if particular management practices were associated with a higher or lower prevalence of zoonotic genotypes in pre-weaned cattle and sheep.

Lakes and reservoirs are essential for water supply for humans and agriculture, and have an important role in flow regulation, biodiversity, and streamflow below dams. Australia has been subject in recent decades to severe drought which has heightened the importance of reservoirs for human populations and highlighted the need for careful management of water levels to maintain continuity of supply. Climate change is likely to exacerbate water shortages, with extended periods of drought, interspersed with more discrete and intense rainfall, leading to challenges for storing water in reservoirs and potentially affecting the quality of water.

In this project, Griffith University researchers examined the water quality risks from low and variable water levels in dams and reservoirs in Eastern Australia.