Aquatic Animal Health and Biosecurity Subprogram: Perkinsus olseni in abalone - development of fit-for-purpose tools to support its management
Department of Primary Industries and Regional Development (DPIRD) WA
Cecile J. Dang
Abalone are economically important species of molluscs, ranking fourth nationally and worth $190 million. These species have strong potential for future farming and ranching production development. However, with industry increasingly exploring live trade and developing new market access, infections with the parasite Perkinsus olseni can be a barrier for jurisdictions that have previously reported detection of Perkinsus sp. Overseas, Taiwan recently implemented a ban on live imports of abalone from Perkinsus-infected areas and this may be adopted by other countries in the future. Perkinsus spp. have caused significant mortalities in commercially important mollusc species worldwide. Of these, the OIE listed pathogen, P. olseni, is the only species known to infect abalone in Australia. P. olseni has been reported from molluscs in NSW, VIC, SA, and WA. This parasite has been associated with mass mortality events and subsequent demise of blacklip abalone fisheries in NSW since the early 1990¶s (FRDC Project No. 2004/084). Recent investigations in greenlip abalone populations in Western Australia have revealed up to 80% prevalence and highly variable intensities of infection. However, the investigation of the parasite dynamics and the associated risk factor(s) requires access to effective and efficient detection tools to measure the intensity of infection in an individual abalone and the prevalence of infection in large population surveys. These recent investigations have revealed severe analytical and diagnostic sensitivity and specificity deficiencies within the current protocols including the OIE one, and the various P. olseni strains present in Australia. The industry has highlighted the need for a reliable, rapid and specific method to detect this parasite at the species level (to date, 3 Perkinsus species have been described in Australia) in abalone tissues as well as in haemolymph, and water samples. This will lead to a better understanding of the prevalence and intensity of P. olseni infections on farm and in the wild, which will lead to the implementation of management measures. This lack of effective diagnostic tools is currently severely limiting Australia¶s capabilities to develop effective management
1. Develop and evaluate optimised diagnostic capabilities for Australian Perkinsus spp. isolates for sampling and testing based on estimates of sensitivity and specificity to meet accepted standards for detecting infection and for testing for freedom.