Estuary surveillance Student task sheet for QX disease The following tables show data collected Estuary Surveillance 2002: during estuary surveillance from 2001– During the 2002 sampling period a total of 2004 for New South Wales and 5250 oysters were received and processed Queensland. N is the number of oysters from 18 NSW estuaries and three tested in a random sample of the oyster Queensland zones using tissue imprints. population. Dr Adlard used two methods of disease detection in surveillance — tissue imprint and PCR. Table 2A: Tissue imprints used to detect the QX disease parasite Estuary Surveillance 2001: 2002 Survey results Table 1: Tissue imprint results for 2001 N 2001 Survey Results Estuary N infected % N Northern Moreton Bay 250 0 0 Estuary N infected % Central Moreton Bay 250 0 0 Tweed River 316 0 0 Southern Moreton Bay 250 2 0.8 Brunswick River 320 0 0 Tweed River 250 0 0 Richmond River 248 0 0 Brunswick River 250 0 0 Clarence River 330 5 1.52 Richmond River 250 102 40.8 Wooli River 294 0 0 Clarence River 250 55 22 Kalang /Bellinger 295 0 0 Wooli River 250 0 0 Rivers Kalang /Bellingen Rivers 250 0 0 Macleay River 261 0 0 Macleay River 250 0 0 Hastings River 330 0 0 Hastings River 250 0 0 Manning River 286 0 0 Manning River 250 0 0 Wallis Lakes 271 0 0 Wallis Lakes 250 0 0 Port Stephens 263 0 0 Port Stephens 250 0 0 Hawkesbury River 323 0 0 Hawkesbury River 250 0 0 Georges River 260 123 47.31 Georges River 250 40 16 Shoalhaven/ 255 0 0 Crookhaven Shoalhaven/Crookhaven 250 0 0 Bateman's Bay 300 0 0 Bateman's Bay 250 0 0 Tuross Lake 304 0 0 Tuross Lake 250 0 0 Narooma 300 0 0 Narooma 250 0 0 Merimbula 250 0 0 Merimbula 250 0 0 © Queensland Museum 2006 Table 2B: PCR results from 2002 on Estuary Surveillance 2003: oysters which had tested negative to QX During 2003 a total of 4450 oysters were disease parasite using tissue imprints received and processed from 22 NSW estuaries and three Queensland zones. N PCR sampled +ve's Table 3: Survey results for 2003 using Northern Moreton Bay 100 7 PCR to detect the QX disease parasite Central Moreton Bay 100 6 2003 Survey Results Southern Moreton Bay 100 16 N Brunswick River 100 8 Estuary N infected % Clarence River 100 9* Northern Moreton Bay 150 0 0 Macleay River 100 35 Central Moreton Bay 150 0 0 Hastings River 100 3 Southern Moreton Bay 150 1 0.67 Wallis Lakes 100 7 Tweed River 150 0 0 Port Stephens 100 2 Cudgen Lake (P2) 150 3 2 Hawkesbury River 100 0 Brunswick River 150 2 1.3 Georges River 100 0 Richmond River 150 20 13.3 Shoalhaven/Crookhaven 100 0 Clarence River 150 9 6 Bateman's Bay 100 4 Wooli River 150 0 0 Tuross Lake 100 19 Bonville Creek (P1) 150 0 0 Narooma 100 25 Kalang /Bellinger Rivers 150 0 0 Merimbula 140 1 Macleay River 150 0 0 Hastings River 150 0 0 Manning River 150 0 0 Wallis Lakes 150 0 0 Port Stephens 150 0 0 Hawkesbury River 150 0 0 Sydney Harbour (P4) 150 0 0 Georges River 150 1 0.67 Shoalhaven/Crookhaven 150 0 0 Sussex Inlet (P3) 150 0 0 Bateman's Bay 150 0 0 Tuross Lake 150 0 0 Narooma 150 0 0 Merimbula 150 0 0 2 © Queensland Museum 2006 Estuary Surveillance 2004: always present here. Name these estuaries. Durimg the 2004 sampling period a total of Are disease outbreaks are more frequent in 450 oysters were received and processed these estuaries? Use the data to support from three Queensland zones using PCR your answer. methods. 4. For a long time QX disease was Table 4: PCR used to detect Marteilia considered endemic in the Richmond River sydneyi in northern New South Wales. Is this correct? Provide evidence from the data for 2004 Survey results your response. N 5. List the estuaries that appear to have no Estuary N infected % oysters with the QX disease parasite. Can you think of a reason for the absence of QX Northern Moreton Bay 150 0 0 disease organism in these estuaries? Explain. Central Moreton Bay 150 0 0 6. A common practice of oyster farmers is to translocate, or move, oysters from one Southern Moreton Bay 150 21 14 estuary to another either to fatten them, or to reduce the risk of QX disease infection. However, the translocation of oysters has Data Analysis: also been linked to the outbreak of QX disease in the Georges River. Can oysters You may wish to graph the data be moved into or out the Georges River appropriately to help your data analysis. now? Should oysters be moved from the For extra help refer back to Rob’s Lab. Crookhaven and Shoalhaven estuaries to 1. Summarise the trends in QX disease in the Georges River? From the Georges River affected estuaries from 2001. to these estuaries? Support your ideas using 2. In some estuaries the detected levels of the data provided. QX disease increased over the surveillance 7. An outbreak of QX disease occurred in period, yet no outbreaks have occurred. the Hawkesbury River in 2004. Look at the Give a reason. data. Record the warning signs of the 3. QX disease is considered endemic in outbreak, if there were any. What are the some estuaries, which means the parasite is implications for the management of the industry because of this outbreak? 3 © Queensland Museum 2006 .