Gladstone Fish Health Investigation 2011 - 2012 - Western Basin ...

Samples were tested for more than 160 organic chemicals. Only two organic chemicals weredetected in the fish samples analysed. These were p’p’-DDE and DEET. p’p’-DDE is adegradation product of the organochlorine pesticide DDT, which was a commonly usedpesticide in the agricultural sector, but has not been permitted in Australia for more than 20years. The samples were from barramundi from China Bay and Turkey Beach in Gladstone.DEET is a very commonly used ingredient in personal insect repellents. Given that it wasfound in only one sample, it is possible that this fish sample may have been contaminated.Concentration of metals, aluminium, barium, copper and zinc were slightly higher in the fishtissue from the reference sites than Gladstone Harbour sites. Cadmium, nickel, selenium andsilver were very similar among sites. Iron and arsenic were present at higher levels in theGladstone barramundi population. Further details can be found atwww.qld.gov.au/gladstoneharbourObservational findings Phase 2April 2012: A total of 111 barramundi were collected from all planned netting sites. NoNeobenedenia sp. or eye abnormalities were observed on fish collected from any of thesampling locations. In the Boyne River, a high prevalence (50-75%) of physical damage wasobserved on the barramundi caught. Conditions described as physical damage appeared asgraze–type injuries and included large areas of scale loss often on one side of the body,operculum damage and some mandible fractures. Physical damage (Figure 7) was attributedto fish passing over the Awoonga spillway earlier this year (Awoonga overtopped in lateJanuary to early February and late March 2012). The observed damage is consistent withinjuries seen in fish after being washed over spillways of other impoundments, andconsistent with observations made by recreational anglers following the 2011 overtopping ofAwoonga Dam.Seven barramundi caught at the reference sites and six barramundi caught in the Gladstonearea (Hamilton Point and Rodds Bay) showed varying levels of redness on the skin. Thisranged from pinpoint marks to more general redness over areas of the body and fins. Noother signs of ill health were observed, with most fish considered to be in good condition.Observations are summarised in Figure 8.Seven barramundi were caught incidentally during trawl sampling in Gladstone Harbour(Figure 9). The commercial fisher involved in the sampling identified this as an unusualcapture, which may indicate a larger number of barramundi than normal being present inGladstone Harbour. No significant signs of ill health were observed on these barramundi.Figure 7. Barramundi caught in the Boyne River showing physical damage consistent with beingwashed over the Awoonga spillway.29