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

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Figure 12. A barramundi caught in the Calliope River during the June/July <strong>2012</strong> sampling event with anold injury in an advanced stage of healing. Note the new skin completely covering the old injury.Conditions observed in barramundi sampled at each site during June/July, Phase 2Skin Colour Normal Skin Pale Pink Areas Ventrally Skin Minor Redness Skin General rednessSkin Extensive Redness Minor Lesion Areas of detached scales Physical Damage3025Number of <strong>Fish</strong>20151050Fitzroy River(n = 35)Hamilton Point(n = 20)Calliope River(n = 13)lower Boyne River(n = 10)upper Boyne River(n = 6)Rodds Bay(n = 2)Bundaberg(n = 7)LocationFigure 13. Conditions observed (skin colour and lesions) in barramundi sampled at each site duringJune/July, Phase 2. Note, (n) refers to the total number of fish examined at each site. Some fish may havebeen observed with multiple conditions.Targeted barramundi surveys to examine Neobenedenia sp. infectionTargeted barramundi surveys in the Boyne River were undertaken by <strong>Fish</strong>eries Queenslandin October <strong>2011</strong> and September <strong>2012</strong> to investigate parasitism by the monogeneanNeobenedenia sp. Neobenedenia had been implicated as a causative agent for some of theobserved conditions affecting barramundi during Phase 1 of the fish health investigation.Neobenedenia is known to exist naturally in the marine environment in the <strong>Gladstone</strong> areagiven previous occurrences of Neobenedenia on barramundi broodstock in the <strong>Gladstone</strong>Area Water Board fish hatchery (pers. comm. Kirt Hutchby, Hatchery Manager).Neobenedenia does not survive in freshwater.Neobenedenia are known to cause disease and mortalities in aquaculture. Deveney et al.(2001) documented an outbreak of Neobenedenia that occurred in the Hinchinbrook Channelon barramundi cultured in sea cages where parasite burdens exceeded 400 specimens perfish, however these parasites have not previously been associated with documented fishhealth issues in wild populations.32

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