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

Figure 44. Banana prawns collected during the sampling program with the isopod present under thecarapace (a) Prawn caught from the offshore Fitzroy River site with an isopod present under the carapace(circled); (b) Prawn caught at Bundaberg with part of its carapace removed to reveal the isopod.Bopyrid isopods and larval stages of tapeworms are common parasites of prawns and are anormal occurrence in wild populations along the Queensland coast. The prevalence ofbopyrid isopods observed during this sampling program was low across all areas (Gladstoneand reference sites), suggesting a normal background prevalence in the populationthroughout. This information, along with the low prevalence of shell erosion observedthroughout the study, provide no evidence of health issues in the wild banana prawnpopulation in the Gladstone region.Laboratory testing Phase 2Samples collected for histopathology and residue testing during Phase 2 have been archivedfor future testing if required.Trawl caught finfish speciesObservational findings Phase 1In November 2011, trawl sampling was conducted in Gladstone Harbour targeting prawns.Approximately 350 of each of the following finfish species were caught as incidental catch:river jew, anchovy, Australian threadfin and ponyfish. Three river jew displayed some minorredness on the ventral surface, and all other fish caught were in good condition. Three out of31 herring caught showed injuries on the dorsal side between the dorsal fin and head.In December 2011, trawled finfish (bycatch) were observed in catches from the Fitzroy River(149) and Gladstone Harbour (62). All fish caught by trawling were assessed as beinghealthy with no skin discolouration.In February 2012, Fisheries Queensland observers monitored the health condition of fishcaught in Gladstone by trawl net while aboard commercial fishing boats. In total,approximately 490 bycatch fish were observed. None of these fish showed any signs of skindiscolouration.65