Gladstone Fish Health Investigation 2011 - 2012 - Western Basin ...
Gladstone Fish Health Investigation 2011 - 2012 - Western Basin ... Gladstone Fish Health Investigation 2011 - 2012 - Western Basin ...
obvious abnormalities were included to ensure that health conditions not apparent byexternal observation alone could be detected during further laboratory investigations.Statistical analysis was performed to determine significant relationships and trends in thefield and necropsy data, histopathology data and chemical residue data (Appendices B, Cand D respectively).Field observations by Fisheries Queensland: Fish were observed upon capture andassessed visually for external signs of ill health. Data collected included an assessment ofskin discolouration, eye condition, lesions and presence of ecto-parasites. For the purposeof this data collection, skin lesions were distinguished from skin discoloration by observablesigns other than colour change, such as missing scales, ulceration or bleeding (seeAppendix A).Prawns were assessed visually for signs of ill health including shell erosion/lesions and thepresence of parasites. Crabs were assessed for shell abnormalities. Shell lesions weregraded according to the methods described by Andersen (2001).Fish collected using trawl methods (prawns, herring, grinner, Australian threadfin) werenecropsied while onboard the vessel by a veterinarian, and tissue samples were collected forfurther histopathology investigations and residue testing.Laboratory observations by Biosecurity Queensland: Fish were assessed visually forsigns of ill health once received in the lab by a veterinarian. Data collected included, but wasnot limited to, an assessment of skin discolouration, eye condition, lesions and presence ofecto-parasites. Observations of internal organs were made during necropsy, and tissuesamples were collected for further histopathology investigations and residue testing.Crabs were assessed for external shell abnormalities once received in the lab by an aquaticveterinary officer. Shell lesions were graded and location on the carapace recordedaccording to the methods described by Andersen (2003). Further observations were made ofinternal organs during necropsy and, in order to allow a statistical comparison of the fish fromdifferent sites, discrete categories were assigned to capture these observations based onAdams et al. (1993). Chemical residue test results were interpreted by the Department ofScience, Innovation Technology, Innovation and the Arts. For a detailed description of thesampling methods, refer to Appendix A.Histopathology and chemical residue testingA subset of individuals were selected for histopathology examination and chemical residuetesting (Table 1).For barramundi, gills, liver and skin (with muscle) were chosen for microscopic investigation,due to their known sensitivity as indicators of environmental stress. Specifically, thefollowing abnormalities were rated from zero to three to enable quantitative comparisonbetween sites and time points: gill hyperplasia; gill parasites; liver melanomacrophagecentres; skin lesions; and muscle lesions.Barramundi gills and liver were used for chemical residue testing, as they were deemed themost likely tissues to show evidence of short to medium term exposure to contamination.Since there were no significant findings in organic testing of barramundi tissues during Phase1, only metals were tested in Phase 2.19
For mud crabs, hepatopancreas, gills and muscle were examined histopathologically.Hepatopancreas tissue was also used for chemical residue testing, which included testing formetals and organic contaminants.Grinner were chosen due to their benthic and relatively immobile nature, size (ease /feasibility of processing) and previous evidence provided by members of the public of red /sick grinner from Gladstone Harbour. Since no grinner were caught from Bundaberg duringApril, a total of 25 fish were tested. Gill, liver and muscle were used for histopathologyexamination. For chemical residue testing, only muscle tissue could be sampled in sufficientvolume due to the small size of these fish.Since insufficient numbers of sharks were caught for a balanced statistical analysis, theywere used for histopathology only.Chemical residue test results were interpreted by the Department of Science, InformationTechnology, Innovation and the Arts.20
- Page 1 and 2: Department of Agriculture, Fisherie
- Page 3 and 4: ContentsTable of tables 1Table of f
- Page 5 and 6: Mullet (Mugilidae) 80Banana prawn (
- Page 7 and 8: Figure 7. Barramundi caught in the
- Page 9 and 10: Figure 38. Sharks caught in the Cal
- Page 11 and 12: Phase 1 (August 2011-February 2012)
- Page 13 and 14: The results in this study support t
- Page 15 and 16: ecognised expertise and research pu
- Page 17 and 18: Mr Mitchell reported high catches u
- Page 19 and 20: Figure 2. Sampling sites within the
- Page 21 and 22: Phase 2: Expanded Gladstone Fish He
- Page 23: Mud crab (Scylla serrata): Mud crab
- Page 27 and 28: Table 2. The number of fish, crusta
- Page 29 and 30: Significant findings and discussion
- Page 31 and 32: Commercial barramundi catch and cat
- Page 33 and 34: Figure 6. Eye condition observed in
- Page 35 and 36: Conditions observed in barramundi s
- Page 37 and 38: Figure 12. A barramundi caught in t
- Page 39 and 40: provided another environmental stre
- Page 41 and 42: was somewhat reduced because post-m
- Page 43 and 44: 4,000Commercial effort (days fished
- Page 45 and 46: Size structure of mud crabs observe
- Page 47 and 48: Figure 21. Examples of shell abnorm
- Page 49 and 50: Of the 58 crabs observed to have sh
- Page 51 and 52: HistopathologyLipid storage vacuola
- Page 53 and 54: Commercial fishing effort for mulle
- Page 55 and 56: Figure 28. (a) Mullet caught in Rod
- Page 57 and 58: June/July: Mullet samples were coll
- Page 59 and 60: Sharks and raysThe monitoring progr
- Page 61 and 62: Observational findings Phase 1Phase
- Page 63 and 64: Encysted larval parasites were foun
- Page 65 and 66: in particular bull sharks, have bee
- Page 67 and 68: Commercial banana prawn catch for t
- Page 69 and 70: Observational findings Phase 2April
- Page 71 and 72: Laboratory testing Phase 1Seven riv
- Page 73 and 74: four displayed signs of redness. Th
For mud crabs, hepatopancreas, gills and muscle were examined histopathologically.Hepatopancreas tissue was also used for chemical residue testing, which included testing formetals and organic contaminants.Grinner were chosen due to their benthic and relatively immobile nature, size (ease /feasibility of processing) and previous evidence provided by members of the public of red /sick grinner from <strong>Gladstone</strong> Harbour. Since no grinner were caught from Bundaberg duringApril, a total of 25 fish were tested. Gill, liver and muscle were used for histopathologyexamination. For chemical residue testing, only muscle tissue could be sampled in sufficientvolume due to the small size of these fish.Since insufficient numbers of sharks were caught for a balanced statistical analysis, theywere used for histopathology only.Chemical residue test results were interpreted by the Department of Science, InformationTechnology, Innovation and the Arts.20