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

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The key variables analysed were the percentage abnormal carapace assessed in the fieldusing all 1599 observations (a Binomial proportions model), the distribution of countsaccording to highest lesion class (a Poisson linear model), and HSI (Normal model). In theseanalyses, ‘crab category’ was always significant (P ≤ 0.05), justifying its inclusion as astratifying term. The relevant means are listed in Table 6.Table 6. Mean values and standard errors (s.e.) for the crab categories.Hepato-somatic index s.e. Percent abnormal s.e.Female large 0.059 0.002 3.8 0.8Female small 0.064 0.004 1.8 0.7Male legal 0.043 0.003 7.1 1.7Male undersize 0.056 0.002 2.5 0.7Regarding locations and sampling events, the only significant (P ≤ 0.05) effect was for theHSI, where combined results for June/July (0.061 ± 0.002) were higher than those forApril/May (0.050 ± 0.002). Results for HSI are to be expected given HSI is generally highestduring the non-reproductive period for crabs (winter), and then decreases as crabs move intotheir reproductive season and energy stores are utilised in gonad production (Table 7).Table 7. Mean values and average standard errors for hepato-somatic index and per cent abnormal foreach location and sampling event.Location Hepato-somatic index Per cent abnormalApril/May June/July April/May June/JulyFitzroy River 0.046 0.060 4.5 1.4Bundaberg 0.050 0.061 3.7 3.1The Narrows 0.055 0.059 3.2 5.2Port Development Area 0.057 0.068 8.8 4.4Hamilton Point 0.050 0.061 3.1 3.7Calliope River 0.049 0.063 5.8 2.7Rodds Bay 0.043 0.056 2.3 2.4(average s.e.) 0.004 (average s.e.) 2.0June/July also sees similar or lower percentages of abnormal crabs than April/May for allsites except for the Narrows, while no significant difference was detected between Gladstoneand the reference sites.Possibly due to the low number of abnormal crabs (58), there were no significant effects forlocation or trip on the distributions of these counts (P = 0.14 and 0.13 respectively). Thedistribution of observed lesions across sites is shown in Table 8.Table 8. Lesion categories as observed in the field, according to categories described by Andersen, 2001.Where individual crabs had more than one lesion, only the most severe lesion was included.LocationLesion CategoryL1 L2 L3 L4 L5Fitzroy River 2 6 1 1 4Bundaberg 0 1 1 2 2The Narrows 1 0 2 2 1Port Development Area 2 5 1 1 1Hamilton Point 0 2 1 2 2Calliope River 1 1 2 1 0Rodds Bay 1 3 0 4 145
HistopathologyLipid storage vacuolation in the digestive organ (hepatopancreas) was evaluated accordingto the categories none, mild, moderate or severe. The location had no effect on thesevalues, however there was a significant reduction (P = 0.006) in lipid between April 2012 andJune/July 2012 sampling.When comparing the combined Gladstone sites with the combined reference sites, therewere no significant differences for any findings for the June/July 2012 sampling. However, inthe April 2012 sampling, crabs from the reference sites had significantly higher ratings of gillparasites (P = 0.015) and muscle lesions (P = 0.000) than the score for the crabs from thereference sites (P = 0.015). The findings of muscle lesions should be interpreted with cautionbecause there were only five crabs that were rated any score other than zero.The crabs assessed were essentially normal based on histopathology findings, other thansome shell lesions, which are not specific to Gladstone Harbour and occur naturally asdiscussed previously.Residue testingThe concentration of aluminium and selenium was found to be significantly higher in crabswith shell lesions than crabs without. As this occurred at all sites, these elevated metalconcentrations may be associated with mud crab with shell lesions in general, not just inGladstone Harbour.Comparison of measured concentrations of metals and metalloids in the hepatopancreascollected from the Gladstone Port Development Area and the Narrows were similar to othercatchments along the east coast of Australia when compared to historical data. The fact thatthe tissue concentrations from Gladstone were typical for the area indicates that the metalsinvestigated in tissues are not responsible for health issues particular to Gladstone Harbour.None of the 114 organic chemicals analysed were detected in the crabs from either of theGladstone harbour sites.For a detailed analysis of chemical residue results, please see Appendix D.MulletThe monitoring program collected information on mullet size and sex, presence and severityof observed signs of abnormalities, as well as commercial catch information supplied byfishers via commercial logbooks.Several species were encountered during sampling including sea mullet (Mugil cephalus),diamond scale mullet (Liza vaigiensis), goldspot mullet (Liza argentea) and bluespot mullet(Valamugil sp.). These species are commonly caught by commercial fishers in the region andare often known under different common names, so examples of each are shown in Figure24.46
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 and 24: Mud crab (Scylla serrata): Mud crab
Page 25 and 26: For mud crabs, hepatopancreas, gill
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: Of the 58 crabs observed to have sh
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
Page 75 and 76: Conditions observed in pelagic fish
Page 77 and 78: FinfishObservational findingsDuring
Page 79 and 80: ConclusionsIn 2011, a wide range of
Page 81 and 82: Mud crabsFisheries Queensland did n
Page 83 and 84: Owens, L. 1983. Bopyrid isopod Epip
Page 85 and 86: Candidate speciesThe monitoring pro
Page 87 and 88: Table 1: Candidate species for each
Page 89 and 90: Sample processingSample processing
Page 91 and 92: Herring/grinner/Australian threadfi
Page 93 and 94: For example: the third specimen, re
Page 95 and 96: oooGonad - present/absentHepatopanc
Page 97 and 98: Cloudy eye,swollen,redness orhemorr
Page 99 and 100: Red pin pointmarks - nogeneral redn
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Lesion photos Description GradeThis
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L4continuedoperculumgrazing;cuts or
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Appendix A-3: Fish health assessmen
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Appendix B - Statistical report: Gl
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analyses, but this was not done for
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was a significant (P < 0.05) locati
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Percentage with fin condition > 015
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Table 3.6b. Effects of locations an
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Table 3.7d. Spleen categories - cou
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32Bundy2Bundy1UpBoyne1UpBoyne2LwBoy
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Table 3.9c. Regional group means an
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Table 4.2c. Effects of locations an
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4.5 Summarising by regionsThe means
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Ta ble 5.2a. Effects of locations a
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5.5 Summarising by regionsThe means
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6.3 ResultsThere was no significant
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Table 6.5 lists the mean values whe
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Standardized residualsStandardized
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Table 2.3f. Muscle lesions.Lake Fit
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Table 4. 1f. Muscle lesions.Fitzroy
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Table 5.6. Regiona l m eans for the
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Contaminants in Tissue ofFish and C
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Contaminants in Tissue of Fish and
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Department of Science, Information
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Appendix E - Time line BarraBy John
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friends. Rapidly rising flood water
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To make note - condition loss was e
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May/June- FinsMy initial observatio
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Thes e escapee were now also in awo
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Figure N. Barramundi showing net ma
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September- Deaths and SicknessFigur
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There is numerous distinguishing fe
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Department of Agriculture, Fisherie
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Gladstone Fish Health Investigation 2011 - 2012 - Western Basin ...

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