Fitzroy River Fish Pathology Report - Department of Primary ...

Department of Agriculture, Fisheries and Forestry
Biosecurity Queensland
Fitzroy River Fish Pathology Report
May 2012
Fitzroy River Fish Pathology Report May 2012
1

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Fitzroy River Fish Pathology Report May 2012
2

Contents
Contents 3
Executive Summary 4
Background 5
Methods 6
Study design 6
Variations to study design 7
Sampling method 8
Laboratory testing 8
Gross pathology 8
Histopathology 8
Metal and metalloid residues 9
Statistical analysis of metal and metalloid residues 9
Results 10
Fish catch summary 10
September 2008 10
January 2009 10
May 2009 10
Fish length 10
Gross pathology and histopathology 10
Discussion 25
Gross pathology and histopathology 25
Metal and metalloid residues 26
Appendix 1: Fish sampling procedure 27
Appendix 2: Pathology lesion severity 30
Appendix 3: Gross pathology and histopathology for species, site and sampling occasion 36
Appendix 4: Concentrations (mg/kg) of metals and metalloids in gill, liver and muscle
sampled from A. graeffei at Bedford Weir and Tartrus Weir, and M. Ambigua at Fairbairn
Dam in September 2008, January 2009 and May 2009 41
Fitzroy River Fish Pathology Report May 2012
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Executive Summary
In November 2008, Professor Barry Hart prepared a report for the Queensland Government that
reviewed concerns over water quality in the Fitzroy River. The review addressed the potential
impacts associated with the discharge of water from the Ensham coal mine between February and
September 2008. The review recommended that the Biosecurity Queensland study that had been
conducted on the health of the fish in weirs in 2008, be repeated, to focus on other fish species
and storages, and with an improved study design. By late January 2009, heavy rainfall had
effectively flushed the mine water from the river system.
This report summarises the findings from an additional two sampling occasions which occurred in
January 2009 and May 2009. Sampling was undertaken at two reference sites that were
unaffected by the mine water discharge, and four investigation sites, that were downstream of the
discharge and potentially affected. Fish were sampled to determine their disease status and their
tissues were analysed for concentrations of a range of metals and metalloids.
The lack of baseline data (i.e. pre-impact data) for fish in the river systems of concern makes it
difficult to attribute differences between sites to the mine water discharge. Unfortunately, it is
common in impact assessments to only have comparisons between affected and non-affected
sites. Evidence of an effect and its size are therefore only suggestive.
The study did not identify any evidence by gross pathology (external and internal evidence of
disease) or histopathology (microscopic evidence of disease) associated with any significant
infectious agents of concern for fish health. A number of parasite species, both metazoan and
protozoan, were identified for each of the fish species examined, but both the variety and level of
infection in investigation sites were comparable with observations in reference samples. These
types of endemic parasites do not normally cause serious disease in wild fish populations in
freshwater systems.
Red marks and lesions were observed on the skin and fins of a number of fish in all sites. The fish
were tested for Epizootic Ulcerative Syndrome (EUS), otherwise known as red spot disease. EUS
was found in two bony bream, one from the Fitzroy Barrage and one from Bingegang Weir. The
cause of lesions in other fish remains unknown, however EUS has been ruled out. EUS is an
endemic ulcerative disease of fish caused by the fungus Aphanomyces invadans and occurs
spasmodically in fish along the east coast and in the Gulf of Carpentaria.
The major findings in the report include:
A large proportion of fish at investigation sites downstream of the mine water discharge did
display signs of ill-health but the proportion declined over time suggesting that a change in
water conditions had occurred.
Signs of ill-health were also apparent in areas that were not affected by the discharge of
Ensham mine water indicating that some signs were typical of these river systems and
potentially independent of mine water discharge.
A number of metals and metalloids were recorded in fish, with concentrations greater at the
investigation sites compared to the reference sites.
The concentration of many metals and metalloids in fish at investigation sites had diminished
over time to levels similar to those in fish at reference sites. This is consistent with a recovery
following cessation of discharge and flushing from heavy rainfall.
Fitzroy River Fish Pathology Report May 2012
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Background
The Ensham Coal Mine pits are situated adjacent to the Nogoa section of the Fitzroy River. On
19 January 2008, the pits were inundated with water following the flooding of the Emerald region
due to heavy rains.
Dewatering of the pits occurred over a period of seven months between 3 February 2008 and
9 September 2008 with approximately 138 gigalitres (GL) of water released. During the release, it
was reported that there was no significant dilution of the discharge as the river flow was very low,
except for the dewatering period from 19 June 2008 to 8 September 2008. During this period of
time, a reported rate of 69.3 megalitres (ML) per day from Fairbairn Dam mixed with the
discharged water. This volume amounted to approximately 5.7 GL or 4 per cent of the total
dewatering volume.
In conjunction with reports of the release of waters from the Ensham Coal Mine pits, communities
of Blackwater, Bluff and Tieri raised concerns regarding the water quality in the Fitzroy River
catchment in August 2008. A fisherman from Tartrus Weir reported several forked-tail catfish (Arius
graeffei) with redness of all fins and tails to Biosecurity Queensland on 2 September 2008.
Following these reports, Biosecurity Queensland participated in a whole-of-government response
and undertook a study in September 2008 of the Bedford and Tartrus Weirs. The aim of the study
was to examine the health of fish from gross pathological and histopathological perspectives. A
limited survey of fish health in the areas was undertaken with results indicating that the catfish
sampled from the sites were in poor health at that time i,ii,iii .
Professor Barry Hart was commissioned in late 2008 to review the situation regarding the
discharge of water from the Ensham Coal Mine pits and report findings and recommendations to
the Premier of Queensland. In November, Hart (2008) iv concluded there had not been any
catastrophic effects (e.g. major fish kills) on the fish population in the Nogoa-Mackenzie-Fitzroy
River system during the time of the Ensham Coal Mine water discharge. This conclusion was
consistent with available evidence indicating that most Australian adult fish species are relatively
tolerant of salinity increases, and unlikely to be adversely affected v,vi . Hart (2008) further stated
that there was no evidence of adverse effects on the aquatic biota due to metals and metalloids in
the pit water.
As part of the Hart (2008) review, the study undertaken by Biosecurity Queensland in September
2008 was assessed. The Hart review recommended that the “Biosecurity Queensland study of the
‘health’ of the fish in weirs be repeated with other fish species and other storages included, and the
study design improved’. The Hart review also commented that “it is not possible to relate the
results of this study back to the mine-affected water because there is no information on:
i
Department of Employment, Economic Development and Innovation. (2008). Fitzroy Catchment Fish Sampling and Health Assessment
Final Report 2008.
ii
Department of Environment and Resource Management. (2008). Ecosystem Heath Evaluation – Bedford Weir.
iii
Department of Environment and Resource Management. (2008). Ecosystem Health Evaluation – Tartrus Weir.
iv
Hart, B.T. (2008). Report to Queensland Premier – Review of the Fitzroy River Water Quality Issues.
v
Hart, B.T., Bailey, P., Edwards, R., James, K., Swadling, K., Meredith, C., McMahon, A. and Hortle, K. (1990). Effects of saline
discharges on aquatic ecosystems. Water Research, 24: 1103-1117.
vi
Hart, B.T., Bailey, P., Edwards, R., James, K., Swadling, K., Meredith, C., McMahon, A. and Hortle, K. (1990). Biological effects of
saline discharges to streams ad wetlands: a review. Hydrobiologia, 210: 105-144.
Fitzroy River Fish Pathology Report May 2012
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a. water quality in the weirs at the time of sampling (e.g. was dissolved oxygen concentration
low?)
b. the age of the fish, necessary to assess the potential bioaccumulation of metals and metalloids
c. the health or metal and metalloid concentrations of the fish species before the mine-affected
water was added to the system”.
In addition, the Hart (2008) review also recommended that the then Department of Environment
and Resource Management continue their study “because there is little baseline information
available, this study will be challenged in determining if any short-term biological impacts have
occurred due to the mine-affected water. For this reason, it is recommended that the study
continues for at least 2 years (3 wet-dry cycles) so that any recovery in the condition of the biota
can be measured”.
By late January 2009, flooding rainfall had effectively flushed the mine water from the system,
resulting in similar water quality between downstream ‘affected’ sites and sites upstream and
elsewhere vii .
This study, Fitzroy River Fish Pathology Report, was conducted in response to five
recommendations outlined in the Hart (2008) review.
Methods
Study design
The aim of this study was to describe the health of fish at a number of sites in the Fitzroy River
system over a nine month timeframe commencing in January 2009. Sampling was planned to be
conducted three times during this period at both ‘investigation’ sites (sites potentially affected by
mine water discharge) and ‘reference’ sites (sites not affected by mine water discharge), see
Figure 1.
The investigation sites chosen were:
Bedford Weir (also sampled in September 2008);
Tartrus Weir (also sampled in September 2008);
Bingegang Weir; and
Fitzroy Barrage.
The reference sites selected were:
Comet Weir; and
Moura on the Dawson River.
Samples of four species of fish were sought from each of the six sites during each sampling
occasion. The fish species were:
Fork-tailed catfish, Arius graeffei;
vii Tripodi, N. and Limpus, C. 2011. Assessment of the Fitzroy River Aquatic Ecosystem following the 2008 Discharge of
Coal Mine-affected Floodwaters from the Ensham Coal Mine. Report to Queensland Department of Environment and
Resource Management.
Fitzroy River Fish Pathology Report May 2012
6

Golden perch, Macquaria ambigua;
Sleepy cod, Oxyeleotris lineolatus; and
Saratoga, Scleropages leichardti.
Target numbers were five individuals from each of the four species to be collected from the six
sites described above during each sampling occasion (i.e. 5 x 4 x 6 = 120 fish). Animal ethics
approval (CA 2007/10/217) covered the ethical and scientific use of fish in this work.
The following data were scheduled to be collected for each fish:
body length and weight;
qualitative assessment of general fish health;
signs of clinical disease and exclusion of an infectious pathogen as the casual agent; and
concentration of a range of metals and metalloids.
The scope of this study did not extend to the collection of water for water quality parameters such
as dissolved oxygen and pH.
Figure 1: Map showing sites (solid red circles) where fish were sampled
Variations to study design
During the course of this study, four amendments were made to the study design. These were:
1. The investigation was limited to two sampling events. These were conducted in January and
May 2009.
Fitzroy River Fish Pathology Report May 2012
7

2. Fairbairn Dam, highlighted in Figure 1, also sampled in 2008, was chosen as a replacement
reference sampling site due to difficulty in accessing Comet Weir.
3. Scleropages leichardti was unavailable, so leathery grunter (Scortum hillii) and Bony Bream
(Nematolosa erebi) were sampled in addition to the other three target species.
4. Fish weights were not taken prior to necropsy. Fish length was used as an indicator of age.
Sampling method
Fish were collected by a combination of electro-fishing, gill nets or fyke nets. Fish that were caught
were kept live and placed in a basket held in the river until necropsy. This method of holding live
fish meant that supplementary aeration was not required. Water exchange occurred naturally with
the river water flow. When fish were required for necropsy, they were placed in a plastic container
filled with fresh river water and anaesthetised using anaesthetic AQUI-S (isoeugenol).
Once a fish reached an appropriate level of anaesthesia, it was removed from the AQUI-S bath
and placed on the necropsy table. Over a collection tray, the fish was rinsed down with distilled
water to remove any extraneous sediments/soil on the fish and skin mucus. The fish was then
placed on a dissecting board which had been wiped down with a 70 per cent ethanol spray and
tissue paper. A measurement of fish length was made, followed by photography of the whole fish
including the accession number for the sample and any external abnormalities of the fish.
While still anaesthetised, the cervical spine of the fish was severed with a pair of secateurs, which
had been wiped down with a 70 per cent ethanol spray and tissue paper, and the fish bled out to
complete euthanasia. Necropsy commenced as soon as possible to minimise possible post
mortem change due to high ambient temperature and humidity.
During necropsy, tissue samples, including gills, liver and muscle, were obtained from each fish
collected. For the full details on the process for fish necropsy and tissue collection for analysis,
see Appendix 1. Tissue samples for histology testing were prepared on site and held in 10 per cent
formalin while being transported to the Biosecurity Sciences Laboratory at Coopers Plains in
Brisbane. At the laboratory, fish tissues in formalin were trimmed into histology holding cassettes
and embedded in wax for processing, sectioning and staining by hematoxylin and eosin.
Tissue samples for metal and metalloid residue testing were prepared on site and kept frozen
during delivery to the Queensland Health Scientific Services Laboratory at Coopers Plains in
Brisbane.
Laboratory testing
Gross pathology
Fish were initially examined for external abnormalities. Gross signs related to handling were
identified as artifactual. The measurement of the fish length was then made and the fish
photographed against the accession number for the sample.
Histopathology
Histopathology was used to investigate the role, if any, of infectious and parasitic pathogens in the
health of the fish. Non-infectious abnormalities thought to be caused by environmental, physical or
nutritional factors were also assessed by histopathology.
Histopathology assessments were made on tissues including the eyes, gills, liver, heart, spleen,
spine, kidney, gastrointestinal tract, pancreas, skin/muscle and gonads. Prepared sections were
examined by light microscopy at 40x, 100x, 200x, 400x or 1000x magnification as required.
Fitzroy River Fish Pathology Report May 2012
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Diagnostic interpretation was made utilising fish pathology reference tests and experience with
previous fish pathology cases.
Metal and metalloid residues
Tissue samples were analysed for ten metals and metalloids: aluminium (Al), selenium (Se), iron
(Fe), cadmium (Cd), lead (Pb), chromium (Cr), copper (Cu), zinc (Zn), mercury (Hg) and arsenic
(As). All analyses were undertaken on a wet weight basis.
Each sample, as received, was homogenised and a sub-sample was taken for analysis. The
concentrations of metals and metalloids were analysed by ICP-MS after microwave digestion. The
analyses were carried out with appropriate standard reference materials, where available, as a
quality control for the recoveries of elements.
Statistical analysis of metal and metalloid residues
Residue concentrations were significantly skewed and so were log-transformed prior to analysis.
Residual Maximum Likelihood (REML) analyses were conducted using Genstat viii . The fixed effects
included treatment (reference vs investigation sites), time (January 2009 and May 2009), species
of fish, and tissue (gill, liver and muscle), along with their respective interactions as appropriate.
Sites (2 x reference, 4 x investigation) were taken as the random effect in the REML models.
Investigative general linear model analyses were also conducted, using sites as a fixed effect and
having no treatment effect. Where residues for Al, As and Hg were below the level of detection on
some samples, the standard assumption of taking half the limit of detection was adopted. The data
were weighted with the number of fish contributing to a sample. If an interaction was not significant
it was dropped from the model.
For A. graeffei and M. ambigua, the analyses were repeated with 2008 data included (i.e.
September 2008, January 2009 and May 2009).
To provide an overview, the concentrations of metals and metalloids in fish tissues in January and
May 2009 at all six sites was further examined using a principal component analysis ix . This
reduces a large number of variables into a smaller, more manageable set of new variables that are
correlated with the original set. The variables here are the concentrations (adjusted for species and
tissue in the generalised linear model above) of each of the metals and metalloids. The locations of
objects of interest, in this case the six sampling sites, can then be examined in the two or three
dimensional space described by the new variables. Most of the variation in the original variables is
explained in the first principal component, while the second principal component contains the next
most amount of the variation, and so on. The expectation was that the investigation sites would
move closer to the reference sites between January and May 2009.
viii
Payne, R.W., Harding, S.A., Murray, D.A., Soutar, D.M. Baird, D.B., Wlham, S.J., Kane, A.F., Gilmour, A.R., Thompson, R. and
Tunnicliffe Wilson, G. (2007). The Guide to Genstat Release 10, Part 2: Statistics. VSN International, Hemel Hempstead.
ix
Tabachnick, B.G. and Fidell, L.S. (1996). Using multivariate statistics. 3 rd edn. Harper Collins: New York.
Fitzroy River Fish Pathology Report May 2012
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Results
Fish catch summary
September 2008
A total of 15 target fish were collected for testing from three sites:
A. graeffei – 10 (10 from investigation sites)
M. ambigua – 5 (5 from reference sites).
January 2009
A total of 114 target fish were collected for testing from six sites:
A. graeffei – 24 (5 from reference sites; 19 from investigation sites)
M. ambigua – 21 (7 from reference sites; 14 from investigation sites)
O. lineolatus – 18 (6 from reference sites; 12 from investigation sites)
N. erebi – 30 (10 from reference sites; 20 from investigation sites)
S. hillii – 21 (9 from reference sites; 12 from investigation sites).
May 2009
A total of 114 target fish were collected for testing from six sites:
A. graeffei – 23 (6 from reference sites; 17 from investigation sites)
M. ambigua – 16 (4 from reference sites; 12 from investigation sites)
O. lineolatus – 19 (9 from reference sites; 10 from investigation sites)
N. erebi – 32 (10 from reference sites; 22 from investigation sites)
S. hillii – 24 (10 from reference sites; 14 from investigation sites).
Fish length
Fish length varied somewhat between samples at each site and time period (Table 1), but with no
consistent pattern and no significant differences between sites and sampling occasions for each
species. In some cases, (e.g. S. hillii in May 2009), there was a tendency for fish at references
sites to be larger than those sampled at investigation sites. The tendency would therefore be for
fish at reference sites to have higher metal and metalloid concentrations. The pooling of fish for the
metal and metalloid samples, along with the large number of missing values, precluded using
length as a covariate in the metals and metalloids analysis.
Gross pathology and histopathology
The gross pathology and histopathology findings for each of the sampling sites are summarised in
Table 2. These findings are further summarised in Table 3 by combining reference sites and
investigation sites. In both tables, the percentage of fish showing the pathology lesion type with
three levels of severity is given for each of the sampling occasions, pooled across species. For
descriptions of the pathology lesion types and the levels of severity, see Appendix 2. Notably,
sample size is low in September 2008 relative to January and May 2009.
At the reference sites, there is an increase in the incidence and severity of many pathology types
between September 2008 and May 2009. In contrast, at the investigation sites, there is a decrease
in the incidence of gill-related pathologies between September 2008 and May 2009. There is also a
decrease in the incidence of melanomacrophage centres over this period.
Fitzroy River Fish Pathology Report May 2012
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Table 1: Average ± standard error (s.e.) fish length (cm) in samples at the six sites in January and
May 2009
Species
A. graeffei
M. ambigua
O. lineolata
Legend:
N. erebi
S. hillii
Jan 2009 May 2009
Site
Standard
Standard
Average
Average
error
error
Fairbairn Dam - N/A - N/A
Moura, Dawson River 46.2 1.5 35.1 2.4
Bedford Weir 39.5 2.3 34.5 2.0
Bingegang Weir 41.0 5.3 25.2 2.2
Tartrus Weir 34.0 * 34.5 4.8
Fitzroy Barrage 40.0 * 38.0 6.0
Fairbairn Dam 24.0 3.3 22.0 N/A
Moura, Dawson River 38.0 1.3 34.5 0.8
Bedford Weir - N/A 23.0 5.5
Bingegang Weir 29.6 1.4 33.7 1.4
Tartrus Weir 31.6 3.6 26.0 2.4
Fitzroy Barrage 15.5 0.9 - N/A
Fairbairn Dam 31.0 * 31.5 2.9
Moura, Dawson River 28.8 2.2 32.3 2.2
Bedford Weir 29.3 4.5 - N/A
Bingegang Weir 31.3 3.3 26.4 1.5
Tartrus Weir 31.8 3.7 - N/A
Fitzroy Barrage - N/A 34.7 3.3
Fairbairn Dam 21.1 2.5 27.2 1.1
Moura, Dawson River 22.3 2.7 25.2 1.8
Bedford Weir 28.4 1.7 25.6 0.2
Bingegang Weir 23.5 0.8 25.1 1.2
Tartrus Weir 26.7 3.9 24.7 2.0
Fitzroy Barrage - N/A 24.3 1.7
Fairbairn Dam 21.8 0.9 32.5 2.9
Moura, Dawson River 27.8 2.6 32.6 0.2
Bedford Weir - N/A 20.0 3.1
Bingegang Weir 31.8 0.6 19.8 1.4
Tartrus Weir 24.8 3.4 24.7 0.9
Fitzroy Barrage - N/A 26.5 *
Fitzroy Barrage 40.0 * 38.0 6.0
- – length not recorded
N/A – not available due to no length measurement
* – One length recorded, standard error not available
Comparing investigation and reference sites at each time period (Table 3), there was a higher
incidence of gill-related pathologies, parasites and melanomacrophages centres at investigation
sites in September 2008. The incidence of gill-related pathologies and melanomacrophage centres
at the investigation sites were only marginally higher than their incidence at the reference sites in
January 2009. Incidence of organ congestion, gonad lesions and parasites and other lesions were
also higher at the investigation sites in January 2009. In May 2009, the incidence of severe gillrelated
pathologies and the incidence of melanomacrophage centres at investigation sites were
lower than their incidence at the reference sites.
Red marks and lesions were observed on the skin and fins of a number of fish at all sites. EUS
(red-spot disease) was diagnosed in the May 2009 samplings in one bony bream from the Fitzroy
Barrage in May 2009 and one bony bream from the Bingegang Weir in May 2009.
Fitzroy River Fish Pathology Report May 2012
11

Table 2: Percentage of fish with lesions and their severity for all species combined for the
reference and investigation sites during the September 2008, January 2009 and May 2009
sampling occasions
Site Reference Site 1
Reference
Site 2
Investigation Site 1
Investigation Site 2
Investigation
Site 3
Investigation
Site 4
Severity
Fairbairn Dam
Moura,
Dawson
River
Jan May
09 09
Bedford Weir
Tartrus Weir
Bingengang
Weir
Fitzroy
Barrage
Sampling occasion Sep
08
Jan
09
May
09
Sep
08
Jan
09
May
09
Sep
08
Jan
09
May
09
Jan
09
May
09
Jan
09
May
09
Total no. of fish 5 16 16 21 23 5 15 15 5 30 21 22 23 10 16
collected
Pathology Lesion Type (%)
Gill hyperplasia M - 38 12 29 26 60 33 13 - 23 10 27 - - 31
D 40 12 12 5 30 40 27 33 20 33 52 27 61 - 12
S 20 - 6 - 22 - - 13 80 - - - 17 - -
Gill lamellar lifting
Bronchitis
Lamellar fusion
Granulomasnematodes
etc
Trematodes
Cestodes
Gill/skin parasites
Melanomacrophage
centres
Kidney eosinophilic
change
Kidney vacuolar
change
Organ congestion
Myopathy
Gonad lesion,
parasites
Other lesions
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
40
-
-
40
20
-
-
-
-
-
-
-
40
40
-
-
-
-
-
-
-
40
40
-
-
25
-
-
-
-
19
-
-
25
25
6
25
-
-
6
-
-
31
-
-
-
12
-
-
19
-
-
-
-
-
6
-
31
-
-
-
-
-
-
6
-
-
6
6
-
-
-
6
-
19
38
12
-
19
-
-
12
-
-
31
-
-
31
6
12
6
6
-
-
-
-
-
31
6
-
-
-
-
-
-
19
-
-
5
-
-
-
-
-
5
-
-
38
-
-
62
-
5
19
-
-
19
-
5
24
29
5
14
-
-
-
-
-
-
10
-
5
-
-
-
-
-
29
-
-
4
13
17
-
9
17
-
17
4
39
-
13
57
4
4
9
-
-
43
-
-
39
35
22
-
-
-
4
4
-
-
17
9
-
-
-
4
-
-
17
-
-
40
40
-
-
-
-
20
-
-
-
-
-
80
-
-
-
-
-
60
-
-
40
40
-
-
-
-
-
-
-
-
60
-
-
-
-
-
-
-
7
20
-
20
13
-
-
-
-
33
-
7
33
-
-
-
-
-
27
-
-
33
-
13
-
13
-
-
-
-
-
-
7
40
-
-
-
-
-
-
20
-
-
13
7
7
7
7
-
7
7
40
-
-
7
-
-
13
7
-
40
20
-
-
-
-
-
20
-
-
47
-
7
-
-
-
-
-
20
-
-
-
60
20
-
-
-
60
-
-
40
-
-
40
-
-
-
-
-
20
-
-
40
60
-
-
-
-
-
-
-
-
80
-
-
-
-
-
-
-
17
-
-
-
3
-
17
-
-
27
3
23
33
7
-
10
-
-
63
-
13
27
10
13
-
-
-
-
7
-
-
10
-
10
-
-
7
3
3
-
19
-
-
19
-
5
-
5
24
24
10
43
14
5
24
-
-
52
-
10
52
10
-
-
-
-
-
-
-
-
24
Legend: - – pathology lesion type not observed M – mild D – moderate S – severe
20
60
-
13
73
-
80
-
-
7
-
-
-
-
-
-
-
5
-
24
5
24
-
9
-
-
-
-
5
-
-
45
-
9
36
-
9
-
-
-
41
-
-
23
14
18
-
-
-
-
-
-
-
23
-
-
-
-
-
9
-
23
9
-
4
17
-
-
17
-
-
9
4
22
17
17
43
4
-
9
-
-
48
-
-
43
4
4
4
9
-
-
35
-
-
52
4
13
-
-
4
-
-
26
4
13
-
10
-
-
-
-
10
-
-
30
10
-
60
-
-
10
-
-
50
-
-
30
10
20
-
-
-
-
-
-
-
20
-
-
-
-
10
-
-
-
-
-
12
19
-
6
12
-
6
-
-
75
6
-
44
-
12
12
-
-
25
6
-
31
12
6
-
-
6
6
6
-
-
19
25
-
6
-
6
-
-
6
12
-
Fitzroy River Fish Pathology Report May 2012
12

Table 3: Percentage of fish with lesions and their severity for all species combined for the
reference sites combined and the investigation sites combined for the September 2008, January
2009 and May 2009 sampling occasions
Site Reference Sites Combined Investigation Sites Combined
Sampling occasion Sep 08 Jan 09 May 09 Sep 08 Jan 09 May 09
Total no. of fish collected 5 37 39 10 77 75
Pathology Lesion Type
Gill hyperplasia
M -
32
21
30
23
12
D 40
8
23
30
26
43
S 20
-
15
40
-
8
Total %
60 40 59 100 49 55
Gill lamellar lifting
Bronchitis
Lamellar fusion
Total %
Total %
Total %
Granulomas-nematodes etc
Trematodes
Cestodes
Gill/skin parasites
Total %
Total %
Total %
Total %
Melanomacrophage centres
Total %
Kidney eosinophilic change
Total %
Kidney vacuolar change
Organ congestion
Myopathy
Total %
Total %
Total %
Gonad lesion, parasites
Total %
Severity
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
M
D
S
-
-
-
3
11
-
3
10
13
20
50
10
8
9
-
4
19
-
0 14 26 80 17 23
-
-
-
-
-
-
-
-
-
-
-
-
4
4
-
1
16
1
0 0 0 0 8 18
-
-
-
11
-
-
3
10
10
0 0 23 40 9 12
-
-
-
32
11
3
38
5
8
20
-
-
34
13
3
29
15
9
0 46 51 20 50 53
-
-
-
46
-
3
41
3
3
0 49 47 60 44 52
-
-
-
14
-
-
10
-
-
-
-
-
5
-
-
13
-
-
0 14 10 0 5 13
40
-
-
24
-
3
38
-
-
40 27 38 40 53 43
40
20
-
14
22
3
36
23
18
40
-
-
60
-
-
40
-
-
40
50
-
60 39 77 90 52 57
-
-
-
8
8
-
3
3
-
-
-
-
-
3
-
1
3
1
0 16 6 0 3 4
-
-
-
40
40
-
-
-
-
-
-
-
-
-
-
9
-
-
38
3
3
48
-
5
27
9
16
-
3
-
4
4
4
43
5
4
37
3
3
43
11
3
1
16
-
0 0 0 0 3 17
-
-
-
-
-
8
23
70
13
36
-
8
-
1
7
80 8 31 70 14 43
-
-
-
16
-
-
-
-
-
-
-
-
12
-
-
5
1
-
0 16 0 0 12 6
-
-
-
-
-
-
-
-
-
0 0 0 0 9 4
16
18
50
12
20
3
-
30
17
5
-
-
-
-
11
Other lesions
M
D
S
40
40
-
Total %
80 19 18 80 29 36
Legend: - – pathology lesion type not observed M – mild D – moderate S – severe
-
-
-
4
4
1
3
1
-
Fitzroy River Fish Pathology Report May 2012
13

Metal and metalloid residues
Changes in the concentrations of metals and metalloids in fish tissues over time are presented in
five ways.
1. Average concentrations of each metal and metalloid at each site in each time period were
tabulated. These concentrations are the adjusted means from the overall analysis, so are
correctly balanced for any missing values (primarily, when a fish species was not captured at
a location on a date).
2. These adjusted concentrations of individual metals and metalloids at each site in January and
May 2009 are also expressed as a percentage of the mean concentration for two reference
sites across both time periods.
3. Plots of metal and metalloid concentrations in fish over time for each site and metal and
metalloid.
4. Following the principal component analysis, the location of each site and time combination
was graphed in two dimensions described by the first two principal components.
5. Significant differences in metal and metalloid concentrations for particular tissues and species
between reference and investigation sites were identified separately for January and May
2009.
Adjusted mean concentrations of metals and metalloids at each site in January and May 2009 are
shown in Table 4. Notably high values are Al, Fe, Cr and Cd at Bedford Weir in January 2009.
The percentage differences between adjusted concentrations of metals and metalloids at each site
relative to the average at reference sites over January and May 2009 are shown in Figure 2.
Separate calculations were made for January and May 2009. There is considerable variation
among metals and metalloids, even at the reference sites. Particularly high values (>200%) in
January 2009 are for Al (328%), Cr (326%) and Se (289%) at Bedford Weir, and Al (237%) at
Bingegang Weir, and Cr (243%) and Se (249%) at Tartrus Weir. In May 2009, Al (222%) was
particularly high at Tartrus Weir.
The relevant comparisons in Figure 2 are between January and May 2009 for the four investigation
sites. For each site, there is a tendency for most metals and metalloids to be closer to 100% (i.e.
closer to the reference site concentrations) in May than in January. This is most noticeable for
Bedford Weir, which is the site closest downstream to the mine water discharge.
Adjusted concentrations of metals and metalloids at each site in January and May 2009 are shown
in Figure 3. Improvement in fish health would be seen as a shift in metal and metalloid
concentration in fish at investigation sites to concentrations recorded in fish at reference sites. This
was seen for at least some investigation sites for Cr, Fe, Al, Se and Cd. In these cases, metal and
metalloid concentration at Bedford Weir and sometimes other investigation sites were higher than
reference site concentrations in January and declined to be at a similar concentration in May.
For other metals and metalloids, there was no clear pattern of an initial state of relatively elevated
concentration followed by a decline. Fish at all sites had similar concentrations of Cu, while
concentrations of As declined at all sites except for the Dawson River reference site. Hg
concentration was highest at the reference sites, declining at these and two of the investigation
sites. Pb concentrations in fish actually increased at the two reference sites and two of the
investigation sites.
Actual concentrations of metals and metalloids at each site in September 2008, January 2009 and
May 2009 are shown in Appendix 3. For each metal and metalloid, there are two investigation sites
and one reference site. A different species of fish was sampled at the latter. Despite the limited
Fitzroy River Fish Pathology Report May 2012
14

sample size and different fish species sampled, it was still of interest to see if there were declines
in metal and metalloid concentrations in fish at investigation sites relative to the reference site.
There is a striking decline for Cr at Tartrus Weir. However, for other cases, the changes are either
small, not maintained over time (e.g. increase again in May 2009) or mirrored and at the same
concentration at the reference site.
Table 4: Adjusted mean concentrations (mg/kg) of metals and metalloids in all species at the
reference and investigation sites during the January and May 2009 sampling occasions
Time Location Fe Al Cr Cu Zn As Se Cd Hg Pb
Jan Fairbairn Dam 29.81 5.36 0.04 1.08 17.08 0.05 0.52 0.02 0.11 0.04
2009 Moura, Dawson River 31.69 2.09 0.03 1.01 23.36 0.17 0.64 0.01 0.10 0.04
Bedford Weir 59.56 10.72 0.13 0.83 21.12 0.20 1.70 0.02 0.06 0.03
Tartrus Weir 37.64 4.85 0.09 1.22 23.20 0.18 1.46 0.02 0.07 0.03
Bingegang Weir 37.34 7.75 0.05 1.01 19.38 0.20 0.93 0.01 0.05 0.03
Fitzroy Barrage 30.72 2.01 0.03 1.03 16.81 0.21 1.14 0.02 0.04 0.03
May
2009
Fairbairn Dam 38.94 3.87 0.05 1.04 21.65 0.08 0.68 0.01 0.09 0.07
Moura, Dawson River 27.06 1.76 0.02 0.79 17.27 0.14 0.51 0.02 0.07 0.07
Bedford Weir 26.63 5.55 0.03 0.91 20.41 0.15 0.75 0.01 0.03 0.03
Tartrus Weir 29.67 7.24 0.03 0.66 16.54 0.10 0.63 0.01 0.04 0.11
Bingegang Weir 31.98 5.09 0.04 0.81 21.41 0.11 0.82 0.01 0.07 0.03
Fitzroy Barrage 42.06 2.81 0.06 1.09 22.92 0.10 0.81 0.01 0.06 0.07
The principal component analysis reduced the ten metals and metalloids to two variables or
components that explained 60% of the variation in the original data from January and May 2009.
The six sites are graphed in the two-dimensional space described by these new variables in Figure
4. In January 2009, the reference sites occupy an area in the top left-hand corner of the plot,
whereas the investigation sites tend to be in the bottom right-hand corner. Improvement in fish
health would be seen as a spatial shift in the investigation sites towards the reference sites. This
occurs for Bingegang Weir and Fitzroy Barrage, but not Bedford and Tartrus Weirs. The latter two
sites shift in the expected direction along the first principal component, but not the second.
However, this shift is in parallel with the temporal (January to May) shift observed in the Dawson
River reference site.
Tables 5 and 6 identify metals and metalloids whose concentrations in fish tissues differed
significantly between reference and investigation sites in January and May 2009, respectively.
What is noteworthy is that there are fewer significant cases for May 2009 than in January 2009. By
May 2009, Al and As no longer differ between sites, but Cu now does, albeit at a marginally
significant level. Similarly, N. erebi and A. graeffei are no longer affected in May. However,
differences in Se are maintained across three species.
The statistical results reported in Tables 5 and 6 are consistent with the patterns described above.
Figure 2 suggests that the disparity in Se concentrations between sites is diminishing.
Finally, the data can also be used to indicate which species of fish and tissue should be targeted
for future monitoring. The best candidates are likely to be those fish and tissues with the highest
concentrations of each metal and metalloid, but particularly those apparently affected by the mine
water discharge as identified above (i.e. Se, Al and possibly Cr). The liver of N. erebi had the
highest concentration of Al and As and was within 20% of the highest value for Cd and Cr. Liver of
A. graeffei recorded the highest concentrations of Cu, Fe, Hg, Se and Zn. Liver of M. ambigua was
within 20% of the maximum concentration recorded for Se. Gill of S. hillii recorded the highest
concentration of Pb.
Fitzroy River Fish Pathology Report May 2012
15

Figure 2: The percentage difference between adjusted concentrations of metals and metalloids at each site relative to the average at reference
sites over January and May 2009. Percentage differences >200% are given in the text.
(a) Fairbairn Dam, January 2009, (b) Fairbairn Dam, May 2009, (c) Dawson River, January 2009, (d) Dawson River, May 2009, (e) Bedford
Weir, January 2009, (f) Bedford Weir, May 2009, (g) Bingegang Weir, January 2009, (h) Bingegang Weir, May 2009, (i) Tartrus Weir, January
2009, (j) Tartrus Weir, May 2009, (k) Fitzroy Barrage, January 2009, (l) Fitzroy Barrage, May 2009.
Fairbairn Dam, Jan.
Fairbairn Dam, May
200
200
Percentage
100
Percentage
100
0
Fe Al Cr Cu Zn As Se Cd Hg Pb
0
Fe Al Cr Cu Zn As Se Cd Hg Pb
Fitzroy River Fish Pathology Report May 2012 16

Dawson River, Jan.
Dawson River, May
200
200
Percentage
100
Percentage
100
0
Fe Al Cr Cu Zn As Se Cd Hg Pb
0
Fe Al Cr Cu Zn As Se Cd Hg Pb
Bedford Weir, Jan.
Bedford Weir, May
200
200
Percentage
100
Percentage
100
0
Fe Al Cr Cu Zn As Se Cd Hg Pb
0
Fe Al Cr Cu Zn As Se Cd Hg Pb
Fitzroy River Fish Pathology Report May 2012 17

Bingegang Weir, Jan.
Bingegang Weir, May
200
200
Percentage
100
Percentage
100
0
Fe Al Cr Cu Zn As Se Cd Hg Pb
0
Fe Al Cr Cu Zn As Se Cd Hg Pb
Tartarus Weir, Jan.
Tartarus Weir, May
200
200
Percentage
100
Percentage
100
0
Fe Al Cr Cu Zn As Se Cd Hg Pb
0
Fe Al Cr Cu Zn As Se Cd Hg Pb
Fitzroy River Fish Pathology Report May 2012 18

Fitzroy Barrage, Jan.
Fitzroy Barrage, May
200
200
Percentage
100
Percentage
100
0
Fe Al Cr Cu Zn As Se Cd Hg Pb
0
Fe Al Cr Cu Zn As Se Cd Hg Pb
Fitzroy River Fish Pathology Report May 2012 19

Figure 3: Adjusted (for fish species and tissue) concentrations (mg/kg) of metals and metalloids in fish at reference (open symbols) and
investigations sites (closed symbols) in January and May 2009.
(a) chromium, (b) copper, (c) iron, (d) aluminium, (e) zinc, (f) arsenic, (g) selenium, (h) cadmium, (i) mercury, and (j) lead.
Arrows connect samples taken in January and May 2009
Cr
Cu
Fe
0.15
Bedford Weir
Bingegang Weir
Dawson River
Fairbairn Dam
Fitzroy Barrage
Tartarus Weir
1.5
80
60
Bedford Weir
Bingegang Weir
Dawson River
Fairbairn Dam
Fitzroy Barrage
Tartarus Weir
0.1
1
Concentration
Concentration
Concentration
40
0.05
0.5
Bedford Weir
Bingegang Weir
Dawson River
Fairbairn Dam
Fitzroy Barrage
Tartarus Weir
20
0
Jan 2009 May 2009
0
Jan 2009 May 2009
Jan 2009 May 2009
Fitzroy River Fish Pathology Report May 2012 20

Al
Zn
As
12
10
Bedford Weir
Bingegang Weir
Dawson River
Fairbairn Dam
Fitzroy Barrage
Tartarus Weir
25
Bedford Weir
Bingegang Weir
Dawson River
Fairbairn Dam
Fitzroy Barrage
Tartarus Weir
0.25
0.2
Bedford Weir
Bingegang Weir
Dawson River
Fairbairn Dam
Fitzroy Barrage
Tartarus Weir
Concentration
8
6
Concentration
20
Concentration
0.15
0.1
4
0.05
2
Jan 2009 May 2009
15
Jan 2009 May 2009
0
Jan 2009 May 2009
Fitzroy River Fish Pathology Report May 2012 21

Se
Cd
Hg
2
1.5
Bedford Weir
Bingegang Weir
Dawson River
Fairbairn Dam
Fitzroy Barrage
Tartarus Weir
0.025
0.02
Bedford Weir
Bingegang Weir
Dawson River
Fairbairn Dam
Fitzroy Barrage
Tartarus Weir
0.15
0.1
Bedford Weir
Bingegang Weir
Dawson River
Fairbairn Dam
Fitzroy Barrage
Tartarus Weir
Concentration
1
Concentration
0.015
0.01
Concentration
0.05
0.5
0.005
0
Jan 2009 May 2009
0
Jan 2009 May 2009
0
Jan 2009 May 2009
Fitzroy River Fish Pathology Report May 2012 22

Pb
0.15
0.1
Bedford Weir
Bingegang Weir
Dawson River
Fairbairn Dam
Fitzroy Barrage
Tartarus Weir
Concentration
0.05
0
Jan 2009 May 2009
Figure 4: Location of sites in space described by the first two principal components, which explains
60% of the variation in the original metal and metalloid concentrations
Arrows connect samples taken in January and May 2009.
2.5
2
Fair_Jan
Fair_May
1.5
Daws_Jan
Fitz_May
Dimension 2 (19% variation)
1
0.5
0
-0.5
Daws_May
Bing_May
Bing_Jan
Tart_Jan
Bedf_Jan
-1
-1.5
Tart_May
Bedf_May
Fitz_Jan
-2 -1 0 1 2 3 4 5
Dimension 1 (41% variation)
Fitzroy River Fish Pathology Report May 2012 23

Table 5: Tissue samples from fish at investigation sites (I) with metal and metalloid concentrations
(mg/kg) significantly (P

Discussion
Gross pathology and histopathology
Improvement in health of a population can be difficult to quantify. At a subjective level, the
pathologist performing the necropsies in this project noted that fish health appeared to have
improved in 2009 compared with the limited samples from 2008. This is consistent with the trends
in fish pathology reported in Tables 2 and 3. The improvement coincided with a cessation of large
mine-affected water discharges and flushing rains in late January 2009 between the three
sampling occasions.
This overall conclusion needs to be made cautiously. There were no baseline (i.e. pre-impact) data
on fish health in this river system with which to compare post-impact data and thus draw strong
inference. Unfortunately, this is a common problem in impact studies. Nevertheless, some
assessment can be made through comparing affected and unaffected areas as has been done
here. The problem is that there is invariably environmental variation between sites and this may
translate into differences in fish health and concentrations of metals and metalloids in fish tissues,
making it difficult to ascribe differences between affected and unaffected sites to an event such as
mine water discharge. However, trends in health or metal and metalloid concentration can be more
appropriately compared between sites. Evidence of an impact and its size can thus be
strengthened by monitoring over time if affected sites display an expected recovery.
The sampling in September 2008, immediately post-impact, was limited as it involved only two
species of fish (10 individuals) at two investigation sites and a different species sampled (5
individuals) at one reference site. In addition, the small sample size (n=10 at investigation sites;
n=5 at the reference site) makes it difficult to generalise. Sampling in 2009 was more substantial
and indicated two contrasting trends in fish health. Fish health, while initially poorer at investigation
sites, appeared to be improving there over time, but the trend was opposite at the reference sites.
Skin and gill parasites are common in fish and in small numbers cause little harm. The response
they evoke may vary from almost negligible and mild to severe and extensive causing lesions and
tissue damage as well as producing side affects such as hyperplasia. Hyperplasia, fusion and
necrosis are the dominant type of lesion with the most common response to the irritation being
hyperplasia – an abnormal increase in the number of cells in an organ, in this case the gill
epithelium. Many of the fish species had low levels of gill parasitism, however the pathologist
noted that not all fish displaying gill hyperplasia were affected by parasites.
Melanomacrophage centres are a common histological observation in fish kidney, liver and spleen.
The presence and size of melanomacrophage centres is known to vary between different fish
species and tissue types. Many biological functions are ascribed to melanomacrophage centres,
including processing of endogenous and exogenous waste material and immune responses. An
increase in the presence or size of melanomacrophage centres is often reported in fish exposed to
metals and metalloids, but other factors such as age, diet, starvation, disease and exposure to
other pollutants may also be contributing factors and have not been ruled out by the sampling
conducted in this study. It is unknown whether the increase in presence or size of
melanomacrophage centres has long-term implications for fish health in the Fitzroy catchment.
Epizootic Ulcerative Syndrome, recorded in two fish in May 2009, is an endemic ulcerative disease
of fish caused by the fungus Aphanomyces invadans and occurs spasmodically in fish along the
Fitzroy River Fish Pathology Report May 2012
25

east coast and in the Gulf of Carpentaria. The disease is most commonly seen when there are low
temperature and heavy rainfall in tropical and sub-tropical waters x .
Metal and metalloid residues
As with the pathology results, the lack of baseline (i.e. pre-impact) data on metal and metalloid
concentration makes it difficult to ascribe differences between the sites to the mine water
discharge. For many metals and metalloids, there is substantial site-to-site variation in their
concentrations in fish tissues. For example, mercury concentrations were lower in fish at the
investigation sites than in fish at the reference sites, suggesting pre-existing site-specific variation.
This compromises an assessment of mercury contamination of the waterway from the mine water
discharge. Nevertheless, an assessment of the trends in the concentrations of metals and
metalloids should still be valid. To that end, an expected decline in concentration in at least some
metals and metalloids was observed at investigation sites by May 2009.
Regardless of these difficulties, there is good suggestive evidence that some metal and metalloid
concentrations were elevated in fish tissue at sites downstream of the mine water discharge.
Selenium and aluminium were of concern. There is also support for a reduction in the
concentrations of these metals and metalloids over time at investigation sites. This was most
noticeable at Bedford Weir, the investigation site closest downstream to the mine water discharge.
Unfortunately, inclusion of the 2008 data did not clarify any of the patterns observed in just the
2009 data. The 2008 data were limited in that fewer sites and fish species were sampled.
x
Bondad-Reantaso, M. G., Lumanlan, S. C., Natividad, J. M. and Phillips, M. J. (1992). Environmental monitoring of the epizootic
ulcerative syndrome (EUS) in fish from Munoz, Nueva Ecija in the Philippines. In: Shariff, M., Subasinghe, R. P, Arthur, J. R. eds.
Diseases in Asian Aquaculture 1. Manila, The Philippines: Fish Health Section, Asian Fisheries Society, 475-490.
Fitzroy River Fish Pathology Report May 2012
26

Appendix 1: Fish sampling procedure
Flow of sampling:
a. Sample gill for histology
b. Sample gill for metals and metalloids
c. Gill scraping
d. Skin scraping
e. Examine gill and skin scrapings under microscope
f. Open fish abdomen
g. Sample liver for histology
h. Sample liver for metals and metalloids
i. Sample internal organs for histology
j. Sample muscle for histology
k. Sample muscle for metals and metalloids
A. Perform a gill scraping (use external instrument set)
1. Open the gill cover
2. Using scissors snip 2-3 tips of the gill filaments
3. Place the sample on a clean glass slide
4. Add 2-3 drops of water to the sample
5. Cover sample with a glass cover slip
6. Label the slide with the fish number
B. Perform a skin scraping (use external instrument set)
1. Attach a clean blade to the scalpel handle
2. Using the blunt edge of a scalpel, scrape from the head to tail direction the skin mucus of
the fish. Some scales may be included
3. Place the sample on a clean glass slide
4. Add 2-3 drops of water to the sample
5. Cover sample with a glass cover slip
6. Label the slide with the fish number
C. Examine the gill and skin scraping samples under the light microscope
7. Adjust the focus and light intensity
8. Use the 4X objective first
9. Then use the 10X and 20X objectives for more magnification
10. Photograph any parasites that may be found in the samples
D. Dissect and observe the internal organs of the fish specimen
Part I. Tissues for metal and metalloid analysis
1. Use external sample instruments for gills/skin-muscle. Use internal sample instruments for
liver. Alternatively, if only a single set of instruments is available, then, clean and rinse
down the instruments with 70% ethanol and distilled water prior to working on internal
Fitzroy River Fish Pathology Report May 2012
27

organs or between fish or batches of fish. Take photograph of any gross abnormality with
the identifying accession no. 1. Remove the gill cover to expose the gills. With scissors, cut
1 gill arch. Rinse gill sample with distilled water. Place in yellow top sterile plastic bottle.
Label – ‘gills’ and add accession sticker. Pool 5 gills from 5 fish into 1 bottle of the same
species of fish.
2. Cut open the abdominal flank muscle. Identify following organs: heart, liver, stomach,
spleen, intestines, gall bladder, swim bladder, kidney-spinal cord, pyloric caeca and
gonads.
3. Cut a 1 cm X 1cm X 1 cm piece of liver. Rinse liver sample with distilled water. Place in
yellow top sterile plastic bottle. Label – ‘liver’ and add accession sticker. Pool 5 liver
samples from 5 fish into 1 bottle of the same species of fish.
4. Using a new scalpel blade, cut a 1 cm X 1cm X 1 cm piece of muscle with skin from the
dorsal flank area. Rinse muscle with distilled water. Then place in yellow top sterile plastic
bottle. Label – ‘muscle’ and add accession number. Pool 5 muscle samples from 5 fish into
1 bottle of the same species of fish.
5. Place bottles of gill, liver and muscle samples into the freezing-refrigeration unit.
6. Wipe down instruments with 70% ethanol using paper tissues.
Part II. Histology sampling
1. Use external sample instruments for gills/skin-muscle. Use internal sample instruments for
internal organs. Alternatively, if only a single set of instruments is available, then, clean and
rinse down the instruments with 70% ethanol and distilled water prior to working on internal
organs. Take photograph of any gross abnormality with the identifying accession number.
2. Remove the gill cover to expose the gills. With scissors, cut 1 gill arch and place in 10%
formalin bottle.
3. Sample up to 1 cm x 1 cm x 1 cm piece of liver, stomach, spleen, intestines, gall bladder,
swim bladder, kidney-spinal cord, pyloric caeca and gonads. Sample whole heart. Place
these into the 10% formalin bottle.
4. Open the skull, exposing the brain. Remove the brain. Remove an eye. Place the brain and
eye into the 10% formalin bottle.
5. With a scalpel blade, cut a 1 cm x 1 cm x 1 cm piece of skin with muscle including the
lateral line - place these into the 10% formalin bottle.
6. Tissues from 5 fish can be placed into 1 formalin bottle. Wipe down instruments with 70%
ethanol using paper tissues.
E. Measures to exclude contamination risks of samples for metals and metalloids analysis –
Fish caught should be held in water collected from the river of which the sampling site is set
up.
Avoid holding fish from different sites together in the same live fish tank.
Do not use water from other sites to keep fish caught in the sampling area/site.
Rinsing down of whole fish with distilled water from the catch/euthanasia container to remove
any attached sediment/mucus before necropsy.
Rinsing of tissues for metals and metalloids analysis in distilled water prior to placement into
sterile containers.
Use new sterile, packed instruments and scalpel blades for each batch of fish. A batch of fish
is fish of the one species sampled from one site.
Different sets of instruments for external (gills, skin-muscle) and internal (viscera/brain) tissue
samples, or clean instruments between uses with distilled water and 70% ethanol.
Fitzroy River Fish Pathology Report May 2012
28

Wipe down of dissection board with 70% ethanol and paper tissues.
Wear new and clean gloves for each batch of fish.
Tissue samples were held in 10% formalin and transported by road to the Biosecurity
Sciences Laboratory.
Tissue samples including gills, liver and muscle were prepared on site and kept frozen in a
freezer for metals and metalloids residue analysis. Samples were kept frozen using a portable
freezer unit during delivery to the Queensland Health Scientific Services Laboratory.
Fitzroy River Fish Pathology Report May 2012
29

Appendix 2: Pathology lesion severity
Pathology Lesion Type Mild Moderate Severe
Gill hyperplasia
The section of gill
showing primary
filaments and secondary
lamellae demonstrating
filling of the interlamellar
space with gill epithelial
cell types between the
secondary lamellae to up
to 25% of the space.
The section of gill
showing primary
filaments and secondary
lamellae demonstrating
filling of the interlamellar
space with gill epithelial
cell types between the
secondary lamellae to up
to 50% of the space.
The section of gill
showing primary
filaments and secondary
lamellae demonstrating
filling of the interlamellar
space with gill epithelial
cell types between the
secondary lamellae to
greater than 50% of the
space.
Gill lamellar lifting
The section of gill
showing secondary
lamellae where the
epithelial membrane
which is normally
attached to the epithelial
cells is detached from
those cells in up to 25%
of the section.
The section of gill
showing secondary
lamellae where the
epithelial membrane
which is normally
attached to the epithelial
cells is detached from
those cells in up to 50%
of the section.
The section of gill
showing secondary
lamellae where the
epithelial membrane
which is normally
attached to the epithelial
cells is detached from
those cells in greater
than 50% of the section.
Branchitis
The section of gill
showing an infiltration of
the subepithelial space
with inflammatory cells
such as lumphocytes,
macrophages in up to
25% of the section.
The section of gill
showing an infiltration of
the subepithelial space
with inflammatory cells
such as lumphocytes,
macrophages in up to
50% of the section.
The section of gill
showing an infiltration of
the subepithelial space
with inflammatory cells
such as lumphocytes,
macrophages in greater
than 50% of the section.
Lamellar fusion
The section of gill
showing a complete loss
of the interlamellar space
with adjacent lamellae
joined together in up to
25% of the section.
The section of gill
showing a complete loss
of the interlamellar space
with adjacent lamellae
joined together in up to
50% of the section.
The section of gill
showing a complete loss
of the interlamellar space
with adjacent lamellae
joined together in greater
than 50% of the section.
Granulomas-nematodes
etc
The section of organ
(e.g. stomach, gut etc)
with the presence of
encapsulating lesions
comprised of
inflammatory cells,
fibrous connective tissue
and degenerate cellular
material or nematode
The section of organ
(e.g. stomach, gut etc)
with the presence of
encapsulating lesions
comprised of
inflammatory cells,
fibrous connective tissue
and degenerate cellular
material or nematode
The section of organ
(e.g. stomach, gut etc)
with the presence of
encapsulating lesions
comprised of
inflammatory cells,
fibrous connective tissue
and degenerate cellular
material or nematode
Fitzroy River Fish Pathology Report May 2012
30

Pathology Lesion Type Mild Moderate Severe
tissue in the central area.
Granulomas may be due
to non-nematode
causes. Where the
granulomas take up to
25% of the section of
organ either by number
or size of granulomas.
tissue in the central area.
Granulomas may be due
to non-nematode
causes. Where the
granulomas take up to
50% of the section of
organ either by number
or size of granulomas.
tissue in the central area.
Granulomas may be due
to non-nematode
causes. Where the
granulomas take up
greater than 50% of the
section of organ either by
number or size of
granulomas.
Trematodes
The presence of
trematode metacercarial
life stage of the parasite
occurring in the target
organ (e.g. gills, liver,
muscle etc) of the
section at up to 10
individual parasites.
Localised distribution up
to 25% of organ section.
The presence of
trematode metacercarial
life stage of the parasite
occurring in the target
organ (e.g. gills, liver,
muscle etc) of the
section at greater than
10 individual parasites.
Typically 10-50 parasites
per section, some
variation depending on
size of parasite.
Distribution of parasite
up to 50% of organ
section.
The presence of
trematode metacercarial
life stage of the parasite
occurring in the target
organ (e.g. gills, liver,
muscle etc) of the
section at greater than
10 individual parasites.
Typically 50-100 or
greater parasites per
section, some variation
depending on size of
parasite. Distribution of
parasite up to 50% of
organ section.
Cestodes
The presence of either
larval or adult life stages
of cestode in the target
organ (gastrointestinal
tract for adults, nongastrointestinal
tissues
for larvae) of the section
at up to 2-3 individual
parasites. Localised
distribution up to 25% of
organ section.
The presence of either
larval or adult life stages
of cestode in the target
organ (gastrointestinal
tract for adults, nongastrointestinal
tissues
for larvae) of the section
at greater than 2-3
individual parasites.
Typically up to 5-6
parasites per section,
some variation
depending on size of
parasite. Distribution of
parasite up to 50% of
organ section.
The presence of either
larval or adult life stages
of cestode in the target
organ (gastrointestinal
tract for adults, nongastrointestinal
tissues
for larvae) of the section
at greater than 2-3
individual parasites.
Typically 10 parasites or
greater per section,
some variation
depending on size of
parasite. Distribution of
parasite greater than
50% of organ section.
Gill/skin parasites
The presence of
ectoparasites and
endoparasites on/in the
gill and skin tissues. A
mix of parasites is often
The presence of
ectoparasites and
endoparasites on/in the
gill and skin tissues. A
mix of parasites is often
The presence of
ectoparasites and
endoparasites on/in the
gill and skin tissues. A
mix of parasites is often
Fitzroy River Fish Pathology Report May 2012
31

Pathology Lesion Type Mild Moderate Severe
encountered. Each
individual parasite
species up to 10 per
section and localised
distribution up to 25% of
organ section.
encountered. Each
individual parasite
species greater than 10
per section. Typically
10-50 parasites per
section, some variation
depending on size of
parasite. Distribution up
to 50% of organ section.
encountered. Each
individual parasite
species greater than 10
per section. Typically
50-100 parasites or
greater per section,
some variation
depending on size of
parasite. Distribution up
to 50% of organ section.
Melanomacrophage
centres (MMCs)
The presence of distinct
aggregates of
macrophages which
produce melanin pigment
localised in kidney, liver
or spleen sections. Mild
MMCs reaction is
typically identified by
presence of low numbers
(10-20), small MMCs
with limited melanin
content
The presence of distinct
aggregates of
macrophages which
produce melanin pigment
localised in kidney, liver
or spleen sections.
Moderate MMCs reaction
is typically identified by
presence of increased
numbers (greater than
10-20), larger MMCs with
increased melanin
content (more dark,
some brown) and
occupying up to 50% of
organ section.
The presence of distinct
aggregates of
macrophages which
produce melanin pigment
localised in kidney, liver
or spleen sections.
Severe MMCs reaction is
typically identified by
presence of high
numbers (20-50 or
greater) of large MMCs
with mostly melanin
content (dark mostly)
and occupying greater
than 50% of organ
section.
Kidney eosinophilic
change
The presence of renal
tubules with epithelial
cells that contain
granules of eosinophilic
(pink) in the cytoplasm.
There will be a minimal
degree of tubular cell
degeneration. Localised
lesion limited to 25% of
section of kidney.
The presence of renal
tubules with epithelial
cells that contain
granules of eosinophilic
(pink) in the cytoplasm.
There will be an
increasing degree of
tubular cell degeneration.
Lesion up to 50% of
section of kidney.
The presence of renal
tubules with epithelial
cells that contain
granules of eosinophilic
(pink) in the cytoplasm.
There will be an
extensive degree of
tubular cell degeneration.
Lesion greater than 50%
of section of kidney.
Kidney vacuolar change
The presence of renal
tubules with epithelial
cells that have
vacuolated cytoplasm.
There will be a minimal
degree of tubular cell
degeneration. Localised
lesion limited to 25% of
The presence of renal
tubules with epithelial
cells that have
vacuolated cytoplasm.
There will be an
increasing degree of
tubular cell degeneration.
Lesion up to 50% of
The presence of renal
tubules with epithelial
cells that have
vacuolated cytoplasm.
There will be an
extensive degree of
tubular cell degeneration.
Lesion greater than 50%
Fitzroy River Fish Pathology Report May 2012
32

Pathology Lesion Type Mild Moderate Severe
section of kidney. section of kidney. of section of kidney.
Organ congestion
The presence of
increased amount of
erythrocytes within the
blood vessels and
channels invarious
organs mainly spleen,
liver or kidney but also
external symptoms of
reness due to blood
pooling or hyperaemia.
Some organs normally
contain more blood as
part of their function to
filter the blood e.g.
spleen and kidney.
Organ congestion
typically results in organ
swelling and erythrocytes
which don’t appear well
spaced in the vessel.
The erythrocytes are
clumped together and
there may be distension
of the blood vessel or
channel.
Moderate congestion in
spleen – reduced spaces
in the splenic trabeculae,
bulging of splenic
capsule, spleen section
with up to 50% red blood
cells.
Moderate congestion in
the liver – more blood
vessels fully filled with
blood, hepatic canaliculi
with more erythrocytes.
Moderate congestion in
the kidney –
compression of the
haematopoetic cells with
erythrocytes, some
displacement of other
kidney structures with
blood cells.
Severe congestion in
spleen – no spaces in
the splenic trabeculae,
bulging of splenic
capsule, spleen section
with greater than 50%
red blood cells.
Severe congestion in the
liver – most blood
vessels fully filled with
blood, hepatic canaliculi
with more erythrocytes,
areas of blood pooling in
liver parenchyma outside
of main hepatic blood
vessels.
Severe congestion in the
kidney – compression of
the haematopoietic cells
with erythrocytes,
significant displacement
of other kidney structures
with blood cells.
Mild congestion in spleen
– visible spaces in the
splenic trabeculae, no
bulging of splenic
capsule.
Mild congestion in the
liver – some blood
vessels fully filled with
blood, a few cells in the
hepatic canaliculi.
Mild congestion in the
kidney – minimal
compression of the
haematopoietic cells with
erythrocytes although
most cells are
erythrocytes.
Fitzroy River Fish Pathology Report May 2012
33

Pathology Lesion Type Mild Moderate Severe
Myopathy
The presence of muscle
fibres that have a loss in
staining intensity (pale),
with evidence of
fragmentation and
eventual loss of the
muscle fibre or bundle
leaving only the
surrounding connective
tissue. Muscle
fragments with rounded
edges of varying sizes
occur in the space
delimited by the
muscular fascia.
Surrounded by normal
appearing muscle. Note:
artifactual muscle
fracturing is noticeable
when fragments of
muscle have sharp
edges and may float out
of section.
The presence of muscle
fibres that have a loss in
staining intensity (pale),
with evidence of
fragmentation and
eventual loss of the
muscle fibre or bundle
leaving only the
surrounding connective
tissue. Muscle
fragments with rounded
edges of varying sizes
occur in the space
delimited by the
muscular fascia.
Surrounded by normal
appearing muscle. Note:
artifactual muscle
fracturing is noticeable
when fragments of
muscle have sharp
edges and may float out
of section.
The presence of muscle
fibres that have a loss in
staining intensity (pale),
with evidence of
fragmentation and
eventual loss of the
muscle fibre or bundle
leaving only the
surrounding connective
tissue. Muscle
fragments with rounded
edges of varying sizes
occur in the space
delimited by the
muscular fascia.
Surrounded by normal
appearing muscle. Note:
artifactual muscle
fracturing is noticeable
when fragments of
muscle have sharp
edges and may float out
of section.
Up to 25% section
affected.
Up to 50% section
affected.
Greater than 50%
section affected.
Gonad lesion, parasites
Parasites inside either
male or female gonads.
Parasites may form cysts
within the gonad. Up to
10 cysts per section.
Parasites inside either
male or female gonads.
Parasites may form cysts
within the gonad.
Greater than 10 cysts
per section. Typically
10-50 parasites per
section, some variation
depending on size of
parasite
Parasites inside either
male or female gonads.
Parasites may form cysts
within the gonad.
Greater than 10 cysts
per section. Typically
50-100 or greater
parasites per section,
some variation
depending on size of
parasite
Fitzroy River Fish Pathology Report May 2012
34

Pathology Lesion Type Mild Moderate Severe
Other lesions
These are lesions which
are observed
infrequently, that is they
are observed in
individual fish. They
include lesions that do
not have an obvious
cause or parasites that
are not clearly identified.
These are lesions which
are observed
infrequently, that is they
are observed in
individual fish. They
include lesions that do
not have an obvious
cause or parasites that
are not clearly identified.
These are lesions which
are observed
infrequently, that is they
are observed in
individual fish. They
include lesions that do
not have an obvious
cause or parasites that
are not clearly identified.
Up to 25% of target
organ affected.
Up to 50% of target
organ affected.
Greater than 50% of
target organ affected.
Fitzroy River Fish Pathology Report May 2012
35

Appendix 3: Gross pathology and histopathology for
species, site and sampling occasion
Table A3.1: Number and severity of pathology lesions for A. graeffei from the Reference and
Investigation sites during the September 2008, January 2009 and May 2009 sampling occasions
Number of fish collected in September 2008 – 10
Number of fish collected in January 2009 – 24
Number of fish collected in May 2009 – 23
Site Reference Site 1
Sampling occasion
Sep
08
Fairbairn Dam
Jan
09
May
09
Reference
Site 2
Moura,
Dawson
River
Jan
09
May
09
Investigation Site 1
Sep
08
Bedford Weir
Jan
09
May
09
Investigation Site 2
Sep
08
Tartrus Weir
Jan
09
May
09
Investigation
Site 3
Bingengang
Weir
Jan May
09 09
Investigation
Site 4
Fitzroy
Barrage
Jan
09
May
09
No. of fish collected 0 0 0 5 6 5 5 5 5 5 4 5 5 4 3
Range of fish length
(cm)
0 0 0 41-
49
30-
44
34-
68
36-
47
30-
40
36-
72
34 26-
44
26-
59
18-
30
40 32-
44
Av. fish length (cm) 0 0 0 46 N/A N/A N/A 34 47 N/A 34 41 25 N/A N/A
Pathology Lesion Type
Gill hyperplasia - - - M 3
D 1
D 2
S 4
M 3
D 2
M 2
D 2
M 2
D 3
M 1
D 3
D 3
S 1
D 1
S 4
M 2
D 3
M 2
D 1
D 4 M 3
D 2
D 4
S 1
* M 2
D 1
Gill lamellar lifting - - - M 1 D 2
D 2 D 3 D 3 D2 D 3 * M 2
S 4
S 1
D 1
Bronchitis - - - - D 2 - M 3 D 2 - D 1 D 4 - D 4 * D 2
S 4 D 2 S 1
Lamellar fusion - - - - D 1 M 1 - M 1 M 3 - S 1 - - * M 1
D 1
Granulomasnematodes
- - - M 1 M 1 - - - M 2 M 1 - - M 1 - M 2
etc
Trematodes - - - M 3 M 4 M 4 M 1 M 2 M2 M 3 M 3 M 2 M 4 M 3 M 3
Cestodes - - - - - - - - - - - - - - -
Gill/skin parasites - - - M 1 M 1 M 3 M 2 M 1 M 1 M 3 M 2 M 1 - M 1 M 2
Melanomacrophage
centres
- - - M 2
D 2
M 3
D 2
S 1
M 2
D 2
M 2 M 3
D 2
M 2
D 3
M 3
D 1
M 3
D 1
M 1
D 1
M 2 M 1
D 1
S 2
Kidney eosinophilic - - - - - - - - - - - - - - -
change
Kidney vacuolar
change
- - - - M 1
D 1
- - D 3 - - - - D 5 - M 1
D 1
Organ congestion - - - - D 2 D 3 - D 5 D 4 - D 2 D 1 D 5 - D 2
S 1
Myopathy - - - M 1 - - M 4 - - - - - - - -
Gonad lesion, - - - - - - - - - - - - - - -
parasites
Other lesions - - - M 2 - M 1 D 5 M 1 M 4 - M 1 M 1 M 1 - -
D 3
Legend: - – pathology lesion type not observed
M – mild
D – moderate
S – severe
N/A – not available due to length measurements not taken on all of the samples
* – gill samples not taken
D 2
S 1
Fitzroy River Fish Pathology Report May 2012
36

Table A3.2: Number and severity of pathology lesions for M. ambigua from the Reference and
Investigation sites during the September 2008, January 2009 and May 2009 sampling occasions
Number of fish collected in September 2008 – 5
Number of fish collected in January 2009 – 21
Number of fish collected in May 2009 – 16
Site Reference Site 1
Sampling occasion
Sep
08
Fairbairn Dam
Jan
09
May
09
Reference
Site 2
Moura,
Dawson
River
Jan
09
May
09
Investigation Site 1
Sep
08
Bedford Weir
Jan
09
May
09
Investigation Site 2
Sep
08
Tartrus Weir
Jan
09
May
09
Investigation
Site 3
Bingengang
Weir
Jan May
09 09
Investigation
Site 4
Fitzroy
Barrage
Jan
09
May
09
No. of fish collected 5 5 1 2 3 0 0 2 0 7 7 5 3 2 0
Range of fish length 25- 19- 22 36- 34- 0 0 18- 0 18- 21- 25- 31- 14- 0
(cm)
39 37
40 36
28
45 39 32 36 17
Av. fish length (cm) N/A 24 22 38 34 0 0 23 0 32 26 N/A 34 16 0
Pathology Lesion Type
Gill hyperplasia D 2 M 3 - - M 2 - - M 1 - M 1 M 2 D 1 D 1 - -
S 1 D 1
D 1
D 1
D 5 S 2
Gill lamellar lifting - - - - - - - - - - D 1 - M 1 - -
D 1
Bronchitis - - - - - - - - - - - - - - -
Lamellar fusion - M 2 - M 1 - - - - - M 3 M 1 M 1 S 1 M 1 -
Granulomasnematodes
- D 4 M 1 - S 3 - - D 1 - M 2 M 3 M 3 S 3 M 1 -
etc
S 1
S 1 D 1
S 4
D 2
S 2
S 2 D 1
Trematodes - M 1 - M 1 M 2 - - - - M 2 M 2 M 1 M 1 - -
Cestodes - - - - - - - - - - - - - M 1 -
Gill/skin parasites M 2 M 4 - M 1 M 1 - - D 1 - M 6 M 5 M 4 M 2 M 2 -
Melanomacrophage
centres
M 2
D 1
D 1 - M 1
D 1
M 2
D 1
- - - - M 3 M 6 M 2
D 1
M 2
S 1
- -
Kidney eosinophilic - - - - - - - - - - - - - - -
change
Kidney vacuolar - - - - - - - - - - - - - - -
change
Organ congestion M 2 - - - D 1 - - - - D 1 - D 1 D 2 - -
D 2
Myopathy - M 1 - - - - - - - M 2 - - - -
Gonad lesion, - - - - - - - - - - - - M 1 - -
parasites
Other lesions M 2 D 1 - - - - - M 2 - M 1 M 1 D 2 M 3 - -
D 2
Legend: - – pathology lesion type not observed
M – mild
D – moderate
S – severe
N/A – not available due to length measurements not taken on all of the samples
Fitzroy River Fish Pathology Report May 2012
37

Table A3.3: Number and severity of pathology lesions for O. lineolatus from the Reference and
Investigation sites during the January 2009 and May 2009 sampling occasions
Number of fish collected in January 2009 – 18
Number of fish collected in May 2009 – 19
Site
Reference
Site 1
Reference
Site 2
Investigation
Site 1
Investigation
Site 2
Investigation
Site 3
Investigation
Site 4
Sampling occasion
Fairbairn Dam
Jan
09
May
09
Moura,
Dawson River
Jan May
09 09
Bedford Weir
Jan
09
May
09
Tartrus Weir
Jan
09
May
09
Bingengang
Weir
Jan May
09 09
Fitzroy
Barrage
No. of fish collected 1 5 5 4 5 0 4 0 3 5 0 5
Range of fish length 31 30-39 21-34 28-35 15-38 0 25-40 0 28-34 24-30 0 20-39
(cm)
Av. fish length (cm) 31 32 29 N/A 29 0 N/A 0 N/A 26 0 34
Pathology Lesion Type
Gill hyperplasia - - M 3 D 3
S 1
M 3
D 1
- M 1
D 2
- D 2 D 4
S 1
Jan
09
May
09
- M 3
D 1
Gill lamellar lifting - - - - - - - - - - - -
Bronchitis - - - - - - - - - - - M 1
Lamellar fusion M 1 - - D 1 - - M 1 - - D 2 - -
S 1
Granulomasnematodes
etc
M 1 M 2
D 1
M 3 M 2 M 3
S 1
- S 3 - M 3 M 2
D 2
- M 4
D 1
S 1
Trematodes - M 2 M 3 M 1 M 1 - - - M 2 M 1 - M 2
S 1 D 1
Cestodes - - - - - - - - - - - M 1
Gill/skin parasites - M 1 S 1 M 3 M 2 - M 4 - M 1 M 3 -
Melanomacrophage - - - M 3 M 3 - - - M 1 M 4 - M 2
centres
Kidney eosinophilic - M 1 - - - - - - - - - -
change
Kidney vacuolar - - - - - - - - - - - -
change
Organ congestion - D 3 D 2 D 1 - - - - D 1 D 2 - D 1
S 1
S 2
S 1
S 3
Myopathy - - - - M 1 - - - - M 2 - D 1
Gonad lesion,
- - - M 1 - - - - - - - M 1
parasites
Other lesions - M 1 - - M 2 - - - - - - M 1
D 1
Legend: - – pathology lesion type not observed
M – mild
D – moderate
S – severe
N/A – not available due to length measurements not taken on all of the samples
Fitzroy River Fish Pathology Report May 2012
38

Table 3.4: Number and severity of pathology lesions for N. erebi from the Reference and
Investigation sites during the January 2009 and May 2009 sampling occasions
Number of fish collected in January 2009 – 30
Number of fish collected in May 2009 – 32
Site
Reference
Site 1
Reference
Site 2
Investigation
Site 1
Investigation
Site 2
Investigation
Site 3
Investigation
Site 4
Sampling occasion
Fairbairn Dam
Jan
09
May
09
Moura,
Dawson River
Jan May
09 09
Bedford Weir
Jan
09
May
09
Tartrus Weir
Jan
09
May
09
Bingengang
Weir
Jan May
09 09
Fitzroy
Barrage
No. of fish collected 5 5 5 5 5 5 7 5 4 5 4 7
Range of fish length 14-29 26-32 16-30 20-30 25-35 25-26 10-35 20-30 21-25 22-29 0 18-38
(cm)
Av. fish length (cm) 21 27 22 25 28 N/A N/A 25 24 25 N/A 27
Pathology Lesion Type
Gill hyperplasia - - - - - - D 4 - - - - -
Gill lamellar lifting - - - - - D 1 M 1 - - - D 1 D 2
Bronchitis - - - - - - - - - - - -
Lamellar fusion - - - D 1 - - - - - - - -
Granulomas-
M 2 M 2 M 2 M 2 M 2 - M 2 D 2 - M 1 M 2 M 5
nematodes etc
Trematodes M 3 M 1 M 3
S 1
M 2
D 1
S 1
M 3 M 2 M2
D 1
M 1
D 3
Jan
09
May
09
M 1 M 4 M 3 M 1
S 2
Cestodes M 1 - M 2 M 1 - - - - - M 1 - M 1
Gill/skin parasites - - - M 2 - M 1 S 4 M 1 - M 2 M 2 M 2
S 2
Melanomacrophage
centres
D 1 M 5 M 1
D 2
M 1
D 2
S 2 M 2
D 1
M 1
D 2
D 1 M 1 M 1
D 1
M 2 M 3
S 2
Kidney eosinophilic D 3 D 1 M 3 - D 2 - - - - D 2 - S 1
change
Kidney vacuolar - - - - - - D 2 - - D 3 - -
change
Organ congestion - D 1 - - S 1 D 2 - - D 1 - D 2 -
Myopathy - - - - M 1 - - - - M 1 - -
Gonad lesion,
- - - - - - M 2 D 1 D 2 - M 1 -
parasites
D 1
S 1
Other lesions - M 1 M 3 M 2 D 5 - M 1 S 5 M 3 M 1
S 3
Legend: - – pathology lesion type not observed
M – mild
D – moderate
S – severe
N/A – not available due to length measurements not taken on all of the samples
- M 1
D 2
Fitzroy River Fish Pathology Report May 2012
39

Table A3.5: Number and severity of pathology lesions for S. hillii from the Reference and
Investigation sites during the January 2009 and May 2009 sampling occasions.
Number of fish collected in January 2009 – 21
Number of fish collected in May 2009 – 24
Site
Reference
Site 1
Reference
Site 2
Investigation
Site 1
Investigation
Site 2
Investigation
Site 3
Investigation
Site 4
Sampling occasion
Fairbairn Dam
Jan
09
May
09
Moura,
Dawson River
Jan May
09 09
Bedford Weir
Jan
09
May
09
Tartrus Weir
Jan
09
May
09
Bingengang
Weir
Jan May
09 09
Fitzroy
Barrage
No. of fish collected 5 5 4 5 0 3 7 5 5 5 0 1
Range of fish length 19-24 25-42 19-32 32-33 19-24 16-26 20-34 22-27 30-33 17-25 0 26
(cm)
Av. fish length (cm) 22 32 28 33 0 20 N/A 25 N/A 20 0 26
Pathology Lesion Type
Gill hyperplasia M 3 M 2 - M 4 - M 1 M 3 D 2 M 3 D 5 - -
D 1 D 2
S 1
D 1
D 1
S 1
D 1
D 1
Gill lamellar lifting D 4 D 1 - M 1 - - M 2 - - - - -
S 1
D 1
Bronchitis - - - - - - - - - - - -
Lamellar fusion - M 1 - D 1 - S 1 M 1 - - - - -
Granulomasnematodes
etc
S 3
M 1 M 3
D 1
M 2 M4 - - M 3 M 2
M 1
M 4 M 1
D 2
Jan
09
May
09
- M 1
Trematodes - - M 3 M 4 - M 2 M 3 M 3 M 2 - - M 1
D 1 S 1 S 1
Cestodes - M 2 M 2 M 1 - M 1 M 3 M 5 - M 1 - -
Gill/skin parasites M 1 M 4 M 2 M 3 - - M 6 M 3 M 3 M 4 - D 1
Melanomacrophage - D 1 M 1 D 3 - M 1 M 1 M 2 D 1 M 1 - -
centres
S 2 D 1
S 1
S 2
S 4
S 4
Kidney eosinophilic - - - - - - - - - M 1 - -
change
Kidney vacuolar - - - - - - - - - - - -
change
Organ congestion D 1 D 1 - - - - D 2 D 3 D 1 D 3 - -
Myopathy M 4 - - - - M 1 M 1 - - - - -
Gonad lesion,
- - - - - - - - - - - -
parasites
Other lesions - M 1 M 1 M 2 - - - M 3
D 1
Legend: - – pathology lesion type not observed
M – mild
D – moderate
S – severe
N/A – not available due to length measurements not taken on all of the samples
M 1 M 1
D 1
- -
Fitzroy River Fish Pathology Report May 2012
40

Appendix 4: Concentrations (mg/kg) of metals and metalloids in gill, liver and
muscle sampled from A. graeffei at Bedford Weir and Tartrus Weir, and M.
Ambigua at Fairbairn Dam in September 2008, January 2009 and May 2009
(a) iron, (b) aluminium, (c) chromium, (d) copper, (e) zinc, (f) arsenic, (g) selenium, (h) cadmium, (i) mercury and (j) lead
Concentrations are shown on a log 10 scale.
Bedford Weir, Fe
Fairbairn Dam, Fe
Tartarus Weir, Fe
10000
Gill
Liver
Muscle
10000
Gill
Liver
Muscle
10000
Gill
Liver
Muscle
1000
1000
1000
Concentration
100
Concentration
100
Concentration
100
10
10
10
1
Sept 2008 Jan 2009 May 2009
1
Sept 2008 Jan 2009 May 2009
1
Sept 2008 Jan 2009 May 2009
Fitzroy River Fish Pathology Report xx June 2012 41

Bedford Weir, Al
Fairbairn Dam, Al
Tartarus Weir, Al
100
Gill
Liver
Muscle
100
100
Gill
Liver
Muscle
Concentration
10
Concentration
10
Concentration
10
1
1
Gill
Liver
Muscle
1
0.1
Sept 2008 Jan 2009 May 2009
0.1
Sept 2008 Jan 2009 May 2009
0.1
Sept 2008 Jan 2009 May 2009
Fitzroy River Fish Pathology Report May 2012 42

Bedford Weir, Cr
Fairbairn Dam, Cr
Tartarus Weir, Cr
1
Gill
Liver
Muscle
1
Gill
Liver
Muscle
1
Gill
Liver
Muscle
Concentration
0.2
0.1
Concentration
0.2
0.1
Concentration
0.2
0.1
0.02
0.02
0.02
Sept 2008 Jan 2009 May 2009
Sept 2008 Jan 2009 May 2009
Sept 2008 Jan 2009 May 2009
Fitzroy River Fish Pathology Report May 2012 43

Bedford Weir, Cu
Fairbairn Dam, Cu
Tartarus Weir, Cu
100
100
100
Gill
Liver
Muscle
10
10
10
Concentration
1
Gill
Liver
Muscle
Concentration
1
Concentration
1
Gill
Liver
Muscle
0.1
0.1
0.1
0.01
Sept 2008 Jan 2009 May 2009
0.01
Sept 2008 Jan 2009 May 2009
0.01
Sept 2008 Jan 2009 May 2009
Fitzroy River Fish Pathology Report May 2012 44

Bedford Weir, Zn
Fairbairn Dam, Zn
Tartarus Weir, Zn
Gill
Liver
Muscle
100
100
100
Concentration
Concentration
Concentration
10
10
10
Gill
Liver
Muscle
Gill
Liver
Muscle
1
Sept 2008 Jan 2009 May 2009
1
Sept 2008 Jan 2009 May 2009
1
Sept 2008 Jan 2009 May 2009
Fitzroy River Fish Pathology Report May 2012 45

Fairbairn Dam, As
Bedford Weir, As
Tartarus Weir, As
1
1
Gill
Liver
Muscle
1
Gill
Liver
Muscle
0.2
0.2
0.2
Concentration
0.1
Concentration
0.1
Concentration
0.1
0.02
Gill
Liver
Muscle
0.02
0.02
0.01
Sept 2008 Jan 2009 May 2009
0.01
Sept 2008 Jan 2009 May 2009
0.01
Sept 2008 Jan 2009 May 2009
Fitzroy River Fish Pathology Report May 2012 46

Bedford Weir, Se
Fairbairn Dam, Se
Tartarus Weir, Se
10
10
10
2
2
2
Concentration
1
Concentration
1
Concentration
1
0.2
Gill
Liver
Muscle
0.2
Gill
Liver
Muscle
0.2
Gill
Liver
Muscle
0.1
Sept 2008 Jan 2009 May 2009
0.1
Sept 2008 Jan 2009 May 2009
0.1
Sept 2008 Jan 2009 May 2009
Fitzroy River Fish Pathology Report May 2012 47

Bedford Weir, Cd
Fairbairn Dam, Cd
Tartarus Weir, Cd
0.15
0.15
0.15
Gill
Liver
Muscle
0.1
0.1
0.1
Concentration
0.05
Concentration
0.05
Gill
Liver
Muscle
Concentration
0.05
Gill
Liver
Muscle
0
0
0
Sept 2008 Jan 2009 May 2009
Sept 2008 Jan 2009 May 2009
Sept 2008 Jan 2009 May 2009
Fitzroy River Fish Pathology Report May 2012 48

Bedford Weir, Hg
Fairbairn Dam, Hg
Tartarus Weir, Hg
1
1
1
0.2
0.2
0.2
Concentration
0.1
Gill
Liver
Muscle
Concentration
0.1
Concentration
0.1
Gill
Liver
Muscle
0.02
0.02
Gill
Liver
Muscle
0.02
0.01
Sept 2008 Jan 2009 May 2009
0.01
Sept 2008 Jan 2009 May 2009
0.01
Sept 2008 Jan 2009 May 2009
Fitzroy River Fish Pathology Report May 2012 49

Bedford Weir, Pb
Fairbairn Dam, Pb
Tartarus Weir, Pb
1
1
1
Gill
Liver
Muscle
Gill
Liver
Muscle
0.2
0.2
0.2
Concentration
0.1
Gill
Liver
Muscle
Concentration
0.1
Concentration
0.1
0.02
0.02
0.02
0.01
Sept 2008 Jan 2009 May 2009
0.01
Sept 2008 Jan 2009 May 2009
0.01
Sept 2008 Jan 2009 May 2009
Fitzroy River Fish Pathology Report May 2012 50