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Sunfish Scientific Research 2014 to 2025
Written by Dr Barry Pollock
Created / Updated on Monday 3rd of November 2025

During the period 2014 to 2025 Sunfish has supported four scientific research groupings, scientific papers of which which have been published in peer-reviewed scientific journals by the Sunfish Scientific Officer, Dr Barry Pollock. All projects were of high priority for fisheries research as determined by Sunfish. In these projects recreational fishers and others (citizen science contributors) were engaged, and the projects were funded by these volunteers. No government funds were sought or provided. A total of six scientific papers and a book has been produced, and another on Queensland snapper is in progress. This demonstrates the willingness of Sunfish, its associated recreational fishers, and others to contribute to research and scientific knowledge. The research topics are saddleback deformities, flathead, snapper, and luderick. Copies of the scientific papers are provided. In the period 2014 to 2022 Sunfish has supported five scientific research projects which have been published in peer-reviewed scientific journals by the Sunfish Scientific Officer, Dr Barry Pollock. In these projects recreational fishers have made major voluntary contributions, and the projects were fully funded by volunteer recreational fishers. No government funds were sought or provided. This demonstrates the willingness of Sunfish, its associated recreational fishers, and recreational fishers generally to contribute to research and scientific knowledge of the fish they seek to catch.

Summaries of the findings of these five scientific research projects are given below. Details for obtaining the full papers are also given. A huge amount of time and effort has been provided on a voluntary basis to carry out and complete these scientific studies. All those who assisted, including staff at the Ecosciences Precinct, University of Queensland, Fisheries Queensland and NSW Fisheries, are sincerely thanked.


Dr Barry Pollock, Scientific Officer Sunfish, at the Ecosciences Precinct Boggo Road, using a microscope to examine flathead reproductive tissue samples.




Saddleback syndrome in yellowfin bream [ Acanthopagrus australis (Gunther, 1859)] in Moreton Bay, Australia: its form, occurrence, association with other abnormalities and cause*

By B.R. Pollock
Sunfish Queensland Incorporated, Brisbane, Australia

Summary
The aim of this study was to determine if saddleback syndrome (SBS) in a wild population of yellowfin bream ( Acanthopagrus australis) was the result of a developmental defect or caused by physical injury. Information was collected in 2012 on the incidence of SBS and other abnormalities in this species in Moreton Bay, Australia. Abnormalities in adult fish (>250 mm Total Length, TL) with SBS (n = 47) were compared with those without SBS (n = 30). A sample of juvenile fish (n = 404) was checked for the presence of SBS. The results show that scale loss, scale pattern misalignment, lateral line fracture and pectoral fin abnormality were closely associated with SBS. SBS was uncommon (<2%) in juveniles <70 mm TL, but common (>12%) in the larger juveniles (70–215 mm TL). These results, together with the findings that scale loss associated with SBS in adult fish occurred in the range 80–245 mm back-calculated TL, indicate that SBS and the related abnormalities in yellowfin bream are a result of physical injuries to larger juveniles (>70 mm TL). The reduction in the incidence of SBS from approximately 12% in the larger juveniles to 5% in adults is evidence of mortality associated with SBS.

Introduction
In recent years, fishers in Moreton Bay, Australia and nearby regions have reported a deformity on the dorsal margin of yellowfin bream, Acanthopagrus australis (Family Sparidae). This has been identified as a typical saddleback syndrome (SBS), and its occurrence has been as high as 5–10% of individuals in yellowfin bream catches (Diggles, 2013). A stakeholder workshop involving researchers, fishery managers and fishers was held in January 2012 to discuss the extent of the problem, possible causes and future research directions (Campbell and Landers, 2013). The definition of SBS is an abnormality of the dorsal fin and profile, lacking one to all of the dorsal spines, accompanied by shape, number and position abnormalities of associated pterygiophores (Koumoundouros et al., 2001). Deformity and loss of dorsal spines, pterygiophores and neural spines in fish with SBS have been described in several species including yellowfin bream (Diggles, 2013). SBS in wild populations of fish has been attributed to several causes including physical injuries (James and Badrudeen, 1968) such as injuries caused by predatory fish (Almatar and Chen, 2010). Other studies have identified developmental defects associated with unsuitable water conditions, including chemical contamination (Browder et al., 1993; Lemly, 1993; Jawad and Al-Mamray, 2012). There are also studies showing that SBS can be an inherited characteristic (Tave et al., 1983).

The yellowfin bream is endemic to Australia and restricted to the east coast, where it occurs in estuaries and coastal waters extending from tropical to temperate regions. It is extensively fished both recreationally and commercially throughout its range, with Moreton Bay being one of the most productive areas (Williams, 2002; Taylor et al., 2012). The Moreton Bay fishery for yellowfin bream is tightly managed (Queensland Government, 2009, 2012), with restrictions on types of gear that both recreational and commercial fishers may use, limits on the numbers of commercial fishing licences, a bag limit for recreational fishers, and a minimum size of 250 mm total length (TL), which approximates the size at maturity (Pollock, 1982a). The current fisheries monitoring programme and status report classifies yellowfin bream stocks as sustainably fished (Queensland Government, 2010). The population biology of yellowfin bream in Moreton Bay is well understood (Munro, 1945; Blaber and Blaber, 1980; Pollock, 1982a, 1984; Pollock et al., 1983; Morton et al., 1987). Adult yellowfin bream have spawning aggregations at the estuary-ocean interface during winter (June–July); post larvae subsequently settle in estuaries after about 1 month in the plankton (August–September). The juvenile fish grow quickly particularly for the first 3 years.

The aim of the present study was to determine whether SBS in yellowfin bream is a developmental defect or caused by physical injury. To do this, the study investigated the presence of SBS in a wild population of juvenile and adult yellowfin bream, and the association of SBS with other abnormalities, including scale pattern misalignment, scale replacement, and deformities of the lateral line and pectoral fins. Estimates of the size of yellowfin bream when SBS occurs were made by using back-calculations of the total length at scale replacement and by noting changes in the incidence of SBS in juvenile fish of different sizes.

Materials and methods
The study was conducted in southern Moreton Bay, Australia (27° 45 0S; 153°200E) with samples of yellowfin bream with SBS and those without this deformity (Fig. 1a, b) being taken in the region from the Logan River in the North to the Nerang River in the South. These samples came from two sources: adult fish provided by fishing club anglers and juvenile fish collected by the author. On 22 July 2012, at their official weighing-in of catches throughout the sampling area, fishing club anglers provided 47 yellowfin bream with SBS over the legal minimum size (>250 mm TL) that were caught the previous night. Anglers kept approximately 10 additional yellowfin bream with SBS. At this event a total of 86 anglers caught 1170 yellowfin bream over the minimum legal size. A sample of 30 yellowfin bream (>250 mm TL) without SBS was also provided to the study by the anglers as a control sample. A sample of 404 juvenile yellowfin bream less than the legal minimum size (<250 mm TL) was collected in the study area from October to December 2012 using several gear types: baited traps, 600 mm long, 400 mm wide, 200 mm high with two funnel openings and mesh size 20 mm; a cast net (7 m diameter) and a seine both with 20 mm mesh; and lines with baited hooks (sizes 12–20). The majority of juvenile yellowfin bream (n = 398) were caught near the mouth of the Nerang River. The remainder (n = 6) was caught near the mouth of the Logan River. Each of the juvenile fish was measured (TL to the nearest 5 mm) and photographed. These photographs were later examined to determine the presence or absence of SBS.

All adult yellowfin bream obtained on 22 July 2012 (n = 77) were processed the same day whereby each fish was assigned an identifying number, photographed on each lateral surface, measured (TL to the nearest 10 mm), and scale samples (n = 10–12 scales) taken from each side of each fish below the saddleback deformity or from an equivalent location on fish without SBS. During this procedure each fish was examined for fin deformities additional to SBS. Some fish with SBS had pectoral fins that were locked into an abnormal position, approximately perpendicular to the lateral surface (Fig. 2a). Fish without SBS did not have this pectoral fin deformity. The photographs of both lateral surfaces of each of the 77 adult fish sampled were later examined for the presence of scale pattern deformities and lateral line fractures (Fig. 2b). Scale pattern deformity is defined as misalignment in the normal, symmetrical pattern of scale rows on the lateral surface (Browder et al., 1993). A subsample of eight scales from each of the 154 scale samples was cleaned in water and mounted between microscope slides. When dry, the numbers of normal and replacement scales (Fig. 3) in each subsample were identified under magnification and recorded. Measurements to the nearest 1 mm were taken of the scale length and length of the granular section on a typical replacement scale from each scale set (Fig. 4). When both lateral surfaces had replacement scales, the means of the two values of scale length and length of the granular section were calculated. The length of each fish when scales were replaced was back-calculated by the Fraser–Lee method (Duncan, 1980):

Lr ¼ Lg/Ls  (TL-c) + c;

where, Lr is the back-calculated total length (mm) at scale loss, Lg is the length of the granular section on the scale, Ls is the scale radius, TL is the total length (mm). The c value of 10 mm was used, which approximates the length of yellowfin bream when scales are first formed on post larvae (Munro, 1945). Three indices were used to quantify the extent and location of the SBS on each adult fish sampled (n = 47). The relative depth of the deformity into the dorsal margin: Index of SBS depth ¼ Dsbs/Db  100; where Dsbs is the distance from the dorsal margin to the deepest extent of the deformity, and Db is the largest vertical distance from the dorsal margin to the ventral margin (Fig. 5a, b). The relative width of this deformity along the dorsal margin:

Index of SBS width ¼ Wsbs/TL  100;

where Wsbs is the length of the deformity on the dorsal margin, and TL is the total length (Fig. 5a, b)

The relative anterior-posterior position of the deformity on the dorsal margin:

Index of SBS location ¼ Lsbs/TL  100;

where Lsbs is the anterior-posterior distance from the mouth to the deepest part of the deformity (Fig. 5a).

Measurements of Dsbs, Db, Wsbs, and Lsbs were made to the nearest 1 mm.

The Chi-squared test was used to compare the occurrence of SBS in different size-classes of yellowfin bream, and the incidence of scale pattern deformities in SBS fish and those without SBS.

The sampling area in southern Moreton Bay is protected from the Pacific Ocean by South Stradbroke Island, a narrow sand island approximately 20 km in length. The southern sampling area, including the Nerang River, contains numerous waterfront canal developments with dense residential housing, and numerous anchorages for vessels. In the North, including the Logan River, intensive sugar cane agriculture has been carried out adjacent to the shoreline since the 1960s (Gold Coast City Council, 2007). Tides in the area are semi-diurnal with a maximum range of approximately 2 m. The ocean entrances of the Southport Seaway and the Jumpinpin Bar, in association with tidal water movements result in significant flushing of much of the study area (Eyre and McKee, 2002).

Results
In adult yellowfin bream (>250 mm TL), the index of SBS location (Fig. 6) shows that the SBS deformity occurs most frequently on the anterior half of the dorsal margin. The deepest part of the deformity occurs either anterior to the dorsal spines or within the anterior half of the dorsal fin (Fig. 6). The width of the deformity is most commonly 5–10% of the body length, but can be as much as 20% in extreme cases (Fig. 7). Whilst the maximum depth of the deformity may be anterior to the dorsal spines, the deformity extends into the area of the dorsal spines. In all specimens of SBS fish over 250 mm TL observed in this study (n = 47), the dorsal spines were deformed, ranging from deformity of the first dorsal spine only to the deformity or loss of several dorsal spines. In these fish, the SBS depth index (Fig. 8) was slight (1.0 or less) in 13% of the sample, moderate (1.1–5.0) in 76%, and severe (> 5.0) in 11%.

From observations of catches on 22 July 2012, SBS was present in 57 adult fish (> 250 mm TL) from a total catch of 1170 (4.9% of the total catch). Scale pattern deformities occurred on 37 of the 47 fish collected with SBS (79%), comprising 24 fish (51%) with scale pattern deformities on both lateral surfaces, and 13 fish (28%) with this deformity on one lateral surface only. In the control sample of 30 fish without SBS, eight individuals (27%) had scale pattern deformities on one lateral surface; a single specimen (3%) had this deformity on both lateral surfaces. The frequency of occurrence of scale pattern deformity in the control sample of normal fish is 27% compared with 79% in fish with SBS. This difference is highly significant (P < 0.001). Pectoral fin abnormalities occurred in seven of the 47 SBS fish over 250 mm TL (15%), with one of these having the deformity on both pectoral fins. Lateral line fracture occurred in six out of 47 fish with SBS (13%). None of the control sample of adult fish without SBS had pectoral fin abnormalities or lateral line fractures.

Original scales, first laid down at the post larval stage, may be lost and subsequently replaced by new scales (Figs 3 and 4). The replacement scales are distinctive on account of the granular growth area in the central portion of the scale. Replacement scales were much more common in SBS fish compared with those without SBS (Fig. 9). In adult fish with SBS, all specimens (n = 47) had replacement scales on both lateral surfaces at high concentrations (25% or more replacement scales in each scale sample). In adult fish without SBS (n = 30), 60% had low concentrations of replacement scales (< 25% replacement scales in each scale sample), and of these fish, 27% had no replacement scales (Fig. 9).

Based on length back-calculations (Fig. 10), adult fish with SBS exhibit scale loss and replacement at 110–245 mm TL. (mean TL at scale replacement is 160 mm). In the case of yellowfin bream without SBS, scale loss and replacement occurs at 80–175 mm TL, with a mean of 135 mm TL.

Frequency of SBS occurrence in juvenile yellowfin bream increased greatly with size. In the smaller size-class sampled (30–65 mm TL, n = 215), SBS occurrence was low (n = 4, 1.9%). SBS was much more common (n = 23, 12.2%) in the larger juvenile size-class (70–215 mm TL, n = 189). This difference is highly significant (P < 0.0001). The approximate size at which SBS first became common in juvenile fish was 70 mm TL. The difference in occurrence of SBS in the larger juvenile size-class (12.2%), compared with that in adult fish (4.9%) is also highly significant (P < 0.001).

Discussion
The form of SBS on individual fish The frequency distributions of indices for SBS location, width and depth on individual yellowfin bream are all unimodal, with ranges within relatively restricted limits (Figs 6–8). The cause of SBS in yellowfin bream therefore appears to be acting very specifically in terms of the location and extent of the resulting deformity. The skeletal deformities associated with SBS in yellowfin bream are described by Diggles (2013). Radiographs in that study show in a yellowfin bream with mild SBS that skeletal abnormalities comprise pterygiophore deformities and neural spine disorganization. Diggles (2013) also found that a yellowfin bream with severe SBS deformity had the loss of some pterygiophores and severe deformity of the neural spines. From figures of the two specimens in the Diggles (2013) study, it was possible to calculate the SBS depth indices of 0.95 in the case of the specimen with mild SBS, and 5.5 for the specimen with severe SBS. The SBS depth index values, based on a large sample of yellowfin bream with SBS (n = 47) in the present study ranged from 0.8 to 6.5. These findings by Diggles (2013) and by the present study are complementary, and it is reasonable to infer that yellowfin bream with both mild and severe SBS have associated deformities of the pterygiophores and neural spines.

Association of SBS with other abnormalities
Scales in fish are not shed naturally but usually result from an injury. Lost scales in most investigated fish species are replaced quickly (Quilhac and Sire, 1998; Ohira et al., 2007; Vieira et al., 2011). An example of rapid scale replacement is in the marine sea bass, Dicentrarchus labrax, where replacement scales are visible at 3 days after removal and by 6 days the descaled area is covered with new scales. At 21–30 days the newly formed scales appear similar to original scales (Guerreiro et al., 2013). All yellowfin bream with SBS have moderate to severe scale loss. The majority of those without SBS have zero to minor scale loss (Fig. 9). Yellowfin bream with SBS have a significantly higher incidence of scale pattern deformity (approximately 80%), compared with those without SBS (approximately 30%). Both lateral line fracture and pectoral fin deformities are less common overall, but only occur in fish with SBS. Whilst it is possible that pectoral fin abnormalities are due to the way the fish were handled by fishers after capture, the result that these deformities were only observed in SBS fish is evidence that this is a deformity associated directly with SBS.

SBS in yellowfin bream – occurrence and possible cause
In yellowfin bream, SBS first becomes common in large juveniles, a result that corresponds closely with the back-calculations of TL at scale replacement for adult fish with SBS. Based on these findings, SBS and the associated deformities in yellowfin bream are most likely caused by physical injuries to larger juveniles, and not by developmental defects commencing in larval or post larval fish. However, the appearance of the SBS-associated deformities in yellowfin bream without SBS needs explanation. It appears that the overall injury trauma in the case of yellowfin bream consists of a group of associated deformities. The number and severity of these deformities on individual adult yellowfin bream are variable, and may or may not include SBS.

Juvenile yellowfin bream with SBS were collected at both extremities of the study area, a distance of approximately 20 km, although the sample size from the North region was relatively small. Juvenile yellowfin bream in this region undertake only small-scale movements up to a maximum of 6 km (Pollock, 1982b). This indicates that SBS is acquired by juvenile fish at multiple locations within the study area. Adult fish are much more mobile than the juveniles. It is therefore expected that the adult fish with SBS could have moved considerable distances from where they acquired SBS as juveniles. The present study did not specifically investigate causes of physical injuries that could result in SBS and ssociated deformities, however the most likely are: escapement from piscivorous birds or predatory fish, ectoparasite injuries and removal or escapement from fishing gear. In Moreton Bay the most abundant piscivorous birds likely to prey on demersal species such as yellowfin bream are cormorants (Family Phalacrocoracidae) and pelicans (Family Pelecanidae) (Simpson and Day, 1998). Several predatory fish species are abundant in the same habitat as juvenile yellowfin bream, most notably flathead ( Platycephalus fuscus), tailor ( Pomatomus saltatrix), and mangrove jack ( Lutjanus argentimaculatus) (Grant, 1975). No ectoparasites were observed on any of the yellowfin bream taken in the present study, hence this is unlikely to be the cause of injuries in this case.

Several studies of yellowfin bream and other species show that physical damage may occur as a result of fishing operations and the subsequent escape or release of the fish. Halliday et al. (2001) describe the capture of yellowfin bream by commercial fishers in gill-nets used north of Moreton Bay; about half of the yellowfin bream caught in that study were discarded as being under the legal minimum size. In the case of enmeshed yellowfin bream, the fish were mainly removed tail first from the net, and released. Several studies have reported injuries to fish as a result of net damage (Chopin and Arimoto, 1995). The study of gill-netting in inshore waters in New Zealand by Hickford and Schiel (1996) categorises the resulting injuries in order of severity: chafing or scale loss, minor lesions and fin damage, major lesions and flesh loss, and loss of skeletal material. These injuries are consistent with SBS and associated abnormalities observed on yellowfin bream in the present study.

Mortality associated with SBS and future research
The reduction in the incidence of SBS in the larger juveniles compared with adult yellowfin bream (from 12.2% to 4.9%) is highly significant and consistent with a differential ortality of juvenile fish with SBS. However, this interpretation needs to acknowledge the possibility of annual and site-specific variability of SBS. In eastern Australia, the yellowfin bream fishery is very important from both social and economic perspectives. Whilst the yellowfin bream fishery has been well managed and monitored by the relevant fisheries agencies, further research is important to fully understand the exact cause and impacts of SBS and associated abnormalities on yellowfin bream stocks. In particular, future research is needed regarding the variability of SBS in both juvenile and adult yellowfin bream in different locations and years, with emphasis on estimating mortalities associated with SBS. Further research is also needed on the injuries caused by catching and releasing yellowfin bream that are under the legal minimum size.

Acknowledgements
Matthew Campbell assisted with the collection of juvenile fish under General Fisheries Permit Number 147714 (Queensland fisheries legislation), and provided helpful suggestions throughout the course of the study. Ben Diggles suggested the control sample of adult fish and discussed interpretations of some of the findings. Jason McGilvray and Glenys Pollock helped photograph the scales and prepare the figures, respectively. David Bateman, Martin Cowling and Laurie Stone arranged for the provision of fish samples from anglercatches and assisted with the sampling of juveniles. Bob Pearson kindly reviewed the manuscript.

*The editorial office has received comments on the manuscript (Dr. Diggles), offering a different potential origin of the saddleback syndrome (e.g. defects during ontogenetic development). Although such causes can not be totally outruled, it is highly likely that in the present study these deformaties were caused by injury. Controversial views stimulate scientific debate and it is for this reason why I provide two recent references for further reading: (a) Pollock BR (2015). Comments on Saddleback deformities in yellowfin bream from South-East Queensland by Diggles (2013). JFD doi:10.1111/jfd.12334 (early view); (b) Diggles BK (2015). Reply to Pollock (2014) Comments on Saddleback deformities in yellowfin bream from South East Queensland by Diggles (2013). JFD doi:10.1111/jfd.12339 (early view).
Harald Rosenthal, Editor-in-Chief


Filesize: 682 KB    Date: 03 Nov 2025 13:47
Saddleback syndrome in yellowfin bream
Summary: The aim of this study was to determine if saddleback syndrome (SBS) in a wild population of yellowfin bream

7 Pages

Comments by an anonymous referee on initial paper: I believe saddleback syndrome may be caused by fish being captured in gillnets as juveniles and healing externally as they grow. I believe thorough histological investigation is required, as suggested by Pollock.


Causation of Saddleback Deformities in The Yellowfin Bream Acanthopagrus australis Fishery: Evidence of Physical Injury

Barry Pollock
Sunfish Queensland, 25 Uther Street, Brisbane, Queensland, 4152, Australia.

ABSTRACT
The yellowfin bream A. australis supports an important commercial net and angling fishery on the east coast of Australia. Saddleback, a deformity of the dorsal fin and profile, occurs in this species, with the occurrence of fish with saddleback being as high as 10% in some areas. The present study provides new information and analysis of causation of the saddleback deformity in the yellowfin bream fishery. Lateral line scale regeneration due to injury, and soft tissue abnormalities indicative of deep wounding are present in yellowfin bream with saddleback. X-ray images of the entire skeleton of specimens with saddleback were also examined. An unpublished government report on chemical residues in saddleback and normal yellowfin bream is appended and discussed. The absence of both chemical residues, and lack of other skeletal deformities in yellowfin bream with saddleback provide indirect evidence of physical injury as the cause of saddleback in this case. The role of discarding of meshed yellowfin bream, which are smaller than the legal minimum size, as causation of the saddleback deformity is evaluated..

Filesize: 898 KB    Date: 03 Nov 2025 14:12
Causation of Saddleback Deformities
Causation of Saddleback Deformities in The Yellowfin Bream Acanthopagrus australis Fishery: Evidence of Physical Injury

This is a 14 page PDF document



The Saddleback Deformity in Teleost Fish: Identification of a Unique Global Hotspot in Eastern Australia

Barry Pollock
a Sunfish Queensland, 25 Uther Street, Brisbane, Queensland-4152, Australia.

ABSTRACT
The saddleback deformity, an abnormality of the dorsal fin and profile, lacking one to all of the dorsal spines, accompanied by shape, number and position abnormalities of associated pterygiophores, has been reported in teleosts under culture conditions and in the wild in many locations throughout the world, including North and South America, Asia, Australia, Europe, India and the Middle East. A unique global hotspot for saddleback deformities in wild teleosts is the southeast Queensland Australia coastal region between 26° S and 28° S. At this location the incidence of saddleback has been relatively stable but very high at about 10% of individual teleosts taken in the associated fishery since 1997. Opinions on causation have focused on two possibilities, a developmental defect associated with water pollution or a physical injury. The range of skeletal deformities is vastly different in cultured teleosts compared with those occurring in the wild. There is now mounting evidence that physical injury is causing saddleback in teleosts in southeast Queensland Australia. Such injury could be caused by predatory behaviour of piscivorous fish or birds, parasites, or escapement or release from fishing nets and other fishing gear. Population mortality rates associated with saddleback in southeast Queensland are unknown, but expected to be high. The high level of occurrence of saddleback in teleosts in southeast Queensland Australia together with the good understanding of their fisheries biology

Filesize: 762 KB    Date: 03 Nov 2025 14:13
Saddleback review global
The Saddleback Deformity in Teleost Fish: Identification of a Unique Global Hotspot in Eastern Australia

A 14 Page PDF document.



THE ANNUAL SPAWNING AGGREGATION OF DUSKY FLATHEAD PLATYCEPHALUS FUSCUS AT JUMPINPIN, QUEENSLAND

POLLOCK, B.R.

Dusky flathead Platycephalus fuscus form seasonal spawning aggregations where estuaries meet the ocean in eastern Australia. The present study at Jumpinpin in south Queensland shows that dusky flathead have a protracted spawning period with serial spawning during summer (November to April). They are rudimentary hermaphrodites with sex determined at an early juvenile stage. Sex ratios are skewed with males most common in the smaller size-classes (< 50 cm TL). Mid-sized females (45 cm - 69 cm TL) dominate the production of eggs due to their abundance in the spawning aggregation. Within the female component of the spawning aggregation, the occurrence of individuals exceeding the current maximum size limit of 75 cm TL is low (2.6%). Parasitic nematodes (philometrids) occurred in 8% of ovaries. Degenerated ovaries, in which atretic oocytes are common, are present in half of the very large females (70 cm — 75cm TL) examined. The current minimum size restriction of 40 cm TL for dusky flathead provides protection for 73% of males and 15% of females within the spawning aggregation.

Filesize: 5,837 KB    Date: 03 Nov 2025 14:11
Flathead reproduction
THE ANNUAL SPAWNING AGGREGATION OF DUSKY FLATHEAD PLATYCEPHALUS FUSCUS AT JUMPINPIN, QUEENSLAND



Oogenesis, Oocyte Atresia, Ovarian Development and Reproductive Senescence in the Dusky Flathead Platycephalus fuscus (Teleostei)

Abstract
The aim of the present study is to examine developmental changes of oocytes and ovaries of a wild population of dusky flathead Platycephalus fuscus (Cuvier, 1829). This fish is endemic to the east coast of Australia where it inhabits estuaries and coastal waters. It is extensively fished throughout its range. It is a serial spawning teleost, capable of producing vast numbers of externally fertil- ised eggs in batches over a protracted annual spawning period. Successful egg production, as indicated by the presence of hydrated oocytes and post ovulatory follicles, is commonly observed in small and mid-size females (35cm–65cm Total Length; 2-6 years old) which numerically dominate the female component of the spawning aggregation. Oocyte atresia, at various levels, commences at the vitellogenic oocyte stage, and occurs in all mature fish during the spawning period. Mass oocyte atresia and degenerate ovaries were commonly observed in large fish (>70 cm Total Length and 7 years old), indicating that reproductive senescence occurs after females reach this size.

Filesize: 3,674 KB    Date: 03 Nov 2025 14:13
Flathead reproduction NSW
Oogenesis, Oocyte Atresia, Ovarian Development and Reproductive Senescence in the Dusky Flathead Platycephalus fuscus (Teleostei)
The NSW paper has been highly praised by international scientists/



Do Dusky Flathead, Platycephalus fuscus (Cuvier, 1829),Spawn in Upper Estuarine Areas?

Barry R. Pollock

Abstract
This study is based on monthly samples of dusky flthead ( n = 87) in the size range 40 cm TL (total length) to 75 cm TL, collected by angling methods from upper estuarine areas in southern Queensland during the spawning period (September to April). Ovaries at two stages of development were identifid by macroscopic and microscopic examination: unyolked (translucent) ovaries, the most common form, in which oocytes are undergoing mass atresia up to α stage; and yolked (vitellogenic) ovaries which are also undergoing mass atresia to both α and β stages. An unusual fiding is mass atresia of previtellogenic oocytes, showing multiple irregular vacuoles within the oocyte cytoplasm, which commonly occurs in both ovary types. Mature males have testes that are small and degraded. No ripe or running ripe gonads were found in the upper estuarine fih during the spawning period. It is concluded that these dusky flthead are not spawning, in contrast to the spawning aggregation fih at the Jumpinpin estuarine/oceanic interface which is 10 km to 20 km distant from the study site. Given the major differences in gonads and oocytes between spawning aggregation fih and those from upper estuarine areas, it is unlikely that mixing of the two subpopulations occurs during the spawning period. A review of size at maturity of dusky flthead estimated that L50 (length at which 50% of the size class has reached maturity) for females is 35 cm TL to 39 cm TL, and 30 cm TL to 34 cm TL for males.

Filesize: 2,908 KB    Date: 03 Nov 2025 15:18
Flathead in upper Qld
Do Dusky Flathead, Platycephalus fuscus (Cuvier, 1829), Spawn in Upper Estuarine Areas? Barry R. Pollock



The Queensland Snapper (Chrysophrys auratus) Fishery
History, Stock Assessments and Management Second Edition. Update, 2024
Barry Pollock
A Sunfish open access publication

econd edition update of this book. The first edition of this book was published in 2022. Since then another stock assessment is due by Fisheries Queensland (Northrop et al 2024 under internal peer review). The Queensland snapper management advisory committee has not met since February 2022 and a harvest strategy for the Queensland snapper fishery has not been determined. This second edition of the book on the Queensland snapper fishery provides an update to mid-2024.

Filesize: 5,949 KB    Date: 03 Nov 2025 14:15
Queensland snapper book second
The Queensland Snapper (Chrysophrys auratus) Fishery History, Stock Assessments and Management Second Edition. Update, 2024 Barry Pollock
A Sunfish open access publication

A 76 Page PDF


Barry Pollock with snapper he caught in 90m depth off Moreton Island 2023.



New Queensland snapper research

A new snapper research project on their reproductive biology in southern Queensland commenced in September 2025 and will be completed in August 2026. This is a joinr study between Sunfish (Dr Barry Pollock) and the University of Queensland (Dr Daryll Whitehead). Monthly samples will be taken under fisheries and marine parks permits by Dr Barry Pollock. Citizen science contributers will take large snapper in accord with the legislation, and under the National code of conduct for recreational fishing. Little is known of the reproductive biology of Queensland snapper. This project will determine size at maturity, spawning times and locations, macroscopic and microscopic features of ovaries and testes, whether sex inversion or rudimentary hermaphrodism occurs, and implications for management of the Queensland snapper fishery.



Luderick
This scientific study is one of the few which significantly correlates decreasing abundance with increasing water temperature for a single fish species on the Australian east coast.

Latitudinal change in the distribution of luderick Girella tricuspidata (Pisces: Girellidae) associated with increasing coastal water temperature in eastern Australia
B. R. Pollock
Sunfish Queensland Incorporated, PO Box 3013, Warner, Qld 4500, Australia.

Abstract.
During the past two decades there has been a major decline in the luderick (Girella tricuspidata) population and fishery in the coastal areas of southern Queensland, Australia. This region is the northern limit of the range of luderick. An analysis of annual time series information from the luderick fishery and from sea surface temperature records from 1976 to 2015 found a moderate and significant negative correlation (Pearson r ¼ 0.39, P , 0.05) between water temperature and population abundance in southern Queensland. Previous studies of juvenile and adult luderick indicate their sensitivity to elevated water temperature at the northern limit of their range, further supporting the hypothesis that declines in population abundance of luderick in southern Queensland are associated with increased water temperature. Other possible factors for the luderick population decline (overfishing and habitat loss) are discussed. Any future increases in coastal water temperatures in eastern Australia may result in further southward shifts of the luderick population, and may have similar effects on other fish species that have their northern range limits in southern Queensland.

Filesize: 425 KB    Date: 03 Nov 2025 14:16
Luderick and climate change
Latitudinal change in the distribution of luderick Girella tricuspidata (Pisces: Girellidae) associated with increasing coastal water temperature in eastern Australia

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QUARTERLY NEWSLETTER No 17 DECEMBER 2024
Written by David Bateman
Created / Updated on Wednesday 25th of June 2025

This newsletter is for general distribution to your members & the public.

QUARTERLY NEWSLETTER No 17 DECEMBER 2024

Editors Note – This newsletter is being produced to ensure our Members are kept informed on relevant matters. Issues will be covered briefly & for further details please contact Myself by phone or email.

Sunfish activities. The State elections was a busy time for Sunfish in reviewing our policy documents & contacting all the parties for their Policies.

The main thrust of our policies were:-

  • Reviewing the use of our Recreational Use Fee ($8m paid through boat registration).
  • More effective involvement of & consultation with recreational fishers
  • Independent peer review of science used to support Fisheries Management decisions taking climate change into account.
  • Simplify Recreational fishing regulations
  • Urgent review on the science re Spanish Mackerel & Snapper/pearl perch
  • Removal of commercial gill & ring netting in Moreton Bay
Before the election we were able to meet with the LNP shadow minister for fisheries (Tony Perrett) who was subsequently elected.

This was followed up with a face-to-face meeting on 5th December 2024.

We raised the matters listed in our policy document & explained the reasoning for them. The Minister agreed that we should know how the recreational levy was spent & he would follow it up. He was happy to advance further communications & suggested we meet with Fisheries to discuss our issues & keep him informed of the results. He made no actual commitment on any conflict issues as he was still to meet with other “fishing related groups”. As a result, Sunfish will submit a list of the concerns raised to Fisheries Qld for discussion with their Officers.

FQ Grants;-

Sunfish Members have received grants & are proceeding with their activities. Hopefully these will occur with the incoming government but under a different format to be discussed with Fisheries Qld.

Fisheries Updates.

It is disappointing that the Working Groups for the East Coast Inshore & Rocky Reef Fisheries have not been reformed but hopefully this may change as they are 2 of the most important recreational fisheries. The submission on proposed legislation changes re crab pot specifications, some reef species, black jewfish & freshwater apparatus are still in limbo but action has been promised in the new year. Don’t expect any decisions soon as regulations will need to change & be subject to public consultation & some will need a phase in period.

Marine Parks & Area closures.

Community consultation on the Moreton Bay MP will occur early next year & hopefully more consideration will be given to the public use rather than closing access. An assessment should also be done of the values of existing green areas. GBRMPA are proceeding with their 3-year consultation on the future management of the Southern section of the GBR. This generally extends from Mackay to Bundaberg & seawards.

Research Projects affecting Recreational fishing –

Our Scientific Officer Dr Barry Pollock is continuing to work on several “Citizen Science” projects for Sunfish including a new grant application to “research” tailor.

Discussions are still underway re the value of spawning closure periods especially in light os FQ science which indicates that the Pearl perch closure is not a breeding period. We have approached Fisheries to remove Pearl Perch from the “no take” species during that closure period & reassess the value of the snapper closure. A study s being conducted yet again on how to communicate & get the support of recreational fishers to provide information. More to come in the new year.

Wishing you all a MerryXmas & a Happy New Year from the Chairman of Sunfish & the Management Committee.

David Bateman AM, Secretary Sunfish Qld. 5/12/2024

Note- Information contained in this newsletter is as accurate as possible as of this date.

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QUARTERLY NEWSLETTER No 18, MARCH 2025
Written by David Bateman
Created / Updated on Wednesday 25th of June 2025

This newsletter is for general distribution to your members & the public.

QUARTERLY NEWSLETTER No 18, MARCH 2025

Editors Note – This newsletter is being produced to ensure our Members are kept informed on relevant matters. Issues will be covered briefly & for further details please contact Myself by phone or email.

Sunfish activities. Following the election we met with the LNP Minister for fisheries (Tony Perrett). At that meeting we raised the matters contained in our policy document & he suggested that we discuss these with Fisheries & Marine Parks.

As a result, Sunfish submitted a list of the concerns raised to Fisheries Qld for discussion with their Officers & a meeting was held on11th March.

The main thrust of our policies were:-

  1. Reviewing the use of our Recreational Use Fee ($7m) paid through boat registration).
    • The monies are used for a range of statewide activities such as recreational surveys, research, education, consultation, Boating Patrol, information distribution etc.
    • It is & will remain part of the FQ budget.
    • The freshwater SIP scheme is administered separately.
  2. More effective involvement of & consultation with recreational fishers
    • This is a government commitment & will increase in the future. The East coast inshore working group will be reformed,
    • As the current Harvest Strategy concludes in 2 years, Consultants have been commissioned to develop a future strategy pathway for Fisheries after that date & will be contacting stakeholders for feedback.
  3. Independent peer review of science used to support Fisheries Management decisions taking climate change into account.
    • Before any regulation changes are introduced because of stock assessments, the appropriate working group will be convened to discuss all the information including environmental factors.
    • An independent scientist is being used to verify the Spanish mackerel assessments which are due to be released soon.
  4. Simplify Recreational fishing regulations
    • The matter was discussed with Sunfish presenting examples of how it could be done. FQ agreed & will progress the matter through the working groups & further consultation with us.
  5. Urgent review on the science re Spanish Mackerel & Snapper/pearl perch.
    The major priority at present is on Spanish mackerel & there is no priority or changes proposed for Snapper or Pearl perch.
  6. Information on current Fisheries activities raised by sunfish.
    • Proposed changes distributed last April for comment on crab pots etc. are still being assessed but no action expected before late 2025.
    • An additional person on the Crab WG is under consideration but at this stage the rocky reef WG will not be reformed as there is no priority on these species & no changes anticipated.
    • The Moreton Bay WG activities are on hold pending the MB Marine Park review.
    • Commercial gill & ring netting in Moreton Bay is controlled by Total Allowable catches.
    • Filleting fish at sea will be addressed through the relevant working groups.
    • Generally there will be no changes to regulations this year.
Moreton Bay MP.
  • The current MBMP plan was renewed in its existing form.
  • Planning has started on the next review with Minister still to be briefed
  • Some stakeholder consultation will take place later this year.
  • Discussion paper/Regulatory Impact Statement is expected to be released in 2026
  • Consultation will occur with stakeholders after that.
  • Final MBMP new plan has to be legislated by 2029
  • Removal of MP boundary markers was raised & would be investigated by the responsible MP section.
Marine Parks & Area closures.
GBRMPA are proceeding with their 3-year consultation on the future management of the Southern section of the GBR. This generally extends from Mackay to Bundaberg & seawards.

Research Projects affecting Recreational fishing –
A study is being conducted yet again on how to communicate & get the support of recreational fishers to provide information.

David Bateman AM, Secretary Sunfish Qld. 13/3/2025
Note- Information contained in this newsletter is as accurate as possible as of this date.

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QUARTERLY NEWSLETTER No 19, JUNE, 2025
Written by David Bateman
Created / Updated on Wednesday 25th of June 2025

This newsletter is for general distribution to your members & the public.

QUARTERLY NEWSLETTER No 19, JUNE, 2025

Editors Note – This newsletter is being produced to ensure our Members are kept informed on relevant matters. Issues will be covered briefly & for further details please contact Myself by phone or email.

Sunfish activities.

Congratulations to Bruce Alvey AM on his appointment as a Member of the Order of Australia- the recognition is well deserved for his contribution to recreational fishing. Members are reminded that the Sunfish AGM will be held on August 10th at the Chermside Library starting at 9.30 am.

Following our March meeting with Fisheries Qld another has been held this month & the following information has been provided.

  • Information on the use of the Recreational Use fee is still being prepared & we will circulate it when received.
  • Contact points for all Fishery Managers have been provided
  • Issues in relation to simplifying Recreational fishing regulations will be part of the new working group responsibilities. (see later)
Additionally we raised other following issues in relation to recreational fishing & the strategic direction for Fisheries Qld.

With the Sustainable Fisheries Strategy due to finish next year the Government is embarking on a new pathway that builds on previous work but with increasing community consultation.

This pathway will consist of the following

  • A DPI 2050 Action Plan for all primary industries including fishing - submissions for this have closed & will be collated by a consultant in the near future.
  • Later this year a “Ministerial Round Table for recreational fishing” will be convened with appointed statewide anglers voicing their thoughts for the future management of recreational fishing. A similar commercial round table will occur.
  • This will lead to the development of a 5-year industry specific Strategic Plan for recreational fishing.
  • Working groups will be reappointed with a change in responsibilities to reflect the industry strategic plans.
  • Consideration is being given to having an FQ Manager for recreational fishing.
Research –

The new Spanish Mackerel stock assessment shows that the stocks are now stable.

The Sunfish Scientific Officer has commenced a new project in conjunction with the U of Qld on snapper reproduction. This follows Barry Pollock’s successful paper on flathead reproduction & several publications on snapper & bream.

The current Recreational Fishing Surveys by FQ will be scaled down in favor of other data collection methods.

The Fisheries Research & Development Corporation are calling for people to nominate for a position on the Qld Research Advisory Committee. The application form can be accessed through the FRDC website.

FQ Grants.

Several Members have applied successfully for grants to conduct fishing events for Juniors. Others have been “knocked back” & we have asked why.

Marine Parks.

Stakeholder consultation is expected to commence later this year on the Moreton Bay MP.

with a completion date for the new plan by 2029

GBRMPA are proceeding with their 3-year consultation on the future management of the Southern section of the GBR. This generally extends from Mackay to Bundaberg & Seawards. Research

David Bateman AM, Secretary Sunfish Qld. 14/6/2025

Note- Information contained in this newsletter is as accurate as possible as of this date.

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News Article

About SUNFISH QLD Inc.
Created / Updated on Saturday 22nd of January 2022
Photos / Files Available

SUNFISH QLD was formed in 1993 out of the Queensland Sport and Recreational Fishing Council (QSRFC) which had been operational for some 20 years.

Representing all recreational anglers as well as members, SUNFISH QLD is the state's peak recreational fishing group and consults all the major Statewide fishing organizations such as:

Australian Underwater Federation Queensland (AUFQ)
Blue Fin Fishing Club (over 5,000 members)
South Queensland Amateur Fishing Clubs Association
Junior Anglers Association
3 Regional Branches
Pine Rivers Fish Management Association
Caloundra Power Boat Club

SUNFISH QLD services its members in many ways and has

  • a democratically elected Executive
  • 11 Member organizations spaced from the NT border to the Gold Coast
  • a registered membership of over 45 000 club, group and individual anglers

The SUNFISH QLD management committee (Sunfish Central) (list attached) services the members of SUNFISH through a centralized information and administrative function, keeping members up to date on relevant issues. Some of the benefits are:

  • daily information
  • contact with Government
  • coordination of replies to Government Discussion Papers
  • strategic observation of fisheries and environmental matters
  • liaison between 45,000 individual member anglers and the angling public


We have as partners, the Queensland Boating Industry, the Queensland Tackle Industry, Healthy Waterways, SEQ Catchments and the Fish Habitat Network..

The Executive of SUNFISH has developed working relationships with The Queensland Minister for Primary Industries and other State and Federal Ministers whose portfolios impact on the fishery.

SUNFISH QLD has regular stakeholder meetings with the Queensland Department of Primary Industry & Fisheries and the Great Barrier Reef Marine Park Authority. These communication lines are used when necessary to advise of our position on relevant issues or give advice on matters concerning anglers.

SUNFISH QLD is primarily an advisory group for recreational fishers throughout Queensland. We are consulted by Government for a variety of purposes such as a recreational fishing advisory source and networking with recreational fishers throughout Queensland. Our members sit on the Queensland Fisheries Management and Advisory Committees. We have some fifty people on those and other groups, all working voluntarily.

SUNFISH QLD is involved in many other areas such as habitat protection/restoration, land care, coast care, education, research and a myriad of other committees.

SUNFISH QLD is however, at arms length from the Government and is APOLITICAL.

SUNFISH QLD has established the most efficient and effective fisheries information network in Queensland.

SUNFISH QLD works with Department of Primary Industries & Fisheries , the Environmental Protection Authority (EPA) and the Department of Natural Resources (DNR) but at the same time are not constrained if we think that they are ignoring our concerns. We also have a good working relationship with the Great Barrier Reef Marine Park Authority (GBRMPA) and are part of their Resource Advisory Committees (RAC's) and Local Management Advisory Committees (LMAC's). All these areas of voluntary consultation save Governments time and money.

SUNFISH QLD prepare submissions on EIS's that impact on fishery resources, respond to Fisheries Discussion papers, draft Management Plans and Regulatory Impact Statements (RIS), etc.

We have a strong input into fishery research and assist with fish stock assessment in rivers and estuaries. Our Freshwater Fishing & Stocking Groups provide the manpower to assist DPI fisheries in the stocking of Queensland's dams and impoundment's. We also have a professionally developed and (voluntarily) run Angler Education Program including professional quality instruction for junior anglers and an education Manual for School curriculum use.

SUNFISH QLD has established the most efficient and effective fisheries information network in Queensland.

Since 1999 SUNFISH QLD and all our Member Bodies have been equipped with computers and e-mail facilities, SUNFISH QLD has a WEB page at www.sunfishqld.com.au. Our web page has become a source of information for members, educators, recreational fishers and other recreational fishing interests.

Queensland continues to have concerns with fisheries habitat destruction, inappropriate commercial fishing practices, and downstream impacts on our fishery by residential, industrial, rural and mining industries and the list goes on. However, our voice is being heard and we are getting the message across on how the economic input from the recreational fishing industry will be affected through inappropriate land practices.

Our Fishing Industry, worth some $1 billion per annum, is too economically important to be put at risk through being ignored by Government or by allowing other industries to impact on it adversely.

Working with Fisheries, a comprehensive data base on how many people fish in Queensland, where they fish, what they fish for and how often they fish has been established. The original survey included some 26 000 phone calls throughout the State. DPI & F has now completed 4 such surveys with our assistance. At present SUNFISH QLD has completed four expenditure surveys throughout Queensland and more are planned on "what it costs to go fishing."

The monies for all these surveys comes from the $3.8 million collected annually from Queensland's recreational boat owners in the form of the PPV levy & from the Stocked Impoundment (SIP) Permit. Some of these monies are available to SUNFISH as project grants.

Monies to finance our operations come from varied sources such as the QDPI & F for project work, the Commonwealth Rec Fishing Community Grants project, affiliation fees & donations from businesses. Some equipment is supplied through the Qld Government Gaming fund grants.

Some of our members have, on our behalf, produced reports on various aspects of the fishery and its associated habitat including an excellent paper on the requirements of natural river floods for the spawning of Barramundi and a paper on fish kills in Queensland.

The Chairman and members of the Executive normally manage to visit every Queensland SUNFISH Branch at least once per year. The travel requirement are significant but it has been time well spent, as we believe it is essential that the senior executive visit these areas to explain many issues which are hard to get across without face to face contact.

I FISH and I VOTE originated here in Queensland just before the 96 State elections and it had a devastating effect, especially in North Queensland. It was an ANSA innovation. This theme has been taken up all over the country and the politicians are now well aware of the slogan.

The above thumbnail sketch is to point out what is possible. We still have much to achieve including a significant increase in independent funding if we are to be truly effective and if we are to stop relying on the goodwill of volunteers and the Government. We need a broader membership base and we need to achieve a better level of corporate support.

SUNFISH QLD however, is nowhere near where it wants to be in the future and needs your assistance to represent our angling community.


Bruce Alvey, Chairman,
SUNFISH QUEENSLAND Inc.

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