ORCID Profile
0000-0002-0884-8386
Current Organisation
NSW Department of Primary Industries
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Publisher: Canadian Science Publishing
Date: 08-2013
Abstract: Changes to the global climate are driving alterations to boundary current-influenced marine ecosystems. The diet of a pelagic teleost, Arripis trutta, was examined in the East Australian Current (EAC)-dominated coastal waters of southeastern (SE) Australia. The diet of A. trutta was dominated by pelagic baitfish, primarily Australian sardine (Sardinops sagax) and scads (Trachurus spp.). Diet varied substantially with both latitude and season linked to variability in the distribution and abundance of key prey species. An ontogenetic diet shift occurred, with crustaceans and polychaetes making up a large proportion of the diet of small fish compared with the dominance of baitfish at larger sizes. The diet of A. trutta has undergone a dramatic shift from one dominated by krill (Nyctiphanes australis) historically to baitfish today. This change is consistent with a well-documented regime shift caused by the increasing intensity of the EAC on coastal SE Australian waters. Understanding the temporal dynamics of this ecosystem is crucial for management of coastal fisheries and also for understanding the impacts of climate change on boundary current-dominated marine ecosystems worldwide.
Publisher: Elsevier BV
Date: 10-2014
Publisher: CSIRO Publishing
Date: 03-08-2023
DOI: 10.1071/MF22142
Abstract: Context As social–ecological systems, recreational fisheries often vary temporally in response to environmental changes affecting ecological processes and human behaviour. Monitoring such variability in this ecosystem service can guide adaptive management measures for sustainability. Aims This novel research for Australian, sought to quantify interannual changes in the freshwater recreational fisheries of five key (i.e. commonly caught) finfish species (Murray cod, Maccullochella peelii golden perch, Macquaria ambigua Australian bass, Percalates novemaculeata brown trout, Salmo trutta and rainbow trout, Oncorhynchus mykiss) in relation to a series of extreme climate-related events and the COVID-19 pandemic. Methods Annual estimates during 2013–14, 2017–18 and 2019–20 of freshwater fishing effort and catch across New South Wales, Australia, were derived from off-site surveys and compared in relation to a severe drought period, the ‘Black Summer’ bushfires, widespread flooding and the COVID-19 pandemic, all of which affected fish productivity or human mobility. Key results There were significant declines in fishing effort between 2013–14, the year preceding the extreme environmental events and the pandemic, and 2017–18 and 2019–20. Catch across the five species was also significantly lower in 2019–20. Catch of species such as golden perch and rainbow trout declined from 2013–14 to 2019–20. Conclusions and implications This study can inform adaptive measures against societal and climate-related changes in weather by enabling scientists and managers to identify problematic trends.
Publisher: Wiley
Date: 25-02-2022
DOI: 10.1002/EDN3.185
Abstract: Environmental DNA (eDNA) has revolutionized our ability to identify the presence and distributions of terrestrial and aquatic organisms. Recent evidence suggests the concentration of eDNA could also provide a rapid, cost‐effective indicator of abundance and/or biomass for fisheries stock assessments. Globally, fisheries resources are under immense pressure, and their sustainable harvest requires accurate information on the sizes of fished stocks. However, in many cases the required information remains elusive because of a reliance on imprecise or costly fishery‐dependent and independent data. Here, we review the literature describing relationships between eDNA concentrations and fish abundance and/or biomass, as well as key influencing factors, as a precursor to determining the broader utility of eDNA for monitoring fish populations. We reviewed 63 studies published between 2012 and 2020 and found 90% identified positive relationships between eDNA concentrations and the abundance and/or biomass of focal species. Key influencing biotic factors included the taxon examined as well as their body size, distribution, reproduction, and migration. Key abiotic factors mostly comprised hydrological processes affecting the dispersal and persistence of eDNA, especially water flow and temperature, although eDNA collection methods were also influential. The cumulative influence of these different factors likely explains the substantial variability observed in eDNA concentrations, both within and among studies. Nevertheless, there is considerable evidence to support using eDNA as an ancillary tool for assessing fish population abundance and/or biomass across discrete spatio‐temporal scales, following preliminary investigations to determine species‐ and context‐specific factors influencing the eDNA abundance/biomass relationship. Advantages of eDNA monitoring relative to other approaches include reduced costs, increased efficiencies, and nonlethal s ling.
Publisher: Wiley
Date: 25-01-2022
DOI: 10.1002/AQC.3769
Abstract: Bycatch in fishing gear is a threat to the conservation of seabird populations globally. Factors affecting interactions with commercial fisheries are well documented however, little comparable information exists for recreational fisheries. High participation rates in many recreational fisheries globally mean that interactions with seabirds may have population‐level impacts. This study specifically assessed factors affecting seabird interactions with a recreational hook‐and‐line fishery in New South Wales (NSW), Australia. Observers on ‘for hire’ nearshore charter vessels collected data on seabird abundance, interactions and various fishing and environmental variables which could affect the numbers of seabirds in attendance at vessels. In 2017/18, observers were present on 135 fishing trips spanning ~33–36°S off coastal NSW recording 3,183 seabirds, including 10 species from seven families. The majority consisted of shearwaters (Procellariidae 76%), albatrosses (Diomedeidae 8%) and gulls/terns (Laridae 10%), including several species of conservation concern. Significant seasonal variation in the abundances of the three main seabird families were recorded however, none of the fishing or environmental variables influenced abundances of seabirds (except for the positive effect of inclement weather on shearwaters). Eleven direct interactions and a single incidence of (shearwater) bycatch were recorded in over 630 h of observed fishing (1.74 and 0.16 per 100 h fishing, respectively) these rates were likely due to the active fishing methods used which allows fisher behaviour to minimize interactions. Despite this, these rates indicate that the nearshore charter fishery does have the potential to present a threat to the conservation of seabird populations in this region. Furthermore, globally, for regions with high recreational fishing participation rates, increased and ongoing monitoring of seabird interactions with recreational fisheries is required. This study also highlights that such interactions are likely to be rare events and future monitoring may require utilization of existing broadscale recreational fisheries monitoring programmes, as well as the development of new or enhanced programmes.
Publisher: Wiley
Date: 13-10-2021
DOI: 10.1002/AQC.3726
Abstract: Effective conservation and fisheries management requires data to capture demographic processes and range limits for each species to maximize population health and productivity. This need is constrained by limited funding and resources, particularly for countries with large land areas and coastlines as well as expansive exclusive economic zones. This imbalance means that monitoring efforts are often focused on targets of commercial and recreational fishing, which results in incomplete distributional records for non‐target, small‐bodied, and/or cryptic species. Community‐based citizen science projects offer one potential alternative for scientists and fisheries managers needing this type of information but lacking sufficient resources to gather it. This study investigated whether data sourced from an online citizen science project (iNaturalist: Australasian Fishes) can assist in the distributional monitoring of a subset of fish species. Given the regional focus of this citizen science project, distributional data in the form of occurrence records for abundant, protected, and threatened fish species as assessed by the International Union for Conservation of Nature in Australia and New Zealand were explored. Data for important commercial and recreational fishery targets in New South Wales were also explored, as a case study of a large jurisdiction with extensive monitoring requirements. The occurrence records for some of these categories of fishes were well represented in the quality‐filtered citizen science data set, particularly endemic fishes whose threat status had not yet been assessed and species not currently under any form of management. Despite gaps in coverage between major urban centres, citizen science data for the best represented endemic fishes were qualitatively comparable to the available geographic distributions for these species. We suggest that quality‐filtered citizen science data can in fact be used to improve taxonomic representation and the geographic breadth of species monitoring with increased participation.
Publisher: Oxford University Press (OUP)
Date: 14-01-2022
Abstract: Recreational fishing (RF) is a popular pastime resulting in substantial fish mortality in many regions. Yet inclusion of RF in fishery harvest strategies is limited, because the sector's objectives are poorly understood, as are the data required to track their performance. To address this, we reviewed RF data sources available from a region of globally high participation (New South Wales [NSW], Australia) and evaluated their utility for RF-specific performance indicators within harvest strategies. We then linked these data sources to RF objectives they may be used to monitor. A total of 21 RF data sources were identified in NSW over the past two decades, spanning all major aquatic environments and 146 fished species. Numerous data sources were available to monitor ecological objectives, providing time-series and potential reference points for key indicators such as catch-per-unit-effort. Few data sources were available for social, economic, and institutional objectives, consistent with a global paucity of these data. We found that most social objectives of RF lie outside the scope of traditional harvest strategies, although some are linked to underlying ecological performance. Harvest strategy performance for RF will depend on the relative importance of social objectives and whether these can be achieved by controlling harvest.
Publisher: Public Library of Science (PLoS)
Date: 06-11-2015
Publisher: Springer Science and Business Media LLC
Date: 02-2006
Publisher: Wiley
Date: 03-04-2022
DOI: 10.1002/AQC.3809
Abstract: Analysis of environmental (e)DNA can facilitate an understanding of the presence and distribution of aquatic species. However, eDNA detection using quantitative PCR requires validated and standardized species‐specific assay designs. This study presents two eDNA assays to detect Murray cod, Maccullochella peelii , and mulloway, Argyrosomus japonicus (two ecologically vulnerable Australian species), based on small fragments of the mitochondrial 12S ribosomal RNA gene. A comprehensive description of species‐specific assay development, from assay design to testing in silico, in vitro and in situ , has been included to guide effective assay design and validation in future studies. The results indicate that the assay was species specific for M. peelii within its natural distribution. However, the assay also lified genomic DNA from two allopatric and endangered congeners ( Maccullochella ikei and Maccullochella mariensis ), thus potentially facilitating their eDNA detection elsewhere. In contrast, the A. japonicus assay was highly species specific with no lification among close relatives. Both target‐species assays are highly sensitive to as few as four and 10 copies per PCR reaction, respectively. This study has demonstrated that the assays assessed are effective tools for detecting the targeted species in situ from environmental DNA s les, which will assist efforts to conserve and manage their stocks.
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/MF08102
Abstract: The growth and reproductive biology of the commercially and recreationally important sparid fish, tarwhine (Rhabdosargus sarba), was examined from the coastal waters of New South Wales (NSW), south-eastern Australia. Previous research on this species in other parts of the world has yielded conflicting results concerning its growth and reproductive biology. Age estimates were made by counting opaque zones in otolith sections. The method was validated by marking the otoliths of captive fish with alizarin complexone, and also by marginal increment analyses using otoliths from wild-caught fish. Both sexes grew at a similar rate. Von Bertalanffy growth function parameters were: L∞ = 26.40 ± 0.40 cm fork length (FL), k = 0.39 ± 0.02 year–1 and to = –0.56 ± 0.09 years. The maximum estimated age was 16.5 years. Spawning occurred from May to August with a peak in July. Both sexes matured at a similar size (L50 = 19.44 ± 0.15 cm FL), which was larger than the current minimum legal length in NSW. Ovotestes were identified in adult tarwhine and were confirmed by histological analyses. Results of this study provided evidence that tarwhine are likely to be rudimentary hermaphrodites in eastern Australia and are more similar in growth rate, maximum size/age, and reproductive biology to tarwhine from Western Australia than those from other parts of the world.
Publisher: Elsevier BV
Date: 03-2009
Publisher: Elsevier BV
Date: 04-2019
Publisher: Springer Science and Business Media LLC
Date: 09-07-2016
Publisher: Hindawi Limited
Date: 27-03-2013
DOI: 10.1111/JAI.12185
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/MF14247
Abstract: This study investigated how the stock structure of Arripis trutta is influenced by the movement of adult fish. Five-year-old fish were s led from four regions in south-east Australia encompassing ~1500km of coastline. Transverse otolith sections were analysed using laser-ablation inductively coupled plasma-mass spectrometry, providing age-related elemental profiles. Multivariate analyses showed that for most age groups, the elemental fingerprint of northern New South Wales (NSW) fish was significantly different from those of the other locations. Northern NSW fish also had a different fingerprint from those of all other locations for the first part of the fish’s life. These results indicate that most A. trutta originate in southern NSW, Victoria and Tasmania and move progressively northward with increasing age. Some recruitment occurs in northern NSW but these fish may not mix with immigrants from further south until they are more than 5 years old. When assessed with the strong latitudinal age gradient of the population, these data are consistent with a single, panmictic stock. The data also highlight the utility of otolith transect analysis in understanding the influence of age-related movements on stock structure and appropriate spatial management of exploited fish species.
Publisher: Oxford University Press (OUP)
Date: 17-01-2023
Abstract: Recreational fishing can have substantial ecological impacts, which must be managed against a background of critical socio-economic factors. However, it is often difficult to assess the effect of altered management arrangements on this sector’s harvest. Recreational fishing surveys can assist in quantifying the impact of changes to harvest limits. Here, we use survey data collected in 2013/2014 and 2017/2018 to estimate the total catch of Dusky Flathead (Platycephalus fuscus), a key Australian marine species, under a daily harvest limit of 10 fish per angler and simulated scenarios where the limit is reduced to 5, 3, or 1 fish per angler. We then test the significance of these changes in harvest limit on catch and also model the potential effects of year and region using generalized linear mixed models (GLMMz). For both s led time periods, the GLMMz found that only the most stringent harvest limit reduction to 1 fish per angler would lower retained harvest significantly. None of the reductions in harvest limit increased the number of released Dusky Flathead significantly. We discuss how this novel quantitative approach can be used to inform alternative output management regulations by taking into account their potential ecological and socio-economic benefits for a recreational fishery.
Publisher: Inter-Research Science Center
Date: 26-02-2009
DOI: 10.3354/MEPS07794
Publisher: Springer Science and Business Media LLC
Date: 09-12-2016
Publisher: Springer Science and Business Media LLC
Date: 25-03-2012
Publisher: Springer Science and Business Media LLC
Date: 25-08-2013
DOI: 10.1007/S10695-013-9846-Y
Abstract: Physoclist fish are able to regulate their buoyancy by secreting gas into their hydrostatic organ, the swim bladder, as they descend through the water column and by resorbing gas from their swim bladder as they ascend. Physoclists are restricted in their vertical movements due to increases in swim bladder gas volume that occur as a result of a reduction in hydrostatic pressure, causing fish to become positively buoyant and risking swim bladder rupture. Buoyancy control, rates of swim bladder gas exchange and restrictions to vertical movements are little understood in marine teleosts. We used custom-built hyperbaric chambers and laboratory experiments to examine these aspects of physiology for two important fishing target species in southern Australia, pink snapper (Pagrus auratus) and mulloway (Argyrosomus japonicus). The swim bladders of pink snapper and mulloway averaged 4.2 and 4.9 % of their total body volumes, respectively. The density of pink snapper was not significantly different to the density of seawater (1.026 g/ml), whereas mulloway were significantly denser than seawater. Pink snapper secreted gas into their swim bladders at a rate of 0.027 ± 0.005 ml/kg/min (mean ± SE), almost 4 times faster than mulloway (0.007 ± 0.001 ml/kg/min). Rates of swim bladder gas resorption were 11 and 6 times faster than the rates of gas secretion for pink snapper and mulloway, respectively. Pink snapper resorbed swim bladder gas at a rate of 0.309 ± 0.069 ml/kg/min, 7 times faster than mulloway (0.044 ± 0.009 ml/kg/min). Rates of gas exchange were not affected by water pressure or water temperature over the ranges examined in either species. Pink snapper were able to acclimate to changes in hydrostatic pressure reasonably quickly when compared to other marine teleosts, taking approximately 27 h to refill their swim bladders from empty. Mulloway were able to acclimate at a much slower rate, taking approximately 99 h to refill their swim bladders. We estimated that the swim bladders of pink snapper and mulloway ruptured after decreases in ~2.5 and 2.75 times the hydrostatic pressure to which the fish were acclimated, respectively. Differences in buoyancy, gas exchange rates, limitations to vertical movements and acclimation times between the two species are discussed in terms of their differing behaviour and ecology.
Publisher: MDPI AG
Date: 22-02-2023
DOI: 10.3390/D15030322
Abstract: Non-invasive, low-cost methods for censusing depleted fish populations are being prioritised among many jurisdictions worldwide. Collecting environmental DNA (eDNA) could offer one such option for augmenting fish population assessments. However, candidate species need to be carefully selected because species-specific DNA shedding and decay rates are affected by many biotic and abiotic factors that may influence relative abundance estimates. In this study, we sought to ascertain if the eDNA of a depleted Australian teleost, mulloway, Argyrosomus japonicus, reflects its weight under controlled aquaria conditions. With four experiments, we investigated the relationships between mulloway eDNA concentrations and their weight tank−1 as a function of: (1) time post-tank establishment (2) water temperatures (within the species’ tolerance range) (3) stocking densities and (4) among in idual, similar-sized fish. The concentrations of eDNA in tanks stabilised after six days, and a positive relationship was found between fish weight and eDNA concentration, despite some variability in shedding rates by similar-sized fish. There was also a positive effect of water temperature on eDNA concentrations, which reinforces the need to control for such abiotic factors. We conclude that there is strong utility in applying eDNA concentrations as an index of relative abundance for mulloway under controlled conditions, which justifies future field-based investigations.
Publisher: CSIRO Publishing
Date: 2010
DOI: 10.1071/MF10040
Abstract: Fishes of the family Scorpaenidae (scorpionfish/rockfish) are important to benthic rocky-reef communities and fisheries globally. The present study is the first to provide biological information for any species of the genus Scorpaena (Scorpaena cardinalis) in southern hemisphere waters, namely south-eastern Australia. Growth of S. cardinalis was estimated using size-at-age data from sectioned otoliths. Growth was slow, with fish attaining ∼22 cm after 5 years and 26 cm after 10 years. The oldest fish s led was estimated to be 33 years old. In contrast to similar-sized congeneric species, males increased in length significantly faster and attained larger sizes than females. Variable recruitment patterns were evident from the age composition of the s led population. Males of S. cardinalis had mean gonadosomatic index levels (0.09%) an order of magnitude smaller than did the females (2.8–4%) during the March spawning peak. S. cardinalis possesses a cystovarian Type II-3 ovary, a highly specialised form associated with external fertilisation and the production of eggs in a floating gelatinous mass. Traits such as slow growth, substantial longevity, variable recruitment patterns and a highly specialised reproductive strategy may make this species vulnerable to over-exploitation as has occurred with other members of the family Scorpaenidae elsewhere.
Publisher: Wiley
Date: 2007
Publisher: CSIRO Publishing
Date: 2008
DOI: 10.1071/MF07216
Abstract: Labrids are abundant on temperate rocky reefs yet their life histories are poorly known. Three co-occurring Australian labrids (Ophthalmolepis lineolatus, Notolabrus gymnogenis and Pictilabrus laticlavius) exhibited protogynous hermaphroditism typical of labrids. Juveniles reached sexual maturity at 184 mm total length (TL) (2.1 years) in O. lineolatus, 177 mm TL (1.8 years) in N. gymnogenis and mm TL ( .9 years) in P. laticlavius. In iduals were sexually active initial phase females until changing to a terminal phase male at 295 mm TL (5.2 years) in O. lineolatus, 273 mm TL (4.5 years) in N. gymnogenis and 138 mm TL (2.0 years) in P. laticlavius. The occurrence of males only at greater lengths and older ages suggests that O. lineolatus and N. gymnogenis are monandrous, whereas P. laticlavius appears to be diandrous. Reproduction was asynchronous among species with reproductive activity peaking in January–March for O. lineolatus, April–October for N. gymnogenis and October–December for P. laticlavius. Sectioned otoliths revealed that O. lineolatus and N. gymnogenis grew rapidly to 300 mm TL (6 years) and P. laticlavius to 180 mm TL (3 years). Longevity was at least 13.8, 9.6 and 4.8 years respectively. These life history data will aid management of these frequently harvested species.
Start Date: 2015
End Date: 2017
Funder: Australian Research Council
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