ORCID Profile
0000-0002-9620-5064
Current Organisation
Government of Western Australia Department of Primary Industries and Regional Development
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In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Genomics | Population, Ecological and Evolutionary Genetics | Biogeography and Phylogeography | Genetics |
Climate Variability (excl. Social Impacts) | Marine Flora, Fauna and Biodiversity | Ecosystem Assessment and Management of Mountain and High Country Environments
Publisher: Elsevier BV
Date: 12-2015
Publisher: Frontiers Media SA
Date: 12-10-2021
DOI: 10.3389/FMARS.2021.658135
Abstract: The ongoing need to sustainably manage fishery resources can benefit from fishery-independent monitoring of fish stocks. Camera systems, particularly baited remote underwater video system (BRUVS), are a widely used and repeatable method for monitoring relative abundance, required for building stock assessment models. The potential for BRUVS-based monitoring is restricted, however, by the substantial costs of manual data extraction from videos. Computer vision, in particular deep learning (DL) models, are increasingly being used to automatically detect and count fish at low abundances in videos. One of the advantages of BRUVS is that bait attractants help to reliably detect species in relatively short deployments (e.g., 1 h). The high abundances of fish attracted to BRUVS, however, make computer vision more difficult, because fish often obscure other fish. We build upon existing DL methods for identifying and counting a target fisheries species across a wide range of fish abundances. Using BRUVS imagery targeting a recovering fishery species, Australasian snapper ( Chrysophrys auratus ), we tested combinations of three further mathematical steps likely to generate accurate, efficient automation: (1) varying confidence thresholds (CTs), (2) on/off use of sequential non-maximum suppression (Seq-NMS), and (3) statistical correction equations. Output from the DL model was more accurate at low abundances of snapper than at higher abundances (& fish per frame) where the model over-predicted counts by as much as 50%. The procedure providing the most accurate counts across all fish abundances, with counts either correct or within 1–2 of manual counts ( R 2 = 88%), used Seq-NMS, a 45% CT, and a cubic polynomial corrective equation. The optimised modelling provides an automated procedure offering an effective and efficient method for accurately identifying and counting snapper in the BRUV footage on which it was tested. Additional evaluation will be required to test and refine the procedure so that automated counts of snapper are accurate in the survey region over time, and to determine the applicability to other regions within the distributional range of this species. For monitoring stocks of fishery species more generally, the specific equations will differ but the procedure demonstrated here could help to increase the usefulness of BRUVS.
Publisher: Elsevier BV
Date: 05-2011
Publisher: Cold Spring Harbor Laboratory
Date: 02-02-2021
DOI: 10.1101/2021.02.01.429285
Abstract: The ongoing need to sustainably manage fishery resources necessitates fishery-independent monitoring of the status of fish stocks. Camera systems, particularly baited remote underwater video stations (BRUVS), are a widely-used and repeatable method for monitoring relative abundance, required for building stock assessment models. The potential for BRUVS-based monitoring is restricted, however, by the substantial costs of manual data extraction from videos. Computer vision, in particular deep learning models, are increasingly being used to automatically detect and count fish at low abundances in videos. One of the advantages of BRUVS is that bait attractants help to reliably detect species in relatively short deployments (e.g. 1 hr). The high abundances of fish attracted to BRUVS, however, make computer vision more difficult, because fish often occlude other fish. We build upon existing deep learning methods for identifying and counting a target fisheries species across a wide range of fish abundances. Using BRUVS imagery targeting a recovering fishery species, Australian snapper ( Chrysophrys auratus ), we tested combinations of three further mathematical steps likely to generate accurate, efficient automation: 1) varying confidence thresholds (CTs), 2) on/off use of sequential non-maximum suppression (Seq-NMS), and 3) statistical correction equations. Output from the deep learning model was accurate at very low abundances of snapper at higher abundances, however, the model over-predicted counts by as much as 50%. The procedure providing the most accurate counts across all fish abundances, with counts either correct or within 1 to 2 of manual counts (R 2 = 93.4%), used Seq-NMS, a 55% confidence threshold, and a cubic polynomial corrective equation. The optimised modelling provides an automated procedure offering an effective and efficient method for accurately identifying and counting snapper in BRUV footage. Further testing is required to ensure that automated counts of snapper remain accurate in the survey region over time, and to determine the applicability to other regions within the distributional range of this species. For monitoring stocks of fishery species more generally, the specific equations will differ but the procedure demonstrated here would help to increase the usefulness of BRUVS, while decreasing costs.
Publisher: Informa UK Limited
Date: 11-01-2016
Publisher: CSIRO Publishing
Date: 2015
DOI: 10.1071/ZO15026
Abstract: Bight redfish, Centroberyx gerrardi, is a demersal teleost endemic to continental shelf and upper slope waters of southern Australia. Throughout most of its range, C. gerrardi is targeted by a number of separately managed commercial and recreational fisheries across several jurisdictions. However, it is currently unknown whether stock assessments and management for this shared resource are being conducted at appropriate spatial scales, thereby requiring knowledge of population structure and connectivity. To investigate population structure and connectivity, we developed 16 new polymorphic microsatellite markers using 454 shotgun sequencing. Two to 15 alleles per locus were detected. There was no evidence of linkage disequilibrium between pairs of loci and all loci except one were in Hardy–Weinberg equilibrium. Cross- lification trials in the congeneric C. australis and C. lineatus revealed that 11 and 16 loci are potentially useful, respectively. However, deviations from Hardy–Weinberg equilibrium and linkage disequilibrium between pairs of loci were detected at several of the 16 markers for C. australis, and therefore the number of markers useful for population genetic analyses with C. lineatus is likely considerably lower than 11.
Publisher: Inter-Research Science Center
Date: 18-11-2010
DOI: 10.3354/MEPS08834
Publisher: Wiley
Date: 09-2011
DOI: 10.1111/J.1095-8649.2011.03051.X
Abstract: Biological characteristics of the marine species King George whiting Sillaginodes punctatus and Australian herring Arripis georgianus in three seasonally open estuaries (Broke, Irwin and Wilson Inlets), one permanently open estuary (Oyster Harbour) and one normally closed estuary (Wellstead Estuary) on the south coast of Western Australia have been determined and compared. Sillaginodes punctatus enters the seasonally and permanently open estuaries early in life and reaches total lengths (L(T)) >280 mm at which it can be legally retained and thus contributes to commercial and recreational fisheries in these systems. This sillaginid almost invariably emigrates from these estuaries before reaching its typical size at maturity (L(T50)) and does not return after spawning in marine waters. In contrast, virtually all female A. georgianus (≥ 98%) in the three seasonally open estuaries and the majority in the normally closed (89·5%) and permanently open estuaries (83%) exceeded the L(T50) of this species at maturity, reflecting the fact that the nursery areas of this species are predominantly located much further to the east. Although adult females of A. georgianus in seasonally open and normally closed estuaries had developed mature ovaries by autumn, at which time they were prevented from migrating to the sea by closure of the estuary mouths, this species did not spawn in those estuaries. The oocytes in their ovaries were undergoing extensive atresia, a process that had been incipient prior to oocyte maturation. As the adult females of A. georgianus in the permanently open Oyster Harbour at this time all possessed resting gonads, i.e. their oocytes were all previtellogenic, the adults that were present in that estuary earlier and were destined to spawn in autumn must have emigrated from that permanently open estuary to their marine spawning areas prior to the onset of gonadal recrudescence. The body masses at length of A. georgianus, which were almost invariably higher in summer and autumn than in winter and spring, were greater in the very productive environments of the seasonally open and normally closed estuaries than in the less productive and essentially marine environment of Oyster Harbour and coastal marine waters. In general, the same pattern of differences between water bodies was exhibited by the growth of A. georgianus and by the more restricted data for body mass at L(T) and growth of S. punctatus. Despite an increase in anthropogenic activities in Wilson Inlet over the last two decades, the growth of both species was very similar to that recorded 20 years earlier. The fisheries implications of the results for the two species are discussed.
Publisher: Elsevier BV
Date: 11-0007
Publisher: Wiley
Date: 27-07-2022
DOI: 10.1111/COBI.13807
Abstract: Marine fisheries in coastal ecosystems in many areas of the world have historically removed large‐bodied in iduals, potentially impairing ecosystem functioning and the long‐term sustainability of fish populations. Reporting on size‐based indicators that link to food‐web structure can contribute to ecosystem‐based management, but the application of these indicators over large (cross‐ecosystem) geographical scales has been limited to either fisheries‐dependent catch data or er‐based methods restricted to shallow waters ( m) that can misrepresent the abundance of large‐bodied fished species. We obtained data on the body‐size structure of 82 recreationally or commercially targeted marine demersal teleosts from 2904 deployments of baited remote underwater stereo‐video (stereo‐BRUV). S ling was at up to 50 m depth and covered approximately 10,000 km of the continental shelf of Australia. Seascape relief, water depth, and human gravity (i.e., a proxy of human impacts) were the strongest predictors of the probability of occurrence of large fishes and the abundance of fishes above the minimum legal size of capture. No‐take marine reserves had a positive effect on the abundance of fishes above legal size, although the effect varied across species groups. In contrast, sublegal fishes were best predicted by gradients in sea surface temperature (mean and variance). In areas of low human impact, large fishes were about three times more likely to be encountered and fishes of legal size were approximately five times more abundant. For conspicuous species groups with contrasting habitat, environmental, and biogeographic affinities, abundance of legal‐size fishes typically declined as human impact increased. Our large‐scale quantitative analyses highlight the combined importance of seascape complexity, regions with low human footprint, and no‐take marine reserves in protecting large‐bodied fishes across a broad range of species and ecosystem configurations.
Publisher: Elsevier BV
Date: 09-2023
Publisher: Public Library of Science (PLoS)
Date: 29-11-2012
Publisher: Frontiers Media SA
Date: 21-05-2020
Publisher: Elsevier BV
Date: 11-2016
Publisher: Canadian Science Publishing
Date: 09-2017
Abstract: As commercial fishing activity shifts to target different grounds over time, spatial gaps can be created in catch rate data, leading to biases in derived indices of fish abundance. Imputation has been shown to reduce such biases. In this study, the relative performance of several imputation methods was assessed using simulated catch rate data sets. Simulations were carried out for three fish stocks targeted by a commercial hook-and-line fishery off the southwestern coast of Australia: snapper (Chrysophrys auratus), West Australian dhufish (Glaucosoma hebraicum), and baldchin groper (Choerodon rubescens). For high-growth scenarios, the mean squared errors (MSEs) of geometric and linear imputations were lower, indicating higher accuracy and precision than that for base method (constant value) imputations. For low-growth scenarios, the lowest MSEs were achieved for base method imputations. However, for the final standardized and imputed abundance indices, the base method index consistently demonstrated the largest biases. Our results demonstrate the importance of selecting an appropriate imputation method when standardizing catch rates from a commercial fishery that has changed its spatial pattern of fishing over time.
Publisher: Wiley
Date: 06-03-2019
DOI: 10.1111/FME.12343
Publisher: Elsevier BV
Date: 03-2018
Publisher: Wiley
Date: 24-09-2020
Publisher: Frontiers Media SA
Date: 28-08-2018
Publisher: Elsevier BV
Date: 05-2021
Publisher: Elsevier BV
Date: 07-2011
Publisher: Wiley
Date: 12-05-2011
DOI: 10.1111/J.1095-8649.2011.02961.X
Abstract: This study demonstrated that the dietary composition of each of three abundant reef-associated labrid species in temperate Western Australia differed significantly with latitude and changed with increasing body size and almost invariably differed among those species when they co-occurred. These results were derived from comparisons and multivariate analyses of volumetric dietary data, obtained from the foregut contents of Coris auricularis, Notolabrus parilus and Ophthalmolepis lineolatus from the Jurien Bay Marine Park (JBMP) and waters off Perth, 250 km to the south. Latitudinal differences in the dietary compositions of each species in exposed reefs typically reflected greater contributions by large crustaceans, bivalve molluscs, echinoids and annelids to the diets in the waters off Perth than in the JBMP, whereas the reverse was true for gastropods and small crustaceans. The diet of each species exhibited similar, but not identical, quantitative changes with increasing body size, with the contributions of small crustaceans declining and those of large crustaceans and echinoids increasing, while that of gastropods underwent little change. Within the JBMP, the dietary compositions of both C. auricularis and N. parilus were similar in exposed and sheltered reefs and the same was true for N. parilus in the sheltered reefs and interspersed areas of seagrass. The latter similarity demonstrated that, in both of those ergent habitat types, N. parilus feeds on prey associated with either the sand or the macrophytes that cover and lie between the reefs. Although the main dietary components of each species were the same, i.e. gastropods, small crustaceans (mainly hipods and isopods), large crustaceans (particularly penaeids and brachyuran crabs) and echinoids, their contributions varied among those species, which accounts for the significant interspecific differences in diet. Coris auricularis had the most distinct diet, due mainly to an ingestion of greater volumes of small crustaceans, e.g. hipods and isopods, and lesser volumes of large crustaceans, e.g. brachyuran crabs, which was associated with a relatively narrower mouth and smaller teeth and the absence of prominent canines at the rear of the jaw. The above intra and interspecific differences in dietary composition would reduce, on the south-west coast of Australia, the potential for competition for food among and within these three abundant labrids, each of which belongs to different genera within the Julidine clade.
Publisher: Wiley
Date: 08-04-2012
Publisher: Wiley
Date: 20-05-2021
DOI: 10.1111/GCB.15635
Abstract: Marine reserves are a key tool for the conservation of marine bio ersity, yet only ~2.5% of the world's oceans are protected. The integration of marine reserves into connected networks representing all habitats has been encouraged by international agreements, yet the benefits of this design has not been tested empirically. Australia has one of the largest systems of marine reserves, providing a rare opportunity to assess how connectivity influences conservation success. An Australia‐wide dataset was collected using baited remote underwater video systems deployed across a depth range from 0 to 100 m to assess the effectiveness of marine reserves for protecting teleosts subject to commercial and recreational fishing. A meta‐analytical comparison of 73 fished species within 91 marine reserves found that, on average, marine reserves had 28% greater abundance and 53% greater biomass of fished species compared to adjacent areas open to fishing. However, benefits of protection were not observed across all reserves (heterogeneity), so full subsets generalized additive modelling was used to consider factors that influence marine reserve effectiveness, including distance‐based and ecological metrics of connectivity among reserves. Our results suggest that increased connectivity and depth improve the aforementioned marine reserve benefits and that these factors should be considered to optimize such benefits over time. We provide important guidance on factors to consider when implementing marine reserves for the purpose of increasing the abundance and size of fished species, given the expected increase in coverage globally. We show that marine reserves that are highly protected (no‐take) and designed to optimize connectivity, size and depth range can provide an effective conservation strategy for fished species in temperate and tropical waters within an overarching marine bio ersity conservation framework.
Publisher: CSIRO Publishing
Date: 2000
DOI: 10.1071/MF99119
Abstract: Arripis georgiana was collected from along the Western Australian and South Australian coasts at regular intervals between October 1996 and December 1998. The trends exhibited during the year by gonadosomatic indices, gonadal maturity stages and oocyte stages demonstrate that spawning is restricted to south-western Australian waters from at least as far north as ~28˚43′S to as far east as ~119˚24′E, and that it occurs mainly during late May and early June. The simultaneous presence of post-ovulatory follicles and hydrated and yolk-granule oocytes in some ovaries during the spawning period indicates that A. georgiana is a multiple spawner, i.e. females spawn more than once in a breeding season. In south-western Australia, where all life-cycle stages are found, the overall sex ratio in catches collected by netting was close to parity, whereas females predominated in those obtained by anglers. The length at which 50% of fish reached maturity was 197 mm for females and 179 mm for males, and just over 50% of females and ~80% of males attained maturity at the end of their second year of life. The implications of these data for management of the fishery for A. georgiana are discussed.
Publisher: Elsevier BV
Date: 04-2008
Publisher: CSIRO Publishing
Date: 2000
DOI: 10.1071/MF99118
Abstract: Arripis georgiana was collected from coastal waters in Western Australia and South Australia. The opaque zones on the otoliths were shown to be formed annually and thus their number could be used to age the in iduals of this species. Although the catches of A. georgiana in south-western Australia, where spawning occurs, were dominated by the 0+ to 5+ age classes, they did contain females and males up to ten and nine years old, respectively. The von Bertalanffy growth parameters for the two sexes in this region differed significantly, with the asymptotic length (L& infin ) being significantly greater for females (262 mm) than for males (239 mm), whereas the reverse was true for the growth coefficient (k), i.e. 0.813 v. 0.992. The catches of A. georgiana eastwards of 121˚44′E on the south coast of Western Australia, where spawning does not occur, were dominated by the 0+ to 2+ age classes. The above data, when taken in conjunction with earlier tagging experiments and the marked decline that occurs in the number of 2+ fish in South Australia in summer, imply that, during this period, many two-year-old in iduals of A. georgiana start migrating towards their spawning areas in south-western Australia.
Publisher: Elsevier BV
Date: 2022
DOI: 10.1016/J.MARENVRES.2021.105543
Abstract: Understanding the connectivity of exploited fish populations is critical to their management under both rapid and long-term environmental change. Patterns of connectivity are unknown for most fishes in the Shark Bay World Heritage Area (Western Australia), a large, shallow embayment in the eastern Indian Ocean, vulnerable to marine heatwaves. The composition of oxygen (δ
Publisher: Springer Science and Business Media LLC
Date: 28-10-2021
DOI: 10.1038/S42003-021-02733-7
Abstract: Rising temperatures and extreme climate events are propelling tropical species into temperate marine ecosystems, but not all species can persist. Here, we used the heatwave-driven expatriation of tropical Black Rabbitfish ( Siganus fuscescens ) to the temperate environments of Western Australia to assess the ecological and evolutionary mechanisms that may entail their persistence. Population genomic assays for this rabbitfish indicated little genetic differentiation between tropical residents and vagrants to temperate environments due to high migration rates, which were likely enhanced by the marine heatwave. DNA metabarcoding revealed a erse diet for this species based on phytoplankton and algae, as well as an ability to feed on regional resources, including kelp. Irrespective of future climate scenarios, these macroalgae-consuming vagrants may self-recruit in temperate environments and further expand their geographic range by the year 2100. This expansion may compromise the health of the kelp forests that form Australia’s Great Southern Reef. Overall, our study demonstrates that projected favourable climate conditions, continued large-scale genetic connectivity between populations, and diet versatility are key for tropical range-shifting fish to establish in temperate ecosystems.
Publisher: Elsevier BV
Date: 2013
Publisher: Springer Science and Business Media LLC
Date: 28-11-2014
DOI: 10.1038/SREP07249
Publisher: Elsevier BV
Date: 05-2017
Publisher: Public Library of Science (PLoS)
Date: 21-03-2013
Publisher: Wiley
Date: 21-07-2021
DOI: 10.1111/COBI.13756
Abstract: Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a "Green List of Species" (now the IUCN Green Status of Species). A draft Green Status framework for assessing species' progress toward recovery, published in 2018, proposed 2 separate but interlinked components: a standardized method (i.e., measurement against benchmarks of species' viability, functionality, and preimpact distribution) to determine current species recovery status (herein species recovery score) and application of that method to estimate past and potential future impacts of conservation based on 4 metrics (conservation legacy, conservation dependence, conservation gain, and recovery potential). We tested the framework with 181 species representing erse taxa, life histories, biomes, and IUCN Red List categories (extinction risk). Based on the observed distribution of species' recovery scores, we propose the following species recovery categories: fully recovered, slightly depleted, moderately depleted, largely depleted, critically depleted, extinct in the wild, and indeterminate. Fifty-nine percent of tested species were considered largely or critically depleted. Although there was a negative relationship between extinction risk and species recovery score, variation was considerable. Some species in lower risk categories were assessed as farther from recovery than those at higher risk. This emphasizes that species recovery is conceptually different from extinction risk and reinforces the utility of the IUCN Green Status of Species to more fully understand species conservation status. Although extinction risk did not predict conservation legacy, conservation dependence, or conservation gain, it was positively correlated with recovery potential. Only 1.7% of tested species were categorized as zero across all 4 of these conservation impact metrics, indicating that conservation has, or will, play a role in improving or maintaining species status for the vast majority of these species. Based on our results, we devised an updated assessment framework that introduces the option of using a dynamic baseline to assess future impacts of conservation over the short term to avoid misleading results which were generated in a small number of cases, and redefines short term as 10 years to better align with conservation planning. These changes are reflected in the IUCN Green Status of Species Standard.
Publisher: Elsevier BV
Date: 09-2022
Publisher: Springer Science and Business Media LLC
Date: 19-08-2017
Publisher: Elsevier BV
Date: 09-2023
Publisher: Elsevier BV
Date: 02-2018
Publisher: Wiley
Date: 17-05-2022
Abstract: Global warming is modifying the phenology, life‐history traits and biogeography of species around the world. Evidence of these effects have increased over recent decades however, we still have a poor understanding of the possible outcomes of their interplay across global climatic gradients, hindering our ability to accurately predict the consequences of climate change in populations and ecosystems. We examined the effect that changes in biogeography can have on the life‐history traits of two of the most successful range‐extending fish species in the world: the tropical rabbitfishes Siganus fuscescens and Siganus rivulatus . Both species have established abundant populations at higher latitudes in the northern and southern hemispheres and have been identified as important ecological engineers with the potential to alter the community structure of seaweed forests (Laminariales and Fucales) in temperate regions. Life‐history trait information from across their global distribution was compiled from the published literature and meta‐analyses were conducted to assess changes in (i) the onset and duration of reproductive periods, (ii) size at maturity, (iii) fecundity, (iv) growth rates, (v) maximum body sizes and (vi) longevity in populations at the leading edge of range expansion in relation to sea surface temperature and primary productivity (a common proxy for nutritional resource levels). Populations at highest latitudes had shortened their reproductive periods and reduced growth rates, taking longer to reach sexual maturity and maximum sizes, but compensated this with higher fecundity per length class and longer lifespans than populations in warmer environments. Low primary productivity and temperature in the Mediterranean Sea resulted in lower growth rates and body sizes for S. rivulatus , but also lower length at maturity, increasing life‐time reproductive output. The results suggest that plasticity in the phenology and life‐history traits of range‐expanding species would be important to enhance their fitness in high latitude environments, facilitating their persistence and possible further poleward expansions. Quantifying the magnitude and direction of these responses can improve our understanding and ability to forecast species redistributions and its repercussions in the functioning of temperate ecosystems.
Publisher: Wiley
Date: 04-2018
DOI: 10.1111/JFB.13541
Abstract: Contemporary multivariate statistics were used to test the hypotheses that the dietary compositions of three populations of labrids on the west Australian coast are related to body size and undergo seasonal changes and to elucidate the relative extents and basis for any dietary differences within and between those populations. Gut content analyses determined the dietary compositions of Choerodon rubescens in marine waters of the outer reefs in the World Heritage Area of Shark Bay (26° S 114° E) and of Choerodon schoenleinii in inner protected reefs of that large embayment. The dietary compositions of C. rubescens and C. schoenleinii differed significantly among length classes, progressed serially with increasing body size, both overall and almost invariably in each season and were more closely related to body size than season, whose effect was at best minimal. The size-related dietary change in C. rubescens involved, in particular, a shift from crustaceans and non-mytilid bivalves to mytilid bivalves and echinoid echinoderms. Although the diet of C. schoenleinii followed similar size-related changes, it contained a greater volume of gastropods when the fish were small and mytilids when large and only a small volume of echinoids. The dietary composition of C. rubescens in the Abrolhos Islands, 300 km to the south of Shark Bay, was related both to length class and season and differed from that of this labrid in Shark Bay with the ingestion of lesser volumes of mytilids and greater volumes of echinoids. The size-related changes in diet imply that these species shift from foraging over soft substrata to over reefs as their very well-developed jaws become sufficiently strong to remove attached and larger prey. The dietary compositions of C. rubescens and C. schoenleinii in Shark Bay and of C. rubescens at the Abrolhos Islands were related far more to habitat-locational differences than to length class and season. The above intraspecific and interspecific differences in diet are consistent with qualitative accounts of the relative abundances of the main prey in their respective environments, supporting the view that, despite specializations in their feeding apparatus, these labrids can feed opportunistically to a certain extent and could thus potentially respond to moderate changes in the composition of their prey caused by climate change and other anthropogenic effects.
Publisher: Elsevier BV
Date: 04-2022
Publisher: Springer Science and Business Media LLC
Date: 17-08-2017
DOI: 10.1038/S41598-017-09224-Y
Abstract: Understanding source-sink dynamics is important for conservation management, particularly when climatic events alter species’ distributions. Following a 2011 ‘marine heatwave’ in Western Australia, we observed high recruitment of the endemic fisheries target species Choerodon rubescens , towards the cooler (southern) end of its distribution. Here, we use a genome wide set of 14 559 single-nucleotide polymorphisms (SNPs) to identify the likely source population for this recruitment event. Most loci (76%) showed low genetic ergence across the species’ range, indicating high levels of gene flow and confirming previous findings using neutral microsatellite markers. However, a small proportion of loci showed strong patterns of differentiation and exhibited patterns of population structure consistent with local adaptation. Clustering analyses based on these outlier loci indicated that recruits at the southern end of C . rubescens ’ range originated 400 km to the north, at the centre of the species’ range, where average temperatures are up to 3 °C warmer. Survival of these recruits may be low because they carry alleles adapted to an environment different to the one they now reside in, but their survival is key to establishing locally adapted populations at and beyond the range edge as water temperatures increase with climate change.
Publisher: Wiley
Date: 07-2022
DOI: 10.1111/EVA.13439
Abstract: The efficacy of fisheries management strategies depends on stock assessment and management actions being carried out at appropriate spatial scales. This requires understanding of spatial and temporal population structure and connectivity, which is challenging in weakly structured and highly connected marine populations. We carried out a population genomics study of the heavily exploited snapper ( Chrysophrys auratus ) along ~2600 km of the Australian coastline, with a focus on Western Australia (WA). We used 10,903 filtered SNPs in 341 in iduals from eight s ling locations to characterize population structure and connectivity in snapper across WA and to assess if current spatial scales of stock assessment and management agree with evidence from population genomics. Our dataset also enabled us to investigate temporal stability in population structure as well as connectivity between WA and its nearest, eastern jurisdictional neighbour. As expected for a species influenced by the extensive ocean boundary current in the region, low genetic differentiation and high connectivity were uncovered across WA. However, we did detect strong isolation by distance and genetic discontinuities in the mid‐west and south‐east. The discontinuities correlate with boundaries between biogeographic regions, influenced by on‐shelf oceanography, and the sites of important spawning aggregations. We also detected temporal instability in genetic structure at one of our sites, possibly due to interannual variability in recruitment in adjacent regions. Our results partly contrast with the current spatial management of snapper in WA, indicating the likely benefits of a review. This study supports the value of population genomic surveys in informing the management of weakly structured and wide‐ranging marine fishery resources.
Publisher: Elsevier BV
Date: 12-2017
Publisher: CSIRO Publishing
Date: 2020
DOI: 10.1071/MF18445
Abstract: The discovery and identification of species is fundamental to the documentation, conservation and management of bio ersity. The taxonomy of the antitropical Pseudocaranx dentex complex (Carangidae) is confused and inconsistently reported. Previous morphological analyses concluded that this complex consisted of three species, namely P. sp. ‘dentex’, P. georgianus and P. dinjerra, in Australian waters. This study used genetic (COI sequence) and morphological data to evaluate the validity of this conclusion. The COI data showed the presence of three discrete lineages within this complex, which appear to correspond to the above-mentioned three species. They also suggested that P. sp. ‘dentex’ is closely related to, and possibly the same species as, P. dentex from southern Africa and the Mediterranean Sea. Also, the extent of morphological and geographical overlap between P. georgianus and P. dinjerra was greater than previously documented which, uncorrected, could lead to identification errors and present challenges for monitoring and management of harvested stocks of these species. By answering important taxonomic questions, our results will facilitate the proper interpretation of the results of past studies and the design of future studies of the P. dentex complex. They have also highlighted the value of molecular data for identifying species in morphologically conservative taxa.
Publisher: Elsevier BV
Date: 10-2023
Publisher: Elsevier BV
Date: 02-2017
Publisher: Wiley
Date: 27-09-2012
DOI: 10.1111/J.1095-8649.2012.03446.X
Abstract: The size and age data and patterns of growth of three abundant, reef-dwelling and protogynous labrid species (Coris auricularis, Notolabrus parilus and Ophthalmolepis lineolata) in waters off Perth at c. 32° S and in the warmer waters of the Jurien Bay Marine Park (JBMP) at c. 30° S on the lower west coast of Australia are compared. Using data for the top 10% of values and a randomization procedure, the maximum total length (L(T) ) and mass of each species and the maximum age of the first two species were estimated to be significantly greater off Perth than in the JBMP (all P 0.05). These latitudinal trends, thus, typically conform to those frequently exhibited by fish species and the predictions of the metabolic theory of ecology (MTE). While, in terms of mass, the instantaneous growth rates of each species were similar at both latitudes during early life, they were greater at the higher latitude throughout the remainder and thus much of life, which is broadly consistent with the MTE. When expressed in terms of L(T), however, instantaneous growth rates did not exhibit consistent latitudinal trends across all three species. The above trends with mass, together with those for reproductive variables, demonstrate that a greater amount of energy is directed into somatic growth and gonadal development by each of these species at the higher latitude. The consistency of the direction of the latitudinal trends for maximum body size and age and pattern of growth across all three species implies that each species is responding in a similar manner to differences between the environmental characteristics, such as temperature, at those two latitudes. The in idual maximum L(T), mass and age and pattern of growth of O. lineolata at a higher and thus cooler latitude on the eastern Australian coast are consistent with the latitudinal trends exhibited by those characteristics for this species in the two western Australian localities. The implications of using mass rather than length as the indicator variable when comparing the maximum sizes of the three species and the trends exhibited by the instantaneous growth rates of those species at different latitudes are explored. Although growth curves fitted to both the L(T) and masses at age for the males of each species lay above those for their females, this would not have influenced the conclusions drawn from common curves for both sexes.
Publisher: Acoustical Society of America (ASA)
Date: 10-2013
DOI: 10.1121/1.4818775
Abstract: Biological examinations of Glaucosomatid fish species have suggested that they could produce sound via swimbladder vibration, using “sonic” muscles. However, there have been few reported instances of it in the family. West Australian dhufish (Glaucosoma hebraicum) is an iconic teleost, endemic to Western Australia. Dissection of G. hebraicum in this study identified the presence of “sonic” muscle pairs in immature and sexually mature in iduals. The muscle tissue originates in the otic region of the skull with its insertion at the anterior of the swimbladder. Recordings of sounds were acquired from two male G. hebraicum, at a range of 1 m, during capture. Calls comprised 1 to 14 swimbladder pulses with spectral peak frequency of 154 ± 45 Hz (n = 67 calls) and 3 dB bandwidth of 110 ± 50 Hz. The mean of all call maximum source levels was 126 dB re 1 μPa at 1 m with the highest level at 137 dB re 1 μPa at 1 m. The confirmation of sound production by G. hebraicum and the acoustic characteristics of those sounds could be used to gain a better understanding of its ecology and, particularly, whether the production of sound is associated with specific behaviors, such as reproduction.
Publisher: Oxford University Press (OUP)
Date: 19-02-2013
Abstract: Wakefield, C. B., Newman, S. J., Marriott, R. J., Boddington, D. K., and Fairclough, D. V. 2013. Contrasting life history characteristics of the eightbar grouper, Hyporthodus octofasciatus (Pisces: Epinephelidae), over a large latitudinal range reveals spawning omission at higher latitudes. – ICES Journal of Marine Science, 70: 485–497. Demographic data on deep-water groupers are limited despite them being highly exploited throughout the Indo-Pacific. In Western Australia, the continuous distribution of the eightbar grouper, Hyporthodus octofasciatus, spans tropical to temperate waters over ∼3500 km from 12°S–35°S. The maximum age was markedly higher in the northern tropical waters than in southern temperate waters, i.e. 47 vs 20 years. Females attained a significantly larger length-at-age in southern temperate waters. Macroscopic and microscopic examination of gonads and annual trends in mean monthly gonadosomatic indices (GSIs) were used to determine that this monandric protogynous hermaphrodite spawns from late spring to summer (October–February) in northwestern Australia. In the temperate waters of WA, there was no evidence of reproduction and no males were observed south of ∼30°S latitude. The lengths at which 50% of female H. octofasciatus matured and changed sex were estimated from northern tropical populations at 560 mm (6.1 years) and 1022 mm (≥11 years). Although the population connectivity of H. octofasciatus is unknown, the spawning omission in temperate waters suggests recruitment from the northern tropical areas and highlights the importance of preserving spawning stocks in those northern waters.
Publisher: Wiley
Date: 06-09-2021
DOI: 10.1111/JFB.14889
Abstract: The yellowspotted rockcod, Epinephelus areolatus , is a small‐sized grouper that is widely distributed throughout the Indo‐Pacific, where it forms a valuable component of the harvest derived from multispecies fisheries along continental and insular shelves. S les of E. areolatus were collected from 2012 to 2018 from commercial catches and research surveys in the Kimberley, Pilbara and Gascoyne regions of north‐western Australia to improve the understanding of the life history, inherent vulnerability and stock status of this species. Histological analysis of gonads ( n = 1889) determined that E. areolatus was a monandric protogynous hermaphrodite. Non‐functional spermatogenic crypts were dispersed within the ovaries of 23% of mature functioning females nonetheless, these crypts were not observed during the immature female phase. The length and age at which 50% of females matured were 266 mm total length ( L T ) and 2.7 years, respectively. The spawning period was protracted over 10–12 months of the year with biannual peaks at the start of spring and autumn ( i.e ., September and March) when the photoperiod was at its mid‐range ( i.e ., 12.1 h). Estimates of the lengths and ages at which 50% of E. areolatus change sex from female to male were very similar ( i.e ., % difference) between the Kimberley and Pilbara regions, i.e ., of 364 and 349 mm L T and of 7.9 and 7.3 years, respectively. A maximum age of 19 years was observed in all three regions, but there was significant regional variation in growth. These variations in growth were not correlated with latitude instead a parabolic relationship was evident, where the smallest mean length‐at‐age and fastest growth rates ( k ) occurred in the mid‐latitudes of the Pilbara region. In the Kimberley and Pilbara regions, in iduals were not fully selected by commercial fish traps until 5–6 years of age, hence, several years after reaching maturity. These life‐history characteristics infer a high population productivity, which underpins the sustainable harvest of this species, despite comprising the largest catches of all epinephelids in the multispecies tropical fisheries across north‐western Australia.
Publisher: Canadian Science Publishing
Date: 07-2019
Abstract: Understanding migration dynamics of fishes that aggregate-spawn is critical if spatiotemporal closures to fishing are expected to protect them. Concern over fishing of Chrysophrys auratus spawning aggregations in embayments near a west Australian city led to an annual 4-month spatial fishing closure. However, the extent to which it protects fish migrating to and from aggregations is unclear. Acoustic telemetry demonstrated a bimodal pattern of entry to and departure from the main embayment via only one of several pathways. Among years, 33%–56% of fish occurred in the pathway prior to the closure, but most left before it ceased. Fish were detected within the closure in multiple but not always consecutive years. Variation in migration timing and aggregation philopatry may alter capture risk, but pre- and postspawning migratory fish are fished in the main pathway and adjacent reefs, which would presumably impact spawning aggregation biomass. Assessment of this would assist in understanding whether expansion of the closure’s spatial and temporal limits is necessary to ensure spawning biomass or whether current management is sufficient.
Publisher: Cold Spring Harbor Laboratory
Date: 19-02-2022
DOI: 10.1101/2022.02.17.479830
Abstract: The efficacy of fisheries management strategies depends on stock assessment and management actions being carried out at appropriate spatial scales. This requires understanding of spatial and temporal population structure and connectivity, which is challenging in weakly structured and highly connected marine populations. We carried out a population genomics study of the heavily exploited snapper ( Chrysophrys auratus ) along ∼2,600 km of the Australian coastline, with a focus on Western Australia (WA). We used 10,903 filtered SNPs in 341 in iduals from eight locations to characterise population structure and connectivity in snapper across WA and to assess if current spatial scales of stock assessment and management agree with evidence from population genomics. Our dataset also enabled us to investigate temporal stability in population structure as well as connectivity between WA and its nearest, eastern jurisdictional neighbor. As expected for a species influenced by the extensive ocean boundary current in the region, low genetic differentiation and high connectivity was uncovered across WA. However, we did detect strong isolation by distance and genetic discontinuities in the mid-west and south-east. The discontinuities correlate with boundaries between biogeographic regions, influenced by on-shelf oceanography, and the sites of important spawning aggregations. We also detected temporal instability in genetic structure at one of our sites, possibly due to interannual variability in recruitment in adjacent regions. Our results partly contrast with the current spatial management of snapper in WA, highlighting the need for a review. This study supports the value of population genomic surveys in informing the management of weakly-structured and wide-ranging marine fishery resources.
Publisher: Wiley
Date: 28-12-2016
DOI: 10.1111/JFB.12864
Abstract: In this study, a total of 212 eggs were visually identified as snapper Chrysophrys auratus. Real-time PCR confirmed visual identification in 69% of cases but corroboration varied widely among plankton s les. The use of molecular tools to support visual identification prior to adopting daily egg production stock assessment methods should be considered.
Location: Australia
Location: No location found
Start Date: 01-2020
End Date: 01-2023
Amount: $321,113.00
Funder: Australian Research Council
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