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Riyadi Subur - One of the best experts on this subject based on the ideXlab platform.
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Studi Komparatif Komunitas Ikan Padang Lamun Pada Bulan Perbani Awal Dan Perbani Akhir Di Perairan Loleo Kecamatan Weda Selatan Kabupaten Halmahera Tengah
'Universitas Mataram', 2016Co-Authors: Dan Salim Abubakar, Farjan Kaeli, Riyadi SuburAbstract:ABSTRAK Ikan memanfaatkan padang lamun sebagai habitatnya, ada yang hidup menetap dan adapula yang berkunjung ke padang lamun hanya untuk mencari makan atau untuk memijah, sebagai tempat untuk berlindung. Tujuan dari penelitian ini adalah mengetahui jumlah dan jenis ikan padang lamun yang tertangkap pada bulan perbani awal dan perbani akhir di Perairan Desa Loleo,mengetahui struktur komunitas ikan padang lamun yang tertangkap pada bulan perbani awal dan perbani akhir dan untuk mengetahui perbandingan komunitas ikan padang lamun yang tertangkap pada bulan perbani awal dan perbani akhir di Perairan Desa Loleo. Hasil penelitian diperoleh komposisi jenis ikan pada bulan perbani awal sebanyak 14 jenis yaitu Caranx ignobilis, Caranx melampygus, Alectis ciliaris, Selar crumenophthalmus, Choerodon anchorago, Cheilio inermis, Lethrinus microdon, Mulloidichthys flavolineatu, Gerres acinaces Bleeker, Siganus spinu, Siganus canaliculatus, Siganus doliatus, Hemiramphus sp, Balistoides viridescens. Sedangkan ikan pada bulan perbani akhir sebanyak 8 jenis yaitu Sphyraena barracuda, Siganus canaliculatus, Siganus doliatus, Zanclus cornutus, Lethrinus miniatus, Moolgarda seheli, Hemiramphus sp, Amanses scopas. Keanekaragaman jenis baik ikan yang tertangkap pada bulan perbani awal dan perbani akhir tergolong sedang, dan tidak ada jenis yang mendominansi serta penyebaran jenisnya sangat merata. Rata-rata hasil tangkapan antara bulan perbani awal dan perbani akhir memiliki perbedaan dan rata-rata hasil tangkapan terbanyak adalah pada bulan perbani awal. Kata Kunci : Komunitas, Ikan, Perbani Awal, Perbani Akhir, Padang Lamun.ABSTRACT Fish utilize seagrass beds as habitat, there were sedentary and those that visit to seagrass beds only to find food or to spawn, as a place of refuge. The purpose of this study was to determine the number and type of fish seagrass caught in neap beginning and neap end in Water Village Loleo, know the community structure of seagrass beds had been arrested in neap beginning and neap end and to compare the fish communities of seagrass caught in neap neap beginning and ending at the village Aquatic Loleo. The results obtained by the composition of fish species in neap early as 14 types of Caranx ignobilis, Caranx melampygus, Alectis ciliaris, scad crumenophthalmus, Choerodon anchorago, Cheilio inermis, Lethrinus microdon, Mulloidichthys flavolineatu, Gerres acinaces Bleeker, Siganus spinu, Siganus canaliculatus, Siganus doliatus, Hemiramphus sp, Balistoides viridescens. While the fish in neap late as 8 types of Sphyraena barracuda, Siganus canaliculatus, Siganus doliatus, Zanclus cornutus, Lethrinus miniatus, Moolgarda seheli, Hemiramphus sp, Amanses scopas. Good species diversity of fish caught in neap neap beginning and end is classified, and no kind mendominansi and very uneven spread of its kind. The average catches between the moon neap neap early and late have differences and average catches neap most was in the beginning. Keywords: Community, Fish, Early neap, neap End, Seagrass.
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Studi Komparatif Komunitas Ikan Padang Lamun Pada Bulan Perbani Awal Dan Perbani Akhir Di Perairan Loleo Kecamatan Weda Selatan Kabupaten Halmahera Tengah
Mataram University, 2016Co-Authors: Dan Salim Abubakar, Farjan Kaeli, Riyadi SuburAbstract:Fish utilize seagrass beds as habitat, there were sedentary and those that visit to seagrass beds only to find food or to spawn, as a place of refuge. The purpose of this study was to determine the number and type of fish seagrass caught in neap beginning and neap end in Water Village Loleo, know the community structure of seagrass beds had been arrested in neap beginning and neap end and to compare the fish communities of seagrass caught in neap neap beginning and ending at the village Aquatic Loleo. The results obtained by the composition of fish species in neap early as 14 types of Caranx ignobilis, Caranx melampygus, Alectis ciliaris, scad crumenophthalmus, Choerodon anchorago, Cheilio inermis, Lethrinus microdon, Mulloidichthys flavolineatu, Gerres acinaces Bleeker, Siganus spinu, Siganus canaliculatus, Siganus doliatus, Hemiramphus sp, Balistoides viridescens. While the fish in neap late as 8 types of Sphyraena barracuda, Siganus canaliculatus, Siganus doliatus, Zanclus cornutus, Lethrinus miniatus, Moolgarda seheli, Hemiramphus sp, Amanses scopas. Good species diversity of fish caught in neap neap beginning and end is classified, and no kind mendominansi and very uneven spread of its kind. The average catches between the moon neap neap early and late have differences and average catches neap most was in the beginning
Euan S. Harvey - One of the best experts on this subject based on the ideXlab platform.
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Similarities between Line Fishing and Baited Stereo- Video Estimations of Length-Frequency: Novel Application of Kernel Density Estimates
2016Co-Authors: Timothy J. Langlois, Benjamin R. Fitzpatrick, David V. Fairclough, Corey B. Wakefield, Alex S. Hesp, Dianne L. Mclean, Euan S. Harvey, Jessica J. MeeuwigAbstract:Age structure data is essential for single species stock assessments but length-frequency data can provide complementary information. In south-western Australia, the majority of these data for exploited species are derived from line caught fish. However, baited remote underwater stereo-video systems (stereo-BRUVS) surveys have also been found to provide accurate length measurements. Given that line fishing tends to be biased towards larger fish, we predicted that, stereo-BRUVS would yield length-frequency data with a smaller mean length and skewed towards smaller fish than that collected by fisheries-independent line fishing. To assess the biases and selectivity of stereo-BRUVS and line fishing we compared the length-frequencies obtained for three commonly fished species, using a novel application of the Kernel Density Estimate (KDE) method and the established Kolmogorov–Smirnov (KS) test. The shape of the length-frequency distribution obtained for the labrid Choerodon rubescens by stereo-BRUVS and line fishing did not differ significantly, but, as predicted, the mean length estimated from stereo-BRUVS was 17 % smaller. Contrary to our predictions, the mean length and shape of the length-frequency distribution for the epinephelid Epinephelides armatus did not differ significantly between line fishing and stereo-BRUVS. For the sparid Pagrus auratus, the length frequency distribution derived from the stereo-BRUVS method was bi
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high recruitment associated with increased sea temperatures towards the southern range edge of a western australian endemic reef fish Choerodon rubescens family labridae
Environmental Biology of Fishes, 2015Co-Authors: Katherine Cure, Jean-paul A. Hobbs, Euan S. HarveyAbstract:Choerodon rubescens is a subtropical wrasse endemic to Western Australia which has recently recruited in high abundance into lagoonal habitats at the southern end of its distribution. Abundance, size structure and habitat associations of juvenile C. rubescens were assessed during summer and autumn 2013 (January–May) via underwater visual census across available shallow water habitats towards the southern range edge of their distribution (32°S, 115°E). High abundances of juveniles (up to 14 fish/40 m2) were found in areas where they were previously absent or in low abundance. Lagoonal habitats presented abundances three to eight times higher than seagrass beds or rocky reef, indicating preference of C. rubescens for mixed lagoonal habitats as settlement grounds. Such habitats contain open sandy areas with small rocks and rubble that are important feeding grounds for juveniles. Based on the size structure of populations encountered, recruitment was estimated to occur during summer 2011–12 and 2012–13. This coincides with water temperatures 1 to 2 °C higher than long-term averages in the region, making conditions more favourable for recruits to survive in greater numbers. We conclude that the high abundance of C. rubescens recruits towards the southern end of their distribution together with trends of increasing water temperature and the availability of suitable settlement habitat to the south of their present range, indicate a capacity for the species to shift its distribution southwards. Monitoring of future recruitment events will be crucial to determining range expansion capacity and guiding management efforts for this endemic and important fisheries species.
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Relative abundance of each of five target species for each of the different types of bait and status.
2013Co-Authors: Stacey R. Dorman, Euan S. Harvey, Stephen J NewmanAbstract:Average relative abundance (y axis; average number of individuals ±1 SE) for different types of bait (x-axis) and status (□ = Fished, ▪ = TFC) is shown for (A) Choerodon rubescens, (B) Lethrinus nebulosus, (C) Lethrinus miniatus, (D) Pagrus auratus and (E) Plectropomus leopardus. Significant differences are shown with (*) where P
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Minimum legal length of retention (MLL), length-frequency mean and standard deviation (SD) and mode, estimated by the kernel density estimate (KDE) for Choerodon rubescens, Epinephelides armatus and Pagrus auratus sampled by fishing (Line) and baited remote underwater stereo-video (stereo-BRUVS).
2012Co-Authors: Timothy J. Langlois, Benjamin R. Fitzpatrick, David V. Fairclough, Corey B. Wakefield, Alex S. Hesp, Dianne L. Mclean, Euan S. Harvey, Jessica J. MeeuwigAbstract:Minimum legal length of retention (MLL), length-frequency mean and standard deviation (SD) and mode, estimated by the kernel density estimate (KDE) for Choerodon rubescens, Epinephelides armatus and Pagrus auratus sampled by fishing (Line) and baited remote underwater stereo-video (stereo-BRUVS).
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effects of protection from fishing on the lengths of targeted and non targeted fish species at the houtman abrolhos islands western australia
Marine Ecology Progress Series, 2009Co-Authors: Dianne L Watson, Kim Nardi, Marti J Anderson, Gary A Kendrick, Euan S. HarveyAbstract:The effects of fishing and protection on the length of targeted and non-targeted warm- temperate and tropical reef fishes were studied using baited remote underwater stereo-video cameras at the Houtman Abrolhos Islands, Western Australia. Video images were obtained from inside a marine protected area (MPA) and from 3 replicate fished locations within each of 3 island groups. The effects of protection on the lengths of 6 targeted and 4 non-targeted fish species were examined. Five of the 6 targeted fish species were larger inside MPAs than in areas open to fishing (Choerodon rubescens, Lethrinus miniatus, Lethrinus nebulosus, Pagrus auratus and Plectropomus leopardus). Targeted species were, on average, 48 mm (10%) larger inside MPAs than in areas open to fishing. The vast majority of the individuals of C. rubescens, P. auratus and P. leopardus recorded were smaller than their minimum legal size for first capture. For non-targeted species, only 1 of the 4, Coris auricularis, showed an effect of protection, with the mean length of individuals reduced by 85 mm (33%) inside MPAs relative to areas open to fishing. This study demonstrated clear effects of protection from fishing on the size structure of populations of common warm-temperate and tropical reef fishes.
Fairclough D. - One of the best experts on this subject based on the ideXlab platform.
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Spatiotemporal patterns of abundance and ecological requirements of a labrid's juveniles reveal conditions for establishment success and range shift capacity
'Elsevier BV', 2018Co-Authors: Cure K., Fairclough D., Langlois T., Hobbs Jean-paul, Thillainath E., Harvey EuanAbstract:Distribution shifts of demersal fishes are important adaptive responses to warming oceans for species' persistence. Shifts are facilitated by factors such as adult movement and dispersal of pelagic larvae to normally cooler regions, where increasing ocean temperatures are now enhancing larval and juvenile survival. However, successful recruitment (i.e. larval settlement) at these new regions can be constrained by resource availability, specialisation (food, habitat) and ecological interactions (competition, predation). Evaluating the capacity or likelihood of a species to successfully shift or expand its range, provides information relevant to biodiversity conservation and fisheries management, and is particularly important for species with restricted ranges. Choerodon rubescens (Günther, 1862) is an exploited labrid endemic to ~ 1400 km of the west Australian coastline, encompassing 13° of latitude and a 6°C temperature gradient. This region recently experienced a rapid warming event of ~ 3°C, which lasted 3 months and mirrored ocean temperatures expected in the next 50 years. Following this event, high levels of recruitment of C. rubescens occurred towards its southern, cooler distribution limit. Juvenile abundances were surveyed in this study to evaluate: (1) the effect of elevated temperatures on recruitment success across shallow water habitats spanning the species' distribution, (2) temporal variation in recruitment success in the typically cooler, southern part of its range and (3) ecological characteristics important to recruit survival, including habitat preferences, diet and behaviour. Juvenile C. rubescens were significantly more abundant at the margin between reef and sand and towards the cooler southern range end. Reef margin habitat provides access to shelter from predators within the reef and to sand-associated invertebrate prey in adjacent soft sediments, where most feeding activity occurred. Juveniles were abundant (0.3 to 4 fish/40 m 2 ) in reef margin habitats of the southern cooler region for three consecutive years, with individuals represented by multiple cohorts, indicating suitable environmental conditions for ongoing recruitment and survival. Juveniles at this habitat were able to compete effectively with other co-occurring labrids for invertebrate prey. As oceans warm, the number of recruits arriving and surviving beyond the existing cooler range limit will be dependent on factors such as successful spawning, larval delivery and survival, and availability of reef margin habitat with associated prey; these factors will determine the successful range shift or expansion of C. rubescens. We present an example of how range-wide spatiotemporal ecological studies of juvenile fish can identify range shift capacity and inform management adaptive to climate change
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West coast demersal scalefish resource status report. In: Status reports of the Fisheries and Aquatic Resources of Western Australia 2012/13: State of the Fisheries eds. W.J. Fletcher and K. Santoro.
Department of Fisheries Western Australia, 2013Co-Authors: Fairclough D., Lai E., Holtz M., Nicholas T., Jones R.Abstract:The West Coast Demersal Scalefish Resource comprises inshore and offshore suites of demersal scalefish species that are exploited by different commercial fisheries and recreational and charter fishers that operate in the West Coast Bioregion (WCB). The West Coast Inshore Demersal suite occurs in waters 20-250 m deep with approximately 100 species of this suite caught by these fisheries. The most important species are the West Australian Dhufish (Glaucosoma hebraicum) and Pink snapper (Pagrus auratus) with other species captured including Redthroat Emperor (Lethrinus miniatus), Bight Redfish (Centroberyx gerrardi) and Baldchin Groper (Choerodon rubescens). The West Coast Offshore Demersal suite, which occurs in waters > 250 m deep, includes Eightbar Grouper Hyporthodus octofasciatus, Hapuku Polyprion oxygeneios, Blue-eye Trevalla Hyperoglyphe antarctica and Ruby Snapper Etelis carbunculus
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West Coast demersal scalefish resource status report. In: State of the fisheries and aquatic resources report 2010/11. Eds W. J. Fletcher and K. Santoro.
Department of Fisheries, 2011Co-Authors: Fairclough D., Lai E., Bruce C., Moore N., Syers C.Abstract:The West Coast Inshore Demersal suite includes about 100 scalefish species which are caught by a number of different fisheries that operate in the West Coast Bioregion (WCB). The most important species of this suite are the West Australian Dhufish (Glaucosoma hebraicum) and Pink Snapper (Pagrus auratus). Substantial catches are also taken of other species from this suite, such as Red Throat Emperor (Lethrinus miniatus), Bight Redfish (Centroberyx gerrardi) and Baldchin Groper (Choerodon rubescens). The West Coast Offshore Demersal suite, which occurs in offshore waters (> 250 m), includes Eightbar Grouper Hyporthodus octofasciatus, Hapuku Polyprion oxygeneios, Blue-eye Trevalla Hyperoglyphe antarctica and Ruby Snapper Etelis carbunculus
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West coast demersal scalefish fishery status report. In: State of the fisheries report 2008/09. Eds W. J. Fletcher and K. Santoro.
Department of Fisheries, 2009Co-Authors: Fairclough D., Johnson C., Lai E.Abstract:The West Coast Demersal Scalefish Fishery (WCDSF) includes a complex of mostly line based fishing operations by commercial, charter and recreational sectors. Approximately 100 species are caught in the fishery each year, with fishers each sector primarily targeting West Australian Dhufish (Glaucosoma hebraicum) and Pink Snapper (Pagrus auratus). Substantial catches are also taken of other species in this suite, such as red throat emperor (Lethrinus minitus), Bight Redfish (Centroberyx gerrardi) and Baldchin Groper (Choerodon rubescens)
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West coast demersal scalefish fishery status report. In: State of the fisheries report 2007/08. Eds W. J. Fletcher and K. Santoro.
Department of Fisheries, 2008Co-Authors: Fairclough D., Johnson C., Lai E.Abstract:The West Coast Demersal Scalefish Fishery (WCDSF) includes line fishing by commercial, charter and recreational sectors. Fishers in each sector primarily target West Australian dhufish (Glaucosoma hebraicum) and pink snapper (Pagrus auratus), but also catch substantial numbers of other species, such as emperors (Lethrinus nebulosus, Lethrinus miniatus), baldchin groper (Choerodon rubescens) and breaksea cod Epinephelides armatus
Dan Salim Abubakar - One of the best experts on this subject based on the ideXlab platform.
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Studi Komparatif Komunitas Ikan Padang Lamun Pada Bulan Perbani Awal Dan Perbani Akhir Di Perairan Loleo Kecamatan Weda Selatan Kabupaten Halmahera Tengah
'Universitas Mataram', 2016Co-Authors: Dan Salim Abubakar, Farjan Kaeli, Riyadi SuburAbstract:ABSTRAK Ikan memanfaatkan padang lamun sebagai habitatnya, ada yang hidup menetap dan adapula yang berkunjung ke padang lamun hanya untuk mencari makan atau untuk memijah, sebagai tempat untuk berlindung. Tujuan dari penelitian ini adalah mengetahui jumlah dan jenis ikan padang lamun yang tertangkap pada bulan perbani awal dan perbani akhir di Perairan Desa Loleo,mengetahui struktur komunitas ikan padang lamun yang tertangkap pada bulan perbani awal dan perbani akhir dan untuk mengetahui perbandingan komunitas ikan padang lamun yang tertangkap pada bulan perbani awal dan perbani akhir di Perairan Desa Loleo. Hasil penelitian diperoleh komposisi jenis ikan pada bulan perbani awal sebanyak 14 jenis yaitu Caranx ignobilis, Caranx melampygus, Alectis ciliaris, Selar crumenophthalmus, Choerodon anchorago, Cheilio inermis, Lethrinus microdon, Mulloidichthys flavolineatu, Gerres acinaces Bleeker, Siganus spinu, Siganus canaliculatus, Siganus doliatus, Hemiramphus sp, Balistoides viridescens. Sedangkan ikan pada bulan perbani akhir sebanyak 8 jenis yaitu Sphyraena barracuda, Siganus canaliculatus, Siganus doliatus, Zanclus cornutus, Lethrinus miniatus, Moolgarda seheli, Hemiramphus sp, Amanses scopas. Keanekaragaman jenis baik ikan yang tertangkap pada bulan perbani awal dan perbani akhir tergolong sedang, dan tidak ada jenis yang mendominansi serta penyebaran jenisnya sangat merata. Rata-rata hasil tangkapan antara bulan perbani awal dan perbani akhir memiliki perbedaan dan rata-rata hasil tangkapan terbanyak adalah pada bulan perbani awal. Kata Kunci : Komunitas, Ikan, Perbani Awal, Perbani Akhir, Padang Lamun.ABSTRACT Fish utilize seagrass beds as habitat, there were sedentary and those that visit to seagrass beds only to find food or to spawn, as a place of refuge. The purpose of this study was to determine the number and type of fish seagrass caught in neap beginning and neap end in Water Village Loleo, know the community structure of seagrass beds had been arrested in neap beginning and neap end and to compare the fish communities of seagrass caught in neap neap beginning and ending at the village Aquatic Loleo. The results obtained by the composition of fish species in neap early as 14 types of Caranx ignobilis, Caranx melampygus, Alectis ciliaris, scad crumenophthalmus, Choerodon anchorago, Cheilio inermis, Lethrinus microdon, Mulloidichthys flavolineatu, Gerres acinaces Bleeker, Siganus spinu, Siganus canaliculatus, Siganus doliatus, Hemiramphus sp, Balistoides viridescens. While the fish in neap late as 8 types of Sphyraena barracuda, Siganus canaliculatus, Siganus doliatus, Zanclus cornutus, Lethrinus miniatus, Moolgarda seheli, Hemiramphus sp, Amanses scopas. Good species diversity of fish caught in neap neap beginning and end is classified, and no kind mendominansi and very uneven spread of its kind. The average catches between the moon neap neap early and late have differences and average catches neap most was in the beginning. Keywords: Community, Fish, Early neap, neap End, Seagrass.
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Studi Komparatif Komunitas Ikan Padang Lamun Pada Bulan Perbani Awal Dan Perbani Akhir Di Perairan Loleo Kecamatan Weda Selatan Kabupaten Halmahera Tengah
Mataram University, 2016Co-Authors: Dan Salim Abubakar, Farjan Kaeli, Riyadi SuburAbstract:Fish utilize seagrass beds as habitat, there were sedentary and those that visit to seagrass beds only to find food or to spawn, as a place of refuge. The purpose of this study was to determine the number and type of fish seagrass caught in neap beginning and neap end in Water Village Loleo, know the community structure of seagrass beds had been arrested in neap beginning and neap end and to compare the fish communities of seagrass caught in neap neap beginning and ending at the village Aquatic Loleo. The results obtained by the composition of fish species in neap early as 14 types of Caranx ignobilis, Caranx melampygus, Alectis ciliaris, scad crumenophthalmus, Choerodon anchorago, Cheilio inermis, Lethrinus microdon, Mulloidichthys flavolineatu, Gerres acinaces Bleeker, Siganus spinu, Siganus canaliculatus, Siganus doliatus, Hemiramphus sp, Balistoides viridescens. While the fish in neap late as 8 types of Sphyraena barracuda, Siganus canaliculatus, Siganus doliatus, Zanclus cornutus, Lethrinus miniatus, Moolgarda seheli, Hemiramphus sp, Amanses scopas. Good species diversity of fish caught in neap neap beginning and end is classified, and no kind mendominansi and very uneven spread of its kind. The average catches between the moon neap neap early and late have differences and average catches neap most was in the beginning
D V Fairclough - One of the best experts on this subject based on the ideXlab platform.
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rapid and cost effective assessment of connectivity among assemblages of Choerodon rubescens labridae using laser ablation icp ms of sagittal otoliths
Journal of Experimental Marine Biology and Ecology, 2011Co-Authors: D V Fairclough, I S Keay, John S Edmonds, Rod C J Lenanton, Gary Jackson, B M Crisafulli, Stephen J NewmanAbstract:A rapid and cost-effective assessment was required to provide advice to management on the connectivity between juvenile and adult life cycle stages of Baldchin Groper Choerodon rubescens, a labrid endemic to the west coast of Australia, which has high social value, but relatively low commercial fishery importance. To minimise costs we used laser ablation ICP-MS to analyse levels of a small suite of elements (Ca, Mg, Mn, Cu, Zn, Sr, Rb, Ba and Pb) at the margin (adult phase) and core (juvenile phase) of the same otoliths of adult C. rubescens, collected at ten locations in five management zones. The elemental composition of both otolith margins and cores differed significantly among management zones and in some cases among locations within zones. Similarity of the pattern of among-zone elemental composition in otolith margins and cores indicated that, when cores are laid down, individuals have already recruited to the zones they will occupy as adults and there is no evidence of discrete juvenile nurseries. Thus, movement of juvenile or adult C. rubescens is likely to occur at relatively small spatial scales. Monitoring and management of adult stocks at the management zone level may be appropriate to sustain stocks broadly, but may not detect more localised depletion. Methods of elemental analyses are discussed and costs and benefits of this study vs an equivalent tagging study were compared.
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west coast demersal scalefish fishery status report in state of the fisheries report 2008 09 eds w j fletcher and k santoro
Fairclough D. Johnson C. and Lai E. (2009) West coast demersal scalefish fishery status report. In: State of the fisheries report 2008 09. Eds W. J. F, 2009Co-Authors: D V Fairclough, C Johnson, E LaiAbstract:The West Coast Demersal Scalefish Fishery (WCDSF) includes a complex of mostly line based fishing operations by commercial, charter and recreational sectors. Approximately 100 species are caught in the fishery each year, with fishers each sector primarily targeting West Australian Dhufish (Glaucosoma hebraicum) and Pink Snapper (Pagrus auratus). Substantial catches are also taken of other species in this suite, such as red throat emperor (Lethrinus minitus), Bight Redfish (Centroberyx gerrardi) and Baldchin Groper (Choerodon rubescens).
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habitat partitioning by five congeneric and abundant Choerodon species labridae in a large subtropical marine embayment
Estuarine Coastal and Shelf Science, 2008Co-Authors: D V Fairclough, K R Clarke, F J Valesini, I C PotterAbstract:The habitats occupied by the juveniles and adults of five morphologically similar, diurnally active and abundant Choerodon species in the large subtropical environment of Shark Bay, a “World Heritage Property” on the west coast of Australia, have been determined. The densities of the two life cycle stages of each Choerodon species in those habitats were used in various analyses to test the hypotheses that: (1) habitats are partitioned among these species and between their juveniles and adults; (2) such habitat partitioning is greatest in the case of the two Western Australian endemic species, i.e. Choerodon rubescens and Choerodon cauteroma; and (3) the extent of habitat partitioning between both of these two species and the only species that is widely distributed in the Indo-West Pacific, i.e. Choerodon schoenleinii, will be less pronounced. Initially, catches of each of the five congeneric species, obtained during other studies in Shark Bay by angling, spearfishing and otter trawling, were collated to elucidate the broad distribution of these species in that embayment. Underwater visual census was then used to determine the densities of the juveniles and adults of each Choerodon species at sites representing the four habitat types in which one or more of these species had been caught, i.e. reefs in marine waters at the western boundary of the bay and seagrass, reefs and rocky shorelines in the two inner gulfs. The compositions of the Choerodon species over marine (entrance channel) reefs and in seagrass were significantly different and each differed significantly from those in both inner gulf reefs and rocky shorelines, which were, however, not significantly different. Choerodon rubescens was restricted to exposed marine reefs, and thus occupied a different habitat and location of the bay than C. cauteroma, the other endemic species, which was almost exclusively confined to habitats found in the inner gulfs. Choerodon cauteroma differed from other Choerodon species in being relatively abundant in each inner gulf habitat and undergoing an ontogenetic change in habitat. Thus, while its juveniles lived predominantly in seagrass, its adults occupied mostly reefs and rocky shorelines. Choerodon cephalotes occurred almost exclusively in seagrass, while C. cyanodus was relatively most abundant along rocky shorelines. Choerodon schoenleinii, the only one of the five Choerodon species to be widely distributed outside Australia, occupied reefs and, to a lesser extent, rocky shorelines in the inner gulfs. The above differences in habitat among Choerodon species would reduce the potential for competition for spatial resources among these abundant and similar species and between the juveniles and adults of one of the species.
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west coast demersal scalefish fishery status report in state of the fisheries report 2007 08 eds w j fletcher and k santoro
Fairclough D. Keay I. Johnson C. and Lai E. (2008) West coast demersal scalefish fishery status report. In: State of the fisheries report 2007 08. Eds, 2008Co-Authors: D V Fairclough, I S Keay, C Johnson, E LaiAbstract:The West Coast Demersal Scalefish Fishery (WCDSF) includes line fishing by commercial, charter and recreational sectors. Fishers in each sector primarily target West Australian dhufish (Glaucosoma hebraicum) and pink snapper (Pagrus auratus), but also catch substantial numbers of other species, such as emperors (Lethrinus nebulosus, Lethrinus miniatus), baldchin groper (Choerodon rubescens) and breaksea cod Epinephelides armatus.
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Choerodon schoenleinii in iucn 2011 iucn red list of threatened species version 2011 2
Fairclough D. and Nakazono A. (2004) Choerodon schoenleinii. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2., 2004Co-Authors: D V Fairclough, A NakazonoAbstract:Choerodon schoenleinii is a highly sought after food fish throughout its distribution. It is high on the list of regularly caught species by recreational fishers at surveyed locations in Western Australia and is a prized species in many areas of south-east Asia, including Sabah, Japan and Hong Kong. There has been a severe decline in its abundance in Hong Kong since the 1940s and it is now considered rare in that location (A. Cornish, pers. comm.; Cornish 2003). Choerodon schoenleinii is a large species, reaching up to 100 cm, and it is a monandric protogynous hermaphrodite, with very low numbers of males recorded in Shark Bay, Western Australia (Ebisawa et al. 1995, Fairclough in prep.). Those two studies demonstrated that male fish occur only in the largest size classes, i.e., > ca. 50 cm, and these are commonly the target of fishers, e.g., in Hong Kong (Cornish 2003). Heavy fishing pressure for local and live reef fish trade use would have rapidly reduced the numbers of males in assemblages of this species and would have undoubtedly contributed to its rapid decline in locations such as Hong Kong. It is also considered to be overexploited in Japan (Ebisawa et al. 1995). Thus, heavy fishing pressure coupled with the large scale use of destructive fishing practices in south-east Asia and overall low abundances in that region (Werner and Allen 2000, Allen and McKenna 2001) put this species at risk in a substantial proportion of its range. Choerodon schoenleinii should be considered to be Near Threatened and it almost meets the criteria for Vulnerable: VU A2cd and/or VU A3cd and/or VU A4cd. This species should be monitored regularly for further evidence of population decline/ or fragmentation and every effort made to obtain information on its fishery, especially in southeastern Asia and Japan.