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Barnes, Thomas C., Claudia Junge, Steven A. Myers, Mathew D. Taylor, Paul J. Rogers, Greg J. Ferguson, Jason A. Lieschke, Stephen C. Donnellan e Bronwyn M. Gillanders. "Population structure in a wide-ranging coastal teleost (Argyrosomus japonicus, Sciaenidae) reflects marine biogeography across southern Australia". Marine and Freshwater Research 67, n.º 8 (2016): 1103. http://dx.doi.org/10.1071/mf15044.
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Population structure in marine teleosts is often investigated to aid conservation and fisheries management (e.g. to assess population structure to inform restocking programs). We assessed genetic population structure of the important estuary-associated marine fish, mulloway (Argyrosomus japonicus), within Australian waters and between Australia and South Africa. Genetic variation was investigated at 13 polymorphic microsatellite markers. FST values and Bayesian estimates in STRUCTURE suggested population differentiation of mulloway within Australia and confirm strong differentiation between South Africa and Australia. The 12 Australian sample sets fell into one of four spatially separated genetic clusters. Initially, a significant signal of isolation-by-distance (IBD) was evident among Australian populations. However, further investigation by decomposed-pairwise-regression (DPR) suggested five sample sets were influenced more by genetic-drift, rather than gene-flow and drift equilibrium, as expected in strong IBD cases. Cryptic oceanographic and topographical influences may isolate mulloway populations from south-western Australia. The results demonstrate that DPR is suitable to assess population structure of coastal marine species where barriers to gene flow may be less obvious than in freshwater systems. Information on the relative strengths of gene flow and genetic drift facilitates a more comprehensive understanding of the evolutionary forces that lead to population structure, which in turn informs fisheries and assists conservation management. Large-bodied predatory scale-fish may be under increasing pressure on a global scale, owing to a variety of anthropogenic reasons. In southern Australia, the iconic sciaenid A. japonicus (mulloway, jewfish or kob) is no exception. Despite the species supporting important fisheries, much of its ecology is poorly understood. It is possible that a greater understanding of their genetic population structure can help ensure a sustainable future for the only southern Australian sciaenid.
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Creighton, Colin, Paul I. Boon, Justin D. Brookes e Marcus Sheaves. "Repairing Australia's estuaries for improved fisheries production – what benefits, at what cost?" Marine and Freshwater Research 66, n.º 6 (2015): 493. http://dx.doi.org/10.1071/mf14041.
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An Australia-wide assessment of ~1000 estuaries and embayments undertaken by the National Land and Water Resources Audit of 1997–2002 indicated that ~30% were modified to some degree. The most highly degraded were in New South Wales, where ~40% were classified as ‘extensively modified’ and <10% were ‘near pristine’. Since that review, urban populations have continued to grow rapidly, and increasing pressures for industrial and agricultural development in the coastal zone have resulted in ongoing degradation of Australia's estuaries and embayments. This degradation has had serious effects on biodiversity, and commercial and recreational fishing. A business case is developed that shows that an Australia-wide investment of AU$350 million into repair will be returned in less than 5 years. This return is merely from improved productivity of commercial fisheries of a limited number of fish, shellfish and crustacean species. Estuary repair represents an outstanding return on investment, possibly far greater than most of Australia's previous environmental repair initiatives and with clearly demonstrated outcomes across the Australian food and services economies.
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Lynch, T. P., C. B. Smallwood, F. A. Ochwada-Doyle, J. Lyle, J. Williams, K. L. Ryan, C. Devine, B. Gibson e A. Jordan. "A cross continental scale comparison of Australian offshore recreational fisheries research and its applications to Marine Park and fisheries management". ICES Journal of Marine Science 77, n.º 3 (10 de junho de 2019): 1190–205. http://dx.doi.org/10.1093/icesjms/fsz092.
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Abstract Recreational fishing is popular in Australia and is managed by individual states in consultation with the Commonwealth for those fisheries that they regulate and also for Australian Marine Parks (AMPs). Fishers regularly access both state and offshore Commonwealth waters but this offshore component of the recreational fishery is poorly understood. Our study tested the functionality of existing state-based surveys in Western Australia (WA) and New South Wales (NSW) to better inform Commonwealth fisheries and AMP managers about recreational fishing in their jurisdictions. Catch estimates for nine species of interest to the Commonwealth were developed and two case study AMPs [Ningaloo (WA) and The Hunter (NSW)] were also chosen to test the ability of the state survey data to be disaggregated to the park scale. As each state’s fishery survey designs were contextual to their own management needs, the application of the data to Commonwealth jurisdictions were limited by their statistical power, however aspects of each states surveys still provided useful information. Continued evolution of state-wide survey methods, including collection of precise spatial data, and regional over-sampling would be beneficial, particularly where there are multiple stakeholder and jurisdictional interests. National coordination, to temporally align state surveys, would also add value to the existing approaches.
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Morgan, Jess A. T., Wayne D. Sumpton, Andrew T. Jones, Alexander B. Campbell, John Stewart, Paul Hamer e Jennifer R. Ovenden. "Assessment of genetic structure among Australian east coast populations of snapper Chrysophrys auratus (Sparidae)". Marine and Freshwater Research 70, n.º 7 (2019): 964. http://dx.doi.org/10.1071/mf18146.
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Snapper Chrysophrys auratus is a high-value food fish in Australia targeted by both commercial and recreational fisheries. Along the east coast of Australia, fisheries are managed under four state jurisdictions (Queensland, Qld; New South Wales, NSW; Victoria, Vic.; and Tasmania, Tas.), each applying different regulations, although it is thought that the fisheries target the same biological stock. An allozyme-based study in the mid-1990s identified a weak genetic disjunction north of Sydney (NSW) questioning the single-stock hypothesis. This study, focused on east-coast C. auratus, used nine microsatellite markers to assess the validity of the allozyme break and investigated whether genetic structure exists further south. Nine locations were sampled spanning four states and over 2000km, including sites north and south of the proposed allozyme disjunction. Analyses confirmed the presence of two distinct biological stocks along the east coast, with a region of genetic overlap around Eden in southern NSW, ~400km south of the allozyme disjunction. The findings indicate that C. auratus off Vic. and Tas. are distinct from those in Qld and NSW. For the purpose of stock assessment and management, the results indicate that Qld and NSW fisheries are targeting a single biological stock.A
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Shaughnessy, Peter D., Simon D. Goldsworthy, Paul Burch e Terry E. Dennis. "Pup numbers of the Australian sea lion (Neophoca cinerea) at The Pages Islands, South Australia, over two decades". Australian Journal of Zoology 61, n.º 2 (2013): 112. http://dx.doi.org/10.1071/zo13015.
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The Australian sea lion is an Australian endemic, restricted to South Australia and Western Australia, with 86% of the population in South Australia. It was listed under the Commonwealth Environment Protection and Biodiversity Conservation Act as Vulnerable in February 2005, and the International Union for the Conservation of Nature has listed it as Endangered. Sea lions are taken as bycatch in the gill-net fishery for school shark and gummy shark, and the risk of extinction of breeding colonies is high even from low levels of bycatch. We assessed trends in pup population size at The Pages Islands, a large breeding colony in South Australia. Pup abundance was estimated by direct counting of live and dead pups; the maximum count in each breeding season was used for trend analysis. The average of direct counts of pups in 14 breeding seasons between 1989–90 and 2009–10 was 473 (s.d. = 58.4). There was no trend in pup numbers, contrasting with two other large colonies: Seal Bay, Kangaroo Island (decreasing), and Dangerous Reef (increasing since 2000). The Australian Sea Lion Management Strategy of the Australian Fisheries Management Authority aims to reduce sea lion bycatch in the shark fishery; a key item is a fishery closure around each breeding colony in South Australia. Implementation of the closure around The Pages should lower the risk of bycatch of its sea lions with foraging areas that previously overlapped with the fishery and should allow the colony’s population size to increase.
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Faulkner, Adam. "A study of aboriginal fisheries in northern New South Wales, Australia". Human Dimensions of Wildlife 5, n.º 4 (dezembro de 2000): 83–88. http://dx.doi.org/10.1080/10871200009359197.
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Nottage, Jonathan D., Ronald J. West, Steven S. Montgomery e Ken Graham. "Cephalopod diversity in commercial fisheries landings of New South Wales, Australia". Reviews in Fish Biology and Fisheries 17, n.º 2-3 (23 de dezembro de 2006): 271–81. http://dx.doi.org/10.1007/s11160-006-9032-8.
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Raoult, V., V. Peddemors e J. E. Williamson. "Biology of angel sharks (Squatina sp.) and sawsharks (Pristiophorus sp.) caught in south-eastern Australian trawl fisheries and the New South Wales shark-meshing (bather-protection) program". Marine and Freshwater Research 68, n.º 2 (2017): 207. http://dx.doi.org/10.1071/mf15369.
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Two species of angel shark (Squatina australis, S. albipunctata) and two species of sawshark (Pristiophorus nudipinnis, P. cirratus) are frequently caught in south-eastern Australia. Little is known of the biology of these elasmobranchs, despite being caught as secondary target species in large numbers. The present study collected morphometric and reproductive data from sharks caught in shark-control nets, commercial fishing trawlers and research trawlers in south-eastern Australia. All four species had female-biased sexual size dimorphism, but growth curves between sexes did not differ. Male S. australis individuals were fully mature at ~800-mm total length, male P. nudipinnis at ~900mm, and male P. cirratus at ~800mm. Anterior pectoral margins could be used to determine total length in all species. No morphometric measurement could reliably separate Squatina spp. or Pristiophorus spp., although S. albipunctata over 1000-mm total length had larger eyes than did S. australis.
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Prince, Jeremy D. "Ecosystem of the South East Fishery (Australia), and fisher lore". Marine and Freshwater Research 52, n.º 4 (2001): 431. http://dx.doi.org/10.1071/mf00042.
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A description of the marine ecosystem that sustains fisheries production around south-eastern Australia is based on a synthesis of fisher lore of the demersal trawling sector, a review of the literature and a decade of the author’s field observations. A wide range of species are fished demersally in the South East Fishery (SEF). Until recently, managers and researchers have often implicitly assumed that many of these demersally caught species were neritic and lived in close association with the seabed. In contrast, fisher lore emphasizes the pelagic and oceanic nature of the commercial resource together with its environmentally forced variability. This paper substantially supports the views of the fishers. Up to 90%of the primary production of the SEF ecosystem may be garnered by fish foraging through extensive, but relatively sparse, oceanic phytoplankton and gelatinous zooplankton communities. Sporadically, climatic conditions cause oceanographic features to interact with shelf-break features and create ephemeral hotspots of primary production along the shelf break. Fish of the SEF take advantage of these productivity events to aggregate for feeding and breeding and their episodes of aggregation and dispersion cause the large seasonal variations in catchability observed with the shelf-break species. Implications for ecosystem management are briefly discussed.
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Hitchcock, Garrick. "Cross-border trade in Saratoga fingerlings from the Bensbach River, south-west Papua New Guinea". Pacific Conservation Biology 12, n.º 3 (2006): 218. http://dx.doi.org/10.1071/pc060218.
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Saratoga Scleropages jardinii (Saville-Kent 1892) is a popular aquarium and sportsfish native to southern New Guinea and northern Australia. In recent years the people of the Bensbach River area in Papua New Guinea's Western Province have been harvesting wild fingerlings for sale across the nearby international border in Indonesia's Papua Province. From there the fish are sold to dealers in other parts of Asia. The species is protected by law in Indonesia, and subject to various regulations in Australia. In Papua New Guinea there are no controls on its exploitation. Uncontrolled harvesting of fingerlings from the Bensbach and other river systems in south New Guinea has had negative impacts on local fisheries, and led to a decline in the Australian export trade in wild-caught and farm-bred Saratoga.
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Gardner, M. G., e R. D. Ward. "Population structure of the Australian gummy shark (Mustelus antarcticus GÜnther) inferred from allozymes, mitochondrial DNA and vertebrae counts". Marine and Freshwater Research 49, n.º 7 (1998): 733. http://dx.doi.org/10.1071/mf98009.
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The gummy shark (Mustelus antarcticus) is the main target of southern Australian shark fisheries. Its stock structure was investigated through allozymes (up to 28 loci), mitochondrial DNA (up to 10 restriction enzymes) and vertebrae counts. The average heterozygosity per allozyme locus (0.099) and degree of polymorphism (0.255) was high for sharks. Composite mitochondrial DNA haplotype diversity (0.534) and mean nucleotide sequence diversity (0.16%) were also moderately high. Three of the seven polymorphic allozyme loci (CK-A*, LDH-1*, PEP*) and the mtDNA haplotypes showed significant spatial differentiation. Two genetic stocks were identified: one along the southern coast of Australia from Bunbury in Western Australia to Eden in New South Wales and one off northern New South Wales (in the region of Newcastle to Clarence River). There was some evidence for a third stock off Townsville, Queensland. The northern occurrences extend the known geographical range of this species. Vertebrae counts from Eden northwards increased, supporting the conclusion of population heterogeneity off eastern Australia.
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Wulandari, Indah, e Harlinda Kuspradini, Irawan Wijaya. "agriculture, fisheries, forestry, West Kutai, zone". AGRIFOR 17, n.º 2 (10 de outubro de 2018): 275. http://dx.doi.org/10.31293/af.v17i2.3354.
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Litsea is a important genus from Lauraceae family, found in the tropic and subtropic Asia, Australia and from North to South America. Related literature review with biology activity show that secondary metabolite compounds in the Lauraceae plants contained insecticide and cytotoxic activities. Insecticide activities show bioactive compounds such as alkaloid, terpenoid and flavonoid. Botanical insecticides by terpenoid groups that found is piretrin, camphene and azardirakhtin. This research do to analyze secondary metabolite compunds by five species Litsea extract from bole, bark and leaf. Analysis of phytochemical compunds using qualitative method. Based on test result can be known that five species positively contains alkaloids, flavonoids, tannins, carbohydrate and coumarins.
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Tixier, Paul, Mary-Anne Lea, Mark A. Hindell, Christophe Guinet, Nicolas Gasco, Guy Duhamel e John P. Y. Arnould. "Killer whale (Orcinus orca) interactions with blue-eye trevalla (Hyperoglyphe antarctica) longline fisheries". PeerJ 6 (8 de agosto de 2018): e5306. http://dx.doi.org/10.7717/peerj.5306.
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Over the past five decades, marine mammal interactions with fisheries have become a major human-wildlife conflict globally. The emergence of longline fishing is concomitant with the development of depredation-type interactions i.e., marine mammals feeding on fish caught on hooks. The killer whale (Orcinus orca) is one of the species most involved in depredation on longline fisheries. The issue was first reported in high latitudes but, with increasing expansion of this fishing method, other fisheries have begun to experience interactions. The present study investigated killer whale interactions with two geographically isolated blue-eye trevalla (Hyperoglyphe antarctica) fisheries operating in temperate waters off Amsterdam/St. Paul Islands (Indian Ocean) and south-eastern Australia. These two fisheries differ in the fishing technique used (vertical vs. demersal longlines), effort, catch, fleet size and fishing area size. Using 7-year (2010–16) long fishing and observation datasets, this study estimated the levels of killer whale interactions and examined the influence of spatio-temporal and operational variables on the probability of vessels to experience interactions. Killer whales interactions occurred during 58.4% and 21.2% of all fishing days, and over 94% and 47.4% of the fishing area for both fisheries, respectively. In south-eastern Australia, the probability of occurrence of killer whale interactions during fishing days varied seasonally with a decrease in spring, increased with the daily fishing effort and decreased with the distance travelled by the vessel between fishing days. In Amsterdam/St. Paul, this probability was only influenced by latitude, with an increase in the southern part of the area. Together, these findings document two previously unreported cases of high killer whale depredation, and provide insights on ways to avoid the issue. The study also emphasizes the need to further examine the local characteristics of fisheries and the ecology of local depredating killer whale populations in as important drivers of depredation.
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Navarro, Matthew, Atakelty Hailu, Tim Langlois, Karina L. Ryan e Marit E. Kragt. "Determining spatial patterns in recreational catch data: a comparison of generalized additive mixed models and boosted regression trees". ICES Journal of Marine Science 77, n.º 6 (15 de julho de 2019): 2216–25. http://dx.doi.org/10.1093/icesjms/fsz123.
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Abstract Marine recreational fisheries (MRFs) are often highly spatially heterogenous, with effort concentrated into small areas, and fisheries spanning large environmental gradients. However, spatially resolved catch data is rarely collected in MRFs, preventing the study of spatial heterogeneity in catch. This study uses recreational catch reported in 10 × 10 nm blocks across eight degrees of latitude in Western Australia to map spatial predictions of the probability of a recreational catch on an average trip for two key species: West Australian dhufish (Glaucosoma hebraicum) and snapper (Chrysophrys auratus). Two spatial modelling techniques are compared for the analysis, generalized additive mixed models (GAMMs) and boosted regression trees (BRTs). We find that BRTs outperform GAMMs, but performance gains are small. We also find marked spatial variations in recreational catch probabilities: high catches of dhufish are found in the north of the study area, and low catches in the Perth Metropolitan area and in the south; snapper catches are highest in the north and low in the south. These patterns are used to identify important spatial processes in the fishery. The analysis also suggests that modelling approach (GAMMs or BRTs) has only a minor effect on outcomes of spatial catch analysis in MRFs.
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Gallo-Cajiao, Eduardo. "Evidence is required to address potential albatross mortality in the New South Wales Ocean Trawl fishery." Pacific Conservation Biology 20, n.º 3 (2014): 328. http://dx.doi.org/10.1071/pc140328.
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To examine the current management of trawl fisheries is important to ensure albatross mortality is not being overlooked. By-catch of albatrosses in trawl fisheries occurs cryptically, which has hindered the development of conservation policy. The implementation of tasked seabird observer programmes in trawl fisheries, nevertheless, has shown that albatross mortality can happen at threatening levels. Consequently, mitigation measures have been developed and adopted in some trawl fisheries. Despite this, some trawl fisheries lack clear policy in relation to albatross mortality. In this context, I investigated the management of potential albatross mortality in a state trawl fishery, the New South Wales Ocean Trawl, in Australia. I conducted a literature search and addressed a set of questions to the responsible management agency through questions on notice at the State Parliament of New South Wales to understand albatross interactions from a policy standpoint. My results indicate that current policy neither encompasses albatross mortality nor is evidence-based. However, the combination of characteristics of this fishery and its overlap with albatross occurrence, along with the reported albatross mortality from other trawl fisheries, may warrant the need to collect empirical evidence on potential albatross interactions. Hence, the responsible management agency should take action according to legal obligations. In this scenario, I recommend the implementation of a tasked seabird observer programme, collection of baseline data, and adoption of adaptive management by the examined fishery. As uncertainty can hamper conservation efforts because management actions require evidence, it is imperative to fill current information gaps in this fishery. Additionally, an improved understanding of albatross mortality from individual trawl fisheries across different fisheries management jurisdictions will enable the prioritization of conservation efforts of this avian taxon in an international and multi-gear fishing context.
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Alleway, Heidi K., Bronwyn M. Gillanders e Sean D. Connell. "‘Neo-Europe’ and its ecological consequences: the example of systematic degradation in Australia's inland fisheries". Biology Letters 12, n.º 1 (janeiro de 2016): 20150774. http://dx.doi.org/10.1098/rsbl.2015.0774.
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The antiquity of human impact on ecosystems is increasingly understood, though the arrival of settlers to new lands remains a defining period. Colonization of the ‘neo-Europes’, a reference from the discipline of history, precipitated changes in aquatic ecosystems through modification of waterways and introductions of non-native species. We considered historical fisheries and fish market records from South Australia (1900–1946) against contemporary production statistics (1987–2011). Native inland species historically contributed large quantities to the market but have deteriorated such that fishing is now limited, and conservation regulations exist. This pattern mirrors the demand-driven transition from freshwater to marine fisheries in Europe; hence, we propose that this pattern was predicated on societal expectations and that European settlement and introduction of non-native fishes led to systematic overexploitation and degradation of native inland fisheries species in Australia, representing a further consequence of neo-European colonization to ecology. Accurate interpretation of ecological change can ensure more appropriate management intervention. Concepts, such as neo-Europe, from alternative disciplines can inform the recognition and evaluation of patterns at regional and global scales.
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Schnierer, S., e H. Egan. "Composition of the Aboriginal harvest of fisheries resources in coastal New South Wales, Australia". Reviews in Fish Biology and Fisheries 26, n.º 4 (5 de outubro de 2016): 693–709. http://dx.doi.org/10.1007/s11160-016-9452-z.
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Punt, André E., David C. Smith, Geoff N. Tuck e Richard D. Methot. "Including discard data in fisheries stock assessments: Two case studies from south-eastern Australia". Fisheries Research 79, n.º 3 (julho de 2006): 239–50. http://dx.doi.org/10.1016/j.fishres.2006.04.007.
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Alleway, Heidi K., Sean D. Connell, Tim M. Ward e Bronwyn M. Gillanders. "Historical changes in mean trophic level of southern Australian fisheries". Marine and Freshwater Research 65, n.º 10 (2014): 884. http://dx.doi.org/10.1071/mf13246.
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Decreases in the mean trophic level (MTL) of fishery catches have been used to infer reductions in the abundance of high trophic level species caused by fishing pressure. Previous assessments of southern Australian fisheries have been inconclusive. The objectives of the present study were to provide more accurate estimates of MTL using disaggregated taxonomic and spatial data. We applied the model of MTL to fisheries catch statistics for the state of South Australia from 1951 to 2010 and a novel set of historical market data from 1936 to 1946. Results show that from 1951 to 2010, MTL declined by 0.16 of a trophic level per decade; a rate greater than the global average of 0.10 but equivalent to similar regional investigations in other areas. This change is mainly attributable to large increases in catches of sardine, rather than reductions in the catches of high trophic level species. The pattern is maintained when the historical data is included, providing a time line from 1936 to 2010. Our results show a broadening of the catch of lower trophic levels and suggest care in interpretation of MTL of catches because reductions do not necessarily reflect change in high trophic level species by fishing pressure.
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Dawson, Michael N. "Morphologic and molecular redescription of Catostylus mosaicus conservativus (Scyphozoa: Rhizostomeae: Catostylidae) from south-east Australia". Journal of the Marine Biological Association of the United Kingdom 85, n.º 3 (junho de 2005): 723–31. http://dx.doi.org/10.1017/s002531540501163x.
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Two reciprocally monophyletic mitochondrial clades of the commercially valuable jellyfish Catostylus mosaicus are endemic to south-eastern Australia. Here, medusae in the two clades are shown to differ also in colour and in the dimensions of their papillae, oral disk, and bell depth. They are referred to two varieties recognized in 1884 by von Lendenfeld. The clade occupying localities adjacent to Bass Strait is redescribed as subspecies C. mosaicus conservativus; the clade from New South Wales and southern Queensland spans the type locality (Port Jackson) of C. mosaicus and is designated C. mosaicus mosaicus. Their ecology and colour, in the context of von Lendenfeld's original descriptions, and the implications for fisheries are discussed.
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Kennelly, Steven J. "The Development and Introduction of By-catch Reducing Technologies in Three Australian Prawn-Trawl Fisheries". Marine Technology Society Journal 33, n.º 2 (1 de janeiro de 1999): 73–81. http://dx.doi.org/10.4031/mtsj.33.2.11.
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Three tasks are usually required to introduce new technologies that reduce by-catches in commercial fisheries: (i) identify and quantify the particular by-catch issue that requires the new devices; (ii) develop and test the devices; and (iii) implement the devices into industry by voluntary acceptance and/or legislation. To solve by-catch problems in prawn-trawl fisheries in three regions of Australia, different approaches have been followed with varying success, and their comparison identifies an ideal framework under which such problems can be resolved.In northern Australia’s prawn-trawl fisheries, the main by-catch issues involved turtles and the discard of a large diversity offish species. To quantify these issues, data were obtained from research vessels, industry logbooks and samples from fishers. Before and during this work, modified gears were developed and tested in a flume tank and in the field using research vessels and, to a lesser extent, commercial vessels. Next, a separate project was established to encourage acceptance of the new technologies by industry and involved workshops, newsletters and a library that lent out various by-catch reducing devices to fishers. Voluntary acceptance of the new gears is currently estimated to be 50‐80% in some ports and 0‐20% in others, and a three-phase plan for their legislation is due to occur between 1999 and 2002.In New South Wales, the main by-catch issue was the large number of undersize fish discarded by prawn trawlers as they caught prawns and other species of retained by-catch. Firstly, observer programmes on commercial vessels were used to identify and quantify size- and species-specific by-catches. Then, modifications to fishing gears that reduced the identified problematic by-catches were developed and tested on chartered commercial fishing vessels. Next, involving fishers in this work (and workshops, posters, videos, etc.) led to the voluntary acceptance of the new modifications by the majority of fishers (estimated to be 100% in some fisheries and 50‐100% in others). Finally, the new devices were made mandatory by legislation in several fisheries, with the others to follow within 12 months.In South Australia’s Gulf St. Vincent, the chief by-catch issue mainly came from the prawn-trawl industry itself and concerned the by-catch of small prawns and fish. The approach used was to begin gear-development research without any formal quantification phase. After preliminary trials by industry, only five days of formal tests of new devices were required to recommend a design that was optimal for industry’s (and management’s) requirements. Within two weeks of the completion of the field trials, 100 of the industry was using this new gear voluntarily and its legislation is planned to occur within the next few years to ensure continued compliance.The simple pattern that emerges from these examples is that the sooner industry is fully involved in all stages of the work (driving the issue, quantifying it, developing devices and implementing them), the sooner and more complete is the voluntary acceptance of by-catch reducing fishing technology, and the more painless is the implementation of the relevant legislation.
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Niella, Y., AF Smoothey, V. Peddemors e R. Harcourt. "Predicting changes in distribution of a large coastal shark in the face of the strengthening East Australian Current". Marine Ecology Progress Series 642 (28 de maio de 2020): 163–77. http://dx.doi.org/10.3354/meps13322.
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In the face of accelerating climate change, conservation strategies will need to consider how marine animals deal with forecast environmental change as well as ongoing threats. We used 10 yr (2009-2018) of data from commercial fisheries and a bather protection program along the coast of New South Wales (NSW), southeastern Australia, to investigate (1) spatial and temporal patterns of occurrence in bull sharks and (2) environmental factors affecting bull shark occurrence along the coast of NSW. Predicted future distribution for this species was modelled for the forecast strengthening East Australian Current. Bull sharks were mostly harvested in small to larger estuaries, with average depth and rainfall responsible for contrasting patterns for each of the fisheries. There was an increase in the occurrence of bull sharks over the last decade, particularly among coastal setline fisheries, associated with seasonal availability of thermal gradients >22°C and both westward and southward coastal currents stronger than 0.15 and 0.60 m s-1, respectively, during the austral summer. Our model predicts a 3 mo increase in the availability of favourable water temperatures along the entire coast of NSW for bull sharks by 2030. This coastline provides a uniquely favourable topography for range expansion in the face of a southerly shift of warmer waters, and habitat is unlikely to be a limiting factor for bull sharks in the future. Such a southerly shift in distribution has implications for the management of bull sharks both in commercial fisheries and for mitigation of shark-human interactions.
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Kroon, Frederieke J., e Dean H. Ansell. "A comparison of species assemblages between drainage systems with and without floodgates: implications for coastal floodplain management". Canadian Journal of Fisheries and Aquatic Sciences 63, n.º 11 (1 de novembro de 2006): 2400–2417. http://dx.doi.org/10.1139/f06-134.
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Coastal floodplains provide essential nursery habitat for a large number of fish and prawn species, many of which are commercially and recreationally important. Human activities in coastal floodplains, such as those associated with agriculture and (or) development, can have detrimental impacts on this nursery function. We examined the potential role of flood mitigation structures, in particular tidal floodgates, in depleting estuarine and inshore fisheries stocks in eastern Australia. We compared species assemblages (abundance and biomass) in reference and gated drainage systems in the Clarence River floodplain (New South Wales, Australia) over a 1-year period. We subsequently determined which environmental variables were associated with the observed patterns in species assemblages. Our results show that abundance, biomass, and assemblages of juvenile fishes and invertebrates differed significantly and consistently between drainage systems with and without floodgates. The major environmental variables of concern in systems with floodgates were (i) presence of a floodgate, (ii) elevated concentrations of nutrients, and (iii) abundance of aquatic weeds. We discuss our findings in light of potential strategies to improve coastal floodplain management for fisheries production purposes.
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Schrale, G., R. Boardman e M. J. Blaskett. "Investigating Land Based Disposal of Bolivar Reclaimed Water, South Australia". Water Science and Technology 27, n.º 1 (1 de janeiro de 1993): 87–96. http://dx.doi.org/10.2166/wst.1993.0022.
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The Bolivar Sewage Treatment Works (STW) processes the urban and industrial sewage from the northern and eastern suburbs of Adelaide. The treatment capacity is equivalent to the sewage production of 1.1 million people. The disposal of more than 40 000 ML of reclaimed water into the sea has caused a progressive degradation of about 950 ha of seagrass beds which threatens the sustainability of the fisheries and marine ecosystems of Gulf St. Vincent. The current practice will no longer be viable to achieve compliance with the SA Marine Environment Protection Act, 1990. A Inter-Departmental Working Party recommmended that the Bolivar reclaimed water be disposed by irrigation of suitable land on the coastal plains north of Adelaide. They proposed the construction of two pipelines: a 12 km long pipeline to extend the distribution of reclaimed water in the most intense portion of the 3 500 hectares of irrigated horticulture on the Northern Adelaide Plains, and a second, 18 km long pipeline to deliver the remainder to a more northerly site for irrigation of an estimated 4 000 hectares of hardwood plantations. The paper summarizes the findings as they relate to public health, environmental, technical and financial aspects of land based disposal. Land based disposal would completely eliminate the marine degradation and also arrest the over-use of the NAP underground water resources for horticulture. The total net costs over thirty years for land based disposal are about $ 21.8 million. The ‘horticultural' pipeline of the land based disposal scheme is expected to be commercially viable. A shortfall in revenue from the afforestation component is expected and may need to be considered as an environmental cost of ceasing marine disposal.
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Pease, B. C. "A spatially oriented analysis of estuaries and their associated commercial fisheries in New South Wales, Australia". Fisheries Research 42, n.º 1-2 (agosto de 1999): 67–86. http://dx.doi.org/10.1016/s0165-7836(99)00035-1.
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Padovan, Amanda, Rowan C. Chick, Victoria J. Cole, Ludovic Dutoit, Patricia A. Hutchings, Cameron Jack e Ceridwen I. Fraser. "Genomic analyses suggest strong population connectivity over large spatial scales of the commercially important baitworm, Australonuphis teres (Onuphidae)". Marine and Freshwater Research 71, n.º 11 (2020): 1549. http://dx.doi.org/10.1071/mf20044.
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Barriers to dispersal can disrupt gene flow between populations, resulting in genetically distinct populations. Although many marine animals have potential for long-distance dispersal via a planktonic stage, gene flow among populations separated by large geographic distances is not always evident. Polychaetes are ecologically important and have been used as biological surrogates for marine biodiversity. Some polychaete species are used as bait for recreational fisheries, with this demand supporting commercial fisheries for polychaetes to service the retail bait market. However, despite their ecological and economic importance, very little is known about the life history or population dynamics of polychaetes, and few studies have used genetic or genomic approaches to understand polychaete population connectivity. Here, we investigate the population structure of one commonly collected beachworm species used for bait on the eastern coast of Australia, namely, Australonuphis teres, by using genome-wide single-nucleotide polymorphism data. We sampled A. teres from hierarchical nested spatial scales along 900km of the coast in New South Wales. We identified six genetic groups, but there was no clear geographic pattern of distribution. Our results suggest that there is considerable gene flow among the sampled populations. These high-resolution genomic data support the findings of previous studies, and we infer that oceanographic processes promote genetic exchange among polychaete populations in south-eastern Australia.
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Gales, N. J., B. Haberley e P. Collins. "Changes in the abundance of New Zealand fur seals, Arctocephalus forsteri, in Western Australia". Wildlife Research 27, n.º 2 (2000): 165. http://dx.doi.org/10.1071/wr99027.
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New Zealand fur seals, Arctocephalus forsteri, have been increasing in abundance in South Australia for at least the past three decades. A survey of New Zealand fur seals during the 1989/90 breeding season determined that about 20% of the Australian population bred at 16 sites in Western Australia, amounting to 1429 pups and an absolute abundance estimate of 7100 fur seals. A further survey of all fur seal colonies in Western Australia to determine current pup production and abundance estimates, and trends in pup production since the previous survey was undertaken in January 1999. Of the 17 breeding sites now known in Western Australia, 16 were surveyed and pup production had increased at all but one. The rate of change in pup production at the one unsurveyed site (West Island), was estimated as being equivalent to the mean rate of change at other sites. The estimated mean annual, exponential rate of increase (r) for all sites was 0.09, equivalent to a 9.8% annual increase in pup production and an overall increase in pup production in Western Australia of 113.3% between surveys. Total annual pup production has increased to 3090. The estimate of absolute abundance of New Zealand fur seals in Western Australia is now 15 100, in contrast to the 7100 estimated for the 1989/90 season. Mortality of pups at the time of the survey was estimated to be at least 1.3%. It is predicted that New Zealand fur seal populations will continue to increase in Western Australia. This is likely to have important management implications regarding aquaculture and fisheries activities. The increase in fur seal populations appears to be in contrast to populations of Australian sea lions, Neophoca cinerea, for which preliminary data show no evidence for a population increase. It is unknown whether the dynamics affecting these two species are related.
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Li, Zeya, Neil J. Holbrook, Xuebin Zhang, Eric C. J. Oliver e Eva A. Cougnon. "Remote Forcing of Tasman Sea Marine Heatwaves". Journal of Climate 33, n.º 12 (15 de junho de 2020): 5337–54. http://dx.doi.org/10.1175/jcli-d-19-0641.1.
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AbstractRecent marine heatwave (MHW) events in the Tasman Sea have had dramatic impacts on the ecosystems, fisheries, and aquaculture off Tasmania’s east coast. However, our understanding of the large-scale drivers (forcing) and potential predictability of MHW events in this region off southeast Australia is still in its infancy. Here, we investigate the role of oceanic Rossby waves forced in the interior South Pacific on observed MHW occurrences off southeast Australia from 1994 to 2016, including the extreme 2015/16 MHW event. First, we used an upper-ocean heat budget analysis to show that 51% of these historical Tasman Sea MHWs were primarily due to increased East Australian Current (EAC) Extension poleward transports through the region. Second, we used lagged correlation analysis to empirically connect the EAC Extension intensification to incoming westward-propagating sea surface height (SSH) anomalies from the interior South Pacific. Third, we dynamically analyzed these SSH anomalies using simple process-based baroclinic and barotropic Rossby wave models forced by wind stress curl changes across the South Pacific. Finally, we show that associated monthly SSH changes around New Zealand may be a useful index of western Tasman Sea MHW predictability, with a lead time of 2–3 years. In conclusion, our findings demonstrate that there is potential predictability of advection-dominated MHW event likelihoods in the EAC Extension region up to several years in advance, due to the deterministic contribution from baroclinic and barotropic Rossby waves in modulating the EAC Extension transports.
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Bichler, Martin, Vladimir Fux e Jacob K. Goeree. "Designing combinatorial exchanges for the reallocation of resource rights". Proceedings of the National Academy of Sciences 116, n.º 3 (31 de dezembro de 2018): 786–91. http://dx.doi.org/10.1073/pnas.1802123116.
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We describe the design and implementation of a combinatorial exchange for trading catch shares in New South Wales, Australia. The exchange ended a decades-long political debate by providing a market-based response to a major policy problem faced by fisheries worldwide: the reallocation of catch shares in cap-and-trade programs designed to prevent overfishing. The exchange was conducted over the Internet to lower participation costs and allowed for all-or-nothing orders to avoid fragmented share portfolios. A subsidy was distributed endogenously to facilitate the transfer of shares from inactive to active fishers. Finally, prices were linear and anonymous to ensure that sellers of identical packages received the same payments. These features were crucial to mitigate economic distortions from introducing catch shares and to gain broad acceptance of the program. However, they led to computationally challenging allocation and pricing problems. The exchange operated from May to July 2017 and effectively reallocated shares from inactive fishers to those who needed them most: 86% of active fishers’ bids were matched and their share deficits were reduced by 95% in high-priority share classes. Similar reallocation problems arise in fisheries with catch-share systems worldwide as well as in other cap-and-trade systems for resource rights, e.g., water and pollution rights. The implemented exchange illustrates how computational optimization and market design can provide policy tools, able to solve complex policy problems considered intractable only a few years ago.
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Hallegraeff, GM, e SW Jeffrey. "Annually recurrent diatom blooms in spring along the New South Wales coast of Australia". Marine and Freshwater Research 44, n.º 2 (1993): 325. http://dx.doi.org/10.1071/mf9930325.
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Blooms of phytoplankton (100-280 mg chlorophyll a m-1) occur on the continental shelf off Sydney in the spring of most years. These sudden chlorophyll increases (more than 10 times the normal algal biomass) are due to short-lived diatom blooms that evolve in a predictable sequence from small chainforming species (Nitzschia, Thalassiosira) to large centric species (Lauderia, Rhizosolenia) and eventually to large dinoflagellates (Protoperidinium). Two research cruises (October 1981, September 1984) were conducted to define the longshore extent of this phenomenon. Diatom blooms were widespread along the whole New South Wales coastline, occurring in the 700-km-long region from Cape Hawke in the north (32°S), where the East Australian Current separates from the coast, to Maria Island off Tasmania in the south (43°S). Hydrological mechanisms of these annually recurrent enrichments are related to the action of the East Australian Current and are unlike those triggering spring blooms in temperate European waters. Implications of these diatom blooms for coastal fisheries along the New South Wales coast are briefly discussed.
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Lenanton, RCJ, DI Heald, M. Platell, M. Cliff e J. Shaw. "Aspect of the reproductive biology of the Gummy Shark, Mustelus antarcticus Gunther, from waters off the South coast of Western Australia". Marine and Freshwater Research 41, n.º 6 (1990): 807. http://dx.doi.org/10.1071/mf9900807.
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The gummy shark (Mustelus antarcticus) is a major target species in two substantial shark fisheries that operate in temperate Australian waters. Data on the reproductive biology of M. antarcticus in the waters off south-western Australia were obtained from samples collected by commercial vessels operating from Albany to Esperance, Western Australia. The samples contained a ratio of four females to one male. M. antarcticus is a viviparous, aplacental species. Males mature at a smaller size than females. Since the overwhelming majority of sharks sampled were mature, it was not possible to estimate precisely the mean size at which sexual maturity was attained. Examination of seasonal changes in the development of ova and testes, in uterine contents, and in embryo growth established that the period of parturition, mating and ovulation occurred over the 3 months between early November and early February. The gestation period was 11-12 months. Full-term embryos ranged in size from 30 to 36 cm total length and occurred in a sex ratio of one male to one female. The ovarian and gestational cycles proceed concurrently, with reproduction occurring annually. Only one of the 224 females analysed for uterine content was considered to be in a true post-partum condition. The number of embryos (N) per mother increased with the length of the mother (L) according to the regression N = exp(-4.13398 + 0.049171L). The reproductive biology of females collected off Albany and Esperance differed in some respects from that of females collected off south-eastern Australia.
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Bunn, S. E., E. G. Abal, P. F. Greenfield e D. M. Tarte. "Making the connection between healthy waterways and healthy catchments: South East Queensland, Australia". Water Supply 7, n.º 2 (1 de julho de 2007): 93–100. http://dx.doi.org/10.2166/ws.2007.044.
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The waterways of South East Queensland, Australia, represent unique and complex ecosystems that have a high conservation value and support major recreational and commercial fisheries. The agricultural districts of the region also contribute significantly to the regional economy and, together with the growing urban areas, are heavily reliant on good quality water supplies. However, the human footprint of these activities has led to significant changes in catchment hydrology and sediment delivery, declining water quality and loss of aquatic biodiversity. Predicted population increases in the region are likely to further impact on the ecological and economic health of its waterways and catchments, and there are growing community expectations to reverse the decline in water quality and ecosystem health. In response to these concerns, government, industry and community stakeholders have worked in close cooperation to develop a whole-of-government, whole-of-community approach to understanding and managing the region's waterways. This paper provides an overview of the experience gained through development of the SEQ Healthy Waterways Partnership and highlights some of the key factors we believe have contributed to its success.
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Linnane, Adrian, David Hobday, Stewart Frusher e Caleb Gardner. "Growth rates of juvenile southern rock lobster (Jasus edwardsii) estimated through a diver-based tag - recapture program". Marine and Freshwater Research 63, n.º 2 (2012): 110. http://dx.doi.org/10.1071/mf11121.
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Despite being one of the most economically important fisheries in south-eastern Australia, growth rates of juvenile southern rock lobster (Jasus edwardsii) have not previously been quantified in the wild. This study utilised a diver-based tag–recapture program to estimate growth rates of individuals between 40–80 mm carapace length (CL) in temperate reef sites across south-eastern Australia. Of the 7064 lobsters tagged and released, 978 (14%) were recaptured with recapture rates of 23, 5 and 7% in the States of Tasmania, South Australia and Victoria respectively. Although individual growth increments were similar between the sexes, differences in annual growth rates were evident at 50 mm CL, with males growing ~1.4 times faster than females. Increased levels of growth in males resulted from a higher moult frequency, which was found to significantly reduce in females as they reached sexual maturity at ~70–80 mm CL. No significant difference was found in growth rates of males or females between the States when all sites within each State were combined. The growth estimates from this work contribute to the understanding of juvenile lobster population dynamics and will improve current fishery models by confirming relationships between early juvenile, pre-recruit abundance and entry to the fishable biomass.
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Saintilan, Neil, e Kerrylee Rogers. "The significance and vulnerability of Australian saltmarshes: implications for management in a changing climate". Marine and Freshwater Research 64, n.º 1 (2013): 66. http://dx.doi.org/10.1071/mf12212.
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We review the distribution, status and ecology of Australian saltmarshes and the mechanisms whereby enhanced atmospheric carbon dioxide and associated climate change have influenced and will influence the provision of ecosystem goods and services. Research in temperate and subtropical saltmarsh has demonstrated important trophic contributions to estuarine fisheries, mediated by the synchronised mass-spawning of crabs, which feed predominantly on the C4 saltmarsh grass Sporobolus virginicus and microphytobenthos. Saltmarshes also provide unique feeding and habitat opportunities for several species of threatened microbats and birds, including migratory shorebirds. Saltmarshes increased in extent relative to mangrove in Australia in both tide- and wave-dominated geomorphic settings through the latter Holocene, although historic trends have seen a reversal of this trend. Australian saltmarshes have some capacity to maintain elevation with respect to rising sea level, although in south-eastern Australia, the encroachment of mangrove and, in Tasmania, conversion of shrubland to herbfield in the past half-century are consistent with changes in relative sea level. Modelling of the impacts of projected sea-level rise, incorporating sedimentation and other surface-elevation drivers, suggests that the survival of saltmarsh in developed estuaries will depend on the flexible management of hard structures and other impediments to wetland retreat.
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Trinnie, Fabian I., Terence I. Walker, Paul L. Jones e Laurie J. Laurenson. "Reproductive biology of the eastern shovelnose stingaree Trygonoptera imitata from south-eastern Australia". Marine and Freshwater Research 60, n.º 8 (2009): 845. http://dx.doi.org/10.1071/mf08165.
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In applying a quantitative approach to the reproduction of Trygonoptera imitata, the present study contributes to understanding the wide diversity in the reproductive biology of the family Urolophidae and provides insights to help determine phylogenetic relationships. This localised species is taken as bycatch in several inshore fisheries and potentially impacted by a range of other anthropogenic pressures, including introduced species, particularly in shallow-water pupping areas. T. imitata can be characterised as a species of comparatively low matrotrophic histotrophy with an extended period of relatively large eggs in utero (5–8 months) followed by rapid growth of the embryos (4–6 months). The reproductive cycle is annual with parturition occurring during late-February–April, followed immediately by ovulation. Mean size-at-birth is ~225 mm total length and there is a ~1000% gain in mean wet mass from egg (15 g) to full-term embryo in utero (150 g), the lowest reported for any viviparous batoid. Litter size increases with maternal length, reaching a maximum of seven, and sex ratio of embryos is 1 : 1. Maximum length and estimates of the maturity–ogive parameters l50 and l95 are similar for females and males.
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Whitten, Athol R., Neil L. Klaer, Geoffrey N. Tuck e Robert W. Day. "Accounting for cohort-specific variable growth in fisheries stock assessments: A case study from south-eastern Australia". Fisheries Research 142 (maio de 2013): 27–36. http://dx.doi.org/10.1016/j.fishres.2012.06.021.
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LAST, PETER R., JUSTIN A. CHIDLOW e LEONARD J. V. COMPAGNO. "A new wobbegong shark, Orectolobus hutchinsi n. sp. (Orectolobiformes: Orectolobidae) from southwestern Australia". Zootaxa 1239, n.º 1 (21 de junho de 2006): 35. http://dx.doi.org/10.11646/zootaxa.1239.1.3.
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Orectolobus hutchinsi n. sp.. is a moderate-sized wobbegong shark found in shallow continental shelf habitats off Western Australia. It occurs from Coral Bay (near North West Cape) south to Groper Bluff (west of Bremer Bay) in depths of 9–106 m where it is caught as by-catch of local gillnet, longline, rock lobster and recreational fisheries. It is sympatric with two other commercial wobbegong species, Orectolobus maculatus and O. ornatus, but differs from these and other IndoPacific species in having the combination of a few unbranched dermal lobes, relatively tall dorsal fins, no warty tubercles on the back of adults, and dark brown corrugated saddles without white spots and blotches. Some details of its biology are also provided.
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Meyer-Rochow, Victor Benno. "Ingredients to become a scientist: curiosity, enthusiasm, perseverance, opportunity, and a good pinch of luck". ICES Journal of Marine Science 77, n.º 6 (2 de julho de 2020): 2013–21. http://dx.doi.org/10.1093/icesjms/fsaa102.
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Abstract Writing a 200-word abstract about the life of a 76-year-old scientist, in which luck played a significant role, is not an easy task. Even knowing this scientist well (for I am talking about myself) does not make it any easier. When you notice something is not right, do not fear changing your major (I changed twice before settling on Fisheries and Marine Science). For my PhD in neurobiology, I changed again. Grab opportunities when they arise. Join field trips and expeditions, attend conferences, and spread your interests widely. Spend time in different countries, learn new techniques and languages, and always stay curious. Remain humble. I carried out speleological research in Jamaica and France, participated in a 4-month South Atlantic Fisheries Research Trip and a 3-month Bioluminescence Expedition to the Moluccas, and pioneered comparative physiological and functional anatomical research in Antarctica and the Arctic. Be adventurous. My ethnobiological field work took me to Papua Niugini, NE-India, and Central Australia. Having lived in Australia, Finland, France, Germany, Jamaica, Japan, and New Zealand (I am a New Zealander currently living in Korea) and having spent sabbaticals in Brazil, India, New Caledonia, and North Korea, I consider myself a global scientist. You can become one too.
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McPherson, GR. "Reproductive biology of yellowfin tuna in the eastern Australian Fishing Zone, with special reference to the north-western Coral Sea". Marine and Freshwater Research 42, n.º 5 (1991): 465. http://dx.doi.org/10.1071/mf9910465.
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Developmental stages of oocyte maturation and degenerative stages of postovulatory follicles in yellowfin tuna from the eastern Australian Fishing Zone of the Coral Sea are described. The time of spawning of yellowfin appeared to be during the late evening and early morning. Final oocyte maturation occurred in less than 24 h; postovulatory follicles could not be identified in ovaries after 24 h. Spawning of yellowfin commenced in the north-western Coral Sea by October and had ceased in the central-western Coral Sea by late February. The duration of spawning appeared to be less protracted in the south-western Coral Sea. The average spawning frequency of female yellowfin in the western Coral Sea was once every 1.54 days. Significant differences in spawning frequency were found between different size classes of yellowfin; larger fish spawned more frequently. The spawning stock of yellowfin in the north-western and central-western Coral Sea could be the major source of recruits for the tuna fisheries off the eastern coast of Australia.
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Gray, CA, DJ McElligott e RC Chick. "Intra- and inter-estuary differences in assemblages of fishes associated with shallow seagrass and bare sand". Marine and Freshwater Research 47, n.º 5 (1996): 723. http://dx.doi.org/10.1071/mf9960723.
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Differences in the assemblages of fishes associated with the seagrass Zostera capricorni and bare sand were assessed across eight estuaries spanning 300 km of the coast of northern New South Wales, Australia. Assemblages consistently differed between habitats in all estuaries, as species affinities within each habitat were relatively consistent. A greater diversity and abundance of fishes generally occurred over seagrass than over sand. Great variation in the abundances of individual species was evident but there were no consistent geographic (inter-estuary) effects. The abundances of most species varied as much between locations (0.5-2.0 km apart) within each estuary as among estuaries (15-300 km apart). Juveniles of economically important species occurred over seagrass (e.g. Rhabdosargus sarba, Acanthopagrus australis, Girella tricuspidata) and sand (e.g. Sillago ciliata). Before the true value of different nursery habitats to fisheries resources can be identified, the contribution of the juvenile fishes residing in the different nursery habitats to future (exploited) populations needs to be quantified.
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Pollard, D. A. "A Comparison of Fish Assemblages and Fisheries in Intermittently Open and Permanently Open Coastal Lagoons on the South Coast of New South Wales, South-Eastern Australia". Estuaries 17, n.º 3 (setembro de 1994): 631. http://dx.doi.org/10.2307/1352411.
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Pepperell, J. G. "Possible impacts of the greenhouse effect on the distribution and fisheries of pelagic fishes off south-eastern Australia." Wetlands Australia 10, n.º 1 (7 de janeiro de 2010): 40. http://dx.doi.org/10.31646/wa.136.
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Gray, Charles A. "Spatial variation in by-catch from a prawn seine-net fishery in a south-east Australian coastal lagoon". Marine and Freshwater Research 52, n.º 7 (2001): 987. http://dx.doi.org/10.1071/mf00121.
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Observer-based estimates of the catches and by-catches from prawn seining (locally termed ‘snigging’) in Tuggerah Lake (NSW, Australia) during the 1998/99 fishing season are presented. Observed catches included three species of penaeid prawns, while observed by-catches contained a total of 49 finfish and 5 invertebrate taxa. The overall by-catch:prawn catch ratio by weight was 0.9:1, and in catching an estimated 20 ± 4 t of prawns the fleet took an estimated total by-catch of ± 2 t throughout the 6-month fishing season. The by-catch included large numbers of small (<15 cm total length) finfish species important in other commercial and recreational fisheries, including Gerres subfasciatus,Rhabdosargus sarba and Acanthopagrus australis, as well as several small demersal species of little economic value. Multivariate analyses indicated that by-catch composition differed between seines taken over shallow seagrass and bare substrata, with catch rates of several species being greater over seagrass. It is recommended that strategies to reduce potential ecological impacts and by-catch in this fishery be investigated, including fixed spatial closures over seagrasses and the development of alternative fishing gears and practices.
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Gehrke, Peter C., e John H. Harris. "Large-scale patterns in species richness and composition of temperate riverine fish communities, south-eastern Australia". Marine and Freshwater Research 51, n.º 2 (2000): 165. http://dx.doi.org/10.1071/mf99061.
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Riverine fish in New South Wales were studied to examine longitudinal trends in species richness and to identify fish communities on a large spatial scale. Five replicate rivers of four types (montane, slopes, regulated lowland and unregulated lowland) were selected from North Coast, South Coast, Murray and Darling regions. Fishwere sampled during summer and winter in two consecutive years with standardized gear that maximized the range of species caught. The composition of fish communities varied among regions and river types, with little temporal variation. Distinct regional communities converged in montane reaches and diverged downstream. The fish fauna can be classified into North Coast, South Coast, Murray and Darling communities, with a distinct montane community at high elevations irrespective of the drainage division. Species richness increased downstream in both North Coast and South Coast regions by both replacement and the addition of new species. In contrast, species richness in the Darling and Murray regions reached a maximum in the slopes reaches and then declined, reflecting a loss of species in lowland reaches. The small number of species is typical of the freshwater fish faunas of similar climatic regions world-wide. Fish communities identified in this study form logical entities for fisheries management consistent with the ecosystem-focused, catchment-based approach to river management and water reform being adopted in Australia.
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MacKinnon, MR, e BW Herbert. "Temperature, dissolved oxygen and stratification in a tropical reservoir, Lake Tinaroo, Northern Queensland, Australia". Marine and Freshwater Research 47, n.º 7 (1996): 937. http://dx.doi.org/10.1071/mf9960937.
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Thermal and oxygen depth profiles in Lake Tinaroo were measured monthly at six sites over a two-year period from May 1988 to July 1990. Lake Tinaroo exhibits thermal layering throughout most of the year. Partitioning of the water column into an oxygenated epilimnion and a deoxygenated hypolimnion was well established by October each year. Breakdown of stratification occurred in late May to June and persisted until September. From October to May multiple thermoclines (diurnal, parent) developed, particularly during still weather. Localized disruption of stratification by oxygenated, cool, denser inflows during flood events in the catchment occurred during the rainy season. Thermocline tilting was noted after prolonged periods of south-easterly winds, with a deeper thermocline/oxycline at the north-western end of the lake. South-westerly winds had a corresponding effect on the north-east of the lake. The distribution of oxygenated water and deoxygenated water, affected by seasonal stratification, thermocline tilting, upwelling and flood-mediated disruption of stratification, is of importance to recreational fisheries and the location of water intake points for urban and domestic use. Lake Tinaroo has thermal characteristics of outer tropical rather than equatorial tropical lakes, owing in part to altitude effects.
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Shepherd, S. A., e L. D. Brown. "What is an Abalone Stock: Implications for the Role of Refugia in Conservation". Canadian Journal of Fisheries and Aquatic Sciences 50, n.º 9 (1 de setembro de 1993): 2001–9. http://dx.doi.org/10.1139/f93-224.
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This paper concerns the conservation of abalone stocks in a genetic and fisheries sense. We review genetic and ecological information relating to the differentiation of abalone stocks in South Australia and propose that metapopulation theory provides an apt framework in which to develop the concept of an abalone stock. We consider what is a minimum viable population for abalone and illustrate our discussion with a case study of an abalone population that declined through a combination of fishing, recruitment failure, and inadequate protection by a refugium. Refugia can play an important role in abalone conservation by maintaining egg production and genetic diversity and by preserving populations for scientific study.
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Mayfield, Stephen, Richard McGarvey, Ian J. Carlson e Cameron Dixon. "Integrating commercial and research surveys to estimate the harvestable biomass, and establish a quota, for an “unexploited” abalone population". ICES Journal of Marine Science 65, n.º 7 (26 de junho de 2008): 1122–30. http://dx.doi.org/10.1093/icesjms/fsn105.
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Abstract Mayfield, S., McGarvey, R., Carlson, I. J., and Dixon, C. 2008. Integrating commercial and research surveys to estimate the harvestable biomass, and establish a quota, for an “unexploited” abalone population. – ICES Journal of Marine Science, 65: 1122–1130. A key challenge facing many fisheries managers is the absence of information on the level of harvestable biomass. We describe an integrated, two-stage survey approach that was used to measure the spatial distribution and harvestable biomass of a largely unexploited metapopulation of greenlip abalone (Haliotis laevigata) over a large area of northwestern Spencer Gulf, South Australia. In stage 1, commercial fishers conducted systematic surveys to identify subareas with abalone at harvestable densities. Cpue measures from these surveys were used to map and stratify a bounded survey subregion, within which leaded-line, research-diver surveys measured absolute density and harvestable biomass (stage 2). Decision tables, showing minimum biomass at various probabilities vs. harvest fraction, were developed to provide a risk-assessment framework for quota setting. Within two years, our approach allowed, first, the mapping of the broad-scale, spatial distribution and abundance of greenlip abalone in an area of 1143 km2, second, the estimation of harvestable biomass in a smaller (16.9 km2) area, and finally, the allocation by State fishery managers of an additional quota inside a newly defined management subzone. The collaborative approach we describe for providing estimates of absolute biomass over large spatial scales affords multiple advantages for the assessment and management of invertebrate dive fisheries.
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Pollino, Carmel A., Pat Feehan, Michael R. Grace e Barry T. Hart. "Reply to the comment by Crook and Koster (2006) 'Temporal change in fish assemblages in the lower Goulburn River, south-eastern Australia'". Marine and Freshwater Research 57, n.º 3 (2006): 309. http://dx.doi.org/10.1071/mf05145.
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In an earlier paper, multivariate statistics were used on historic fisheries data sets to show spatial differences between fish communities in the Goulburn Catchment (Victoria, Australia). In this reply paper, some further statistical analyses are presented to provide evidence for the assertion that fish communities at each site were stable over the temporal scale of the data was valid. Indeed, evidence for the stabilisation and persistence of fish communities after a major disturbance has also been recognised in other studies. Furthermore, in making judgements about the stability and persistence of fish communities, the scale of a study is an important factor, with patterns at the catchment scale often not being the same as those at smaller spatial scales.
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Braccini, Matias, e Stephen Taylor. "The spatial segregation patterns of sharks from Western Australia". Royal Society Open Science 3, n.º 8 (agosto de 2016): 160306. http://dx.doi.org/10.1098/rsos.160306.
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The extent to which sharks segregate by size and sex determines the population structure and the scale at which populations should be managed. We summarized 20 years of fisheries-dependent and independent sampling to define the spatial patterns of size and sexual segregation for sharks in Western Australia. Carcharhinus obscurus and C. plumbeus showed a large-scale (more than 1000 km) latitudinal gradient in size. Large individuals occurred predominantly in the northwest and north whereas smaller individuals occurred predominantly in the southwest and south. Mustelus antarcticus and Furgaleus macki showed strong sexual segregation at very large scales. Females occurred predominantly in the west and southwest whereas the proportion of males in catches substantially increased in the southeast. The populations of other shark species did not show sex and size segregation patterns at very large scales; most species, however, showed varying degrees of segregation when data were analysed at a smaller scale. These findings highlight the importance of matching the scale of observation to the scale of the phenomenon observed. As many shark species are highly mobile, if sampling is opportunistic and constrained both temporally and spatially, the observed segregation patterns may not be representative of those at the population level, leading to inaccurate scientific advice.
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Appleford, P., T. A. Anderson e G. J. Gooley. "Reproductive cycle and gonadal development of Macquarie perch, Macquaria australasica Cuvier (Percichthyidae), in Lake Dartmouth and tributaries of the Murray - Darling Basin, Victoria, Australia". Marine and Freshwater Research 49, n.º 2 (1998): 163. http://dx.doi.org/10.1071/mf97012.
Texto completo da fonteResumo:
The gonadal development, reproductive cycle and growth of Macquarie perch, Macquaria australasica Cuvier, in Lake Dartmouth and selected tributaries of the Murray–Darling River Basin in south-eastern Australia were evaluated. Gonadosomatic index (GSI) and histological analysis were used to determine gonadal development and age and size at first maturity in the resident Lake Dartmouth population. GSI analysis was also used to determine age and size of Macquarie perch at first maturity in the inflowing Mitta Mitta River and other riverine populations within the Goulburn River catchment. Males appeared slightly smaller at first spawning than females at all sites; both sexes were fully mature at four years of age. Differences in size at first maturity were found between the lake and river populations; both males and females of river populations tended to mature at a much smaller size than the fish resident in the lake. Spawning occurred around November. Ovarian and testicular development in this species follows a pattern similar to that of other native Australian percichthyids. The implications for management of recreational fisheries based on minimum size regulations is discussed in relation to site-specific differences in growth rates and size of first maturity of fish.