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1
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. 2 (2017): 207. http://dx.doi.org/10.1071/mf15369.
Testo completoAbstract (sommario):
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.
2
McMillan, M. N., C. Huveneers, J. M. Semmens e B. M. Gillanders. "Partial female migration and cool-water migration pathways in an overfished shark". ICES Journal of Marine Science 76, n. 4 (5 dicembre 2018): 1083–93. http://dx.doi.org/10.1093/icesjms/fsy181.
Testo completoAbstract (sommario):
Abstract Knowledge about reproductive movements can be of important conservation value for over-exploited species that are vulnerable when moving between and within key reproductive habitats. Lack of knowledge persists around such movements in the overfished school shark Galeorhinus galeus in Australia. Management assumes all pregnant females migrate between adult aggregations in the Great Australian Bight, South Australia, and nursery areas around Bass Strait and Tasmania. We tracked 14 late-term pregnant females tagged in South Australia using satellite-linked pop-up archival tags to investigate extent, timing, and routes of migrations. We found partial migration, with some females (n = 7) remaining near aggregating areas throughout the pupping season, some migrating to known nursery areas (n = 3), and one migrating ∼3 000 km to New Zealand. We conclude female movements and pupping habitats are less spatially constrained than assumed and propose females use cool-water routes along the shelf break to reduce energy costs of migration. Migrating females using these routes faced greater fishing pressure than sharks in inshore areas and were not protected by inshore shark fishing closures designed to protect them. This study demonstrates the complexity of reproductive movements that can occur in wide-ranging species and highlights the value of explicit movement data.
3
Lowry, Michael, e Jeff Murphy. "Monitoring the recreational gamefish fishery off south-eastern Australia". Marine and Freshwater Research 54, n. 4 (2003): 425. http://dx.doi.org/10.1071/mf01269.
Testo completoAbstract (sommario):
The east coast Australian gamefish fishery is a diverse, multi-species fishery that targets billfish, sharks, tuna and other pelagic fish along the east Australian seaboard. A Gamefish Tournament Monitoring Program (GTMP) was undertaken, and 39021 angler trips from 1996 to 2000 were analysed. The program reports on trends in fishing effort, catch rates, catch composition, proportions of captures tagged and released and spatial distribution of catches for the principal recreational billfish species: black marlin (Makaira indica), striped marlin (Tetrapterus audax) and blue marlin (Makiara nigricans).The GTMP was principally designed as part of an integrated program to monitor the recreational gamefish fishery. The spatial and temporal design of the program restricted statistical analyses however, there were trends in fishing effort, directed effort, catch rates, catch composition, proportions of fish tagged and spatial distribution of catches for the principal recreational billfish species over seven successive years (1994–2000). Analysis of catch data, stratified by directed effort, indicated significant differences in catches of target species, demonstrating the importance of calculating catch rate estimates according to the main target preference. Analysis of tournament based tagging information indicated that while overall tournament tagging rates remained high (88%) there were significant differences in the number of fish tagged between species groups highlighting the impact that angler attitude and the competition point score structure has on the harvest of gamefish target species.
4
Barton, Diane P., Laura Taillebois, Jonathan Taylor, David A. Crook, Thor Saunders, Mark Hearnden, Alan Greig et al. "Stock structure of Lethrinus laticaudis (Lethrinidae) across northern Australia determined using genetics, otolith microchemistry and parasite assemblage composition". Marine and Freshwater Research 69, n. 4 (2018): 487. http://dx.doi.org/10.1071/mf17087.
Testo completoAbstract (sommario):
The grass emperor Lethrinus laticaudis is a conspicuous element of the commercial and recreational catch from nearshore reef systems across northern Australia. The nearshore reef systems across northern Australia are exposed to increasing levels of fishing pressure from commercial and recreational fishers. To inform ongoing management of this species, the present study examined the stock structure of L. laticaudis across northern Australia using a combination of complementary techniques. In all, 342 L. laticaudis samples were collected from 13 locations in the coastal waters of northern Australia ranging from the Pilbara region of Western Australia to Moreton Bay in south-east Queensland. Population genetic analyses using microsatellite markers demonstrated that there were at least four genetically distinct populations across northern Australia with gene flow between management jurisdictions (with significantly more separation between Western Australian and Northern Territory locations than between Northern Territory and Queensland locations). An isolation by distance effect was evident (genetic differences increasing linearly with distance). Otolith microchemistry and parasitology analyses indicated some spatial structuring of populations within broader regions. These findings of restricted connectivity at small spatial scales suggest that L. laticaudis is vulnerable to localised depletion in areas where fishing effort is concentrated. This conclusion is consistent with recent observations of fishery declines in heavily fished locations.
5
Steele, Dominic. "Fishing in Port Jackson, New South Wales–more than met the eye". Antiquity 69, n. 262 (marzo 1995): 47–60. http://dx.doi.org/10.1017/s0003598x00064292.
Testo completoAbstract (sommario):
Contemporary diaries and the water-colours of artists such as the Port Jackson Painter vividly tell of Aboriginal life when the First Fleet in 1788 settled its cargo of convicts in Australia. Fishing was important around the waters of Port Jackson, whose Aboriginal inhabitants are recorded to have used the techniques of spear-fishing and angling. Were other methods also used? Fish remains from a shell midden provide an opportunity to investigate.
6
Stevens, JD. "Blue and Mako Shark by-catch in the Japanese Longline Fishery off South-eastern Australia". Marine and Freshwater Research 43, n. 1 (1992): 227. http://dx.doi.org/10.1071/mf9920227.
Testo completoAbstract (sommario):
During the last 10 years, up to 70 Japanese longline vessels have fished Tasmanian waters of the Australian Fishing Zone each season, targeting bluefin tuna (Thunnus maccoyii). The average seasonal fishing effort in Tasmanian waters is about 3.3 million hooks, and data from observers suggests that, this results in a by-catch of some 34 000 blue sharks (Prionace glauca) each year, representing a weight of about 275 tonnes. In the last few years, fishing effort has increased as the catch rates of southern bluefin tuna have declined. The sharks are discarded after removal of the fins. The actual number of blue sharks hooked is much higher than 34000 because many are released by either shaking or cutting them off the line, although they are often damaged in the process. The majority of blue sharks caught are immature or adolescent females. Smaller numbers of shortfin mako sharks (Isurus oxyrinchus) are also caught and retained both for their fins and their meat. Tasmanian waters represent only one area of the Australian Fishing Zone fished by Japanese longliners.
7
THIRUMARAISELVI, Ramakrishnan, e Muthusamy THANGARAJ. "Genetic Diversity Analysis of Indian Salmon, Eleutheronema tetradactylum from South Asian Countries Based on Mitochondrial COI Gene Sequences". Notulae Scientia Biologicae 7, n. 4 (13 dicembre 2015): 417–22. http://dx.doi.org/10.15835/nsb749668.
Testo completoAbstract (sommario):
Eleutheronema tetradactylum is an important commercial fish species exposed to intense exploitation both in Southeast Asian countries and Northern parts of Australia. Research on the population structure of E. tetradactylum in these coastal waters is substantial in order to ensure sustainable use and appropriate resource management. In this study, genetic variation, diversity and population structure of E. tetradactylum among four FAO fishing areas, along South Asian countries, were evaluated using cytochrome c oxidase subunit I (COI) gene. Totally 30 sequences of COI gene were collected from four FAO fishing areas. Among these 30 individuals, 18 distinct haplotypes were defined. High levels of haplotype diversity (hd = 0.952 ± 0.096) and nucleotide diversity (π = 0.01536 ± 0.00312) were observed in the population within the Bay of Bengal. No haplotype and nucleotide diversity were observed in South China Sea population. Hierarchical analysis of molecular variance (AMOVA) indicated that 0.81% of the genetic variation occurred within the populations, while 7.09% variation occurred among populations. Significant genealogical branches were recognized in North Australian populations (one clade), South China Sea populations (one clade), Arabian Sea and Bay of Bengal populations (one clade) on the neighbor-joining tree. These results suggested that E. tetradactylum populations in FAO fishing areas 51, 57 and 61 have developed different genetic structures. Tests of neutral evolution and mismatch distribution suggest that a population growth of E. tetradactylum may take place in these fishing areas.
8
Harvey, Alison. "A Fishing Legend of the Jaralde Tribe of Lake Alexandrina, South Australia". Mankind 3, n. 4 (10 febbraio 2009): 108–12. http://dx.doi.org/10.1111/j.1835-9310.1943.tb00162.x.
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9
Freeman, Clive, Julie Freeman e Michelle C. Langley. "Gymea and the Fishing Technologies of the New South Wales Coast, Australia". Cambridge Archaeological Journal 31, n. 2 (5 febbraio 2021): 305–12. http://dx.doi.org/10.1017/s0959774320000396.
Testo completoAbstract (sommario):
Stories are important to all modern peoples, and this behaviour was no doubt also the case during the deep past. Consequently, it is important that archaeologists understand that artefacts made and discarded thousands of years ago were woven with stories by the peoples who produced them. In some regions of the world, these stories remain accessible by collaborating with the Traditional Owners of the lands from which they were recovered, while in others such an approach is impossible. Nevertheless, researchers need to remember that items carried meaning usually invisible to those outside communities—a principle often taught and cited, but possibly not fully appreciated. Here we tell the Yuin (coastal New South Wales, Australia) story of Gymea and her connection to fishing technologies. This story is told in order to demonstrate the depth of information that is not accessible to archaeologists if Indigenous collaborators are not sought out or available.
10
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. 6 (2015): 493. http://dx.doi.org/10.1071/mf14041.
Testo completoAbstract (sommario):
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.
11
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 agosto 2018): e5306. http://dx.doi.org/10.7717/peerj.5306.
Testo completoAbstract (sommario):
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.
12
Bansemer, C. S., e M. B. Bennett. "Retained fishing gear and associated injuries in the east Australian grey nurse sharks (Carcharias taurus): implications for population recovery". Marine and Freshwater Research 61, n. 1 (2010): 97. http://dx.doi.org/10.1071/mf08362.
Testo completoAbstract (sommario):
Incidental hooking of Carcharias taurus is a threat to their populations’ recovery on the east coast of Australia. Photo-identification techniques were used to investigate the frequency of hooking at 25 aggregation sites along the east coast of Australia between 2006 and 2008. Of the 673 sharks identified, 113 sharks were identified with signs of 119 incidences of hooking. For sharks with both their left and right flank photographed during a single survey day, up to 29% of females and 52% of males were identified with retained fishing gear or an attributed jaw injury. The largest number of sharks identified (222) were from a year-round aggregation of immature and mature sharks at Fish Rock, New South Wales, Australia. Forty-eight per cent of all sharks identified with retained fishing gear were first identified at this site. Fish Rock, a designated critical habitat for C. taurus, allows most forms of line fishing except fishing with bait or wire trace while anchored or moored. As interactions with fishing gear can result in debilitating disease, morbidity and death, the high incidence of hooked individual C. taurus is considered a key threatening process that is likely to reduce this shark population’s ability to recover.
13
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. 7 (2001): 987. http://dx.doi.org/10.1071/mf00121.
Testo completoAbstract (sommario):
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.
14
Klaer, N. L. "Steam trawl catches from south-eastern Australia from 1918 to 1957: trends in catch rates and species composition". Marine and Freshwater Research 52, n. 4 (2001): 399. http://dx.doi.org/10.1071/mf00101.
Testo completoAbstract (sommario):
Haul-by-haul steam trawler catch and effort data for 1918–23, 1937–43 and 1952–57, which cover a large portion of the history of steam trawling in the Australian South East Fishery, were examined in detail for the first time. There were 64371 haul records in total. The catch-rate for all retained catch combined shows a strong decline overall, with a brief recovery during World War II, probably due to increased retention of previously discarded species. The fishing fleet moved to more distant fishing grounds and deeper waters as the catch-rate declined. The catch-rates of the main commercial species followed a similar pattern in a number of regions within the fishery. The catch-rate of the primary target species – tiger flathead (Neoplatycephalus richardsoni) – dropped considerably from the early, very high, catch-rates. Chinaman leatherjacket (Nelusetta ayraudi) and latchet (Pterygotrigla polyommata) – species that were apparently abundant in the early years of the fishery, virtually disappeared from catches in later years. The appearance of greater catches of jackass morwong (Nemadactylus macropterus), redfish (Centroberyx affinis) and shark/skate during the war and afterwards was probably due to increased retention of catches of these species. The disappearance of certain species from the catch may be due to high fishing pressure alone, or to a combination of fishing pressure, changes in the shelf habitat possibly caused by the trawl gear, and environmental fluctuations.
15
Dortch, C. E. "New perceptions of the chronology and development of Aboriginal fishing in South‐Western Australia". World Archaeology 29, n. 1 (giugno 1997): 15–35. http://dx.doi.org/10.1080/00438243.1997.9980361.
Testo completo
16
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. 3 (10 giugno 2019): 1190–205. http://dx.doi.org/10.1093/icesjms/fsz092.
Testo completoAbstract (sommario):
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.
17
Knuckey, Ian A., e K. P. Sivakumaran. "Reproductive characteristics and per-recruit analyses of blue warehou (Seriolella brama): implications for the South East Fishery of Australia". Marine and Freshwater Research 52, n. 4 (2001): 575. http://dx.doi.org/10.1071/mf00022.
Testo completoAbstract (sommario):
Monthly samples of commercial catches of S. brama were collected between May 1996 and December 1997 in three regions of the fishery:off the east coast of Victoria; eastern Tasmania; and western Bass Strait. Sex ratio, gonadosomatic index, macroscopic and histological development, size at maturity and fecundity were estimated and combined with data on growth and mortality to perform per-recruit analyses. The main spawning period was during winter–spring and there was evidence of spawning in each of the three regions. Blue warehou reach maturity at 30–40 cm fork length. They have a determinate annual fecundity and spawn around three batches of eggs during a season. Eggs-per-recruit analyses revealed maximum egg production at ~40 cm (4–5 years) in an unfished population. Gill-net fishing, which targets fish >45 cm, was less likely to affect the relative eggs-per-recruit in a population than trawl fishing, which catches a wider range of smaller fish. These results are discussed in light of the current management arrangements in the fishery and will be used in models to assess the effect of fishing on the long-term sustainability of the blue warehou.
18
Linnane, A. J., S. S. Penny e T. M. Ward. "Contrasting fecundity, size at maturity and reproductive potential of southern rock lobster Jasus edwardsii in two South Australian fishing regions". Journal of the Marine Biological Association of the United Kingdom 88, n. 3 (maggio 2008): 583–89. http://dx.doi.org/10.1017/s0025315408001021.
Testo completoAbstract (sommario):
The annual commercial catch from the Southern Zone of the South Australian rock lobster (Jasus edwardsii) fishery is ~1900 tonnes, representing ~50% of total landings from south-east Australia. A single minimum legal size (MLS) of 98.5 mm carapace length (CL) exists across the entire zone. Fecundity (F), size at onset of maturity (SOM) and relative reproductive potential (RRP) of female rock lobsters were investigated in two major fishing regions, i.e. the North Southern Zone (NSZ) and South Southern Zone (SSZ) with a view to providing a basis for future fine-scale spatial management of the resource. F ranged from 45,292 to 466,800 eggs per female and increased proportionally with CL according to the relationship: F = 0.0584 × CL3.1642. F was significantly higher in the NSZ compared to the SSZ but was attributed to differences in lobster size between regions. There was no significant difference in the number of eggs · g−1 of egg mass between areas. SOM, estimated as the size at which 50% of females reached sexual maturity (L50) was higher in the NSZ (104.1 mm CL) compared to SSZ (92.3 mm CL). Approximately 20% of lobsters above the MLS in the commercial catch in the NSZ were under the L50 estimate. RRP, as a measure of egg production, was calculated for each size-class from the product of F, SOM and population length–frequency. The modal RRP size-classes in the NSZ were 117.5–122.5 mm CL, while in the SSZ it was 97.5–102.5 mm CL. Only 6% of RRP was contributed by female rock lobsters below the MLS in the NSZ, compared to 34% in the SSZ. Regional differences in SOM and RRP in the Southern Zone of South Australia suggest that different MLSs may be beneficial, particularly if the fishery is to be effectively managed at finer spatial scales.
19
Fowler, A. J., M. A. Steer, W. B. Jackson e M. T. Lloyd. "Population characteristics of southern sea garfish (Hyporhamphus melanochir, Hemiramphidae) in South Australia". Marine and Freshwater Research 59, n. 5 (2008): 429. http://dx.doi.org/10.1071/mf07230.
Testo completoAbstract (sommario):
Population dynamics, demography and spatial distribution of an important species of ‘halfbeak’, the southern sea garfish (Hyporhamphus melanochir), were studied in South Australia, which accounts for most of the national catch. Commercial catch and effort data were used to indicate spatial and temporal abundance. Catch sampling provided fish measurements and estimates of age, sex and reproductive maturity. Catches were from throughout South Australia’s gulf region, but three areas separated by hundreds of kilometres produced the highest catches. These relatively protected areas support extensive beds of intertidal and subtidal seagrasses. Statewide commercial fishery catches demonstrated considerable inter-annual variation of 240–320 t year–1. Catches were dominated by 1+ and 2+ fish, with few individuals from the 3+ to 5+ age classes. Females dominated the sex ratios, were the largest individuals, and the largest from each age class. No running ripe fish were sampled. Seasonal variation in the catch and in the lack of spawning fish suggested that adults might move from fishing areas during the spawning season. Length/weight and length/age relationships did not differ between areas separated by hundreds of kilometres, suggesting large-scale movement. Possible population truncation related to fishery exploitation has prompted a stock rebuilding program for the South Australian stock.
20
Foster, Scott D., Piers K. Dunstan, Franziska Althaus e Alan Williams. "The cumulative effect of trawl fishing on a multispecies fish assemblage in south-eastern Australia". Journal of Applied Ecology 52, n. 1 (3 ottobre 2014): 129–39. http://dx.doi.org/10.1111/1365-2664.12353.
Testo completo
21
Connor, Robin, e Dave Alden. "Indicators of the effectiveness of quota markets: the South East Trawl Fishery of Australia". Marine and Freshwater Research 52, n. 4 (2001): 387. http://dx.doi.org/10.1071/mf99164.
Testo completoAbstract (sommario):
This paper presents some results of an investigation into potential indicators for the assessment of markets for individual transferable fishing quota where price data do not exist. The economic logic for implementing such markets and how they are expected to work is used as a basis for asking questions about how well they are performing, and what might comprise evidence of problems. Given data on quota ownership, transfer and leasing, and associated catches, but no quota price data, indicators are suggested for monitoring and analysing market activity. These are applied to data from the Australian South East Trawl Fishery. Results are discussed in terms of the utility of the methods and the implications for management policy for the fishery.
22
Shaughnessy, PD, e SR Davenport. "Underwater videographic observations and incidental mortality of fur seals around fishing equipment in south-eastern Australia". Marine and Freshwater Research 47, n. 3 (1996): 553. http://dx.doi.org/10.1071/mf9960553.
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Mitchell, Rebecca J., Lauren Ware e Mike R. Bambach. "The role of evidence, standards and education in rock fishing safety in New South Wales, Australia". Australian and New Zealand Journal of Public Health 38, n. 6 (28 agosto 2014): 579–84. http://dx.doi.org/10.1111/1753-6405.12247.
Testo completo
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Alleway, Heidi K., Ruth H. Thurstan, Peter R. Lauer e Sean D. Connell. "Incorporating historical data into aquaculture planning". ICES Journal of Marine Science 73, n. 5 (2 novembre 2015): 1427–36. http://dx.doi.org/10.1093/icesjms/fsv191.
Testo completoAbstract (sommario):
Abstract Marine historical research has made progress in bridging the gap between science and policy, but examples in which it has been effectively applied remain few. In particular, its application to aquaculture remains unexplored. Using actual examples of natural resource management in the state of South Australia, we illustrate how historical data of varying resolution can be incorporated into aquaculture planning. Historical fisheries records were reviewed to identify data on the now extinct native oyster Ostrea angasi fishery throughout the 1800 and early-1900s. Records of catch, number of boats fishing, and catch per unit effort (cpue) were used to test fishing rates and estimate the total quantity of oysters taken from select locations across periods of time. Catch quantities enabled calculation of the minimum number of oysters per hectare for two locations. These data were presented to government scientists, managers, and industry. As a result, interest in growing O. angasi increased and new areas for oyster aquaculture were included in regulatory zoning (spatial planning). Records of introductions of the non-native oyster Saccostrea glomerata, Sydney rock oysters, from 1866 through 1959, were also identified and used to evaluate the biosecurity risk of aquaculture for this species through semi-quantitative risk assessment. Although applications to culture S. glomerata in South Australia had previously been declined, the inclusion of historical data in risk assessment led to the conclusion that applications to culture this species would be accepted. The examples presented here have been effectively incorporated into management processes and represent an important opportunity for the aquaculture industry in South Australia to diversify. This demonstrates that historical data can be used to inform planning and support industry, government, and societies in addressing challenges associated with aquaculture, as well as natural resource management more broadly.
25
Raoult, V., V. Peddemors, K. Rowling e J. E. Williamson. "Spatiotemporal distributions of two sympatric sawsharks (Pristiophorus cirratus and P. nudipinnis) in south-eastern Australian waters". Marine and Freshwater Research 71, n. 10 (2020): 1342. http://dx.doi.org/10.1071/mf19277.
Testo completoAbstract (sommario):
Sawsharks are one of the least well-known groups of sharks globally, yet they are caught in large numbers in south-eastern Australia. In this study we assessed spatiotemporal patterns of distribution of two co-occurring species of sawsharks, namely the common sawshark (Pristiophorus cirratus) and the southern sawshark (Pristiophorus nudipinnis), to guide future research in this area. To identify where the animals may occur in greater numbers, this study used the major commercial fishery datasets in the region, containing nearly 180000 catch records from 1990 to 2017. Several general patterns were evident. Sawsharks occurred at shallower and deeper depths than previously thought, and their geographical range was larger than documented in previous studies. Depth distributions of both species overlapped, but P. cirratus appeared more common in deeper water (at depths up to 500m), with peak common sawshark catch rates at ~400m. Seasonal standardised catch patterns across fishing methods suggested that migrations from deeper to shallower waters may occur in the Australasian autumn and winter. The greatest concentration of sawsharks, inferred by standardised catch rates, occurred to the east and west of Bass Strait between Tasmania and mainland Australia. Although standardised catch rates of sawsharks declined in gill-net fisheries by ~30%, primarily in the Bass Strait and Tasmania, sawsharks appear to be caught at consistent rates since the 1990s, inferring a possible resilience of these sharks to current levels of fishing pressure.
26
Bills, Kym. "Building a world-class Australian decommissioning industry". APPEA Journal 58, n. 2 (2018): 690. http://dx.doi.org/10.1071/aj17154.
Testo completoAbstract (sommario):
Collaboration in decommissioning offshore infrastructure could save both industry and taxpayers billions of dollars and facilitate new industries and exports for Australia, especially in the Asia-Pacific region. At the end of the liquefied natural gas (LNG) plant construction boom, Australia must not miss out on this major new opportunity. The 2017 bid for Commonwealth funding to establish a Decommissioning Offshore Infrastructure Cooperative Research Centre (DOI-CRC) involved more than 30 participants and many other collaborators. High-level commitments were made by Chevron, Woodside, Shell, BHP, ExxonMobil, Quadrant, The University of Western Australia, Curtin University, the University of New South Wales, Deakin University, Australian Maritime College, CSIRO and Australian Institute of Marine Science. A Perth-based DOI-CRC was supported by National Energy Resources Australia, National Offshore Petroleum Safety and Environmental Management Authority and other Australian Government bodies and by the Western Australian Government and its Chief Scientist and agencies but did not receive sufficient support from the CRC Advisory Committee. Meeting decommissioning challenges in the North West Shelf, Bass Strait and the Northern Territory in a timely, robust, scientific, efficient and cost-effective manner that contributes to a sustainable marine environment should draw upon and augment international best practice with local capability and expertise. Good science and innovative engineering are needed to support regulatory approval of options such as ‘rigs to reefs’ and commercial opportunities such as in waste management and expanded fishing and tourism. APPEA and operators wish to maintain DOI-CRC’s momentum and learn from UK research arrangements through funding marine science projects. But we must be much broader if we are to build a sustainable world-class Australian decommissioning industry. In particular, we need to work more closely with state and federal regulators and policymakers and undertake more engineering science research and innovation.
27
McGlennon, David, G. Keith Jones, Janine Baker, W. Bruce Jackson e Martine A. Kinloch. "Ageing, catch-at-age and relative year-class strength for snapper (Pagrus auratus) in northern Spencer Gulf, South Australia". Marine and Freshwater Research 51, n. 7 (2000): 669. http://dx.doi.org/10.1071/mf98095.
Testo completoAbstract (sommario):
Commercial landings of Pagrus auratus declined to 25-year lows in South Australia in 1994, and sustainability of the fishery was questioned. This study investigated two potential explanations for the decline – changes in fishing effort and recruitment variability. Data for 1983–97 from northern Spencer Gulf, which contributes the majority of snapper catches in the State, showed that 74% of the variance in targeted catch was explained by catch per unit effort, and 20% by fishing effort. Recruitment variability was examined by analysis of age structures of the commercial catch. An ageing procedure was established by examining sectioned sagittal otoliths of 1046 snapper caught in 1991 and 1994/5; their use was first evaluated by assessing the bias and precision of multiple readings and by comparing annulus counts with ring counts from scales. The timing of annulus formation was determined by marginal increment analysis. Interpretation of the age structures suggests that year-class strength is highly variable and has a strong influence on catch patterns in the commercial fishery. A qualitative comparison of temperature with year-class strength did not show a strong relationship.
28
Ward, Tim M., David C. Smith, Rod Lukatelich, Rob Lewis, Gavin A. Begg e Rochelle Smith. "INTEGRATED APPROACH TO ECOLOGICAL AND SOCIO-ECONOMIC RESEARCH TO SUPPORT THE OIL AND GAS INDUSTRY: THE GREAT AUSTRALIAN BIGHT COLLABORATIVE RESEARCH SCIENCE PROGRAM". International Oil Spill Conference Proceedings 2014, n. 1 (1 maggio 2014): 2193–205. http://dx.doi.org/10.7901/2169-3358-2014.1.2193.
Testo completoAbstract (sommario):
ABSTRACT BP is investing $A1.43B and drilling four exploratory wells in the hope of discovering a new deep-water oil and gas province in the Great Australia Bight (GAB). The GAB is one of Australia's most valuable marine ecosystems. It supports globally significant populations of seabirds and marine mammals, diverse and endemic benthic assemblages and important fishing, aquaculture and ecotourism industries. Two research agencies (CSIRO, South Australian Research and Development Institute) and two universities (University of Adelaide, Flinders University of South Australia) recently entered into a collaborative research partnership with BP Australia to undertake an integrated study of the ecological processes and socio-economic importance of the GAB. Uniquely, this four year $20M research program is being undertaken during the exploration phase and conducted as a single integrated program. The Research Program is comprised of seven themes: physical oceanography; pelagic ecosystem and environmental drivers; benthic biodiversity; ecology of iconic and apex predators; petroleum geology and geochemistry; socio-economic values; and data integration and ecosystem modelling. Sixteen inter-related projects are being undertaken by some of Australia's leading marine scientists and will involve at least seven post-graduate Ph.D. students. Scientific quality assurance is provided by a review process that involves an Independent Science Panel and BP's international Subject Matter Experts. Ecological data collected during the study will be publically available. Findings will be presented to stakeholders and regulators and published in technical reports and scientific papers throughout the course of the program. The program is one of the few whole of system studies ever undertaken in Australia and is the first large-scale, integrated study of the ecosystems, resources and socio-economic values of the GAB. The approach has several advantages over undertaking discrete projects on key issues near the start of the production phase.1)BP Australia's financial contribution has leveraged significant investment from the other partners.2)Establishing baseline environmental conditions during the exploration phase provides the opportunity to conduct temporally replicated analyses of the ecosystem prior to commencement of production, should it occur.3)Engaging with the local scientific community builds on the existing knowledge base and working relationships with stakeholders and will assist the development of relevant local scientific capability.4)An integrated program provides for efficient development and validation of whole of system (i.e. ecological and socio-economic) models that elucidate interconnections among components of the system and can inform decisions regarding future development and predict, monitor and assess potential future impacts.
29
McLeay, Lachlan, Adrian Linnane, Richard McGarvey, Simon Bryars e Peter Hawthorne. "Response of a southern rock lobster (Jasus edwardsii) population to three years of Marine Protected Area implementation within South Australia". Journal of the Marine Biological Association of the United Kingdom 101, n. 1 (21 gennaio 2021): 141–49. http://dx.doi.org/10.1017/s0025315420001332.
Testo completoAbstract (sommario):
AbstractThe Western Kangaroo Island Marine Park (WKIMP) was declared as part of South Australia's representative system of Marine Protected Areas in 2009. Sanctuary Zone 3 (SZ-3) of the WKIMP is a no-take area protected from fishing since 1 October 2014 and is located within the Northern Zone Rock Lobster Fishery (NZRLF). In February 2017, a dedicated survey was undertaken to estimate the relative abundance (catch per unit effort (CPUE), kg/potlift) and size of southern rock lobster (Jasus edwardsii) inside and outside SZ-3. Survey results were then compared with historical estimates of abundance and size obtained from commercial fishery-dependent data. Survey estimates of relative abundance of legal-size lobsters were 4.4 times greater inside SZ-3 compared with outside in 2017. Since 2014, when fishing was last permitted inside SZ-3, the relative abundance of lobsters increased by 75%. The mean size of legal-size female and male lobsters also increased by 4.1% and 12.5%, respectively. The population responses recorded are consistent with the results recorded for southern rock lobster stocks in marine parks in other jurisdictions.
30
Larcombe, James W. P., Kevin J. McLoughlin e Richard D. J. Tilzey. "Trawl operations in the South East Fishery, Australia: spatial distribution and intensity". Marine and Freshwater Research 52, n. 4 (2001): 419. http://dx.doi.org/10.1071/mf99169.
Testo completoAbstract (sommario):
Trawl areas and intensities were mapped at coarse (22 km 1986–99)and fine (1 km 1995–99)scales, and statistics reported by area and depth stratum. Total effort in hours was relatively stable to 1992, then increased substantially to 1999. The total distance trawled from fine-scale analysis showed a similar trend for the 1995–99 period. Coarse-scale analysis from 1986–99 indicated effort increases in north-east Bass Strait in particular, and also off western Tasmania and west of Bass Strait. There was little change in the total area of the fishery from 1995 to 1999, but grid cells on the periphery showed considerable interannual variation in the presence or absence of fishing. Increased or redistributed effort tended to further concentrate in the relatively small high-effort areas, rather than increasing equally across the grounds, or spreading to new grounds. In the total management area, a small proportion of the 1 km grids was fished. However, in 200–1000 m depth strata, ≥50%of the grids were fished with some intensity. The consequences and compromises of spatial scale are discussed in terms of data quality, the use of trawl effort as a surrogate for marine disturbance, and the interpretation of catch rates.
31
Pepperell, JG. "Trends in the distribution, species composition and size of sharks caught by Gamefish Anglers off South-eastern Australia, 1961-90". Marine and Freshwater Research 43, n. 1 (1992): 213. http://dx.doi.org/10.1071/mf9920213.
Testo completoAbstract (sommario):
Records of shark captures were extracted from the archives of 10 of the major New South Wales gamefishing clubs that operate from ports located between latitudes 33�s and 37�s. Although organized game fishing began off eastern Australia in 1936, the majority of catches were made after 1960. Data normally recorded by these clubs included common name of shark, whole weight, locality of capture, boat name and angler. Recognized single species of sharks recorded by these clubs were blue (Prionace glauca), tiger (Galeocerdo cuvier), white (Carcharodon carcharias), shortfin mako (Isurus oxyrinchus) and grey nurse (Carcharias taurus). Species identified only to generic level, and recorded by clubs, were whalers or requiem sharks (Carcharhinus spp.), hammerheads (Sphyrna spp.) and threshers (Alopias spp.). Analysis of catch records indicated that the mako shark was the most common species caught overall, although whaler sharks dominated the catch in the northern part of the study area and hammerhead sharks dominated the catch in the south. Grey nurse and white sharks were relatively rare in the southern part of the study area. Whaler sharks dominated the catch in the 1960s, and the proportions of blue and tiger sharks in the catch increased in the 1980s. Size ranges and distributions of some species also varied through time and by area. Some of the observed changes could be attributed to changed fishing practices, particularly the increasing popularity of tag-and-release and an increasing tendency to fish further from the coast. A marked decline in the number and proportion of white sharks in the catch since the 1970s gives cause for some concern regarding the status of that species off south-eastern Australia.
32
Mountford, C. P. "Aboriginal Methods of Fishing and Cooking as used on the Southern Coast of Eyre's Peninsula, South Australia". Mankind 2, n. 7 (10 febbraio 2009): 196–200. http://dx.doi.org/10.1111/j.1835-9310.1939.tb00963.x.
Testo completo
33
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. 10 (2014): 884. http://dx.doi.org/10.1071/mf13246.
Testo completoAbstract (sommario):
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.
34
Filby, Nicole E., Mike Bossley e Karen A. Stockin. "Behaviour of free-ranging short-beaked common dolphins (Delphinus delphis) in Gulf St Vincent, South Australia". Australian Journal of Zoology 61, n. 4 (2013): 291. http://dx.doi.org/10.1071/zo12033.
Testo completoAbstract (sommario):
Common dolphins are subject to large-scale fishing activity and tourism operations in South Australia; however, there is a paucity of data on this species. Understanding the behaviour of a population can contribute greatly to our knowledge of a species and how to manage potential population-level threats. This paper describes the behaviour of short-beaked common dolphins (Delphinus delphis) in Australian waters for the first time. Data were collected from 109 independent dolphin groups during boat-based surveys conducted in Gulf St Vincent, South Australia, between September 2005 and May 2008. Activity budgets were used to assess behaviour of common dolphins in relation to diel patterns, season, water depth, sea surface temperature (SST), group size and composition. Foraging (33.9%) and resting (2.8%) were the most and least frequently observed behaviours, respectively. Travelling (33.0%), socialising (20.2%) and milling (10.1%) accounted for the remainder of the activity budget. Diurnal differences were detected, with foraging (59.5%) and socialising (31.8%) groups most frequently observed from 10.00 to 11.59 hours. Behaviour did not vary seasonally or with water depth, SST, group size or composition. Behaviour varied significantly between single- and multispecies aggregations. Foraging was more frequent in multispecies aggregations, as 78.4% of all foraging behaviour observed for common dolphins occurred in the presence of other species. Multispecies aggregations were most frequently observed with flesh-footed shearwaters (Puffinus carneipes), which were present during 29.4% of common dolphin encounters. Behaviour varied significantly during aggregations with shearwaters, as 62.2% of foraging groups occurred in the presence of shearwaters. Resting, milling or socialising was rarely observed in the presence of any other species, indicating that the primary mechanism for aggregations is likely prey-related.
35
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. 5 (1991): 465. http://dx.doi.org/10.1071/mf9910465.
Testo completoAbstract (sommario):
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.
36
Power, Hannah E., Michael A. Kinsela, Caio E. Stringari, Murray J. Kendall e David J. Hanslow. "WAVE OVERWASH ON A ROCK PLATFORM: REMOTE SENSING AND PRESSURE SENSOR OBSERVATIONS". Coastal Engineering Proceedings, n. 36 (30 dicembre 2018): 29. http://dx.doi.org/10.9753/icce.v36.waves.29.
Testo completoAbstract (sommario):
Open ocean rocky shore platforms are typically exposed to high wave energy and are often the location of recreational activities from sightseeing and walking to fishing (Kennedy et al. 2017). The exposure of these environments, combined with the use for recreation, results in a high level of risk for those who use the rock platform. In Australia, for example, 19% of coastal fatalities occur on rock coasts, most commonly when individuals fall from microtidal semi-horizontal platforms into the ocean (SLSA, 2014a,b). Managing the hazards and resultant risk on rocky shore platforms requires a different approach to that taken for sandy beaches as the sites are typically remote. Here we explore the wave overwash hazards on a remote but high visitation rocky shore platform 40 km south of Sydney, Australia.
37
Braccini, Matias, Simon de Lestang e Rory McAuley. "Dusky sharks (Carcharhinus obscurus) undertake large-scale migrations between tropical and temperate ecosystems". Canadian Journal of Fisheries and Aquatic Sciences 75, n. 9 (settembre 2018): 1525–33. http://dx.doi.org/10.1139/cjfas-2017-0313.
Testo completoAbstract (sommario):
Understanding the large-scale migrations of marine predators can allow better representation of their population dynamics. The migration biology of dusky sharks (Carcharhinus obscurus), a cosmopolitan large marine predator with very low resilience to fishing, was quantified using a large-scale network of acoustic receivers deployed across Western Australia. Time-series plotting of individual shark detections and modified logistic modelling were used to determine the timing of acoustically tagged sharks’ seasonal migration, the proportion of the population migrating, and the size at which sharks start to migrate. Large (>200 cm fork length) dusky sharks migrated between areas closed (north) and open (south) to commercial shark fishing. There was limited evidence that smaller sharks occurred in the northern study area, whereas several larger individuals of both sexes undertook repeated north–south displacements, moving between disparate ecosystems within the Indian Ocean (21.7°S–35.4°S) and covering round-trip distances of 2000–3000 km per migratory event. For migrating individuals, the probability of occurring in the north was high in the austral winter–spring and low (males) to moderate (females) during the austral summer–autumn.
38
Liggins, GW, SJ Kennelly e MK Broadhurst. "Observer-based survey of by-catch from prawn trawling in Botany Bay and Port Jackson, New South Wales". Marine and Freshwater Research 47, n. 7 (1996): 877. http://dx.doi.org/10.1071/mf9960877.
Testo completoAbstract (sommario):
Catches and by-catches were surveyed in the commercial prawn trawl fleets of Botany Bay and Port Jackson, two estuaries in the Sydney metropolitan area (NSW, Australia). Catches were surveyed in all tows during replicate fishing trips in each month during the 1990-91 and 1991-92 prawn trawl seasons in each estuary. Significant species-specific variabilities in abundances were detected between estuaries, between years, and between early and late in the fishing season. The mean annual ratio of by-catch to catch of prawns (by weight) was 2.5 : 1 for Botany Bay and 1.8 : 1 for Port Jackson. A mean annual by-catch (� 1 s.e.) of 142 � 14 t was taken from the Botany Bay fishery and 38 � 3 t from Port Jackson. These by-catches included large numbers of small recreationally and commercially important finfish: a mean annual by-catch of 1.52 �0.20 million fish from Botany Bay and 219� 23 thousand fish from Port Jackson. Despite uncertainties about the impacts of such by-catches on interacting commercial and recreational fisheries, it is recommended that strategies for the reduction of such by-catches be considered.
39
Broadhurst, Matt K., Russell B. Millar, Damian J. Young, Michael E. L. Wooden e Stuart Rowland. "Atypical size selection of captive school prawns,Metapenaeus macleayi, by three recreational fishing gears in south‐eastern Australia". New Zealand Journal of Marine and Freshwater Research 38, n. 5 (dicembre 2004): 755–66. http://dx.doi.org/10.1080/00288330.2004.9517275.
Testo completo
40
Momtaz, Salim, e William Gladstone. "Ban on commercial fishing in the estuarine waters of New South Wales, Australia: Community consultation and social impacts". Environmental Impact Assessment Review 28, n. 2-3 (febbraio 2008): 214–25. http://dx.doi.org/10.1016/j.eiar.2007.03.001.
Testo completo
41
Punt, A. E., D. C. Smith, R. B. Thomson, M. Haddon, X. He e J. M. Lyle. "Stock assessment of the blue grenadier Macruronus novaezelandiae resource off south-eastern Australia". Marine and Freshwater Research 52, n. 4 (2001): 701. http://dx.doi.org/10.1071/mf99136.
Testo completoAbstract (sommario):
The fishery can be divided into two subfisheries (‘spawning’ and ‘non-spawning’). Commercial catch rates for the ‘non-spawning’ subfishery declined from the late 1980s to 1997, whereas those for the ‘spawning’ subfishery exhibit no obvious temporal trend. An ‘Integrated Analysis’ assessment, of the feasibility of reconciling these differing trends, uses catch (landed and discarded), catch rate, length-at-age, and catch-at-age data and estimates of absolute abundance based on the egg-production method. It emphasizes uncertainty due to model assumptions and the data included in the assessment. Use of the discard data allows more precise estimation of the magnitude of recent recruitments. Spawning biomass is estimated to have declined from a peak in 1989–91 to 1999 although fishing mortality has consistently been <6%for each subfishery. One main reason for the reduction in population size is the weakness of year-classes spawned from 1988 to 1993. Differences in catch rates between the two subfisheries can therefore be explained by interactions between the components of the population harvested by the two ‘subfisheries’, and the trends in year-class strength. A risk analysis is used to evaluate the consequences of different future levels of harvest for different assessment assumptions. Overall, the spawning biomass is predicted to increase over the next five to ten years as a result of the strong 1994 and 1995 year-classes, although the extent of this increase remains uncertain.
42
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. 9 (1 settembre 1993): 2001–9. http://dx.doi.org/10.1139/f93-224.
Testo completoAbstract (sommario):
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.
43
Francis, Malcolm P., David Harasti e Hamish A. Malcolm. "Surviving under pressure and protection: a review of the biology, ecology and population status of the highly vulnerable grouper Epinephelus daemelii". Marine and Freshwater Research 67, n. 8 (2016): 1215. http://dx.doi.org/10.1071/mf15099.
Testo completoAbstract (sommario):
Epinephelus daemelii is a threatened serranid grouper species that is restricted to the south-western Pacific Ocean, ranging from eastern Australia to northern New Zealand and the Kermadec Islands. Declines in its abundance due to fishing pressure were reported as early as 1916. Aspects of this species’ biology and behaviour that make it vulnerable include its longevity, late age at maturity, protogynous hermaphroditism, territoriality and limited shallow reef habitat. Adults prefer complex habitat with caves and overhangs at depths of less than 50m, whereas juveniles live in rock pools, shallow intertidal reefs and estuaries. Epinephelus daemelii lives at least 65 years and reaches 170-cm total length. Individuals change sex from female to male at ~100–110cm and ~25 years. Absence of large (>100cm) fish across a large part of their range has implications for reproduction. Although nearly fully protected, incidental bycatch still occurs. A lack of long-term data hinders determination of population status, but abundance appears to be much lower than before, except in remote regions (Kermadec Islands, Elizabeth and Middleton reefs) with extensive no-fishing areas. Further prohibitions on fishing in key locations are likely to be important for the recovery and long-term survival of this species.
44
Dowling, Natalie A., Stephen J. Hall e Richard McGarvey. "Assessing population sustainability and response to fishing in terms of aggregation structure for greenlip abalone (Haliotis laevigata) fishery management". Canadian Journal of Fisheries and Aquatic Sciences 61, n. 2 (1 febbraio 2004): 247–59. http://dx.doi.org/10.1139/f03-165.
Testo completoAbstract (sommario):
The greenlip abalone (Haliotis laevigata) population in Waterloo Bay, South Australia, has undergone collapse and fishery closure twice since 1978. A rich data set, including survey measures of degree of spatial aggregation, has been gathered over that time and provides a unique opportunity to identify factors accounting for persistence or collapse, an issue that is of significance to abalone fisheries worldwide. Statistical analyses of fishery and survey data were undertaken to infer functional relationships between catch, effort, recruitment, adult density, and extent of aggregation. Catch rates were hyperstable, an observation consistent with the targeting of large aggregations. Statistical analysis of recruitment showed a significant year effect, implying an environmental signal, and suggested that aggregation size impacts fertilization success. Aggregation size grew under closure, suggesting an impact of fishing on this demographic feature. Aggregative behaviour appears to be critical for subpopulation sustainability. Fishery collapse may be triggered by depletion of larger abalone aggregations by heavy fishing, resulting in declines in fertilized egg production. When heavy fishing coincides with unfavourable environmental conditions, recruitment may be insufficient to sustain the subpopulation. If aggregation is similarly critical for other subpopulations, management strategies could be adapted according to the extent of aggregation in each subpopulation.
45
Simmons, B. L., e S. L. Trengove. "Impact of Catchment Urbanisation on Lake Macquarie (Australia)". Water Science and Technology 21, n. 2 (1 febbraio 1989): 205–10. http://dx.doi.org/10.2166/wst.1989.0051.
Testo completoAbstract (sommario):
Increasing urbanisation of coastal areas is leading to impacts on coastal lakes which decrease their amenity for recreation and tourism. Runoff and wastewater discharge cause siltation, impact seagrass beds and change the characteristics of open waters, affecting boating, swimming, fishing and the aesthetic quality of the locale. Management of urban development and wastewater disposal is required to minimise sedimentation and nutrient enrichment. This could include development restrictions, runoff controls and a strategy for wastewater treatment and discharge. The catchment of Lake Macquarie, a marine coastal lake, has been progressively urbanised since 1945. Urbanisation, through increased stormwater runoff and point source discharges, has caused a major impact on the lake in terms of sedimentation and nutrient enrichment. Losses of lake area and navigable waters have occurred. Accompanying problems include changes in the distribution of seagrass beds and nuisance growths of benthic algae. Since the 1950's, dry weather nutrient concentrations have increased and mean water clarity has decreased. Severe problems, as observed in other New South Wales coastal lakes, for example benthic algae in Lake Illawarra and Tuggerah Lakes, have not yet developed. Because of the lead time taken to implement policies and controls, trends should be identified and policies developed now so as to avoid nutrient buildup and development of sustained problems.
46
Owen, Jennifer F., e John R. Merrick. "Analysis of Coastal Middens in South-Eastern Australia: Selectivity of Angling and Other Fishing Techniques Related to Holocene Deposits". Journal of Archaeological Science 21, n. 1 (gennaio 1994): 11–16. http://dx.doi.org/10.1006/jasc.1994.1003.
Testo completo
47
McGarvey, R., J. M. Matthews e J. H. Prescott. "Estimating lobster recruitment and exploitation rate from landings by weight and numbers and age-specific weights". Marine and Freshwater Research 48, n. 8 (1997): 1001. http://dx.doi.org/10.1071/mf97209.
Testo completoAbstract (sommario):
Aprocedure is presented for incorporating catch totals by both weight and numbers in stock assessment. Their ratio is the weight of an average harvested individual which, in turn, reflects mean mortality rate. The model is age-based and requires, as input, a vector of average age-specific weights in the catch. The model developed for the South Australian rock lobster (Jasus edwardsii) fishery assumes steady state, constant fishing mortality on all age classes and a natural mortality rate equal to 0·1. Also explicit are reduced vulnerability of recruitment-aged lobsters and incidental mortality of lobsters below the legal minimum size. The solution yields estimates of average exploitation rate and yearly recruitment. These give (absolute) age-specific population numbers in the fishable stock. Exploitation rates were estimated for statistical reporting blocks in South Australia using this catch weight–numbers (qR) method and, for comparison, that of Beverton and Holt employing mean length. Each method was also tested with simulated data, the former yielding estimates of lower variance and bias. In practice, counting individuals captured is likely to require less time and to yield lower measurement error than measuring lengths. This method thus offers the possibility for improved precision and accuracy at lower cost.
48
Cheung, William W. L., Jessica J. Meeuwig, Ming Feng, Euan Harvey, Vicky W. Y. Lam, Tim Langlois, Dirk Slawinski, Chaojiao Sun e Daniel Pauly. "Climate-change induced tropicalisation of marine communities in Western Australia". Marine and Freshwater Research 63, n. 5 (2012): 415. http://dx.doi.org/10.1071/mf11205.
Testo completoAbstract (sommario):
A major observed and predicted impact of climate change on marine species is the poleward shift in their distributions and the resulting changes in community structure. Here, we used a Dynamic Bioclimate Envelope Model to project range shift of exploited marine fishes and invertebrates in Western Australia. We combined published data and expert knowledge to predict current species distributions for 30 tropical, sub-tropical and temperate species that occur along the coast of Western Australia. Using outputs from both a Regional Oceanographic Model and a Global Circulation Model, we simulated change in the distribution of each species. Our study shows that under the SRES (Special Report for Emission Scenarios) A1B scenario, the median rate of distribution shift is around 19 km decade–1 towards higher latitudes and 9 m deeper decade–1 by 2055 relative to 2005. As a result, species gains and losses are expected along the south coast and north coast of Western Australia, respectively. Also, the coast of Western Australia is expected to experience a ‘tropicalisation’ of the marine community in the future, with increasing dominance of warmer-water species. Such changes in species assemblages may have large ecological and socio-economic implications through shifts in fishing grounds and unexpected trophic effects.
49
Butcher, Paul A., Matt K. Broadhurst e Craig P. Brand. "Mortality of sand whiting (Sillago ciliata) released by recreational anglers in an Australian estuary". ICES Journal of Marine Science 63, n. 3 (1 gennaio 2006): 567–71. http://dx.doi.org/10.1016/j.icesjms.2005.10.001.
Testo completoAbstract (sommario):
Abstract The mortality of hooked-and-released sand whiting (Sillago ciliata) and the key contributing factors were determined during a recreational fishing event in northern New South Wales, Australia. Participating anglers caught 124 sand whiting, of which 60 were tagged with plastic t-bar anchor tags, and then released into replicate sea cages. In all, 109 sand whiting were seined (54 were tagged) and similarly released into replicate sea cages for use as controls. All fish were monitored for mortalities over 7 days. There were no measurable effects of confinement in the sea cages on the stress (measured as concentrations of plasma glucose) of hooked or seined fish. Ten hooked-and-released (four non-tagged, six tagged) and two control (both tagged) sand whiting died during the monitoring period and mostly within 48 h of capture, providing adjusted mortality rates (i.e. accounting for mortalities of control fish) of approximately 6% for total, tagged, and non-tagged fish. Anatomical hook location (oesophagus-ingested hooks) and bait type (beach worms, Australonuphis teres) were significant predictors of mortality (p > 0.05). The results support current recreational fishing gears and practices for the catch and release of sand whiting.
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Rotherham, Douglas, William G. Macbeth, Steven J. Kennelly e Charles A. Gray. "Reducing uncertainty in the assessment and management of fish resources following an environmental impact". ICES Journal of Marine Science 68, n. 8 (8 giugno 2011): 1726–33. http://dx.doi.org/10.1093/icesjms/fsr079.
Testo completoAbstract (sommario):
Abstract Rotherham, D., Macbeth, W. G., Kennelly, S. J., and Gray, C. A. 2011. Reducing uncertainty in the assessment and management of fish resources following an environmental impact. – ICES Journal of Marine Science, 68: 1726–1733. The limitations of using information from commercial fisheries for assessing and managing resources and ecosystems are well known. Although fishery-independent data may overcome many such limitations, few studies have examined how incorporating data from different sources affects assessments and subsequent management decisions. Here, the value of integrating data from two types of sampling survey to assess the recovery of faunal populations following a severe fish-kill event in the Richmond River (New South Wales, Australia) in 2008 is evaluated. There is occasional large-scale mortality of fish and invertebrates in certain estuaries of eastern Australia following major flood events. In extreme cases, the management response involves closing an entire estuary to all fishing, to facilitate the recolonization and recovery of fish and other fauna. Decisions to resume normal fishing activities have environmental, economic, and social implications. Using lessons learned from a similar fish-kill event in 2001, it is shown how, in 2008, fishery-independent sampling, combined with improved sampling by commercial fishers, reduced uncertainty in decision-making and led to greatly improved socio-economic outcomes for stakeholders. The work highlights the need to examine the value of different sources of information to improve management decisions.