28 resultados para Inland fishing

em Deakin Research Online - Australia


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According to the major texts on Fiji’s birds, fish are considered to form only a small part of the collared kingfisher’s diet, and it appears that when fish are taken, this is only in mangroves and beachpools. This article describes systematic fishing by collared kingfishers in a deep inland freshwater body.

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Long-term records of nesting numbers, or proxies to nesting numbers, show a precipitous decline in the size of many sea turtle populations. Population declines are most frequently attributed to fisheries bycatch, although direct quantification of this level of mortality is rare. We used satellite-tracking records for turtles in the Mediterranean Sea and Pacific, Atlantic and Indian Oceans to identify when turtles had been captured. Evidence for capture came from a combination of an increase in good quality locations from transmitters, transmitters moving inland to coastal towns and villages, and on-board submergence data, showing that transmitters had come out of the water. A high level of mortality was calculated, confirming current concerns regarding the outlook for sea turtles.

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Use of geographical information systems (GIS) in inland fisheries has hitherto been essentially restricted to site evaluation for aquaculture development and assessment of limnological changes in time and space in individual water bodies. The present GIS study was conducted on the land-use pattern of the catchments of nine reservoirs in Sri Lanka, for which detailed fishery data, viz. yield, fishing intensity, landing size of major constituent species, together with selected limnological data such as conductivity and chlorophyll-a, were available. Potential statistical relationships (linear, curvilinear, exponential and second-order polynomial) of fish yield (FY, in kg ha−1 yr−1) to different land-use patterns, such as forest cover (FC, in km2) and shrub-land (SL, in km2), either singly, or in combination, and/or the ratio of each land type to reservoir area (RA in km2) and reservoir capacity (RC in km3), were explored. Highly significant relationships were evident between FY to the ratio of SL and/or FC+SL to RA and/or RC. Similarly, the above land-use types to RA and RC ratios were significantly related to limnological features of the reservoirs. The relationships of FY to various parameters obtained in this study were much better correlated than those relationships of FY to limnological and biological parameters used in yield prediction in tropical and temperate lacustrine waters previously.

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In 1953 the Heard and McDonald Islands Act, which formalised the transfer of sovereignty over the two named sub-Antarctic islands from the United Kingdom, was passed by the Australian Government. For the ensuing 40 years, Australian management of the Islands was uneventful. The first subAntarctic scientific station was established at Atlas Cove, on Heard Island, in December 1947 following the initial indication by Britain of a willingness to transfer rights to the Islands. In 1987 the Islands, together with their 12 mile territorial sea, were proclaimed a wilderness reserve with a number of activities including fishing and mining prohibited. The same area was included on the WorId Heritage List in 1997. In 1979 a 200 nautical mile Australian Fishing Zone (AFZ) was proclaimed around all Australian territories. In 1994 new terminology was embraced and the Exclusive Economic Zone was declared.

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Asia dominates global aquaculture production accounting for over 80% of the total and the mainstay in Asian aquaculture is finfish. Over the years, Asia has experienced a number of inter-continental and intra-continental transfers/introductions/translocation of finfish species, between nations and watersheds, beyond their natural range of distribution, primarily for aquaculture development. In this article all such species are referred to as alien species. An attempt is made to evaluate the importance of the production of alien species in selected Asian nations, using statistics of the Food and Agriculture Organization. Also, negative effects, if any, based on literature surveys, of alien species in relation to displacement of indigenous species, and on biodiversity and/or genetic diversity together with associated pathogen transfers are evaluated. The major alien species, based on their significance to Asian inland aquaculture considered, are the tilapias, catfish, Chinese and Indian major carps and common carp. It is estimated that currently alien species account for nearly 12% of the cultured finfish production (2.6 million tonnes) in Asia, valued at US$ 2.59 billion, and the contribution exceeds 40% when Asian countries excluding China are taken into consideration. Inland finfish aquaculture in some Asian nations, such as Indonesia and the Philippines, is predominated by alien species, and in some others, e.g. Bangladesh and India, the contribution from alien species has been increasing steadily. It is suggested that overall alien finfish species have done little ecological harm to native flora and fauna. However, in the wake of increasing anthropogenic development taking place in watersheds the resulting environments are often made unconducive to indigenous species but not to some alien species, thereby potentially and indirectly making the latter invasive.

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Anthropological discussion of individuality, as a component of masculinity, has tended to focus on either the performance and championing of autonomy in the West (e.g., Kapferer) or the manner in which people in non-Western contexts become explicitly manifest through relationships with others (e.g., Strathern). In this paper, I consider an atypical example of masculine identity by describing intimate interpersonal relationships between Australian commercial shark boat skippers and their young deckhands. As in other Western fisheries (e.g., Icelandic), economic success and physical safety are promoted through synergism among fishers. In the Australian case, however, the degree of corporeal cooperation is so extreme that deckhands resemble living prostheses of their skipper, embodying their peripheral socio-productive status. I consider this bond in the context of the Australian ethos of masculinity, in which displays of "individuality" are key. However, for young deckhands, their prosthetic role can compromise their passage into manhood.

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Inland fisheries contribute only about ten percent to global fish production. Asia is the leading producer of inland fish, accounting for over 80 percent of the total production. Until recently, the inland fisheries sector had taken back stage in fisheries development plans, particularly so, given the emphasis being placed on aquaculture development throughout the world, including Asia. This report evaluates the inland fishery practices in a number of Asian countries according to habitat type, role in overall foodfish supplies and development trends. Special emphasis is laid on stock enhancement in inland fisheries in Asia, and only those fisheries in which some form of stock enhancement is practised are considered in this report.

In Asia, inland fisheries are mostly rural, artisanal activities catering to rural populations and providing an affordable source of animal protein, employment and household income. Stock enhancement is an integral component of many inland fisheries. With recent developments in
artificial propagation techniques for fast-growing and desirable fish species and the consequent increased availability of seed stock, such activities are beginning to affect inland fishery production in most Asian countries. Indeed, new avenues of production such as culture-based fisheries are increasingly adopted and seen as a way forward in most countries. Inland fishery activities also have a distinct advantage in that their development is usually less resource intensive than is aquaculture.

The economic viability of stock enhancement of large lacustrine waterbodies and rivers has not been demonstrated in any of the Asian countries, the fisheries of such waterbodies being dependent on naturally recruited stocks. The most successful stock enhancements in Asia are in floodplain beels and oxbow lakes in Bangladesh where the use of small waterbodies that are not capable of supporting natural fisheries has led to culture-based fisheries having stock and recapture rates that are very high. Culture-based fisheries are not resource intensive and are community-based activities. However, their success requires major institutional changes, and these are affected by national and local governments. In general, they can be considered to have the greatest potential for further development.

A major concern related to stock enhancements in inland waters is their possible effects on biodiversity. This is for two reasons: firstly, most countries depend wholly or partially on exotic species for stock enhancement and secondly, freshwater fishes are known to be among the most threatened of vertebrates. Major studies should be undertaken to evaluate the current situation so that remedial steps can be taken, if needed, without causing serious harm to some of the stock enhancement practices that are gaining momentum.

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Since 1989, and in comparison to the global trend, inland aquaculture production of European finfish has declined. To date, the yearly European freshwater aquaculture production is 371,727 tons, valued at over US$1 billion. Indigenous species accounted for less than one-third of the production, whereas alien species (a species that has been moved beyond its natural range of distribution) accounts for the remainder. However, in general, indigenous species command a higher market price. Currently, food quality and food safety are leading concerns of consumers, and European consumers are also becoming alert to environmentally detrimental practices. Therefore, to aim at economic sustainability, the sector needs to satisfy consumer expectations of environmentally friendly practices. It is believed that farming alien finfish species can threaten local biodiversity through escapes, and this represents a current environmental concern relative to aquaculture. In this context, an attempt is made in this paper to understand and quantify the impacts of alien finfish cultivation in European inland waters, and to suggest remedial measures.

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The aim of this manual is to provide a comprehensive practical tool for the generation and analysis of genetic data for subsequent application in aquatic resources management in relation to genetic stock identification in inland fisheries and aquaculture. The material only covers general background on genetics in relation to aquaculture and fisheries resource management, the techniques and relevant methods of data analysis that are commonly used to address questions relating to genetic resource characterisation and population genetic analyses. No attempt is made to include applications of genetic improvement techniques e.g. selective breeding or producing genetically modified organisms (GMOs). The manual includes two ‘stand-alone’ parts, of which this is the first volume: Part 1 – Conceptual basis of population genetic approaches: will provide a basic foundation on genetics in general, and concepts of population genetics. Issues on the choices of molecular markers and project design are also discussed. Part 2 – Laboratory protocols, data management and analysis: will provide step-by-step protocols of the most commonly used molecular genetic techniques utilised in population genetics and systematic studies. In addition, a brief discussion and explanation of how these data are managed and analysed is also included. This manual is expected to enable NACA member country personnel to be trained to undertake molecular genetic studies in their own institutions, and as such is aimed at middle and higher level technical grades. The manual can also provide useful teaching material for specialised advanced level university courses in the region and postgraduate students. The manual has gone through two development/improvement stages. The initial material was tested at a regional workshop and at the second stage feedback from participants was used to improve the contents.

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The aim of this manual is to provide a comprehensive practical tool for the generation and analysis of genetic data for subsequent application in aquatic resources management in relation to genetic stock identification in inland fisheries and aquaculture. The material only covers general background on genetics in relation to aquaculture and fisheries resource management, the techniques and relevant methods of data analysis that are commonly used to address questions relating to genetic resource characterisation and population genetic analyses. No attempt is made to include applications of genetic improvement techniques e.g. selective breeding or producing genetically modified organisms (GMOs). The manual includes two ‘stand-alone’ parts, of which this is the second volume: Part 1 – Conceptual basis of population genetic approaches: will provide a basic foundation on genetics in general, and concepts of population genetics. Issues on the choices of molecular markers and project design are also discussed. Part 2 – Laboratory protocols, data management and analysis: will provide step-by-step protocols of the most commonly used molecular genetic techniques utilised in population genetics and systematic studies. In addition, a brief discussion and explanation of how these data are managed and analysed is also included. This manual is expected to enable NACA member country personnel to be trained to undertake molecular genetic studies in their own institutions, and as such is aimed at middle and higher level technical grades. The manual can also provide useful teaching material for specialised advanced level university courses in the region and postgraduate students. The manual has gone through two development/improvement stages. The initial material was tested at a regional workshop and at the second stage feedback from participants was used to improve the contents.

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We used lightweight satellite transmitters to follow the movements of 17 Grey Teal Anas gracilis between September 2003 and November 2004 in two contrasting landscapes, the agricultural districts of southern Australia and the desert landscapes of the interior. Tagged birds moved large distances (up to 343 km) between occupied sites in a short period (hours), remained in the vicinity of those sites for extended periods (months), ventured up to 453 km from their point of release and travelled more than 2000 km in one year. We describe patterns of movement in a nomadic waterfowl for 15 months from September 2003, a period of severe drought. Based on the current analysis there appears to be no remarkable difference in the observed patterns of movement of those released in the agricultural landscapes and those released in the desert. As in waterfowl elsewhere, movements appear to occur in response to changes in local food abundance that threaten survival or the imperative to move in order to breed successfully. In Grey Teal, the proximate cues for movement transcend the local landscape and some birds are responding to temporary cues hundreds of kilometres distant. This is in contrast to the universal seasonal cues associated with migration systems elsewhere.