Cheap water, massive federal subsidies and political clout have sustained rice farming in the lower Colorado River basin for decades, but now the industry is in a precarious situation. Drought, population growth upstream and economic boom in Austin are pushing out the practice because of increasing demand for Texas’ scarce water resources. The tightening supply of water raised questions about the sustainability of producing such a water intensive crop in the state. Drought has cut off the cheap water to farmers for three years, and a mobilized coalition of upper river basin interests is calling for a permanent end to subsidized water. It’s increasingly clear that the politics of water in a drought-prone future is likely to side with cities, where voters are heavily concentrated. Rice farmers have scrambled to adapt. Larger rice farms have switched to groundwater. Some farmers have swapped rice for corn, milo or soybeans to keep their income. Crop insurance, which made up for at least 55 percent of the money lost in drought, softened the blow for rice farmers. But revenues in rice-related industries in Wharton, Matagorda and Colorado counties have dropped sharply and some businesses have already packed it in. These new realities cast uncertainties throughout the lower river basin, where locals fear this way of life is disappearing. / text

During recent years the high country of the South Island has attracted a good deal of attention from farm economists, soil conservationists, geographers and also politicians. With the present need for increased national production the problem of keeping the high country in productive occupation is the subject of justifiable concern. The purpose of this regional study is to describe one of the most distinctive areas in the high country, and to discuss the problems which have caused the recent Royal Commission on the Sheep-farming Industry in New Zealand to investigate the general economic position of the runholders. Besides being a well-defined physiographic unit, the Mackenzie Basin or, as it is better known to the local people, the Mackenzie Country has a distinctive character of its own. On entering Burkes Pass even the most casual observer cannot fail to notice how different the landscape within the basin appears compared with that outside. This large, gravel-filled intermontane depression with its vast expanse of dun coloured tussock and its clear, dry climate seems to have a special flavour which distinguishes it from any other part of either Canterbury or Otago. Probably the most striking feature of the basin is its monotonous uniformity of both physical conditions and human activities. The extensive sheep-farming economy has imposed a distinctive pattern of land use over the whole area. Not only does the landscape have a similar appearance everywhere but, because of their common int erests, the people all tend to live alike and think alike. Before 1939 the basin was solely a sheep-grazing area but, with the recent developments connected with the storage of water in the lakes for the generation of hydro-electricity, the Mackenzie Country has assumed a new importance. With the dam-building schemes at Tekapo and Pukaki an entirely new element has been introduced into the landscape - the large Public Works Camp. These camps, however, are, for the most part, temporary features and the sheep-station remains the typical unit of settlement. For this reason the major part of this study is devoted to a description of the landscape as it has developed under the extensive sheep-farming economy and a discussion of the problems resulting from the exploitation of the natural vegetation. When the early settlers first took up their runs they had the opportunity of making the Mackenzie basin one of the best merino grazing areas in New Zealand. In most cases that opportunity was lost, due partly to ignorance of proper grazing methods under sub-humid conditions and partly to short-sighted practices caused by temporary economic difficulties. Over-burning and over-stocking extracted an early toll from the vegetation cover which, in spite of numerous attempts can never be fully repaid. By deliberately introducing rabbits into the area the early runholders made their third and possibly their greatest mistake. These rabbits were allowed to multiply unchecked for nearly twenty years before it was realised what a menace they were likely to become. By that time it was too late. Today, the rabbit is generally considered to be the chief cause of the disturbing decline in the sheep carrying capacity of the Mackenzie Country. Altogether, unwise burning, overstocking and rabbits have caused such a deterioration in the tussock cover that Cumberland's description of some parts of the basin as "deserts in the making" is quite appropriate. Admittedly conditions are not as bad as in the "man-made deserts" of Central Otago but a serious problem at present confronts the Mackenzie runholders.

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No description available.

The long-term effects of large-scale changes in forestry, agriculture and other land use on habitats and the large-scale expansion of wind farming  affects bats foraging environments. In order to predict consequences of exploitations on local bat species and populations, good surveys are important. To get good background information for an Environmental Impact Assessment (EIA) it  is crucial to rapidly assess which areas are most important for bats. The aim of this work was to measure the importance of the two types of forest environment for bats foraging : forest areas located close to or far from the lakes. Bat activity and species diversity was measured with automatic ultrasound recorders in 211  nights of fieldwork at 155 locations in 23 areas in different parts of Sweden during June, July and the first two weeks of August 2011 and 2012. A total of 11 species were recorded in forest far from lakes and 8 species in forest close to lakes. Eptesicus nilssonii , Myotis sp. and Pipistrellus pygmaeus were the most common taxa in both habitat types. Activity levels were higher in the vicinity of lakes compared to forests far away from lakes. Species diversity calculated on base on Chao 2 was similar for both types of habitats . The results suggest that the forests close to lakes are the most important habitats to surveys for bats in Sweden and that inventory efforts should be primarily invested in them.

Fisk är ett hälsosamt livsmedel och allt eftersom världsbefolkningen har växt och hälsotrenden blossat upp, har trycket på fiskerinäringen ökat. Bakgrundens fakta tog upp olika konsekvenser som fiskodling kan medföra och hur stor kunskap konsumenten har om detta och deras makt att påverka industrin. Syftet med studien var att belysa brister i fiskodling kopplat till konsumenters kunskap, samt hur de etiska frågorna påverkar konsumentens val. I metod och materialstycket lades det fram att studien var en litteraturstudie som baserades på vetenskapliga artiklar från olika databaser som gick att tillgå vid Örebro universitet. Resultatet av undersökningen gav inblickar i vad konsumenter visste om odlad fisk, vad de tyckte om produkten och hur eller om de utövade sin makt. Resultatet visar även hur hanteringen av fisk går till på fiskodlingar runt om i Europa. I diskussionsavsnittet i studien lades bakgrundsfakta ihop med fakta ur resultatavsnittet. I diskussionen framkom information om att konsumenters uppfattning och kännedom om odlad fisk inte var tillräcklig, trots de märkningar och informationskällor som presenteras i bakgrunden.I diskussionsavsnittet diskuteras även processen som ledde fram till den här studien och vad som fungerat respektive inte fungerat. / B-uppsatser

Concern about feeding an ever increasing population has long been one of humankind’s most pressing problems. This has been addressed throughout history by introducing into farming systems changes allowing them to produce more per unit of land area. However, these changes have also been linked to negative effects on the socio economic and environmental sphere, that have created the need for an integral understanding of this phenomenon. This thesis describes the application of learning machine methods to induct a relationship between the spectral response of farms’ land cover and their intensification levels from a sample of farming of Urdaneta municipality, Aragua state of Venezuela. Data collection like this is a necessary first steep to implement cost-effective methods that can help policymakers to conduct succesful planing tasks, especially in countries such as Venezuela where, in spite of there being areas capable of agricultural production, nearly 50% of the internal food requirements of recent years have been satisfied by importations. In this work, farm intensification levels are investigated through a sample of farms of Urdaneta Municipality, Aragua state of Venezuela. This area is characterised by a wide diversity of farming systems ranging from crop to crop-livestock systems and an increasing population density in regions capable of livestock and arable farming, making it a representative case of the main tropical rural zones. The methodology applied can be divided into two main phases. First an unsupervised classification was performed by applying principal component analysis and agglomerative cluster methods to a set of land use and land management indicators, with the aim to segregate farms into homogeneous groups from the intensification point of view. This procedure resulted in three clusters which were named extensive, semi-intensive and intensive. The land use indicators included the percentage area within each farm devoted to annual crops, orchard and pasture, while the land management indicators were percentage of cultivated land under irrigation, stocking rate, machinery and equipment index and permanent and temporary staff ratio, all of them built from data held on the 1996- 1997 venezuelan agricultural census. The previous clusters reached were compared to the ones obtained by applying the learning machine method known as self-organizing map, which is also an unsupervised classification technique, as a way to confirm the groups’ existence. In the second stage, the learning machine known as kernel adatron algorithm was implemented seeking to identify the intensification level of Urdaneta farms from a landsat image, which consisted of two sequential steps: namely training and validation. In the training step, a predetermined number of instances randomly selected from the data set were analysed looking for a pattern to establish a relationship between the label and the spectral response in an iterative process which was concluded when the machine found a linear function capable of separating the two classes with a maximum margin. The supervised classification finishes with the validation in which the kernel adatron classifies the unseen samples by using a generalisation of the relationships learned while training. Results suggest that farm intensification levels can be effectively derived from multi-spectral data by adopting a machine learning approach like the one described.

The main parasite affecting the Scottish Atlantic salmon farming industry is Lepeophtheirus salmonis costing approximately £29 million annually through lost production and treatments. As such, the primary aim of this study was to investigate the infection pressure, fecundity and infection dynamics of L. salmonis in a west coast sea loch containing salmonid aquaculture. Atlantic salmon held in small sentinel cages were used to monitor sea lice infection pressure in Loch Shieldaig. Investigation of the factors affecting infection pressure within the loch found no evidence of a direct link between monthly gravid lice counts on local farmed salmon and lice burdens on sentinel cage fish. Copepodid L. salmonis were present throughout the year despite there being low numbers of wild salmonids in the system during much of the year and as such the source of this infection was unclear. In subsequent laboratory trials, L. salmonis from wild salmon were found to be more fecund than those from farmed salmon and similarly, fecundity and survival were also higher in summer compared to winter populations of L. salmonis. These findings raise the possibility that L. salmonis infecting wild salmonids may “seed” previously fallowed systems. Alternatively, trials with atypical hosts found that L. salmonis of farmed origin did re-infect Atlantic cod and produce viable egg strings which moulted through to the infective copepodid stage. Infection challenges demonstrated that L. salmonis copepodids were observed to settle on atypical hosts such as saithe and Atlantic cod in low numbers although failed to develop to the chalimus stages and complete its lifecycle. Challenges utilising the mobile pre-adult stage were similarily unsuccesful in allowing L. salmonis to moult to the adult stage on these atypical hosts. Previous work conducted on Pacific three-spined sticklebacks demonstrated the species could support large burdens. In infection trials with three-spined sticklebacks from Scotland’s west coast, settlement was found to be low, which suggests they play no role in the Scottish inshore infection dynamics of L. salmonis. These series of studies provide novel and timely data on the biology and infection dynamics of L. salmonis on typical and atypical hosts in Scottish marine aquaculture areas. The data will form part of the knowledge used to make informed pest management and policy decisions assisting the future development of the aquaculture industry in Scotland.

The present work reports on extensive plankton sampling surveys in a Scottish sea loch used by wild and farmed salmonids and describes the spatial and temporal distribution of planktonic larval sea lice and identifies factors which affect the larval distribution. The planktonic louse larvae recovered were predominantly <i>Lepeophtheirus salmonis</i> (Krøyer) and so the findings of this thesis refer primarily to this species of sea louse. Copepodids occurred in significantly greater densities at 0 m than at a depth of 5 m, whereas nauplii occurred in significantly greater densities at 5 m than at 0 m depth. Densities of caligid nauplii and <i>L. salmonis</i> copepodids recovered from the open-waters of Loch Shieldaig correlated significantly with the counts of gravid <i>L. salmonis</i> on farmed Atlantic salmon at the farm in Loch Shieldaig. Furthermore, the densities of <i>L. salmonis</i> copepodids were significantly correlated  with the estimated total numbers of gravid <i>L. salmonis</i> on all farmed Atlantic salmon in the Loch Torridon management area. Densities of <i>L. salmonis</i> copepodids did not correlate with estimated numbers of gravid <i>L. salmonis</i> on wild salmonids. Atlantic salmon farms were identified as important sources of <i>L. salmonis</i> larvae and these larvae can be transported several kilometres from the point of release. Husbandry louse control practices were indicated to be able to significantly reduce the densities of <i>L. salmonis</i> larvae in the water column. These findings support the principle of synchronised sea louse management at a hydrographic/management area level.