868 resultados para Lagoon ecology
Resumo:
Countering the trend in contemporary ecocriticism to advance realism as an environmentally responsible mode of representation, this essay argues that the anti-realist aesthetics of literary modernism were implicitly “ecological.” In order to make this argument I distinguish between contemporary and modernist ecological culture (both of which I differentiate in turn from ecological science); while the former is concerned primarily with the practical reform characteristic of what we now call “environmentalism,” the latter demanded an all-encompassing reimagination of the relationship between humanity and nature. “Modernist ecology,” as I call it, attempted to envision this change, which would be ontological or metaphysical rather than simply social, through thematically and formally experimental works of art. Its radical vision, suggestive in some ways of today’s “deep” ecology, repudiated modern accounts of nature as a congeries of inert objects to be manipulated by a sovereign subject, and instead foregrounded the chiasmic intertexture of the subject/object relationship. In aesthetic modernism we encounter not “objective” nature, but “nature-being” – a blank substratum beneath the solid contours of what philosopher Kate Soper calls “lay nature” – the revelation of which shatters historical constructions of nature and alone allows for radical alternatives. This essay looks specifically at modernist ecology as it appears in the works of W. B. Yeats, D. H. Lawrence, and Samuel Beckett, detailing their attempts to envision revolutionary new ecologies, but also their struggles with the limited capacity of esoteric modernist art to effect significant ecological change on a collective level.
Resumo:
Understanding the reasons for long-term population change in a species requires an evaluation of ecological variables that may account for the observed dynamics. In this study, long-term changes in indices of Smallmouth Bass condition and population levels were examined for eastern Lake Ontario and the Bay of Quinte. Smallmouth Bass are an extremely important recreational fish species native to Lake Ontario. They have experienced numerous changes in their environment through direct human impacts, climate change, predation, and habitat sharing with non-native species. Smallmouth Bass have experienced an increase in body length and weight likely due to a diet shift from crayfish to predominantly Round Gobies which has allowed them to increase their growth rate. According to existing assessment data however, this increase in body size has not been associated with an increase in abundance. Long-term data from gill net sampling shows that Smallmouth Bass populations have been declining since the late 1980s with no indication of recovery. This could be due to a variety of factors, but it is most likely due to a change in the selectivity of gill nets because of the change in body size as well as a habitat shift away from gill net sampling sites. Adjusting for gill net selectivity has revealed that sub-adult bass abundance is currently greater than it was historically, and that very large bass are likely not being retained within the gill nets that are currently used. The use of a long-term data set in this study has led to a much better understanding of Smallmouth Bass abundance and ecology.
Resumo:
In this study, we investigated the relationship between vegetation and modern-pollen rain along the elevational gradient of Mount Paggeo. We apply multivariate data analysis to assess the relationship between vegetation and modern-pollen rain and quantify the representativeness of forest zones. This study represents the first statistical analysis of pollen-vegetation relationship along an elevational gradient in Greece. Hence, this paper improves confidence in interpretation of palynological records from north-eastern Greece and may refine past climate reconstructions for a more accurate comparison of data and modelling. Numerical classification and ordination were performed on pollen data to assess differences among plant communities that beech (Fagus sylvatica) dominates or co-dominates. The results show a strong relationship between altitude, arboreal cover, human impact and variations in pollen and nonpollen palynomorph taxa percentages.
Resumo:
Harmful algal blooms can adversely affect fish communities, though their impacts are highly context-dependent and typically differ between fish species. Various approaches, comprising univariate and multivariate analyses and multimetric Fish Community Indices (FCI), were employed to characterise the perceived impacts of a Karlodinium veneficum bloom on the fish communities and ecological condition of the Swan Canning Estuary, Western Australia. The combined evidence suggests that a large proportion of the more mobile fish species in the offshore waters of the bloom-affected area relocated to other regions during the bloom. This was indicated by marked declines in mean species richness, catch rates and FCI scores in the bloom region but concomitant increases in these characteristics in more distal regions, and by pronounced and atypical shifts in the pattern of inter-regional similarities in fish community composition during the bloom. The lack of any significant changes among the nearshore fish communities revealed that bloom impacts were less severe there than in deeper, offshore waters. Nearshore habitats, which generally are in better ecological condition than adjacent offshore waters in this system, may provide refuges for fish during algal blooms and other perturbations, mirroring similar observations of fish avoidance responses to such stressors in estuaries worldwide.
Resumo:
Harmful algal blooms can adversely affect fish communities, though their impacts are highly context-dependent and typically differ between fish species. Various approaches, comprising univariate and multivariate analyses and multimetric Fish Community Indices (FCI), were employed to characterise the perceived impacts of a Karlodinium veneficum bloom on the fish communities and ecological condition of the Swan Canning Estuary, Western Australia. The combined evidence suggests that a large proportion of the more mobile fish species in the offshore waters of the bloom-affected area relocated to other regions during the bloom. This was indicated by marked declines in mean species richness, catch rates and FCI scores in the bloom region but concomitant increases in these characteristics in more distal regions, and by pronounced and atypical shifts in the pattern of inter-regional similarities in fish community composition during the bloom. The lack of any significant changes among the nearshore fish communities revealed that bloom impacts were less severe there than in deeper, offshore waters. Nearshore habitats, which generally are in better ecological condition than adjacent offshore waters in this system, may provide refuges for fish during algal blooms and other perturbations, mirroring similar observations of fish avoidance responses to such stressors in estuaries worldwide.
Resumo:
It is a golden age for animal movement studies and so an opportune time to assess priorities for future work. We assembled 40 experts to identify key questions in this field, focussing on marine megafauna, which include a broad range of birds, mammals, reptiles, and fish. Research on these taxa has both underpinned many of the recent technical developments and led to fundamental discoveries in the field. We show that the questions have broad applicability to other taxa, including terrestrial animals, flying insects, and swimming invertebrates, and, as such, this exercise provides a useful roadmap for targeted deployments and data syntheses that should advance the field of movement ecology.
Resumo:
It is a golden age for animal movement studies and so an opportune time to assess priorities for future work. We assembled 40 experts to identify key questions in this field, focussing on marine megafauna, which include a broad range of birds, mammals, reptiles, and fish. Research on these taxa has both underpinned many of the recent technical developments and led to fundamental discoveries in the field. We show that the questions have broad applicability to other taxa, including terrestrial animals, flying insects, and swimming invertebrates, and, as such, this exercise provides a useful roadmap for targeted deployments and data syntheses that should advance the field of movement ecology.
Resumo:
What is the human being? Which is its origin and its end? What is the influence of the nature in the man and what is his impact on nature? Forthe animalists, men are like other animals; freedom and rationality are not signs of superiority, nor having rights over the animals. For the ecohumanists, human beings are part of nature, but is qualitatively different and superior to animals; and is the creator of the civilization. We analyze these two ecological looks. A special point is the contribution ofecohumanists -from the first half of the Renaissance, who dealt in extenso the dignity and freedom of the human being-, of Michelangelo and finally, of Mozart, through his four insurmountable operas, which display the difficulty of physical ecology to engender so much beauty, so much wealth, so much love for the creatures and so much variety.
Resumo:
Rin de Aveiro is a coastal lagoon located at the Central Region of Portugal subjected to the influence of the tides, resulting in a set of characteristic biotopes favouring anthropic and natural processes. Once managed and controlled correctly, each of these biotopes will allow simultaneously the biodiversity and integration in the making of the wetland landscape. In 1998, one of the final conclusions of the "MARIA" Demonstration Programme for the Integrated Management of Ria de Aveiro was that the poor current state of the environment area resulted from a set of interrelated factors. The Programme selected four (4) pilot-projects towards the integrated management of the lagoon biotopes as possible scenarios for an intervention. This selection was based in criteria related to environmental priorities and the maintenance of traditional economic activities in the region. The idea of choosing projects that would involve the whole geographic space of the Ria, without forgetting the other important themes interrelated with the Management Structure, emerged as a relevant aspect for their definition. Thus, and as a first test of this Management Structure functionality, the following task forces were put forward: Recovery and valorisation of the piers; Recovery of the former salt pans; Management of the agricultural fields of Baixo-Vouga; Implementation of measures for the classification of the Protected Landscape Area of the River Caster Mouth. This payer will report the main results of these pilot-projects attained during their first year period, especially the intervention strategies defined by the Partnership created for this aim.
Resumo:
Palheiros are traditional timber constructions existing in the littoral centre region of Portugal. This is particularly the case of the Aveiro lagoon region where for many years many such constructions have existed. They were originally built to store working tools related with lagoon activity (fishing and sea salt extraction) and to give shelter for the fishermen during the fishing season. These constructions were built with superimposed veneers in vertical or horizontal directions. Since they are mostly located near the sea, they have started to be used as holiday houses and are often painted in vivid colours. Most of these buildings are being replaced by concrete constructions, since their preservation state is rather unsatisfactory or simply because there is a need to increase their size. Additionally, little knowledge about the possibilities of maintenance and building in timber structures exists. In some cases, although the structures were changed from timber to concrete, the exterior appearance of the palheiros remains the same, which might be interesting from the pictorial point of view but it isn’t certainly from a heritage preservation perspective. However in many other situations, they are being substituted by “modern” constructions that were not valuable in any of the previous viewpoints. Fortunately, there are also cases where palheiros have been preserved and remain in good condition. For how long these examples will remain is certainly the major question that must be answered since these are only on the dependence of owner’s will and not based on local authorities concern. A consciousness of local authorities and citizens is mandatory in order to preserve this heritage because it is perfectly possible to preserve the traditional constructions offering all the comfort of modern houses. Keywords: timber construction, vernacular construction, preservation.