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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Assessment of Image Analysis as a Measure of Scleractinian Coral Growth

Gustafson, Steven K. 29 March 2006 (has links)
Image analysis was used to measure basal areas of selected colonies of Montastraea annularis and Porites astreoides, following the colonies over a three-year period from 2002 to 2004. Existing digital images of permanently-marked quadrats in the Caye Caulker Marine Reserve, Belize, were selected based on image quality and availability of images of selected quadrats for all three years. Annual growth rates were calculated from the basal-area measurements. Mean growth rates (radial skeletal extension) for M. annularis and P. astreoides were 0.02 cm yr-1 and -0.20 cm yr-1, respectively. Basal area measurements demonstrated a large degree of variability. Increases were approximately balanced by declines giving the impression of stasis. By removing negative values and correcting by 25% to allow for comparison with vertical growth rates, mean values increased to ~0.5 cm yr-1 for M. annularis and ~0.8 cm yr-1 for P. astreoides. Basal area as a growth measure was compared to methods used in earlier studies. A new growth index based on basal area and perimeter was proposed and modeled. This growth index can be useful for reporting growth measured from basal areas and comparable other methods. The index also measures negative growth, or mortality, which conventional methods cannot do.
132

Variability and trends in the tropical Pacific and the El Niño-Southern Oscillation inferred from coral and lake archives

Thompson, Diane Marie January 2013 (has links)
The background state and changes associated with the El Niño-Southern Oscillation (ENSO) in the tropical Pacific Ocean influence climate patterns all over the world. Understanding how the tropical Pacific will be impacted by climate change is therefore critical to accurate regional climate projections. However, sparse historical data coverage and strong natural variability in the basin make it difficult to assess the response of the tropical Pacific to anthropogenic climate change. Further, climate models disagree regarding the response of the basin to continued anthropogenic forcing into the future. Building off of the limited instrumental record, high-resolution records from coral and lake sediment archives can be used to assess the response of the tropical Pacific to past climate changes and to compare and assess climate model projections. In the present study, I use high-resolution coral and lake records from the equatorial Pacific to assess climate model projections and the response of the coupled ocean-atmospheric climate system in the basin (ocean temperature, salinity, winds, precipitation) to natural and anthropogenic forcing. Using a simple model of how climate is recorded by corals, we compare historical climate data and climate model simulations with coral paleoclimate records to assess climate model projections and address uncertainties in the historical data, models and paleoclimate records. We demonstrate that this simple model is able to capture variability and trend observed in the coral records, and show that the both sea surface temperature and salinity contribute to the observed coral trend. However, we find major discrepancies in the observed and climate model simulated trends in the tropical Pacific that may be attributed to uncertainties in model simulated salinity. We then assess 20th-century variability and trends in SST and salinity in the central tropical Pacific using replicated coral δ¹⁸O and Sr/Ca records from the Republic of Kiribati and the central Line Islands. We find that the coral records from these sites display a warming and freshening trend superimposed on strong interannual and low-frequency variability. Further, we demonstrate an apparent strengthening of the E-W SST gradient across the dateline (between 173°E and 160°W) and a slight weakening of the N-S SST gradient due to enhanced warming along the equator and west of the dateline relative to other sites. However, we find no evidence of increased variability in the central Pacific, suggesting that there has not been an increase in central Pacific style ENSO events. Finally, we show that the salinity response to climate change may be very patchy within the basin. Using a new ~90 year coral Mn/Ca record from the central Pacific, we investigate variability and trends in tropical Pacific trade winds. First, we demonstrate a strong association between westerly wind anomalies and coral skeletal Mn/Ca, which recorded all of the major historical El Niño events of the 20th century. In this new long Mn/Ca record, we find a reduction in the amplitude and frequency of Mn/Ca pulses between 1893 and 1982, suggesting a decrease in westerly wind anomalies in the western equatorial Pacific Ocean. Finally, we use a sediment record from Bainbridge Crater Lake, Galápagos Archipelago to assess variability in the eastern tropical Pacific over the past ~6 thousand years. Based on results from long-term monitoring of the lake, we propose a new climate interpretation of the sediment record and find further evidence reduced mid-Holocene ENSO variability and a ramp up of ENSO variability starting around 1775 cal. years BP.
133

The past, present, and future of incentive-based coral conservation: Sustainability of diving on the Andaman coast of Thailand

Augustine, Skye 29 August 2013 (has links)
Rapidly changing oceans are threatening coastal ecosystems and require effective conservation efforts. On the Andaman coast of Thailand, SCUBA diving tourism is one activity that can aid conservation by providing incentives to conserve, rather than exploit, natural resources such as coral reefs. In 2011, the largest ever recorded coral bleaching event prompted the closure of many of the countries’ most popular dive sites to allow coral to recover. This unprecedented move and the resulting drop in dive tourists demonstrated the vast changes that could confront the dive industry in the face of climate change, altering its role as a vital activity within Thailand as well as its potential as a conservation tool along the coast. Ensuring the sustainability of Thailand’s coral reefs requires that we consider changes to both these components. This thesis tracks changes to the sustainability of diving as a conservation tool and predicts how these trends might vary in a future with continued climate change impacts. This research uses a wildlife tourism model proposed by Duffus and Dearden (1990) as a theoretical framework to examine changes to diving over time. A standardized questionnaire was administered to diving tourists in 2012 and compared against a similar study completed in 2000 to evaluate development and shifting sustainability of diving. Additionally, the ecotourism values and climate change perceptions of divers were measured to explore the present and future conservation potential. This work found that the conservation value of the dive industry has declined and will continue to do so without management interventions. Specifically, the specialization level of divers has declined between the years, yielding a population that has low skill level, generalized motivations, few ecotourism values, is easily satisfied, and spend less money than divers in 2000. Currently, there are many niche companies that all cater to mainstream tourists. However, within this broad industry, this research identified only one diving company that practices all of The International Ecotourism Societies’ principles for ecotourism operators, suggesting that diving on the Andaman coast is not an ecotourism industry. We anticipate that in the face of continuing climate change impacts, there will be a significant loss in clientele, but demand for diving will remain within the generalist divers on the Andaman coast. These findings provide clear evidence for shifting baselines, a phenomenon that will exacerbate declines in the conservation potential of the industry. Despite this, our results show that most divers are concerned about the impacts of climate change and are interested in learning about it, suggesting that there is potential to increase the educational value of the dive industry, and simultaneously boost its conservation contributions. To do so will require the efforts of both protected area managers and dive operators. / Graduate / 0366 / 0814 / 0768
134

The value of Fijian coral reefs by nonusers: a contingent valuation study to investigate willingness-to-pay for conservation, understand scale/magnitude of reef problems and provide tools for practitioners

Fonseca, Carolyn E. 06 July 2009 (has links)
A contingent valuation study was done to investigate the value of Fijian reefs by households in the Metro Atlanta area. Individuals were surveyed and asked questions about their Willingness-to-Pay for coral reef conservation, personal views on the scope/magnitude of coral reef problems, and experience around ocean related activities as well as knowledge. Results from this data, find individuals would donate on average $0.18 taking into account sample and response bias. Less conservative estimates calculated contributions per person to equal $13.9 for the conservation of Fijian reefs. These results imply Atlanta, which is very distant from Fiji, has the potential to contribute to Fijian coral reef conservation programs. Although little empirical work exists on valuation measure for reefs of non-users and groups distant to reefs, this study suggests nonprofits and developing countries could benefit from the inclusion or previously excluded (due to distance to reefs) participants. The study discusses donor characteristics as well as possible market strategies these organizations could utilize to maximize revenue. Findings from this work highlight two important issues rarely discussed in the policy literature: 1-the use of non-market valuation methods to identify stakeholders and 2-the effects of distance on use and non-use value ultimately impacting conservation.
135

Catastrophes, resilience, and the theory of designing marine reserves

Edward Game Unknown Date (has links)
Chronic anthropogenic disturbance has left many marine systems at risk of degrading into undesirable states. In many cases, ecosystem shifts are triggered by catastrophic disturbance events that are beyond the control of local management, such as coral bleaching or cyclones. Recognition of this risk has instigated what has been referred to as a new paradigm for marine stewardship; managing areas with the explicit goal of maintaining ecosystem resilience. Despite this, there has been little synthetic influence of resilience theory on marine conservation planning. This thesis focuses on how to make good decisions regarding the selection of marine protected areas (MPAs), in the face of catastrophic disturbance events and for the conservation of highly dynamic marine systems. Large-scale catastrophic events, although rare, lie generally beyond the control of local management and can prevent marine reserves from achieving biodiversity outcomes. In Chapter 2, I formulate a new conservation planning problem that aims to minimize the probability of missing marine conservation targets as result of catastrophic events. To illustrate this approach, I address the problem of minimizing the impact of large scale coral bleaching events on a reserve system for the Great Barrier Reef, Australia. By explicitly considering the threat of catastrophic bleaching as part of the reserve design problem, it was possible to substantially improve the likely persistence of coral reefs within reserve networks, for a negligible increase in reserve cost. The results also demonstrate that simply aiming to protect the reefs at lowest risk of catastrophic bleaching does not necessarily lead to the best conservation outcomes. It is thought that recovery of marine habitats from uncontrollable disturbance may be faster in marine reserves than in unprotected habitats. But which marine habitats should be protected, those areas at greatest risk or those at least risk? In Chapter 3, I define this problem mathematically for two alternate conservation objectives and determine under which conditions each of the different protection strategies are optimal. With regard to the risk of uncontrollable disturbance, the optimal protection strategy depends on both the conservation objective and the expected rate of habitat recovery inside and outside protected areas. I illustrate this decision making with an example of cyclone disturbance of coral reefs on Australia’s Great Barrier Reef. An adequate consideration of risk can indicate surprising routes to conservation success. The resilience of coral reef systems is closely linked to the presence of grazing herbivores. Although herbivore populations are generally protected through permanent static reserves, the benefits of protection are dynamic in both time and space. Periodically moving protection between reefs allows access to the greatest potential benefits of reservation and can help address social reluctance to permanently close areas. Using analytic methods to solve a theoretical case study, I demonstrate that periodically rotating protection around a reef system can lead to greater average reef resilience than under static protection, but only if the overall level of reservation is high enough or the rotation does not include all reefs in the system. The past ten years have seen increasing enthusiasm for MPAs as a tool for pelagic conservation. However, numerous criticisms have been levelled against the use of place-based management in such a dynamic environment. Evidence, tools and information to address these criticisms and establish the feasibility and relevance of pelagic MPAs are dispersed across the conservation, oceanography and fisheries management literature. In Chapter 5, I review this information and present a synthetic framework for systematic planning of pelagic MPAs. Although many of the lessons learned so far about MPA design in coastal systems can be transferred to pelagic systems, there are some fundamental differences and new challenges involved in the conservation of patchy and highly dynamic resources. These challenges are very much at the leading edge of new conservation science and are likely to stimulate solutions with impact far beyond the design of pelagic MPAs.
136

Integrating Field and Remotely Sensed Data for Assessment of Coral Reef and Seagrass Habitats

Chris Roelfsema Unknown Date (has links)
Coral reef habitats are being threatened by global warming, natural disasters and the increased pressure of the global population. These habitats are in urgent need of efficient monitoring and management programs to sustain their biological, economic and cultural values for the global community. Habitats maps, describing the extent, composition and the condition of the benthos in time and space, form a valuable information source for scientists and managers to answer their management questions. Adequate and accurate habitat maps are needed and can be provided by a range of mapping approaches, which are based on integration of field and remotely sensed image data sets. Scientists, technicians and managers lack knowledge on the cost effectiveness and procedures for calibrating and validating mapping approaches that integratef field data and remote sensing imagery, for use in various coral reef and seagrass environments. This knowledge is required to adequately design, apply and assess operational mapping approaches and their maps. Hence, the aim of this study is to improve habitat mapping capabilities by integrating low cost remote sensing approaches and field-calibration and -validation methods for a range of coral reef and seagrass environments. To achieve this aim, commonly used habitat mapping approaches that integrated field-calibration and -validation methods with remote sensing image based processing techniques were studied, in different coral reef and seagrass environments in Fiji and Australia. These environments varied in: water clarity, water depth, benthic composition, spatial complexity of benthic features, and remoteness. The study had three objectives: (1) to evaluate the accuracy, cost and perceived relevance of eight commonly used benthic cover mapping approaches for three different coral reef environments. (2) Conduct a cost-benefit comparison of two field survey methods for calibrating and validating maps of coral reef benthos derived from high-spatial resolution satellite images in three different coral reef environments. (3) Identify considerations for comparing the thematic accuracy of multi-use image based habitat maps in various coral reef and seagrass environments. A scientific assessment and an evaluation of the relevance for managers, was conducted on eight commonly used habitat mapping approaches for three different coral reef environments. This analysis revealed a preference for a mapping approach based on supervised classification of Quickbird imagery integrated with basic field data. This approach produced an accurate map within a short time with low cost in that suited the user’s purpose. Additionally, the results indicated that user preference in selecting a suitable map was affected by: variations in environmental complexity; map purpose, and resource management requirements. To assess the variation in performance of methods for calibration and validation for coral reef benthic community maps, derived from high-spatial resolution satellite images, a comparison was conducted between spot check and georeferenced photo-transect based mapping approaches. The assessment found that the transect based method was a robust procedure which could be used in a range of coral reef environments to map the benthic communities accurately. In contrast, the spot check method is a fast and low cost approach suitable to map benthic communities which have lower spatial complexity. However, the spot check approach provides robust results, if it is applied in a standardised manner, providing a description of selected homogenous areas with georeferenced benthic cover photos. Considerations for comparing the thematic accuracy of multi-use image based habitat maps in various coral reef and seagrass environments were assessed. This included a review of 80 scientific publications on coral reef and seagrass habitat mapping, which revealed a lack of knowledge and reporting in regards to the assessment of the thematic map accuracy. These publications commonly used thematic accuracy measures and factors controlling their variation were then determined for various habitat mapping approaches for different coral reefs and seagrass environments. Assessment of these measures found that variations in accuracy levels were not only a result of actual differences in map accuracy, but were also due to: spatial complexity of benthic features present in the study area; distribution of the calibration and validation samples relative to each other, and the level of detail provided by these samples. Two main outcomes resulted from this dissertation. The first was the development of a robust mapping approach based on georeferenced photo-transect method integrated with high spatial resolution imagery, which is able to accurately map a variety of coral reef and seagrass habitats. The second outcome is an increase in capacity for coral reef and seagrass habitat mapping by scientists and managers. This increase is accomplished by providing knowledge on various habitat mapping approaches in regards to their: cost/time, accuracy and user relevance; performance of calibration and validation field methods; and performance of accuracy measures, when applied in a range of coral reef and seagrass environments. The findings and outcomes from this dissertation will significantly contribute to management of coral reef and seagrass environments by enabling scientists and managers to choose appropriate combinations of: field and image data sources; processing approaches, and validation methods for habitat mapping in these environments.
137

Understanding and monitoring the consequences of climate change and resilience-based management for coral reefs

Maynard, Jeffrey A. January 2010 (has links)
Climate change is now widely regarded as the single greatest threat to coral reefs. Climate change poses a range of different threats and reef ecosystems are widely reported as being amongst the first ecosystems to be severely affected by increases in global average temperatures. Coral reef managers responding effectively to the climate change threat will require research and monitoring, communication, impact mitigation and informed planning. Aspects of this thesis cover all of those working areas.
138

Ασβεστικά ροδοφύκη στο Αιγαίο πέλαγος (Τραγάνα)

Κοντογιαννάτου, Τρισεύγενη 05 July 2012 (has links)
Η έρευνα που διεξήχθει για την χαρτογράφηση της Τραγάνας έλαβε χώρα μεταξύ των νησιών Τήνου-Μυκόνου, Μυκόνου-Νάξου, Νάξου-Ίου, Σύρου-Τήνου και Ίου-Θήρας, σε μια έκταση περίπου 184 Km2. Η έρευνα επετεύχθει από τον συνδυασμό εφαρμογής ακουστικών μεθόδων : EG & G ηχοβολιστή πλευρικής σάρωσης, ηχοβολιστής μονής ηχητικής δέσμης SIMDAR και υψηλής ευκρίνειας (3,5 KHz) τομογράφο υποδομής πυθμένα. Από τις ηχογραφίες του Η.Π.Σ αποδόθηκαν ακουστικά μοντέλα με βάση την ένταση των ανακλάσεων. Κατά την μελέτη του Κυκλαδικού πεδίου από τις ηχογραφίες του Η.Π.Σ αποκαλύφθηκαν τέσσερις (4) ακουστικές ανακλάσεις: το ακουστικό στίγμα Α που περιελάμβανε περιοχές με χαμηλές έως μέτριες ανακλάσεις και αναπαριστούσε επίπεδο πυθμένα με αμμώδη έως χαλικώδη ιζήματα. Το ακουστικό στίγμα Β περιελάμβανε έντονες ανακλάσεις και αναπαριστούσε περιοχές συσσωματωμάτων από ασβεστολιθικά ροδοφύκη και προεξοχές βράχων. Το ακουστικό στίγμα C περιελάμβανε περιοχές εναλλασσόμενων υψηλών και χαμηλών ανακλάσεων και αναπαριστούσε στρωματοδομές επηρεασμένες από ρεύματα. Τέλος, το ακουστικό στίγμα D περιελάμβανε περιοχές υψηλής ανθρωπογενούς δραστηριότητας (τράτες). 7. Τα ασβεστιτικά ροδοφύκη είναι οι κύριοι κατασκευαστές των βιογενών οικοδομημάτων της τραγάνας που αναπτύσσεται πάνω στα σκληρά υπολείμματά τους. Το αποτέλεσμα είναι κατασκευές ποικίλων μεγεθών και σχημάτων, όπου μόνο το ανώτερο στρώμα τους αποτελείται από ζωντανά άτομα. Αυτές οι αξιόλογες κατασκευές υποστηρίζουν πολλαπλές μικρό-κοινότητες με αποτέλεσμα να χαρακτηρίζονται ως οικοσυστήματα υψηλής βιολογικής και λειτουργικής ποικιλομορφίας (Peres 1967, Steneck 1985, Sartoretto et al 1996, Ballesteros 2006). Οι κοινότητες αυτές έχουν μεγάλη σημασία για την αλιεία και ιδιαίτερα στην Ελλάδα θεωρούνται τα πιο σημαντικά αλιευτικά πεδία. Ωστόσο λόγω της ευάλωτης δομής τους, οι σχηματισμοί καταστρέφονται από την λειτουργία ορισμένων αλιευτικών εργαλείων. Ιδιαίτερα, στο Κυκλαδικό πεδίο, η χρήση διχτυών, οι υδατοκαλλιέργειες, η τοποθέτηση υποβρύχιων καλωδίων αλλά κυρίως η αλιεία έχουν επιπτώσεις σ’ αυτούς τους σχηματισμούς. Επιπλέον η χρήση τρατών είναι ένας ακόμα παράγοντας καταστροφής της τραγάνας. Οι τράτες προκαλούν την επαναιώρηση των ιζημάτων που μπορεί να έχει επίπτωση στην αύξηση των υφάλων. Αν και ο ακριβής οικολογικός ρόλος των σχηματισμών του κοραλλιογενούς στην Μεσόγειο δεν έχει ακόμα μελετηθεί μπορούμε να βγάλουμε κάποια συμπεράσματα : οι κοραλλιογενείς σχηματισμοί αποτελούν περιοχές αναπαραγωγής τόσο για τους ασπόνδυλους οργανισμούς όσο και για τους οργανισμούς των σπονδυλωτών. Επιπλέον έχουν την ικανότητα να δεσμεύουν και να διατηρούν οργανική ύλη. / -
139

Interações competitivas entre Epizoanthus gabrieli Carlgreen, 1951 (Ordem Zoanthidea) e corais na Baía de Todos os Santos e suas implicações para a comunidade recifal. / Competitive interactions between Epizoanthus gabrieli Carlgreen, 1951 (Order Zoanthidea) and corals in Todos os Santos Bay

Igor Cristino Silva Cruz 19 February 2014 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Alguns recifes de coral da Baía de Todos os Santos passaram a ser dominado pelo zoantídeo Epizoanthus gabrieli em 2003. Fenômeno resultante da degradação dos recife de coral que atinge 20% desses ecossistemas e ameaça outros 35% no mundo. Apesar de sua importância, apenas a mudança na comunidade para o domínio de macroalgas foi suficientemente estudado. Assim, torna-se urgente estudos sobres alterações envolvendo a dominância de outros organismos. Estes fornecem subsídios para produção de modelos funcionais que podem ajudar na tomada de decisão para o manejo destes ecossistemas tanto na prevenção destas alterações quanto na recuperação de suas comunidades. Os objetivos deste trabalho são (i) verificar se este fenômeno constitui uma mudança de fase, a partir da redução da abundância de corais e persistência da alta cobertura de E. gabrieli por pelo menos cinco anos, (ii) avaliar os efeitos da competição entre este zoantídeo e corais adultos e recrutas com experimentos manipulativos e (iii) investigar os efeitos desta dominância na assembleia de peixes recifais. Os resultados confirmaram a existência de uma mudança de fase, sugerindo que a abundância de E. gabrieli aumentou em 2003 ou antes e que até 2007 houve uma redução da cobertura de coral, condição que se mantêm pelo menos até 2013. As três espécies de corais testadas mostram-se muito sensíveis ao contato com E. gabrieli, com necrose em 78% das colônias e ocupação do esqueleto dos corais em 35% dos casos em um período de 118 dias. Além disso, um modelo feito a partir dos dados de proporção de colônias de corais em contato com este zoantídeo e a cobertura de E. gabrieli sugere que quando o zoantídeo atinge 6% de cobertura, 50% das colônias de corais entram em contato com o mesmo. Estes dados são fortes evidências de que a redução da cobertura de coral observada entre 2003 e 2007 foi causada por competição entre estes organismos. Não foi observado efeito negativo no recrutamento do coral em substrato artificial livre em recifes dominados por E. gabrieli, nem nas proximidades das suas colônias. Isso sugere que uma suposta redução da cobertura deste zoantídeo deve ser acompanhada pelo aumento da taxa de recrutamento de corais e que a competição com a inibição do recrutamento não suporta um efeito de histerese. Foi constatado que esta mudança de fase reduz a riqueza de espécies de peixes recifais, apresentando dez espécies a menos que os recifes normais, e que favorecem os invertívoros moveis em detrimento dos carnívoros e invertívoros sésseis. Contudo não se observou diferença na abundância de peixes. / Some coral reefs of Todos os Santos Bay have undergone a drastic change in the benthic community. In 2003, they began to be dominated by the zoanthid Epizoanthus gabrieli. This phenomenon is a consequence of coral reef degradation that now reaches approximately 20% of coral reefs worldwide and and threatens another 35%. The most dramatic consequences of this degradation are the phase shift phenomena which are characterized by reduction of coral abundance and increase of organisms that do not build reefs. Despite their importance, only a phase shift to the domain of macroalgae has been sufficiently studied. Given this situation, it is urgent to create functional models that demonstrate the ecological processes that occur in the installation of alternative states that persist over time. These models provide important information that can help in decision making on management measures both for prevention and recovery of these ecosystems. The aims of this work are (i) to verify if this phenomenon is a phase shift, (i.e. the reduction of the abundance of coral and persistence of high coverage E. gabrieli for more than five years of monitoring), (ii) evaluate the effects of competition between this zoanthid and recruits and adult coral with manipulative experiments and (iii) study the effects of dominance on the fish assemblage. The result confirmed the existence of a phase shift, suggesting that the abundance of E. gabrieli increased in 2003 or before and in 2007 there was a reduction in coral cover, and that this condition remained until at least 2013. The three coral species tested show great sensitivity to contact with E. gabrieli, with necrosis in 78% of the colonies and with overgrow in 35% of cases in a period of 118 days. In addition, a model made from the data of a proportion of coral colonies in contact with this zoanthid and coverage of E. gabrieli suggests that when the zoanthid reaches 6% coverage, 50% of coral colonies come in contact with it. These data are strong evidence that the reduction of coral cover observed between 2003 and 2007 was caused by competition between these organisms. There was no negative effect on the recruitment of coral on artificial substrate free in reefs dominated by E. gabrieli or near their colonies. This suggests that a presumed reduction of coverage of this zoanthid should be accompanied by an increase in coral recruitment rates and the competition by inhibition of recruitment does not support an effect of hysteresis. It was found that this phase shift reduces species richness of reef fishes, by ten species unless reefs normal, and that favor mobile invertivores to the detriment of carnivores and sessile invertivores. However there was no difference in the abundance of fish.
140

Novas ferramentas para monitoramento ambiental usando SIG Web

Cabral, Igor Pinheiro de Sales 19 December 2008 (has links)
Made available in DSpace on 2014-12-17T14:55:10Z (GMT). No. of bitstreams: 1 IgorPSC_da_capa_ate_cap5.pdf: 2688023 bytes, checksum: cee6b43b55f77595d45129c9130b17e9 (MD5) Previous issue date: 2008-12-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The use of Geographic Information Systems (GIS) has becoming very important in fields where detailed and precise study of earth surface features is required. Applications in environmental protection are such an example that requires the use of GIS tools for analysis and decision by managers and enrolled community of protected areas. In this specific field, a challenge that remains is to build a GIS that can be dynamically fed with data, allowing researchers and other agents to recover actual and up to date information. In some cases, data is acquired in several ways and come from different sources. To solve this problem, some tools were implemented that includes a model for spatial data treatment on the Web. The research issues involved start with the feeding and processing of environmental control data collected in-loco as biotic and geological variables and finishes with the presentation of all information on theWeb. For this dynamic processing, it was developed some tools that make MapServer more flexible and dynamic, allowing data uploading by the proper users. Furthermore, it was also developed a module that uses interpolation to aiming spatial data analysis. A complex application that has validated this research is to feed the system with data coming from coral reef regions located in northeast of Brazil. The system was implemented using the best interactivity concept provided by the AJAX model and resulted in a substantial contribution for efficiently accessing information, being an essential mechanism for controlling events in the environmental monitoring / O uso de Sistemas de Informa??es Geogr?ficas (SIG) tem se tornado essencial nos campos onde os detalhes e estudos precisos da superf?cie terrestre s?o requeridos. Aplica??es em monitoramento ambiental s?o exemplos que requerem o uso de um SIG para que os gestores e toda a comunidade envolvida possam realizar as an?lises e decis?es em cima das ?reas de prote??o ambiental. Neste campo espec?fico, um desafio ? construir um SIG que possa ser alimentado dinamicamente com dados, permitindo que os pr?prios pesquisadores enviem freq?entemente os dados ao sistema. Em alguns casos, os dados s?o adquiridos de diferentes fontes e precisam ser centralizados em um s? sistema. Para solucionar este problema, ferramentas foram implementadas nesta Tese, possibilitando que os dados espaciais sejam devidamente tratados na Web. Com efeito, a pesquisa envolvida nesta Tese tem in?cio a partir da inser??o e processamento de dados obtidos in-loco, como vari?veis bi?ticas e geol?gicas, e ? finalizada com a representa??o dessas informa??es na Web. Para a consecu??o deste processo din?mico foram desenvolvidas ferramentas que tornam o MapServer mais flex?vel e din?mico, permitindo que o pr?prio usu?rio envie os dados coletados. Al?m disso, um m?dulo que utiliza t?cnicas de interpola??o espacial para auxiliar as an?lises espaciais foi, tamb?m, implementado. Como meio de valida??o do sistema foram utilizados dados provenientes de pesquisas em uma regi?o de recifes de corais, no Nordeste do Brasil. Por fim, este sistema foi implementado atrav?s do uso dos conceitos de interatividade que s?o dados pelo AJAX, se tornando uma ferramenta para controle dos eventos relacionados ao monitoramento ambiental

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