published_or_final_version / Urban Planning / Master / Master of Science in Urban Planning

GIS AND REMOTE SENSING - BASED MODELS FOR DEVELOPMENT OF AQUACULTURE AND FISHERIES IN THE COASTAL ZONE: A case study in Baía de Sepetiba, BraziL. by Philip Conrad Scott The use of Geographical Information Systems (GIS) in regional development is now becoming recognized as an important research tool in identifying potential aquaculture development and promoting better use of fishery resources on a regional basis. Modelling tools of GIS were investigated within a database specifically built for the region of Sepetiba Bay (W44°50', S23°00') Rio de Janeiro - Brazil, where, water based aquaculture development potential for two native species 0 f molluscs: P ema p ema (brown mussel) and Crassostrea rhizophorae (mangrove oyster) was identified, and additionally potential for development of land-based aquaculture of the white shrimp, Litopenaeus vannamei. Taking into consideration a mix of production functions including environmental factors such as water temperature, salinity, dissolved oxygen content, natural food availability as well as shelter from exposed conditions, several aquaculture development potential areas were found. The integration of sub-models comprised of thematic layers in the GIS including human resources available, general infrastructure present, regional markets as well as constraints to aquaculture development was developed. Multi-criteria evaluation within sub-models and between sub-models resulted in identification of several distinct potential areas for mollusc aquaculture development, indicating significant production potential and job creation. Basic field environmental data were collected in field trips in 1996, 1997 and 1998. Fresh market data were collected in 2001-2002 and were used to analyse market potentiaL. The map analyses undertaken with GIS based models support the hypothesis that promising locations for aquaculture development, their extent and potential production capacity can be predicted, making GIS use a useful tool for natural resource management and decision support.

Understanding the influence of disturbance, both natural and human-induced, is a persistent challenge in ecology. Recently, attempts to predict future environments have focused on the consequences of broad scale disturbances. In this thesis I focus on environmental and trophic disturbances as shapers of benthic assemblages. There is growing recognition of the need for greater scientific investment in understanding environmental disturbances to balance the continuing focus of research assessing trophic theories (e.g. herbivory). Historically, it is these theories that have provided a cornerstone to describe and manage subtidal rocky coasts worldwide. In this thesis, therefore, I first assess how our ecological perception of such disturbances (i.e. water pollution and harvesting grazers) may vary as a consequence of the choice of taxonomic classifications used to observe benthic patterns (Chapter 2). I then assess how mechanical disturbance (i.e. wave exposure) may affect the morphology of benthic habitat (Chapter 3) and how temperature disturbances (i.e. oceanographic, cold water pulsing) may affect the consumers of these habitats (Chapter 4). The critical first finding centred on the effectiveness of alternate scales and metrics of taxonomic classification to detect the effects of water pollution (i.e. nutrient enhancement) as the largest disturbing agent on the benthos, and that this effect may be exacerbated by loss of grazers. While observations of the benthos as morphological groups detected the effects of enhanced nutrients, species diversity (as a measure of phylogenetic relatedness) was the only one of the chosen measures sensitive enough to detect the interaction of both top-down and bottom-up stressors. This chapter highlights the importance of choice of classification (e.g. morphology v. species) and indices (e.g. Shannon index v. ABC curves and phylogenetic diversity) in their potential to predetermine our perception of ecological change and thereby predict future environments. Mechanical disturbance (i.e. wave exposure) has been widely studied as a mechanism that creates new space for colonisation by alternate species, but is less well studied as a force that can change the shape of communities by mediating their morphology. Macroalgal morphology varies in response to wave exposure such that individuals at high exposures are often smaller than individuals in more sheltered environments. Observations not only confirmed these patterns for a general assemblage on a wave exposed southern coast, but reciprocal transplants of assemblages between exposures also revealed that morphological differences were likely to be a product of flexibility in morphological response of algae to local environments (Chapter 3). In contrast to the often multi-directional responses of a complex suite of morphological characters (e.g. smoothness, stipe length, frond width), overall size has the potential to be used as a broad and predictive tool to identify hydrodynamic stressors across an entire exposure gradient or geographic range. Strong trophic interactions are often considered characteristic of aquatic systems and due to their perceived ubiquity on temperate rocky coasts, there has been an emphasis in the literature on the influence of herbivores in determining assemblages. Given the importance of the link between herbivores and assemblage structure, in my final chapter I investigated the potential for disturbance to act indirectly on benthos by affecting the survivorship of an herbivorous urchin (Chapter 4). I used observations of variable temperature regimes in a region of upwelling to design an experiment that tested whether this temperature variation could negatively affect the survivorship of settling sea urchins (Heliocidairs erythrogramma). When exposed to cold water, mortality increased by up to 70 %, within 12 h of settlement, representing a massive loss of benthic consumers within a very short time scale. This result was used to assess the potential of temperature to indirectly influence benthic habitats across several spatial scales, a process that may have been profoundly underestimated. In summary, this thesis provides insight into environmental and trophic disturbances as shapers of benthic assemblage patterns, both as natural and human-induced phenomena. I show that our perception of ecological response to the combination of such disturbances can be contingent on the organisational scales and metrics used. Subtle differences in initial choice of such observational units may not only have large affects on the kinds of benthic patterns and disturbances ecologists detect, but also those that they pursue. I recognise that while some physical disturbances can appear subtle (e.g. morphological variation) or strong (e.g. high mortality rate of herbivores), their relative impacts on the broader assemblage (e.g. understorey flora and fauna) will often be dependent on biogeography. Integrating local-scale biological interactions with regional-scale physical processes, therefore, appears to be a potentially progressive line of future enquiry. Indeed, consideration of responses from the physiological through to physical and biogeographical scales will not only strengthen our understanding of the effects of alternate disturbance regimes, but also our predictive power to anticipate future change. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1339116 / Thesis (Ph.D.) - University of Adelaide, School of Earth and Environmental Sciences, 2008

The continental terrace west of Oregon between 43° 50'N and 44° 40' N latitude is 50 to 55 miles wide. It consists of a continental shelf, 16 to 35 miles wide, and a continental slope, 16 to 37 miles wide. The eastern portion of the shelf is a smooth, sediment covered area that slopes very gently west. The western portion of the shelf contains four rocky bank areas. The banks are topographically irregular and appear to be of structural origin. West of the banks the shelf edge occurs at depths of 71 to 90 fathoms. The continental slope extends from the edge of the shelf to the abyssal plain at depths of 1530 to 1610 fathoms. A smooth upper slope of less than three degrees extending to depths of 117 to 250 fathoms occurs north and south of Heceta Bank. West of Heceta Bank the upper slope is formed by a scarp that slopes 10° to 16° to 560 to 725 fathoms. West of the upper slope there is an area of irregular topography, including benches, hills and scarps, which extends to depths of 380 to 1100 fathoms. The lower part of the slope is formed by a north-striking scarp which is 3000 to 6000 feet high and slopes 04° to 15°. The bathymetry indicates that the continental slope was formed by step-type, block faulting. Sediments form a thin surface layer over much of: the terrace. Detrital sand, similar to the coastal sand, covers the shelf from the shoreline to approximately 50 fathoms. The deeper areas on the shelf and upper part of the slope are covered by glauconitic sands and silts on the topographic highs and olive green, clayey silts in the topographic lows. The intermediate and lower portions of the slope are blanketed with olive-green, clayey silt. In these sediments the sand fraction, which generally comprises less than five percent of the sample, is composed chiefly of diatoms, Foraminifera, Radiolaria, and sponge spicules. Sands are also present on the intermediate and deep portions of the slope. Dredge hauls west of Newport obtained sand composed mainly of detrital grains which may have been derived from an underlying friable sandstone. Thin layers of sand occur in cores from other portions of the slope. These sands may have been derived by down slope movement of sediment from the upper slope and the shelf. Sedimentary rocks of Upper Miocene and Pliocene age crop out on the shelf banks and on the continental slope. The banks consist of a sequence of diatomaceous, clayey siltstones with interbeds and concretions of calcareous siltstones. Glauconite sandstone, gray wacke sandstone, and limestone breccia are exposed along with the siltstone, on the northern end of Heceta Bank. Most of the rocks obtamed from the slope are similar to those from the shelf. Friable, wacke sandstone is exposed on the slope west of Newport. Foraminifera, the sand fraction compositions, and textural analyses all indicate that the sediment forming the siltstones from the shelf were deposited at lower littoral to lower bathyal depths. The sediments forming the rocks were deposited in one or more sedimentary basins during the Miocene and Pliocene. The subsidence continued until the. Late Pliocene when the area began to rise. The area was uplifted as much as 1000 fathoms by the Late Pleistocene when the shelf was eroded by transgressions and regressions resulting from sea level changes. The last rise in sea level resulted in the erosion of the shelf to its present form and the deposition of a thin layer of sediment. Sand is presently being deposited on the shallow areas adjacent to the continent, and silt and clay are being laid down on the slope and the sheltered areas of the outer shelf. / Graduation date: 1965

Thesis (Ph. D.)--University of Canterbury, 2009. / Typescript (photocopy). Includes bibliographical references (p. 220-239). Also available via the World Wide Web.

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 356-394).

Linear sandbanks are located globally in areas where there are strong currents and an abundance of sand. In recent years, these sandbanks have become a strategic interest as a potential source of marine aggregates (sand and gravel) and mineral deposits. They also commonly reach the sea surface and thus pose a threat to navigation. Headland-associated linear sandbanks are a specific type of sandbank, which are located in the lee of coastal topographic features such as headlands and islands. Interaction between tidal currents and topographic features generate complex three-dimensional circulation patterns that significantly influence the distribution of sediments in the vicinity of the feature. Field and numerical model investigations of the three-dimensional flow structure have been undertaken on the Levillain Shoal, a headland-associated linear sandbank present in the lee of Cape Levillain (Shark Bay, Western Australia). The field data indicated the presence of secondary flows near the tip of the Cape and around the bank, which were reproduced in the numerical simulations. Sediment transport paths near the Cape and the bank indicate that the sandbank is part of a sand circulation cell where the sand is circulating around the bank with exchanges between the sandbank and the headland. A morphological model (MTM) has been developed to understand processes responsible for the formation of the headland associated linear sandbanks. With an “idealized” Gaussian shaped headland, the formation of two symmetrical sandbanks on each side of the headland is observed. It is shown that sandbanks are formed in regions where there is a net accumulation of sand over a tidal cycle, due to the acceleration/⁄deceleration effects of the flow in the presence of the headland. Initially, sandbanks develop in a circular shape and grow vertically. As the sandbanks interact with the tidal flow, they evolve into elongated linear deposits (as observed in nature). The sandbank growth is dependent on the tidal regime, secondary flow, sand availability, and sediment grain size

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniversitet, 2005. / Härtill 4 uppsatser.

Thèse (D.R.Min.) -- Université du Québec à Chicoutimi, 2005. / Bibliogr.: f. 208-256. Document électronique également accessible en format PDF. CaQCU

Thesis (Ph. D.)--Université Paul Sabatier, Toulouse III, 1975. / Map documentation: p. [I-II] (3rd set of capital Roman numerals). Includes bibliographical references (p. [I]-[XIX]).