O Balneário Chuí é uma estreita feição costeira de traçado irregular, assimétrico, adjacente a uma feição de falésias erosivas, que são produtos da Barreira III, desgastada pela ação dos agentes mesológicos atuantes. O Arroio Chuí, por sua vez, é um sistema de drenagem, localizado exclusivamente na zona costeira, que nasce a partir do banhado Canelões, ao sul do banhado do Taim, e segue quase paralelo à costa no sentido sul até o Balneário Barra do Chuí, onde deságua no Oceano Atlântico. A construção dos molhes para a fixação da desembocadura se fez necessária já que, anteriormente à construção dos molhes, iniciada em 1975, o arroio migrava ao longo da linha de costa, provocando, em algumas situações, o total fechamento da barra. Em 1978 foi finalizada a obra que fixou a desembocadura do Arroio Chuí através de molhes, contribuindo para a consolidação do limite territorial entre o Brasil e o Uruguai. Este estudo tem como propósito identificar e descrever a evolução da desembocadura do Arroio Chuí após a sua fixação, a fim de auxiliar no gerenciamento do uso e da ocupação antrópica desta área Para tornar possível a análise da variabilidade temporal, foram utilizadas fotografias aéreas, uma carta topográfica e imagens de satélite de diferentes datas. As imagens passaram por um pré-processamento, foram vetorizadas manualmente e tiveram suas análises realizadas em ambiente SIG. Os resultados mostraram que a obra de fixação através de molhes causou uma variação de posição da desembocadura de 1260 m na direção sul entre 1964, data das imagens mais antigas disponíveis para a região, e 1975, ano do início da construção dos molhes. Este segmento costeiro representou uma perda de 0,16 km² ao Uruguai. Além disso, não foi observada tendência erosiva no balneário brasileiro, como resultado da interrupção do transporte de sedimentos pela deriva litorânea. Espera-se que a análise contribua para a efetuação de um melhor planejamento ambiental e urbano, auxilie ações de gerenciamento costeiro nos balneários Barra do Chuí (BR) e Barra del Chuy (UY) e motive a geração de mais estudos nesta área costeira ainda pouco estudada. / The balneary of Barra do Chuí is a narrow coastal feature with irregular layout, asymmetrical, adjacent to a set of erosive cliffs, which are products of Barrier III, eroded by the action of the mesological agents acting. The Arroio Chuí, in turn, is a drainage system, located exclusively in the coastal zone, which rises from the Canelões wetlands, to the south of the Taim wetlands, and follows almost parallel to the coast in the south direction, marking the border between the balnearies Barra do Chuí (BR) and Barra del Chuy (UY) until draining into the Atlantic Ocean. The construction of the jetties for the fixation of the mouth was necessary because, prior to construction, started in 1975, the rivulet migrated along the coastline, causing, in some situations, the complete closure of the bar. In 1978, the work that established the mouth of the Arroio Chuí was finalized, contributing for the consolidation of the territorial limit between Brazil and Uruguay. This study aims to identify and describe the evolution of the mouth of the Arroio Chuí after its fixation, with the purpose of assisting in the management of the use and the anthropic occupation of this area To make possible the analysis of the temporal variability were used aerial photographs, a topographic chart and satellite images of different dates. The images were pre-processed, manually vectored and analyzed in a GIS environment. The results showed that the work of fixation through jetties caused a position change of the mouth of 1260 m in the south direction between 1964, date of the oldest images available for the region, and 1975, year of the beginning of the jetties construction. This coastal segment represented a 0.16 km² loss to Uruguay. In addition, no erosive trend was observed in the brazilian balneary, as a result of the interruption of sediment transport by the coastal drift. It is expected that the analysis will contribute to better environmental and urban planning, assist coastal management actions in the Chuí (BR) and Barra del Chuy (UY) balnearies and motivate the generation of further studies in this coastal area that has not been studied yet.

Contemporary sediment transport, suspended sediment flux, rates of intertidal sedimentation, and Holocene sedimentation history are assessed for Hamford Water, a small meso-tidal inlet and saltmarsh embayment in Essex, UK. Sediment transport rates are calculated using semi-empirical equations; suspended sediment flux is computed by integration of suspended sediment concentration and velocity across the inlet throat; intertidal sedimentation rates are assessed from monitoring of discrete markers on saltmarsh and mudflat; and Holocene sedimentation is estimated from radiocarbon dating of buried organic layers, sampled using a vibrocorer. Results show a tidal regime typical of ebb-dominated inlets: moderate, ebb-dominant flow (==1 m S·l) in the central ebb channel is matched by similar flood-dominant marginal channel flows. The sediment dynamics are not influenced by any fluvial input; there is negligible fresh water input. The net direction of sediment transport is predominantly ebb-orientated. Coarse sand transport pathways are circulatory and dependent on longshore drift. Sand (D = 0.25 mm) enters at the margins and is expelled in the central ebb channel. Negligible sand is transported further landward than the mouth; intertidal sedimentation relies mainly on levels of suspended sediment. Rates of intertidal sedimentation are spatially variable: tidal creek sedimentation is greater than saltmarsh, with a mean rate of 4.2mm yr"l. Buried organic horizons. radiocarbon dated to 600 years BP, are attributed to reclaimed land levels. Holocene sedimentation rates since 4300 years BP, estimated from 14C dating of shell bands. accord with current estimates of sea-level rise of approximately 1 mm i 1 • The role and evolution of the inlet entrance and ebb tidal delta are seen as critical to the evolution of the embayment as a whole. The interaction of the embayment with the adjacent coastal zone considered essential when fonnulating shoreline management plans. Hamford Water is considered an integral part of the Stour/OrwelllNaze coastal system.

Comparative ecology and interspecific competition were examined between two sympatric congeners, Sebastes caurinus Richardson 1845 (copper rockfish) and S. maliger (Jordan and Gilbert 1880) (quillback rockfish) in Saanich Inlet, British Columbia, Canada, from 1986-1990. Ecological profiles were constructed through analyses of depth distribution, habitat and species associations, activities, feeding habits, gut allometry, growth, and reproduction. Interspecific competition between copper and quillback rockfish was examined by experimentally manipulating the densities of one or the other species on rocky reefs in Saanich Inlet where they were sympatric. The Pisces IV submersible was used to survey the distribution of rockfish in relatively deep-water (21-140 m) in Saanich Inlet. Copper and quillback rockfish were sympatric in water depths of 21-65 m. They occurred in association with one another the majority of the time (>90%) and their densities were greatest over areas of complex substrate. Size of copper and quillback rockfish was positively correlated with increased depth, primarily due to the absence of small fish in deeper waters. Both species were observed most frequently perched on open substrate or hovering in the water column. Copper rockfish were observed swimming more frequently than quillback rockfish. Copper and quillback rockfish primarily consumed demersal crustaceans throughout the year. Copper rockfish consumed a greater proportion of pelagic fishes than quillback rockfish, whereas quillback rockfish had a greater proportion of pelagic crustaceans in their diet. Levins' (1968) measure of niche breadth of the diet (by mass), as standardized by Hurlbert (1978), was narrow (0.19-0.20) to moderate (0.32-0.51) for quillback and copper rockfish respectively, during spring, summer, and fall. In the winter it was extremely narrow (0.02) for both species due to their feeding predominantly on one prey type, juvenile herring (Clupea harengus) . The Simplified Morisita Index of niche overlap (Horn 1966) in feeding habits (by mass) was relatively high (>0.55) throughout the year, and particularly during the winter (0.99). This high niche overlap in the winter occurred when large schools of juvenile herring were available in the environment and were probably not a limited resource. Extensive niche overlap between copper and quillback rockfish may therefore indicate an abundance of a shared resource rather than competition for the resource. Copper and quillback rockfish consumed the greatest quantity of food during the winter when feeding on juvenile herring, although quillback rockfish consumed significantly less food mass than copper rockfish in the winter. A greater proportion of quillback rockfish were collected with food in their stomachs during the spring and summer, when the numerically dominant food items were pelagic crustaceans. The importance of fish prey in the diets of both copper and quillback rockfish increased with size. Copper rockfish had a shorter intestine and larger stomach relative to similar-sized quillback rockfish. This suggested that the gastrointestinal tract of copper rockfish was better suited to holding and digesting fish and larger crustaceans than quillback rockfish, an observation consistent with differences in their feeding habits. Copper and quillback rockfish had similar growth patterns with no readily identifiable species-specific and sex-specific differences. Both sexes of both species attained asymptotic lengths of 30-31 cm total length and had similar growth coefficients (0.141-0.187). Within each sex, copper rockfish had a smaller increase in mass per unit of body length than quillback rockfish, indicative of a more pelagic lifestyle for copper rockfish. Estimated lengths at first and 100% sexual maturity for female and male copper and quillback rockfish were similar. Male copper rockfish were ripe, and potentially inseminated females, in January and February. Female copper rockfish were found to be carrying fertilized eggs in April and May, and gave birth to their young primarily in June. The reproductive cycle of quillback rockfish preceded that of copper rockfish by approximately one month, with parturition for quillback rockfish occurring mainly in May. The fecundity of copper and quillback rockfish was similar, with a 30-cm fish giving birth to approximately 90,000 young. Visceral fat cycles of mature female copper and quillback rockfish were complementary to their cycles of gonad maturation and increases in gonad size, indicating that they use visceral fat stores as a source of energy for maturation of their eggs and nourishment of their developing young. Visceral fat cycles of mature males were mainly coincident with the maturation and size increase of their gonads, indicating that they did not use visceral fat reserves in the maturation of their gonads. Male rockfish secondarily may have used their fat reserves as an energy source during the period when they were ripe, perhaps for mating activities. Visceral fat accumulation and dissipation in immature males and females appeared to be primarily related to periods of feeding. Interspecific competition between copper and quillback rockfish was asymmetrical, seasonal, and transitory, based on experimental manipulations of the densities of the congeners in natural populations. Copper rockfish did not have a competitive effect on quillback rockfish, but quillback rockfish had a weak competitive effect on copper rockfish. This effect was apparent only during the fall, was strongest in the fall immediately following the density manipulations, and appeared to weaken in the subsequent fall season. The seasonal competitive effect may have been caused by copper rockfish moving onto the study reefs (18-31 m depth) from shallower waters (<20 m) during the fall and winter, creating a short-term 'ecological crunch' in which food or space resources were limited. Overall, comparative ecological profiles of copper and quillback rockfish exhibited a large degree of overlap. Differences observed between them were small but consistently indicated that copper rockfish had a more pelagic lifestyle than quillback rockfish. The otherwise high degree of similarity between the two congeners, however, did not translate into sustained interspecific competition. Ecological theory purporting a major role for interspecific competition in structuring fish communities was therefore not supported by experimental manipulations of population densities of deep-subtidal, temperate zone rockfishes. The asymmetrical, seasonal, and transitory occurrence of weak interspecific competition demonstrated that competition between these rockfish species is dynamic, and cannot account for the pattern of species association. Alternative hypotheses based on the importance of intraspecific competition, predation, or environmental variability must therefore be considered. / Graduate

O Balneário Chuí é uma estreita feição costeira de traçado irregular, assimétrico, adjacente a uma feição de falésias erosivas, que são produtos da Barreira III, desgastada pela ação dos agentes mesológicos atuantes. O Arroio Chuí, por sua vez, é um sistema de drenagem, localizado exclusivamente na zona costeira, que nasce a partir do banhado Canelões, ao sul do banhado do Taim, e segue quase paralelo à costa no sentido sul até o Balneário Barra do Chuí, onde deságua no Oceano Atlântico. A construção dos molhes para a fixação da desembocadura se fez necessária já que, anteriormente à construção dos molhes, iniciada em 1975, o arroio migrava ao longo da linha de costa, provocando, em algumas situações, o total fechamento da barra. Em 1978 foi finalizada a obra que fixou a desembocadura do Arroio Chuí através de molhes, contribuindo para a consolidação do limite territorial entre o Brasil e o Uruguai. Este estudo tem como propósito identificar e descrever a evolução da desembocadura do Arroio Chuí após a sua fixação, a fim de auxiliar no gerenciamento do uso e da ocupação antrópica desta área Para tornar possível a análise da variabilidade temporal, foram utilizadas fotografias aéreas, uma carta topográfica e imagens de satélite de diferentes datas. As imagens passaram por um pré-processamento, foram vetorizadas manualmente e tiveram suas análises realizadas em ambiente SIG. Os resultados mostraram que a obra de fixação através de molhes causou uma variação de posição da desembocadura de 1260 m na direção sul entre 1964, data das imagens mais antigas disponíveis para a região, e 1975, ano do início da construção dos molhes. Este segmento costeiro representou uma perda de 0,16 km² ao Uruguai. Além disso, não foi observada tendência erosiva no balneário brasileiro, como resultado da interrupção do transporte de sedimentos pela deriva litorânea. Espera-se que a análise contribua para a efetuação de um melhor planejamento ambiental e urbano, auxilie ações de gerenciamento costeiro nos balneários Barra do Chuí (BR) e Barra del Chuy (UY) e motive a geração de mais estudos nesta área costeira ainda pouco estudada. / The balneary of Barra do Chuí is a narrow coastal feature with irregular layout, asymmetrical, adjacent to a set of erosive cliffs, which are products of Barrier III, eroded by the action of the mesological agents acting. The Arroio Chuí, in turn, is a drainage system, located exclusively in the coastal zone, which rises from the Canelões wetlands, to the south of the Taim wetlands, and follows almost parallel to the coast in the south direction, marking the border between the balnearies Barra do Chuí (BR) and Barra del Chuy (UY) until draining into the Atlantic Ocean. The construction of the jetties for the fixation of the mouth was necessary because, prior to construction, started in 1975, the rivulet migrated along the coastline, causing, in some situations, the complete closure of the bar. In 1978, the work that established the mouth of the Arroio Chuí was finalized, contributing for the consolidation of the territorial limit between Brazil and Uruguay. This study aims to identify and describe the evolution of the mouth of the Arroio Chuí after its fixation, with the purpose of assisting in the management of the use and the anthropic occupation of this area To make possible the analysis of the temporal variability were used aerial photographs, a topographic chart and satellite images of different dates. The images were pre-processed, manually vectored and analyzed in a GIS environment. The results showed that the work of fixation through jetties caused a position change of the mouth of 1260 m in the south direction between 1964, date of the oldest images available for the region, and 1975, year of the beginning of the jetties construction. This coastal segment represented a 0.16 km² loss to Uruguay. In addition, no erosive trend was observed in the brazilian balneary, as a result of the interruption of sediment transport by the coastal drift. It is expected that the analysis will contribute to better environmental and urban planning, assist coastal management actions in the Chuí (BR) and Barra del Chuy (UY) balnearies and motivate the generation of further studies in this coastal area that has not been studied yet.

The accumulation of butter sole within Skidegate inlet provides an important winter trawl fishery for northern British Columbia. The availability, prior to spawning, has been determined from catch statistics offered willingly by fishermen and industry. The availability fluctuates during the season but the real peak period, after the accumulated stock has been removed, occurs during the last week that fishing was permitted. Distortions which could have been produced by boats of different fishing efficiencies and, also, by boats which fished for only part of the season are compensated for. The minimum estimate of fishing intensity, as determined from tagging experiments, is 30.8%. The abundance of the stock, calculated from the fishing intensity, sex ratios, and length-weight data, is approximately 3,130,000 fish. The differential appearance of the sexes upon the grounds has been determined. The male fish appear upon the grounds first and are later followed by the females. Tag returns provide information concerning movement between the various grounds within the inlet and also dispersion from the inlet into Hecate strait after spawning has occurred. / Science, Faculty of / Zoology, Department of / Graduate

Distributions of salinity, temperature, and oxygen of Bute Inlet based on eleven oceanographic surveys between the period August 1950 to August 1952 have been examined. The shallow salinity structures of the various seasons can be classified under two main groups, those occurring at periods of small river runoff and the others occurring at periods of large river runoff. In general, the surface salinity increases to seaward and with depth during all seasons. The surface water along the western shore is almost always observed to be less saline than along the eastern shore. The salinity of the deep water is 30.6 % during both periods. The seasonal fluctuation of salinities at the surface is well-marked but below a depth of 60 feet no normal cycle exists. The temperature distributions of both seasons can also be grouped under two main seasons, namely, Winter and Summer. During both seasons the surface temperature generally increases to seaward. The temperature gradients in the upper layers during the Winter and Summer are positive (increasing vertically downward) and negative (decreasing vertically downward) respectively. From the Spring Transitional to the late Autumn, a well-defined temperature minimum, which becomes indistinguishable at the mouth, is evident in the intermediate depths. The water in the greater depths has a temperature of 8°C and remains almost unchanged throughout the seasons. The seasonal temperature variation of the surface and sub-surface water down to a depth of 150 feet is in phase with the air temperature cycle but below this it is less noticeable. Insolation and cold runoff water from the rivers are predominant factors in determining the fluctuation in the temperature. The concentration of dissolved oxygen is usually high in the surface layer. The water at the greater depth is not stagnant as evidenced by the oxygen concentration. The characteristic water types of this inlet are: the Deep Water, Runoff Water, Intermediate Water and Winter Surface Water. The three distinct layers in the oceanographic structures are: the upper brackish layer, mixed layer, and lower layer. The main circulation of this inlet is estuarine. Eddy coefficient of diffusivity of values 0.65 and 0.58 g./cm./ sec., have been determined for the water above and below the layer of minimum temperature respectively. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

This study investigated the process by which molybdenum was removed from sea water in Saanich Inlet, an anoxic fjord, whose basin sediments are enriched in molybdenum. Water samples were collected in the inlet from July 1971 to April 1972 at about two month intervals and were analyzed for pH, salinity, temperature, dissolved and suspended molybdenum, suspended manganese and iron, and dissolved oxygen and hydrogen sulphide. A new technique for the determination of dissolved and suspended molybdenum was developed. The data showed a negative correlation between dissolved molybdenum and suspended manganese, and a positive correlation between suspended molybdenum and suspended manganese. This suggested that molybdenum was being scavenged from sea water by suspended manganese oxides. The distribution of molybdenum in the basin surface sediments was qualitatively correlated to the distribution of suspended molybdenum in the overlying basin water. During about September to December, the molybdenum profile was described by a two layer system. In the top 75 m layer the molybdenum followed the salinity profile. Below 75 m the distribution was described by a one dimensional mathematical model. The yearly deposition of molybdenum in the basin sediments was calculated from the estimated sediment deposition rate. This value was not inconsistent with that calculated from the rate molybdenum is scavenged by manganese oxides from the basin water. / Science, Faculty of / Chemistry, Department of / Graduate

During some years Neocalanus plumchrus overwinters in Saanich Inlet while in other years they are absent from the fjord (Harrison et al., 1983). The cause of this variation is not known but the annual development of anoxic conditions followed by an intrusion of dense, oxygenated water, was suspected to influence their distribution and abundance. Vertical and horizontal haul samples collected from Saanich Inlet indicated the overwintering population in 1985 (September 1985 to March 1986) was sparse; in September 1986 the population of N. plumchrus was comparably low. In the spring and summer, N. plumchrus is introduced from the Strait of Georgia and Juan de Fuca Strait, and in some years may arise from reproduction within the inlet. So few adults were collected at the three stations in Saanich Inlet in January-March 1986 (<0.20 m⁻³) that their potential contribution to the spring population was considered negligible. Decline in the overwintering population in September 1985 and 1986 appears to be correlated with the occurrence of an extensive deep water renewal. The distribution of N. plumchrus during early stages of their deep water migration (June to August), is influenced by the low oxygen concentrations in the bottom of the inlet (i.e. 0.10-0.30 mL L⁻¹). During the renewal, copepods occurred above the oxygen minimum (75 m) possibly due to their displacement or their avoidance of the low oxygen zone. Subsequently, they were exposed to tidal transport out of the inlet and perhaps to increased predation. On two occasions in which N. plumchrus was present during the winter in Saanich Inlet (1969 & 1974), a high volume of dense water intruded, disrupting the copepod layer during the mixing of the two water masses. Even though a greater volume of water left the inlet some of the copepods could have remained in the water, below sill depth. Neocalanus plumchrus successfully overwinters and reproduces in Sechelt Inlet which is well-oxygenated but has a very shallow sill (15 m) that 'locks' the copepods into the inlet. The fifth copepodite stages also occupy deeper depths in Sechelt Inlet than in Saanich Inlet, even though the bottom depths are comparable. In low oxygen tolerance experiments many factors such as the period of captivity, and the region of origin (i.e. Saanich Inlet versus the Strait of Georgia) caused variable results. Although the minimum oxygen level tolerable during their migration could not be determined, N. plumchrus tolerated levels as low as 0.56 mL L⁻¹ (12% mortality). Sediment trap samples indicate that a massive die off could not account for the loss of N. plumchrus from Saanich Inlet. / Science, Faculty of / Zoology, Department of / Graduate

Tidal inlets on sandy shorelines separate barrier islands and serve as a conduit for transport of sand and water between embayments and oceans, seas, or other tidally influenced waterbodies. Tides and waves induce currents along the coastline that transport sediment across-shore and alongshore. Coastal managers must optimize barrier-inlet system stability while conserving limited sediment resources, and often base management decisions and engineering design upon geomorphic and numerical models that predict the morphological behavior of tidal inlets on short-to-medium timescales (years to decades). The overall goal of this study was threefold. First, to provide science-based practical guidance for regional sediment management in the vicinity of tidal inlets. Secondly, to enhance the understanding of the temporal and spatial scales of sediment pathways in these regions through numerical simulation of traced sediment transport. And, third, to combine these lessons learned in both regional sediment management and analysis of morphodynamic and sediment bypassing pathways with application to a common practical management practice of inlet shoal mining and adjacent beach placement. The temporal and spatial scales controlling the morphodynamics of barrier-inlet systems were reviewed within a regional sediment management context. Next, the application of regional sediment management methods to case studies of multiple barrier-inlet systems in West-Central Florida led to the development of a decision-support tool for regional sediment management (RSM) as applied to barrier-inlet systems. Connecting multiple barrier islands and inlets at appropriate spatio-temporal scales is critical in developing an appropriately scoped sediment management plan for a barrier-inlet system. Evaluating sediment bypassing capacity and overall inlet morphodynamics can better inform regional sand sharing along barrier-inlet coastlines; particularly where sediment resources are scarce and a close coupling between inlet dredging and beach placement is vital to long-term sustainable management. Continued sea-level rise and anthropogenic activities may intensify the need for investigating longer-term processes and expanding regional planning at a centennial timescale, and are acknowledged as challenging tasks for RSM studies going forward. A regionally focused, multi-inlet study was necessary to improve the management plans for the case study inlets (from north to south): John’s Pass, Blind Pass, Pass-a-Grille Inlet, and Bunces Pass. Key recommendations based on the case studies include: 1) allow the natural sediment bypassing to be re-established at Blind Pass inlet through reduced ebb-tidal delta mining, 2) reduce the interruption to sediment bypassing at John’s Pass and Pass-a-Grille inlets through an improved design of the dredged mining areas located along sediment bypassing pathways, 3) allow for continued natural sediment bypassing at Bunces Pass, and, 4) incorporate the cyclic sediment bypassing through swash-bar attachment into the management plan at Bunces Pass and adjacent barrier-islands. Similar systems in other regions may benefit from the lessons derived in this case study of an adaptively managed multi-inlet system. A numerical model that computes hydrodynamics, sediment transport, and morphodynamics including bed layering was incorporated in this study to analyze sediment transport pathways between littoral sources from adjacent beaches and the geomorphic features of an idealized tidal inlet designed to imitate the John’s Pass tidal inlet in West-central Florida, USA. This study developed a methodology to numerically trace sediment transport, deposition and erosion. This method was applied to investigate sediment-bypassing pathways under varying temporal and spatial scales. The analyses of the adjacent beach’s contribution to tidal inlet sediment bypassing demonstrated variable temporal scales on sediment transport and exchange. High-energy wave events dominated the temporal scale for sand to be transported from the updrift beach to the ebb-tidal delta, whereas cyclical tidal processes had a significant influence on the spatial pattern of exchange between the shoals and channel features of the tidal inlet. The ability to simulate burial and erosion of tracers allowed identification of offshore sedimentation hotspots such as terminal lobe as well as zones of deposition and active transport in shallow water, such as the updrift channel margin linear bar and the downdrift platform of the ebb-tidal delta. The general sediment-bypassing pathway reflected a tidal-driven redistribution following event-driven pulses of wave-induced sediment mobilization. Sediment was transported along the beach during these energetic wave events. Flood- and ebb-tidal currents transported the sediment mobilized by high waves into the inlet channels. This was followed by subsequent gradual redistribution of the deposited channel sediments over the ebb-tidal delta features during fair-weather conditions. The modeling methods were then applied to investigate the sediment pathways and bypassing processes for three validated numerical models of coastal tidal inlets that span a range of forcing conditions. The processes that influence sediment transport along various pathways between the several morphological features of each inlet and its adjacent beaches were examined. The sediment tracing methodology employed in this study allowed for an evaluation of the sediment transport pathways between the various morphologic features of a tidal inlet, as well as their respective processes that drive the exchange of sediments. Characterizing and correlating the sediment pathways between tidal inlet morphologic features can improve the inlet reservoir model, which is a predictive model of inlet shoal volumes based on empirical formulae. The results of this study illustrate the value of including sediment-tracking techniques in simulating sediment bypassing and the potential of this application to inform coastal engineering and design modifications to sediment reservoirs of tidal inlets. And, finally, the spatial patterns of transport and erosion and deposition of traced, littoral source sediment, were investigated using the same modeling framework to evaluate the design of ebb-tidal delta mining on sediment bypassing dynamics of a tidal inlet system based on an idealized model of John’s Pass, Florida. Seven mining areas were simulated with traced sediment sources from the updrift beach, downdrift beach, and adjacent shoals. The tracers’ migration pattern and mining area infilling were analyzed to depict the sediment bypassing pathways and their contributions to mining area infilling. Mining area recovery rates were highest along the channel margin linear bar, and decrease offshore and downdrift. Updrift sand sources contributed more to mining area infilling than downdrift sand sources. The position of the mining area in relation to the updrift or downdrift morphological features dictates whether it will receive primarily updrift- or downdrift-originating littoral sediment from the beach. The source of sedimentation within the mining areas is a combination of inlet-ward transport of beach sediment and nearby shoal sediment. Proximity to the inlet channel determined the degree to which sedimentation had originated from longshore transported beach sediment. This methodology can improve confidence in management decisions concerned with the sand-sharing capacity of barrier-inlet systems in a local and regional context.

<p> Chesterfield Inlet drains an area of 290,000 km^2, between Great Slave Lake and northern Hudson Bay, of predominantly continuous permafrost terrain. The 220-kilometre-long inlet may be used as an important navigation link to Baker Lake and potential pipeline sites. The inlet forms a complex network and is characterized by strong tidal forcing.</p> <p> A one-dimensional numerical model, using a weighted, implicit, finite difference scheme, was modified for application to the network. Sparse matrix techniques were incorporated into the model to speed Gaussian Elimination in the solution of the equations.</p> <p> Tidal constituents, derived from admittance calculations, were used to predict water levels at eight tide gauge locations. Tidal predictions at Sandpiper Island were used as the downstream boundary condition for the numerical model, while tidal predictions at the other gauge locations were used in the model calibration.</p> <p> The observed and model-computed water levels are in good agreement over the lower half of the inlet. Appreciable differences between the observed and computed values were encountered in the upper reaches. Although some of these discrepancies are attributable to errors in the upstream boundary condition and schematization of the model, there is evidence to suggest that time and range errors may exist in some of the recorded tidal data.</p> <p> The variation in the phase and amplitude of the tide throughout the inlet is determined through an examination of the tidal constituents and the model results. Power spectra of the observed and model-predicted water levels reveal that nonlinear interactions of the major tidal constituents take place in the upper portion of the inlet.</p> / Thesis / Master of Engineering (MEngr)