O complexo Estuarino Lagunar Cananéia Iguape abriga um dos ecossistemas mais preservados e sensíveis do Estado de São Paulo, tornando seu litoral Sul uma região de grande importância social e ecológica. Entretanto, a ocupação desordenada e deficiências no sistema de saneamento básico, especialmente durante os meses de verão, aliados ao aumento da influência da vazão do Rio Ribeira de Iguape na circulação local, vêm contribuindo para a alteração das condições costeiras e do estuário e aumento da poluição marinha. A circulação marinha tem um papel fundamental na dispersão ou concentração de poluentes que são despejados no meio marinho. Para analisar a influência da circulação marítima em uma das principais atividades socioeconômicas da região, a pesca, foram determinadas as características das variabilidades do nível do mar e das correntes na Área de Proteção Ambiental Marinha do Litoral Sul (APAMLS) e do Estuário Lagunar Cananéia Iguape, avaliando os efeitos meteorológicos e oceânicos na zona costeira do litoral sul do Estado de São Paulo, através de modelagem numérica. Foi elaborada uma breve caracterização socioeconômica e da atividade pesqueira dos municípios desta região, por meio de síntese de dados secundários. Pode-se constatar que, como esperado, a circulação no estuário lagunar Cananéia Iguape é fortemente influenciada pela maré astronômica na sua porção sul e pela descarga fluvial ao norte, sofrendo poucas alterações devido aos efeitos meteorológicos. Por outro lado, a circulação na área costeira que abrange a APAMLS, além de sofrer grande influência da vazão do Ribeira de Iguape ao norte, tem a magnitude das correntes intensificada pela ação dos ventos e da densidade da água. A circulação marinha influencia intensamente a pesca da região e o conhecimento desse processo é fundamental para a gestão integrada dos recursos naturais e do ambiente com o desenvolvimento sustentável do litoral sul paulista. A atividade pesqueira, que teve grande redução de importância econômica para a região, apesar de ainda ser fundamental, se apoia na captura de algumas espécies; mas os problemas associados ao exercício da pesca são complexos, necessitando de um grande esforço para serem solucionados, para que se possa alcançar um avanço atrelado à manutenção da qualidade ambiental para esta região ainda bastante preservada. O conhecimento da hidrodinâmica da região dá suporte às diretrizes de uma área de preservação, pois os efeitos da circulação marinha são marcantes na região costeira, inclusive nas zonas de pesca. Assim, o manejo da APAMLS deve considerar que as correntes são em geral mais fracas durante o verão do que nos demais períodos do ano; deste modo, a dispersão de poluentes no verão, quando ocorre o maior aporte devido ao aumento do turismo, é mais lenta do que no restante do ano. Outros aspectos da circulação marítima devem ser levados em conta nos planos de manejo, como a predominância das marés e vazões fluviais no interior do estuário e a grande influência meteorológica nas áreas costeira e de plataforma adjacentes. / The complex Estuarine Lagoon Cananeia Iguape houses one of the best preserved and sensitive ecosystems of the State of São Paulo, making its southern coast a region of great social and ecological importance. However, the disorderly occupation and deficiencies in the sanitation system, especially during the summer months, combined with the increasing influence of the flow of Iguape Ribeira River in local circulation, have contributed to the change of coastal and estuary conditions and increased marine pollution. The marine circulation plays a key role in the dispersion or concentration of pollutants that are discharged into the marine environment. To analyze the influence of ocean circulation in one of the main socio-economic activities in the region, fishing, a study was performed to determine the characteristics of the variability of sea level and currents in the Marine Protected Area of the South Coast (APAMLS) and Lagoon Estuary Cananeia Iguape, evaluating the meteorological and oceanic effects in the coastal zone of the south coast of São Paulo, through numerical modeling. A brief socioeconomic characterization about the fishing activity of the municipalities of the region was developed, through synthesis of secondary data. It can be seen that, as expected, the circulation in the lagoon estuary Cananeia Iguape is strongly influenced by the astronomical tide in its southern portion and the river discharge in the north, with small influence of weather effects. On the other hand, the circulation in the coastal area encompassing APAMLS is submitted to great influence of the flow of Iguape Ribeira in the north, and the magnitude of the currents is intensified by the wind and the water density. The marine circulation strongly influences fishing in the area and the knowledge of this process is essential for the integrated management of natural resources and the environment, to a sustainable development of São Paulo south coast. The fishing industry, which had great reduction of economic importance to the region, although still important, is based on the capture of some species; but the problems associated with fishing activity are complex, requiring a great effort to be solved, to achieve a progress to maintaining environmental quality in this still well preserved region. Knowledge of hydrodynamics of the region supports the guidelines of a conservation area , since the effects of marine circulation are striking in the coastal region, including in fisheries areas . Thus, the management of APAMLS should consider that the currents are weaker in general during the summer than in other times of the year ; thus the dispersion of pollutants in summer, when the largest contribution is due to increased tourism is slower than the rest of the year. Other aspects of ocean circulation must be taken into account in the management plans , as the dominance of the tides and river flows into the estuary and the weather great influence on coastal areas and adjacent platform.

Este trabalho teve como objetivo analisar três métodos de avaliação de contaminação ambiental, sendo dois aplicados em um modelo biológico, a espécie Achirus lineatus (Achiridae, Pleuronectiformes) e o terceiro na ictiofauna da baía de Santos e do canal de Bertioga. As amostras foram coletadas mensalmente no ano de 2005 utilizando-se uma rede de arrasto de fundo com um esforço de pesca de 10 minutos. Foram capturados cerca de 40.000 espécimes, dentre eles 260 do modelo biológico. O estudo da dinâmica populacional e reprodutiva indicou que A. lineatus passa todo seu ciclo de vida na região de estudo, com evidências de movimentação entre baía Santos e canal de Bertioga para áreas mais internas do estuário. O índice de lesão do fígado indicou que a estação oceanográfica localizada no canal de Bertioga refletiu o maior grau de contaminação; não houve indícios de intersexo nas gônadas como evidência da presença de disruptores endócrinos no ambiente. A análise elemental PIXE para detecção de metais em tecido muscular revelou um alto grau de contaminação por diversos metais tanto na baía de Santos como no canal de Bertioga, alguns dos quais não detectados por análises químicas. Os indicadores ecológicos analisados, índices de diversidade e o índice ABC, não forneceram um diagnóstico quanto à higidez dos peixes, entretanto, refletiram o esperado para a região de estudo. / The goal of this work was to analyze three evaluation methods of environmental contamination, two of them being applied in a biological model, the species Achirus lineatus (Achiridae, Pleuronectiformes), and the third in the Santos bay and Bertioga channel ichthyofauna. Samples were collected monthly during the year of 2005, using an otter trawl within a 10-minute catch effort. The study of population and reproductive dynamics showed that A. lineatus spends all of its life cycle in the region studied, with evident displacement between Santos bay and the Bertioga channel to inner areas of the estuary. The rate of liver injury showed the station in the Bertioga channel with the greatest degree of contamination; there were no trace of intersex in the gonads as evidence of endocrine disrupter chemical presence in the environment. The PIXE elemental analysis for metal detection in muscular tissue showed high degree of contamination caused by several metals in Santos bay and in Bertioga channel, some of these elements were not detected by chemical analysis. The ecological indicators analyzed, diversity index and ABC index had not supplied one good diagnosis about the fishs health, but they had reflected what was expected to the studied region.

Informações sobre a fitossociologia e produção de serapilheira foram obtidas em 20 transversais distribuídas ao longo dos manguezais do sistema estuarino de Santos. Em cada transversal avaliou-se a estrutura do bosque em quatro parcelas de 100 m2 e a produção mensal da serapilheira coletada em 12 cestos ao longo de um ano. Analisou-se o conjunto de dados principalmente no nível de paisagem, encontrando-se que os descritores fitossociológicos não revelaram diferenças significativas ao longo do gradiente de inundação, embora ao mesmo tempo, os bosques tenham mostrado grandes variações desses descritores. As espécies Rhizophora mangle e Avicennia schaueriana mostraram valores de importância (sensu Curtis) estatisticamente iguais e substancialmente maiores que de Laguncularia racemosa. A produção de serapilheira, ao contrário, mostrou diferença significativa conforme a distância da água. O conjunto de dados foi submetido à análise de agrupamento e de componentes principais. A análise conjunta desses resultados permitiu verificar que os bosques foram agrupados, em quatro grupos: um com características de bosque mais maduro, outro bem mais jovem e os outros dois grupos revelaram-se intermediários e menos definidos. Verificou-se que a grande diversidade estrutural observada pode ser atribuída fundamentalmente ao fato do manguezal do sistema estuarino de Santos estar implantado em um ambiente com geomorfologia complexa, com inúmeros canais, oito bacias de drenagem e pluviosidade diferenciada conforme a distância da Serra do Mar. Isso gera um ambiente hídrico muito variado ao longo dos canais, de forma que essas diferenças no ambiente amplificam as diferenças naturalmente já encontradas nos ecossistemas de manguezal. Eventuais impactos antrópicos sobre este sistema podem ser fatores adicionais para explicar a diversidade estrutural observada. / Information about the phytosociology and litter production were obtained in 20 transects distributed along the mangroves of Santos estuarine system. The forest structure in each transect was evaluated in four parcels of 100 m2 and the monthly litter production was collected in 12 baskets through one year. The data set was analyzed mainly under landscape aspect. The phytosociologic descriptors did not reveal significant differences along the flood gradient, but at the same time, the mangrove forests showed wide variations in these descriptors. Rhizophora mangle and Avicennia schaueriana presented statistically equal importance values (sensu Curtis) which were higher than those of Laguncularia racemosa. Litter production showed significant difference according to the water distance. Data set was submitted to cluster and principal components analysis. The joint analysis of these results indicated four groups: one with mature forest characteristics, other with young forest characteristics whereas the other two groups revealed intermediate and less defined characteristics. The large structural diversity found can be attributed mainly to the fact of the Santos estuarine system to present a complex geomorphology with countless channels, eight drainage basins and differentiated rainfall according to Serra do Mar distance, which produces a widely variable hydrologic environment along the channels. In such a way these environmental variability amplify the differences naturally found in the mangrove ecosystems. Eventual anthropic impacts on this system can be additional factors to explain the observed diversity structure.

Reliable estimates of river discharge and sediment transport to the ocean from large tidal rivers are vital for water resources management, efficient river and harbor management, navigational purposes, and climate analyses. Due to the difficulties inherent in measuring tidal-river discharge, hydrological and sedimentological records are typically too short to adequately characterize long-term (decadal) trends. Also, uncertainties associated with observation and calibration of hydrological models suggest a need for more accurate methods based on longer records of hydrodynamic parameters (e.g. tides). Tidal theory indicates that tides and river discharge interact through quadratic bed friction, which diminishes and distorts the tidal wave as discharge increases. In this study, using tidal constituents, astronomical forcing and a model of the frictional interaction of flow and tides, I propose a novel Tidal Discharge Estimate (TDE) to predict freshwater discharge with an approximate averaging interval of 18 days for time periods with tidal data but no river flow records. Next, using continuous wavelet analysis of tidal properties, I develop a method of estimating river discharge using tides measured on multiple gages along tidal rivers to improve the time-resolution and accuracy of TDE. The applicability of the Multiple-gauge Discharge Estimate (MTDE) is first demonstrated in the two largest tidal-fluvial systems of the Pacific Northwest, the Columbia River Estuary (CRE) and Fraser River Estuary (FRE). A numerical model of an idealized estuary with similar forcing as the FRE and CRE is next run under different hydrologic and morphologic scenarios to evaluate the effect of convergence, friction, and river flow variations on the applicability of MTDE. The TDE method was applied to the San Francisco Bay, using the continuous hourly tide record available since 1858. Results show that TDE reproduces known San Francisco (SF) Bay delta inflows from 1930-present with a Nash-Sutcliffe coefficient of 0.81 and is a useful method for hindcasting historical flows from 1858 - 1929, a period that predates direct measurement of delta discharge. I also recover and digitize ~80 years of Sacramento River daily water level data between 1849 and 1946, from which river discharge to SF Bay is estimated on a daily basis, after adjusting for changes to the river channel. This discharge combined with Net Delta Outflow Index estimates (1930 - 2011) and flow estimates from tidal data (1858 - 2011) provides a more accurate version of SF Bay historic daily inflows from 1849 - 2011. Next, the history of sediment transport and discharge into SF Bay from 1849-present is reevaluated using the daily discharge estimates. A non-stationary rating curve between river flow and sediment transport is developed, with net sedimentation observed during five bathymetric surveys that were used to constrain the total integrated sediment discharge. Results show that ~1600±320 million-tons of sediment have been delivered to SF Bay between 1850 and 2011. There has been an approximately 25 - 30% reduction of annual flow since the 19th century, along with decreased sediment supply. This has resulted in a ~60% reduction in annual sediment delivery to SF Bay. The annual hydrograph of inflow to SF Bay and the seasonality of sediment flux have changed considerably over time, due to both human alteration and climate change. Significant historic spring-melt peak floods have disappeared in the modern system and now peak flows mostly occur in winter. My flow estimation methods also confirm that the flood of January 1862 had the largest daily sediment load and the second largest daily discharge since 1849.

The South Slough Estuary is located off Coos Bay along the southern coast of Oregon. It is divided into two channels that meet and continue to Coos Bay at the Charleston Harbor. There are six major contributing streams to South Slough. After rainfall events, the level of coliform bacteria in the slough increases because of stream bacteria loading. This is due to cattle grazing in the drainage areas, failed septic systems from private homes, and sewage sludge applied to the County landfill, which drains into the slough. The Oregon Health Division has enforced a Sanitation Management Plan for Commercial Shellfish Harvesting in South Slough that specifies closure of commercial shellfish harvesting for certain rainfall and flood events. The purpose of this study is to analyze and improve the current understanding of the hydraulics and water quality of the South Slough Estuary. This was achieved by calibrating the South Slough using the water quality model CEQUAL- W2. It was calibrated for the following parameters water surface elevations, velocity, temperature and total dissolved solids. A management analysis was also done analyzing the transport of bacteria and a conservative tracer. Model predictions for water surface elevations at one of the monitoring sites, Hinch Road Bridge, was significantly lower than measured elevations. There was an excellent correlation of velocity, and reasonable timing of peaks due to tidal effects. Model predictions for temperature and total dissolved solids match measured values well. To improve the accuracy of the model the following was recommended; install a raingage in the South Slough, measure temperature and constituent concentrations at inflow locations, survey the S4 current meter, new soundings performed of the Winchester Creek arm and at the Hinch Road Bridge gaging station, and investigate the possibility of an obstruction near the Hinch Road Bridge gaging station.

The New Zealand (NZ) sea lion Phocarctos hookeri is the only pinniped endemic to NZ with a population of approximately 12,000 individuals. Its breeding range is currently restricted to NZ sub-Antarctic islands, and it has failed to recolonise its pristine distribution around the NZ main islands despite its protection since 1881. The current hypothesis is that the population growth of this pinniped is limited by the distribution of suitable prey on the Auckland Islands (50°30'S, 166°E) shelf, and by the direct and indirect pressure exerted by the arrow squid Nototodarus sloani fishery. However, this hypothesis has not been fully tested to date as there has been limited information on the diet of the NZ sea lion and their potential prey. The objective of this thesis is to analyse the diet of NZ sea lions over several years with particular emphasis on the most reproductively important segment of the population: lactating females. This thesis provides the first quantification by percentage mass of the diet of NZ sea lion using a combination of stomach content analysis, qualitative fatty acid (FA) analysis, and quantitative FA signature analysis (QFASA). Stomach contents and blubber FAs were analysed from 121 individuals incidentally caught (by-caught) in the southern arrow squid fishery from the years 1997 to 2006. The blubber FAs of 78 freeranging lactating females captured at Enderby Island, Auckland Islands, were also examined during January and February of 2000 to 2005. Data obtained from both stomach analysis and QFASA indicate that arrow squid, rattails Macrouridae, hoki Macruronus novaezelandiae and red cod Pseudophycis bachus are key prey species for NZ sea lions in the Auckland Islands region. Because these prey species live mostly at depths greater than 200 m, lactating females must undertake long foraging trips and dive regularly to greater depths than other sea lion species. Data from QFASA indicates that this foraging pattern is conducted over an extended period through the summer and autumn. The daily food requirement of a lactating female was estimated by a simple energetic model to be greater than 20% of its body mass. During years of low arrow squid recruitment such as 1999 and 2001, the amounts of squid required by the NZ sea lion population may have been similar to the amount harvested by the fishery, suggesting that resource competition is likely to occur between the arrow squid fishery and NZ sea lions in years of low squid abundance. Half of the fishing activity of the southern squid fishery occurs in the north of the Auckland Islands shelf where NZ sea lions forage, leading to incidental captures every year. This research emphasises that management of the NZ sea lion must not only consider the direct interactions with the arrow squid fishery, but also the likelihood of food resource competition between the fishery and NZ sea lions.

In 1996, four cores (∼30 cm depth) were extracted from the high marsh zone of Dipper Harbour salt marsh in the Bay of Fundy. Soil bulk densities are shown to be controlled by mineral density and are higher than those reported for salt marshes in the northeastern United States. Examination of variations in mineral content suggests that regular tidal action and ice rafting deposits the majority of the mineral sediment to the high marsh zone. Dating techniques (based upon pollen, 137Cs, 210Pb and total Pb) were applied to selected cores, suggesting accretion rates from 0.25 to 0.31 cm yr-1 which are higher than the rates of local relative sea level rise. Correlation of trace metal densities (Cu, Fe, Pb and Zn) to Al densities were used to justify Al normalization. After consideration of natural sources and adsorption factors, the normalized Pb profiles are shown to reflect historical pollution levels of leaded gasoline consumption. Carbon storage values in the upper 25 cm of sediment range from 7.3--10.5 kg C m-2 and carbon accumulation rates vary from 95 to 124 g C m-2 yr-1, representing 15--29% of the salt marsh macrophyte productivity.

Global climate change is a naturally occurring phenomenon, influencing weather and climate patterns. However, the greatest cause for concern at present is the rate at which climate change is currently occurring. Natural shifts in climate take place over a period of many thousands of years, not in a matter of decades, which is what is occurring at present. In South Africa, climate change is projected to have different regional effects, which in turn could impact on the components of the terrestrial hydrological system, such as land use. The alteration of the catchment upstream of the estuaries could affect the quantity and quality of streamflows entering estuaries. This could impact negatively upon estuaries, thereby reducing the considerable biodiversity in estuaries and the ecosystems goods and services provided by estuaries which would reduce the significant revenue provided by these systems. The research undertaken in this project investigates the possible effects of climate change, and changes in upstream land use on freshwater inflows into estuarine ecosystems using a daily hydrological model. Owing to the regionality of climate change in South Africa 10 estuaries in different climatic regions were selected for this investigation. Climate output from five GCMs under the SRES A2 climate scenario for the present (1971 – 1990), intermediate (2046 – 2065) and distant future (2081 – 2100) periods was used as input for the selected climate input. Results of these simulations show that the eastern regions of South Africa may experience considerable increases in the occurrence of high intensity rainfall events into the future. This could influence the abiotic factors of the system which may impact upon the biotic components of estuaries, as these systems are physically controlled. In the western regions the difference of the magnitude of flows between present and projected future is minimal. However, projected increases in temperature could influence evaporation, thereby decreasing future flows into estuaries. This, in some instances, may result in systems turning hyper-saline, which could have far reaching implications, both ecologically and economically. Additionally, an investigation, as to the possible effects of irrigation and climate change combined on flows entering and breaching events of the Klein estuary, was undertaken. Hence, simulations including and excluding irrigation routines have been completed. Results from these simulations illustrate the detrimental effects of irrigation into the future periods, especially during 1 in 10 low flow years, when flows into the Klein estuary cease completely. Breaching event results illustrate that climate change could have a negative impact on this estuarine system as the number of events decreases into distant future period. The addition of agricultural abstractions decreases the number of breaching events markedly. Therefore, the link between the marine and terrestrial hydrological systems is lost which could, if this estuary is isolated from the ocean for an extended period of time, become extremely detrimental to the ecological integrity of the Klein estuary. This highlights the value and vulnerabilities of estuarine ecosystems in South Africa to future climate and upstream land use changes. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

The Inanda Dam, situated some 32 to 35km upstream of the Mgeni River estuary on the Indian Ocean 5 km north of Durban, was constructed between 1984 and 1989. This impoundment deprived the downstream section of a great volume of water and sediment supply, initiating significant downstream changes. This situation is compounded by sand winning which directly extracts about 210,000 tonnes of sediment from the Lower Mgeni further depriving the estuary of sediment. A 1997 study predicted that assuming a continuous competent discharge and low contribution of sediments from the tributaries, the channel would gradually scour. Other predictions included a reduction in the total sediments reaching the estuary, continued flushing of existing channel sediments downstream towards the estuary, site-specific channel bed erosion at times of peak water release, gradual build up of sediments near the estuary mouth, gradual fining of bed-load channel and estuarine sediments, and ongoing re-establishment of the central island. The main aim of this study was thus to investigate downstream changes in the Mgeni river estuary below the Inanda dam with regards to sediments, water discharge and channel morphology from 1997 to test these assertions. Results show a decrease in competent discharge below the Inanda dam since 1997, resulting in a corresponding decrease in sand and an increase in mud fractions, with the mud content being associated predominantly with heavy minerals. This is reflected in the poorly sorted sediment. The plotting of cross-sectional survey revealed site-specific erosion, as well as estuarine bank failure to be an on-going process, and indicate points of bed scouring and accretion. A number of reasons have been identified as geomorphological explanations for the changes since 1997. These include among others, a lower hydraulic gradient at the estuary, occasional minor flood events, a weak bank material composition along some portions of the estuarine bank, the Tnanda dam , which impounds coarse sediments and large volume of water and increased tidal activity at the Mgeni estuary. It is concluded that although some of the probable responses predicted in 1997 have happened, sufficient relaxation time may not yet have elapsed for others to become evident. / Thesis (M.Sc.)-University of Natal, Durban, 2002.

The St Lucia estuarine system, Africa’s largest estuarine lake, is characterised by cyclic changes from hypersaline to oligo/mesohaline conditions in response to alternations between drought and wetter than average years. In addition, St Lucia also experiences stochastic disturbances, such as flooding events that rapidly decrease salinity levels. Due to their sessile and slow moving nature, bivalves are particularly vulnerable to rapid or prolonged changes in the physico-chemical environment. The recent freshwater deprivation crisis that prevailed for the last decade resulted in a significant loss in bivalve species richness within the system. An annotated and illustrated bivalve census revealed the occurrence of twenty-four species within St Lucia between the years 1925 and 2011. However, only six species were recorded during the most recent survey in March 2011. The infaunal razor clam, Solen cylindraceus, and the epifaunal brackwater mussel, Brachidontes virgiliae, are currently the dominant bivalve species within St Lucia. This study, therefore, aimed to record the species richness of bivalves found in Lake St Lucia and to investigate key biological aspects of the two dominant bivalve taxa within the system, under different salinity regimes. Experiments revealed that S. cylindraceus can tolerate salinities between 15 and 65, while B. virgiliae prefers salinity levels ranging from freshwater to 20. The varying tolerance limits, therefore, dictate the distribution of these species during different climatic conditions within the estuarine lake. During wet periods, S. cylindraceus is restricted to the northern reaches, unable to tolerate the oligohaline conditions present in the rest of the system. Conversely, B. virgiliae, often restricted to the Narrows, becomes ubiquitous throughout the system under such conditions. Solen cylindraceus can reach a maximum length of 95 mm. However, in the St Lucia estuarine system, specimens seldom exceed a length of 55 mm, probably because prevailing/re-occurring harsh conditions prevent them from reaching maximum size. In situ measurements of this species also revealed less growth during the first year of life than for the same species in different systems. While B. virgiliae is substantially smaller than S. cylindraceus, the high densities that this species is able to attain makes it an important grazer with the potential to have significant feeding impacts on the local phytoplankton biomass. Results showed that in localised areas, B. virgiliae populations may consume up to eight times the available phytoplankton biomass. These key bivalve species are strongly influenced by the fluctuation in climatic conditions from wet to dry phases. Thus, understanding the effects that climatic shifts have on key estuarine species is essential, as flood and drought events are predicted to increase in frequency, intensity and duration as a result of global climate change. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2014.