Elementos-traço, de fontes naturais ou antropogênicas, são despejados continuamente nos rios, fato que acarreta sérios problemas, devido a sua toxicidade, longa persistência, bioacumulação e biomagnificação na cadeia alimentar. O sistema lagunar Tijuca-Jacarepaguá-Marapendi recebe um enorme aporte de nutrientes e poluentes devido aos impactos antrópicos em seus rios. Este estudo tem como objetivo principal avaliar os níveis de cobre, zinco, chumbo e alumínio em músculo e víscera na espécie Sardinella brasiliensis (sardinha), que habita a saída do Canal de Sernambetiba, Barra da Tijuca, Rio de Janeiro (RJ). Ao total foram analisados 44 indivíduos. O cobre em músculo apresentou uma concentração média de 0,5 0,66 mg/Kg e de 1,3 10,13 mg/Kg em víscera. Os valores de zinco em músculo e víscera foram de 5,2 3,69 mg/Kg e 25,6 48,16 mg/Kg, respectivamente. A concentração de chumbo foi de 2,48 3,09 mg/Kg (músculo) e 25,6 48,16 mg/Kg (víscera), enquanto a concentração de alumínio variou de 1,68 3,67 mg/Kg em músculo e 28,72 26,99 mg/Kg em víscera. Dentre as amostras, 56,8% apresentaram valores acima do limite estabelecido para consumo humano pela legislação brasileira para chumbo. Os elementos-traço apresentaram tendências de acumulação diferentes de acordo com o local (músculo ou víscera). As concentrações dos metais em músculo foram menores do que em vísceras. Os valores encontrados devem servir de alerta para uma contaminação da população de Sardinella brasiliensis que habita a saída do canal de Sernambetiba. Concluiu-se que a concentração de chumbo nos peixes encontrados estão acima dos limites permitidos para o consumo humano, e que a região encontra-se impactada / Trace elements, of natural or antropogênicas sources, are poured continuously in the rivers, fact that causes serious problems, due its toxicity, long persistence, bioacumulation and biomagnification. The Tijuca-Jacarepagua-Marapendis lagunar system receives an enormous one arrives in port of nutrients and pollutants due to the humans impacts in its rivers. The present study investigated heavy metals (copper, zinc, lead and aluminum) variance in Sardinella brasiliensis (sardines) in Jacarepagua lagoon, Barra da Tijuca, Rio de Janeiro (RJ). 44 samples had been analyzed. The copper in muscle presented an average concentration of 0,50,66 mg/Kg and 1,310,13 mg/Kg in viscera. The values of zinc in muscle and viscera had been of 5,23,69 mg/Kg and 25,648,16 mg/Kg, respectively. The lead concentration was of 2,483,09 mg/Kg (muscle) and 25,648,16 mg/Kg (viscera). The aluminum concentration was of 1,68 3,67 mg/Kg in muscle and 28,72 26,99 mg/Kg in viscera. Amongst samples 56.8% they had presented values above of the limit established for human consumption for the Brazilian legislation for lead. Heavy metals had not presented the same trend of accumulation depending on the place (muscle or viscera). The concentrations of trace elements in muscle had been lesser of what in viscera. The values must serve of alert for a contamination of the population of Sardinella brasiliensis that inhabits the canal of Sernambetiba. Concluded that the concentrations of heavy metal in the fish are above of the limits allowed for the human consumption, and that the region was impacted

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / A presente dissertaÃÃo identifica e analisa as condiÃÃes ambientais do Complexo HÃdrico Papicu/Maceià com o ropÃsito de verificar sua situaÃÃo atual, e propor medidas alternativas para minimizar os impactos ambientais negativos detectados nessa Ãrea. A identificaÃÃo desses impactos no sistema Ãdrico em estudo, teve seu inÃcio com levantamentos cartogrÃficos e observaÃÃes de campo sendo, posteriormente, levantadas as condiÃÃes ambientais por meio da determinaÃÃo da qualidade da Ãgua e sedimento, analisando-se os parÃmetros fÃsicos e quÃmicos em amostras coletadas nas estaÃÃes chuvosa e de estiagem. A anÃlise dos sedimentos em relaÃÃo ao tamanho de grÃo, realizado pelo mÃtodo do peneiramento, apresenta uma classificaÃÃo textural que varia de areia mÃdia a fina. Os parÃmetros fÃsico-quÃmicos da Ãgua referentes a turbidez, cor e odor indicam que esses Ãndices variaram de acordo com os perÃodos chuvoso e de estiagem. Os valores de turbidez abrangeram de 3,5 uT a 39,0 uT no perÃodo de elevada luviosidade e 2,0 uT a 6,5 uT no perÃodo de estiagem. As observaÃÃes da cor indicaram Ãndices superiores a 25,0 uH. O odor apresentou caracterÃsticas de sulfÃdrico a vegetal. Os resultados da demanda bioquÃmica de oxigÃnio mostram que os valores para o perÃodo chuvoso variaram de 14,0 a 53,0 mg/L e para o de estiagem de 4,8 a 37,2 mg/L, estando acima do limite de 5,0 mg/L estabelecido pela ResoluÃÃo 20/86 do CONAMA. Esses dados indicam que esse complexo hÃdrico està recebendo efluentes de origem domÃstica. Os valores do oxigÃnio dissolvido variam de 2,6 a 4,0 mg/L, sendo que nas amostras analisadas da Lagoa do Papicu verifica-se a ausÃncia desse elemento. De acordo com a ResoluÃÃo acima referida, os valores de oxigÃnio dissolvido, em qualquer amostra deve ser superior a 2,0 mg/L, dessa forma somente o corpo hÃdrico, Lagoa do Papicu, està fora dos padrÃes estabelecidos pela resoluÃÃo. A anÃlise dos parÃmetros fÃsico-quÃmicos da Ãgua envolvendo potencial hidrogeniÃnico, alcalinidade e dureza revelam que os valores encontrados estÃo compatÃveis com as caracterÃsticas ambientais da Ãrea de estudo. Os valores de nitrito, nitrato e amÃnia nÃo estÃo, de modo geral, dentro dos padrÃes estabelecidos pela ResoluÃÃo 20/86 do CONAMA. Medidas mitigadoras e corretivas sÃo propostas para eliminar os impactos negativos configurados e preservar a qualidade ambiental do complexo hÃdrico Papicu/MaceiÃ. / The present masterâs thesis identifies and analyzes the environmental conditions of the Papicu/Maceià draining water system as an attempt to evaluate their present situation and to put forward alternative measure to lower the environmental negative impacts dedected in that region. This case study actually started with a cartographic survey and field observations which later carried on with the determination of water and sediment quality by estimating physical and chemical parameters by means of samples collected during the dry and rainy seasons. Sediments analyzed as to its grain size, through the sifting technique, went into a textural classification as median to fine sand. Physical-chemical parameters of the water in relation to turbidity, color and smell varied according to the dry and rainy seasons. Turbidity values ranged from 3,5 uT to 39,0 uT during the rainy season and 2,0 uT to 6,5 uT during the dry season, the color presented indices upwards of 25,0 uH and the smell showed sulphyde and vegetable characteristics. The values of biochemical demand for oxygen varied in the ranges of 14,0 â 53,0 mg.L-1 and 4,8 â 37,2 mg.L-1, respectively during the rainy and dry seasons, therefore well above the 5,0 mg.L-1-limit set up by CONAMAâs Act no 20/86. This is an indication that the studied water system has been receiving domestically-produced effluents. The dissolved oxygen content ranged from 2,6 mg.L-1 to 4,0 mg.L-1, but the Papicu lakelet was shown to be totally devoid of that element. Since that, according to the above-mentioned Act the oxygen content in any samples must be higher than 2,0 mg.L-1, only on the water body Papicu lakelet this parameter was found to be below that standard limit. Other water physical and chemical parameters, such as pH, alcalinity and hardness showed values which are compatible with the environmental features of the study area. Nitrite, nitrate and ammonia contents are not, in general within the standard limits of CONAMAâs Act no 20/86. Amendatory and mitigating guidelines are proposed aiming at ruling out evident negative impacts and at preserving environmentâs quality of Papicu/Maceià draining water system.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A lagoa costeira, AlmÃcegas, està localizada no litoral Oeste do Estado do Cearà na divisa dos municÃpios de Trairi e Paraipaba. O principal objetivo deste trabalho foi avaliar a evoluÃÃo os processos controladores da morfologia e hidrologia da Lagoa das AlmÃcegas visando gerar informaÃÃes Ãteis ao uso e gestÃo desse recurso hÃdrico costeiro. A origem da lagoa das AlmÃcegas està subordinada ao comportamento climÃtico-natural da Ãrea, bastante influenciado pela dinÃmica litorÃnea. Com a gÃnese relacionada aos processos transgressivos e regressivos do mar, e barramento do riacho pelo sistema de dunas (transporte eÃlico) e processos associado (descarga fluvial), sendo posteriormente com a construÃÃo da barragem. A metodologia utilizada para realizaÃÃo desta pesquisa baseia-se na compreensÃo da organizaÃÃo da natureza dentro do espaÃo, e a relaÃÃo que ocorre entre seus componentes. Para tanto foram realizadas analises dos parÃmetros fÃsicos e quÃmicos da Ãgua: temperatura, condutividade elÃtrica, turbidez, pH e transparÃncia. Ademais, foram coletadas amostras de subsuperfÃcie e fundo para a investigaÃÃo de material em suspensÃo. TambÃm, realizou-se a caracterizaÃÃo sedimentolÃgica, analise de matÃria orgÃnica e metaisâtraÃo (cobre, cÃdmio e zinco) no sedimento, e o estudo morfomÃtrico e levantamento batimÃtrico da lagoa. Os resultados demonstram que o sistema estudado apresentou variaÃÃo sazonal relacionada aos dois perÃodos hidrolÃgicos distintos. O perÃodo chuvoso se caracterizou por precipitaÃÃes mais intensas e menor insolaÃÃo, enquanto que o seco apresentou maior insolaÃÃo e maiores velocidades dos ventos, trazendo conseqÃÃncias diretas sobre o nÃvel dâÃgua da lagoa. A coluna dâÃgua apresentou estratificaÃÃo (tÃrmica) significativa devido principalmente à profundidade do sistema, à atuaÃÃo dos ventos e transparÃncia da coluna dâÃgua. A composiÃÃo granulomÃtrica dos sedimentos de fundo da Lagoa das AlmÃcegas resultaram em seis classes principais: areia com cascalho esparso (43,8 %), areia (25%), areia fina (6,3%), areia siltosa (6,3%), areia lamosa (6,3%), silte (6,3%) e silte arenoso (6,3%). Observa-se que as fraÃÃes grossas do sedimento, maiores que 0,063 mm, ocorrem na grande maioria das amostras, o que pode està relacionado ao processo de assoreamento. A distribuiÃÃo da matÃria orgÃnica indica os diferentes graus de aeraÃÃo das diversas Ãreas do ambiente de sedimentaÃÃo. Quanto à morfologia a lagoa apresentando uma Ãrea de 1,3 km2, perÃmetro de 9,935 Km, largura mÃxima de 684 m e comprimento de 3,5 km, volume de 6.688.000 mÂ, profundidade mÃxima de 5,85 m, profundidade mÃdia de 2,55m. A relevÃncia do volume classifica este reservatÃrio como de capacidade de armazenamento satisfatÃrio. Em termos de ocupaÃÃo, a lagoa encontra-se com baixa ocupaÃÃo imobiliÃria, devido principalmente a pouca especulaÃÃo. Mas, as ocupaÃÃes que jà ocorrem na regiÃo ultrapassam os limites impostos pela lei (Ãreas de PreservaÃÃo Permanente), jà a ocupaÃÃo associada à retirada da cobertura vegetal à possÃvel de ser vista, e este problema pode gerar uma instabilidade das margens e conseqÃente alteraÃÃo das caracterÃsticas morfomÃtricas e fÃsicoquÃmicas da lagoa, podendo ocasionar impactos negativos, como aumento do escoamento superficial, erosÃo das margens, maior aporte de sedimentos na lagoa, assoreamento, diminuiÃÃo do volume de Ãgua, e maior concentraÃÃo de poluentes na lagoa, podendo vir a comprometer tambÃm a vida da populaÃÃo local. / The coastal lagoon, AlmÃcegas, are located in the coastal West of the State of the Cearà in the verge of the cities of Trairi and Paraipaba. The main objective of this work was to evaluate the evolution the controlling processes of the morphology and hidrology of the Lagoon of the AlmÃcegas being aimed at to generate useful information to the use and management of this coastal hÃdrico resource. The origin of the lagoon of the AlmÃcegas is subordinated to the climatic-natural behavior of the area, sufficiently influenced for the littoral dynamics. With genesis related to the transgression and regression processes of the sea, and slide bars of the extended river for the dune system (aeolian transport) and processes associated (fluvial discharge), being later with the construction of the barrage. The methodology used for accomplishment of this research is based inside on the understanding of the organization of the nature of the space, and the relation that occurs between its components. For they had been in such a way carried through you analyze of the physical and chemical parameters of the water: temperature, electric condutividade, turbidez, pH and transparency. Furthermore, had been collected samples of deep subsurface and for the inquiry of material in suspension. Also, it was become fullfilled sedimentation characterization, analyzes of organic substance and metal-traces (it has covered, cadmium and zinc) in the sediment, and the morfomÃtrico study and batimÃtrico survey of the lagoon. The results demonstrate that the studied system presented related sazonal variation to the two distinct hidrolÃgicos periods. The rainy period if characterized for more intense precipitations and lesser insolation, whereas the dry one presented greater insolation and greaters speeds of the winds, bringing direct consequences on the water level of the lagoon. The water column presented stratification (thermal) significant had mainly to the depth of the system, to the performance of the winds and transparency of the water column. The grain sized composition of the sediments of deep of the Lagoon of the AlmÃcegas had resulted in six main classrooms: slightly gravelly sand (43.8%), sand (25%), fine sand (6.3%), muddy sand (6.3%), slightly gravelly muddy sand (6.3%), silt (6.3%) and sandy silt (6.3%). It is observed that the thick fractions of the sediment, greaters that 0,063mm, occur in the great majority of the samples, what it can is related to the silting. The distribution of the organic substance indicates the different degrees of aeration of the diverse areas of the sedimentation environment. How much to the morphology the lagoon presenting an area of 1,3km2, perimeter of 9,935Km, maximum width of 684m and length of 3,5km, Volume of 6.688.000m Â, maximum depth of 5,85m, average depth of 2,55m. The relevance of the volume classifies this reservoir as of capacity of satisfactory storage. In occupation terms, the lagoon meets with low real estate occupation, had mainly to little speculation. But, the occupations that already occur in the region exceed the limits taxes for the law (Areas of Permanent Preservation) already the occupation associated with the withdrawal of the vegetal covering are possible of being seen, and this problem can generate an instability of the edges and consequence the alteration of the morfomÃtricas characteristics and physicistchemistries of the lagoon, being able to cause negative impacts, as increase of the superficial draining, erosion of the edges, greater arrives in port of sediments in the lagoon, assoreamento, reduction of the volume of water, and greater concentration of pollutants in the lagoon, being able to come also compromising the life of the population place.

Esta pesquisa propôs o desenvolvimento de um sistema de biofiltros submersos, modificados com base na configuração de filtros de pedra, visando o pós-tratamento do efluente de lagoas de estabilização, inicialmente para a remoção de algas. A modificação consiste na variação das alturas da camada filtrante e na colocação de tampa na superfície do BS, evitando o acesso da luz. O esgoto tratado captado na lagoa de maturação foi feito em duas profundidades – a 60 cm de profundidade da superfície da lagoa (denominada zona superficial) e a 180 cm de profundidade da superfície da lagoa (denominada zona intermediárias). O experimento foi composto por 8 BS sendo 4 BS alimentados pelo esgoto captado na zona superficial (60 cm) e outros 4 BS alimentados pela esgoto captado na zona intermediária (180 cm). Foi utilizado, como recheio dos biofiltros submersos, pedra brita nº 3, nas seguintes alturas de camada filtrante: 50 cm, 100 cm, 150 cm e 200 cm, tendo por objetivo avaliar a influência deste fator sobre a eficiência de remoção de algas mediante análise de Clorofila a, e outras 16 variáveis de qualidade associadas neste estudo. Concluiu-se que a extração a partir da zona superficial da lagoa de maturação, e uma profundidade de leito entre 150 cm e 200 cm, foram os parâmetros operacionais que levaram a um melhor desempenho global dos biofiltros submersos modificados, e mais especificamente quanto às seguintes variáveis: Clorofila a, DQO (Demanda Química de Oxigênio), DBO (Demanda Bioquímica de Oxigênio) e sólidos totais. / This research proposed the development of a submerged bio filters system, modified based in rock filters configuration, aiming the post treatment of the effluent of stabilization lagoons, for algae removal first. The modification consists invariance of the heights of the filter layer and the cover placed on the surface of the BS, preventing access of light. The treated sewage captured in the maturation lagoon was made at two depths – at 60cm depth of the lagoon surface (called superficial zone) and at 180cm depth of the lagoon surface (called intermediary zone). The experiment consisted of 8 BS, with 4 BS being fed by sewage captured in the superficial zone (60 cm) and other 4 BS fed by sewage captured in the intermediary zone (180 cm). It was used, as a stuff of submerged biofilters, rock number three, at the following heights of filtering layers: 50 cm, 100 cm, 150 cm e 200 cm, aiming to evaluate the influence of this factor over algae removal efficiency towards chlorophyll a, and other 16 quality variables associated in this study. It was concluded that the collecting from superficial zone of the maturation lagoon, and a layer depth between 150 cm e 200 cm, were the operational parameters that lead to a better overall performance of modified submerged biofilters, and more particularly to the following variables: Chlorophyll a, COD (Chemical Oxygen Demand), BOD (Biochemical Oxygen Demand) and total solids.

Este trabalho aborda a influência da hidrodinâmica da Lagoa dos Patos (RS) no comportamento de variáveis indicadoras da qualidade da água, como o material em suspensão, o oxigênio dissolvido, os nutrientes inorgânicos dissolvidos e a clorofila-a. Adicionalmente, o trabalho apresenta uma avaliação do efeito do lançamento de efluentes na magnitude das concentrações destas variáveis e nas suas inter-relações. Para o desenvolvimento deste estudo aplicou-se o modelo numérico MOHID 2D, utilizado com êxito na gestão ambiental de regiões costeiras. Os resultados indicam que a Lagoa dos Patos é um corpo lagunar heterogêneo no qual sua hidrodinâmica é regida principalmente pela atuação dos ventos e da vazão fluvial. Esses fatores influenciam diretamente o comportamento das variáveis estudadas. A presença de efluentes altera significativamente a magnitude das concentrações dos nutrientes e da clorofila-a no ambiente, principalmente nas regiões próximas aos locais de lançamento. A modelagem numérica é uma importante ferramenta para a gestão ambiental de sistemas dinâmicos e que variáveis ecológicas são condicionadas pelas suas inter-relações e pela circulação do sistema. / This work assesses the influence of Patos Lagoon- RS hydrodynamics in the behavior of water quality indicator variables as like suspended material, dissolved oxygen, dissolved inorganic nutrients and chlorophyll-a. Also gives an assessment of the effect of effluent discharge in the magnitude of the concentrations of these variables and in their interrelationships. To develop this study we applied the numerical model MOHID 2D, successfully applied in environmental management of coastal areas. The results indicate that Patos Lagoon is a heterogeneous system in which its hydrodynamic is governed mainly by the action of wind and river flow, which directly influence the behavior of water quality variables. Furthermore, the presence of effluent significantly changes the magnitude of the nutrients and chlorophyll-a concentration, particularly in areas close to the sewage launch sites. We concluded that the numerical modeling is an important tool for the dynamics systems management and that ecological variables are not only conditioned by their interrelations, but also by system circulation.

L’étang de Berre est un écosystème lagunaire historiquement perturbé par de forts rejets industriels et par des apports importants en eau douce naturels et anthropiques (centrale hydroélectrique EDF). Alors que les politiques de réhabilitation initiées depuis 1994 commencent à enregistrer leurs premiers succès, l'introduction et la prolifération de Mnemiopsis leidyi en 2005 pourraient limiter leur efficacité. L’originalité de cette étude est d’associer océanographie et sociologie afin d’estimer l’impact de M. leidyi sur le fonctionnement de ce socio-écosystème. Nous avons pu montrer que la population de M. leidyi est capable de se maintenir sur une large gamme de températures (3°C-28°C) et de salinités (10-30), pour une quantité de carbone disponible > 3 µgC L-1, la température étant un facteur déterminant dans la dynamique de la population. L’absence Mnemiopsis au cours d’évènements froids et sa réapparition plusieurs mois après laissent penser soit à l’existence d’une zone refuge qui a été déterminée (étang de Vaine) favorable au maintien des cténaires. Les fortes proliférations de M. leidyi affectent principalement la pêche professionnelle (fort colmatage des filets, mutilation des prises, dégradation accélérée du matériel, augmentation de la pénibilité) induisant une perte économique annuelle estimée à 50 %. Dans le cadre interdisciplinaire, la compréhension des interactions biologiques et anthropiques a permis de montrer que Mnemiopsis présentait une entrave à la mise en œuvre des efforts de réhabilitation. / The Berre Lagoon is an ecosystem historically disturbed by strong industrial discharges and significant freshwaters inputs from both natural and anthropogenic (EDF hydroelectric power station) origins. While rehabilitation policies initiated in 1994 are already showing some success, the introduction and proliferation of Mnemiopsis leidyi since 2005 could limit their effectiveness. The originality of this study is to associate oceanography and sociology in order to estimate the impact of M. leidyi on the functioning of this socio-ecosystem. We were able to show that the population of M. leidyi is maintained within a large range of temperatures (3 °C-28 °C) and salinities (10-30), with a quantity of carbon available ~ 3 mg C L-1 or more, temperature being a determining factor in population dynamics. The absence of this ctenophore on during cold events and its recurrence several months later suggests either the existence of an external source or the presence of a refuge zone that has been determined (Vaine lagoon) favourable to the maintenance of the ctenophores. The strong proliferation of M. leidyi in the Berre lagoon mainly affects professional fishermen. The clogging of nets, the mutilation of catches, the accelerated degradation of the material and the increase in the strenuousness induce an annual economic loss estimated at 50 %. Here in our interdisciplinary framework, the understanding of the biological and the anthropogenic interactions has shown that Mnemiopsis is tempering with the implementation of the rehabilitation efforts.

No description available.

Small towns that operate wastewater treatment lagoons struggle to meet ammonia limits in cold weather. Here we report the performance of a lagoon, retrofitted with submerged attached-growth reactors (SAGRsTM), to provide insight on ammonia effluent compliance and optimal SAGR sizing as functions of water temperature. The lagoon-SAGR water resource recovery facility (WRRF) removed 95% of incoming ammonia with 94% attributable to the SAGRs. The high treatment capacity of the two primary SAGRs, evidenced by nearly continuous dissolved oxygen saturation and exceedingly high ammonia removals, suggested the two secondary SAGRs were essentially unnecessary and that all four SAGRs should be reduced in size. Furthermore, without the secondary SAGRs, the primary SAGR effluent would have exceeded the permitted ammonia discharge limit only four times in the 2.5 year study. At its current size, the lagoon-SAGR WRRF never exceeded permitted ammonia limits, but size reductions should be used for future retrofits. To further understand cold-weather ammonia removal in the lagoon-SAGR WRRF, we investigated the effect of increased ammonia loading on biomass and the effect of biofilms on microbial abundance. When ammonia loading to the SAGRs was increased in the fall, the lagoon-SAGR WRRF never exceeded its ammonia permit limit, the kinetic coefficients were maintained (0.5-0.8 d-1) and the NH3 removal rates improved (0.25 kg d-1 in baseline loading to 0.45 kg d-1) despite a large temperature decrease (25 °C to < 16 °C). In the biofilm, ammonia-oxidizing archaea abundance was 10 times greater than the ammonia-oxidizing bacteria abundance suggesting the potential importance of ammonia oxidizing archaea in biofilm mediated systems. Additionally, the ammonia and nitrite transforming microbes in the SAGRs had a diverse range of dissolved oxygen affinities and were more abundant in the biofilm in comparison to the wastewater. Anaerobic ammonium-oxidizing bacteria were abundant in the biofilm even though the film constantly interacted with high dissolved oxygen. We found that two components of a successful lagoon-SAGR WRRF were increased biomass in the SAGRs before cold-weather due to elevated ammonia loading and diverse oxygen affinities in the microbes related to ammonia removal.

Florida’s Indian River Lagoon (IRL) has experienced myriad anthropogenic impacts and knowledge on elasmobranchs (sharks and rays) in the southern IRL is lacking. A fishery independent survey (longline/gillnet) was implemented to 1) assess the effects of bait type [striped mullet (Mugil cephalus) versus Atlantic mackerel (Scomber scombrus)] and mesh size (15.2 cm versus 20.3 cm stretch mesh) on elasmobranch species composition, catch-per-unit effort, and size distributions and 2) characterize elasmobranch abundance and distribution. From 2016 - 2018, 630 individuals (16 species) were captured, more often in the gillnet than the longline. Catch-per-unit-effort was significantly higher with mullet than mackerel. Species composition differed among gears. Although dependent on gear, there was evidence of seasonal and spatial patterns in abundance and species composition. This study provides the first baseline abundance indices for many elasmobranchs in the IRL and develops the capacity to understand how elasmobranchs may respond to changes in this highly modified estuary. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection

The objective of this research was to examine bottlenose dolphin (Tursiops truncatus) habitat use in the Indian River Lagoon (IRL) based on monthly relocation of photo-identified individuals, prey availability and environmental factors from 2003-2015. We focused on the variation of spatial and temporal abiotic and biotic factors and their influence on bottlenose dolphin habitat use patterns. Harbor Branch Oceanographic Institute (HBOI) conducted monthly photo-identification surveys along the length of the IRL and GPS locations of photographed dolphins were collected at the time of surveying. Stratified random samples of prey and environmental variables were collected monthly by the Florida Fish and Wildlife Conservation Commission (FWC) as part of the Fisheries-Independent Monitoring (FIM) program. Kernel density estimation was used to determine the magnitude-per-unit area of dolphins across a continuous raster surface of the IRL by wet and dry seasons each year, the values of which were used as a response variable in Classification and regression tree (CART) analyses with FIM fish community and environmental factors as predictors. Understanding how dolphins respond to environmental factors over time in the IRL could be used to predict future responses in estuaries and prioritize conservation and restoration actions. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection