The work of this Master of Science thesis project is an analysis of salinity effects on nearshore epifauna along the western shore of Biscayne Bay in southeast Florida, USA. Field collection surveys have found a high probability of occurrence of bigeye mojarra (Eucinostomus havana) in salinities near 25 ppt. In a salinity gradient observation experiment test subjects of the same species and size class were also observed more frequently at 24 ppt. In this analysis presence and abundance patterns found in field surveys were compared with behavioral results obtained in the observation tank. This apparatus provided insight into distribution patterns of the bigeye mojarra (Eucinostomus havana) and possible changes in distribution that may result from habitat changes in the future. Historically, the western shore of Biscayne Bay was more freshwater marsh than the mangrove dominated marine environment that prevails today. Changes to fresh water inputs into the Bay are planned through projects of the Comprehensive Everglades Restoration Plan (CERP). CERP is a joint Florida state and U.S. federal effort to redesign surface water flow through the canal system of South Florida, replenish the Everglades ecosystem, and restore a more natural quantity, timing, and distribution of flow into Biscayne and Florida Bays. Approved by the U.S. Congress as part of the Water Resources Development Act of 2000, CERP will be implemented by the South Florida Water Management District (SFWMD) and the U.S. Army Corps of Engineers (USACE). This plan is designed to restore the ecosystem from its freshwater core to the coastal wetlands recreating a condition close to that existing before the current system of flood control drainage canals was begun in 1903 and continued by the federal Central and Southern Florida Project in 1948 (www.evergladesplan.org). Changes are planned to divert a portion of canal flows to Biscayne Bay into coastal wetlands as sheet flow and surface runoff. Planned changes to freshwater delivery may change the habitat along the shoreline and thus the distribution of prey organisms living in this habitat. This may in turn affect predator fish important to local recreational and commercial fisheries as well as other predators such as wading birds. The analysis and prediction provided in this thesis work is important for better understanding the effects of restoration efforts on the Bay nearshore habitat and its condition as essential fish habitat, which is federally regulated by the Magnuson-Stevens Fishery Conservation and Management Act (Magnuson-Stevens, 1996). The distribution of small fish and invertebrate inhabitants of the nearshore environment and habitat environmental qualities have been recorded over the past five years from throw-trap surveys of the western shoreline of Biscayne Bay as part of a CERP-sponsored monitoring program. This pattern is correlated with salinity, but there may be other factors affecting the distribution of this species.

Submitted by (edna.saturno@ufrpe.br) on 2017-02-14T14:46:32Z No. of bitstreams: 1 Janilson Felix da Silva.pdf: 986185 bytes, checksum: 050d633ae1f790751916afcd3c6fb9bb (MD5) / Made available in DSpace on 2017-02-14T14:46:32Z (GMT). No. of bitstreams: 1 Janilson Felix da Silva.pdf: 986185 bytes, checksum: 050d633ae1f790751916afcd3c6fb9bb (MD5) Previous issue date: 2009-08-03 / The silver mojarra (Diapterus rhombeus) is specie of relevant representation among the fishing community in northeastern Brazil. Also in this region, the fishing is the most representative records despite growing carapeba in extensive systems. Among the parts of the fish are not consumed are the viscera which represent 5% of the total weight of the animals. Thus, to be discarded without treatment, these wastes pose serious environmental problem. However, because they are rich in digestive enzymes, viable for use in certain biotechnological processes these viscera represent an important alternative source of industrial enzymes. Based on this information, the purpose of this study was to purify and characterize an alkaline protease from the viscera of D. rhombeus. Therefore, viscera silver mojarra were used to obtain a crude extract and thereafter used for enzyme purification. The purification process was carried out in three steps: heat treatment (45°C for 30 minutes), precipitation with ammonium sulfate and molecular exclusion chromatography (Sephadex G-75). At the end of the purification process, achieved an increase of 86.80-fold in the specific activity and a yield of 22.34%. An aliquot of purified extract was applied to gel electrophoresis (SDS-PAGE) and its molecular weight was estimated at 24.5 kDa. The optimum pH and optimum temperature for enzyme activity were 8.5 and 55°C, respectively. The enzyme was shown to be sensitive to temperatures above 45°C, after incubation for 30 min, losing 100% of its activity. The values of Km and Kcat of the protease were 0.266 mM and 0.116 mM-1 s-1, respectively, using benzoyl-DL-arginine-p-nitroanilide (BAPNA) as substrate. Its activity was increased in the presence of ions K+, Li+, Ca2+, Mn2+ and Ba2+ ions and inhibited by Fe2+, Cd2+, Cu2+, Al3+, Hg2+, Zn2+ and Pb2+. Tests with protease inhibitors showed that the enzyme was strongly inhibited by TLCK and benzamidine, classic inhibitors of trypsin. The sequence of the first 15 amino acid N-terminal protease was IVGGYECTMHSEAHE and showed high homology with trypsins of various species of fish. The data show that the purified enzyme is one trypsin-like with characteristics compatible to be used in the biotechnology industry. / A Carapeba prateada (Diapterus rhombeus) é uma espécie de relevante representatividade dentre a comunidade pesqueira da região nordeste do Brasil. Ainda nessa região, a pesca artesanal é a mais representativa apesar de registros de cultivo da carapeba em sistemas extensivos. Dentre as partes do peixe não consumidas encontramse as vísceras que correspondem a 5% do peso total dos animais. Desta forma, ao serem descartadas, sem tratamento, esses resíduos representam grave problema ambiental. Entretanto, por serem ricas em enzimas digestivas, viáveis para utilização em determinados processos biotecnológicos essas vísceras representam uma importante fonte alternativa de enzimas industriais. Visando essas informações, o objetivo do presente trabalho foi purificar e caracterizar uma protease alcalina das vísceras de D. rhombeus. Para tanto, vísceras de carapeba prateada foram utilizadas para obtenção de um extrato bruto posteriormente utilizado para purificação enzimática. O processo de purificação foi realizado em três etapas: tratamento térmico (45oC por 30min), precipitação com sulfato de amônio e cromatografia de exclusão molecular (Sephadex G-75). Ao final do processo de purificação obteve-se um incremento de 86,80 vezes na atividade específica e um rendimento de 22,34%. Uma alíquota do extrato purificado foi aplicada em gel de poliacrilamida (SDS-PAGE) e o seu peso foi estimado em 24,5 kDa. O pH ótimo e a temperatura ótima para a atividade enzimática foram 8,5 e 55 °C, respectivamente. A enzima demonstrou ser sensível a temperaturas superiores a 45 ºC, após incubação por 30 min, perdendo 100% de sua atividade. Os valores de Km e do Kcat da protease foram 0,266 mM e 0,116 s-1 μM -1, respectivamente, usando benzoil-DLarginina- p-nitroanilida (BAPNA) como substrato. Sua atividade foi aumentada na presença dos íons K+, Li+, Ca2+, Mn2+ e Ba2+ e inibidas pelos íons Fe2+, Cd2+, Cu2+, Al3+, Hg2+, Zn2+ e Pb2+. Testes com inibidores de proteases mostraram que a enzima foi fortemente inibida por TLCK e benzamidina, inibidores clássicos de tripsina. A sequência dos 15 primeiros aminoácidos do N-terminal da protease foi IVGGYECTMHSEAHE e mostrou alta homologia com tripsinas de diversas espécies de peixes. Os dados obtidos demonstram que enzima purificada é uma tripsina com características compatíveis para ser empregada na indústria biotecnológica.

Florida's estuaries support a wide range of species yet little is known about tracemetal cycling among members of this important ecosystem. To examine the flow of trace metals through the Tampa Bay estuary, four fish species representing different trophic levels were analyzed for copper (Cu), zinc (Zn) and stable isotopes of carbon (C) and nitrogen (N). Species selected were the striped mullet (Mugil cephalus), tidewater mojarra (Eucinostomus harengulus), bay anchovy (Anchoa mitchilli), and sand seatrout (Cynoscion arenarius). Juvenile fish were collected from the Alafia, Hillsborough, Palm, and Little Manatee Rivers. Adults were collected from Tampa Bay. Combinations of trace metal and stable isotope analyses were used to evaluate geographic variability in trace metal concentrations among locations in Tampa Bay and to shed light on trophic pathways that lead to trace metal accumulation. In juvenile mullet, significant trends were found between Zn concentrations, stable isotope ratios, and standard length. Animals of the smallest size classes carry greater concentrations of zinc in their tissues and have distinct stable isotope ratios that reflect their recent life history as offshore planktivorous larvae. Interestingly, the ratio of Zn:Cu concentrations was highly conserved. While species-specific differences were observed, relatively small Zn:Cu variations suggest a possible bioregulatory mechanism that maintains an optimal Zn:Cu ratio even in the presence of elevated absolute metal concentrations. Stable isotope ratios proved to be an effective tracer of ontogenetic changes in fish diet and habitat. Carbon and nitrogen stable isotope analyses revealed that trophic relations between species are established very early in an organism's life history. The bay anchovy, a major prey item of the sand seatrout, has δ15N values very similar to this predator. Although trophic linkages between trace metals and stable isotopes proved difficult to interpret, the relation between zinc concentrations and δ¹³C values suggested that trace metal concentrations are highest in animals that utilize food webs based on terrestrial carbon.

Submitted by (edna.saturno@ufrpe.br) on 2017-02-20T13:11:23Z No. of bitstreams: 1 Robson Tavares Barbosa.pdf: 4522145 bytes, checksum: 55ba3289221c88cade2ebcf2ee0896bc (MD5) / Made available in DSpace on 2017-02-20T13:11:23Z (GMT). No. of bitstreams: 1 Robson Tavares Barbosa.pdf: 4522145 bytes, checksum: 55ba3289221c88cade2ebcf2ee0896bc (MD5) Previous issue date: 2012-02-28 / This study evaluated the profiles of seasonal diets of Eugerres brasilianus and Diapterus rhombeus, and food overlap between these species caught in the channel of Santa Cruz, located on the northern coast of the Pernambuco state, from June 2010 to May 2011. The goal was to provide input as a basis for studies aimed at the sustainable use and cultivation of these species. To understand their eating habits, we analyzed 837 individuals of both species, 567 species of E. brasilianus and 270 species of D. rhombeus, which, through its degree of fullness, frequency of occurrence, frequency number and index of food importance, we could verify their diets. As for the evaluation of overlapping niches, we used the Morisita-Horn index and multivariate analysis (Euclidean Distance). The two species have a very diverse food spectrum with high niche overlap (0.97). The most consumed item by both was Polychaeta, item with more than 75% of important food for both species. Bivalvia and Decapoda, were the most consumed by E. brasilianus item after the Polychaeta, with peak consumption during the year. While, for D. rhombeus, the most consumed items after the item Polychaeta were Amphipoda and Stomatopoda. The two species, as well as most individuals Gerreidae family, can be considered generalists because they present a wide food spectrum, opportunistic taking advantage of food in abundance in the environment, and omnivores with a preference for benthic invertebrates, especially polychaetes. / Neste trabalho foram avaliados os perfis sazonais das dietas de Eugerres brasilianus e Diapterus rhombeus, e, a sobreposição alimentar entre estas espécies capturadas no canal de Santa Cruz, localizado no litoral norte do estado de Pernambuco, no período de junho de 2010 a maio de 2011. Teve como objetivo fornecer subsídios que sirvam de base para estudos voltados para o cultivo e uso sustentável destas espécies. Para entender seus hábitos alimentares, foram analisados 837 indivíduos das duas espécies, 567 da espécie E. brasilianus e 270 da espécies D. rhombeus, dos quais, através do seu grau de repleção, freqüência de ocorrência, freqüência numérica e índice de importância alimentar, pôde-se verificar suas dietas. Já para a avaliação da sobreposição de nichos, utilizou-se o índice de Morisita-Horn e análise multivariada (Distância Euclidiana). As duas espécies apresentaram um espectro alimentar bastante variado com alta sobreposição de nichos (0,97). O item mais consumido por ambas foi o item Polychaeta, com mais de 75% de importância alimentar para ambas as espécies. Decapoda e Bivalvia, foram os itens mais consumidos por E. brasilianus depois do item Polychaeta, apresentando picos de consumo durante o ano. Enquanto que, para D. rhombeus, os itens mais consumidos após o item Polychaeta, foram Amphipoda e Stomatopoda. As duas espécies, assim como a maioria dos indivíduos da família Gerreidae, podem ser consideradas generalistas, por apresentarem um variado espectro alimentar, oportunistas por se aproveitarem do alimento em abundância no ambiente, e, onívoras com preferência para invertebrados bentônicos, especialmente para poliquetas.

This study examined the effects of the January 2010 cold spell on mangrove utilizing coral reef fishes off the southeast coast of Florida, USA, in the vicinity of Biscayne National Park (BNP). An ongoing, fishery-independent mangrove visual survey documenting fish assemblages in BNP provided data from the years 1998 to 2014 for examination. Of particular interest were the presence, abundance, and size structure for five mangrove utilizing coral reef fishes: sergeant major (Abudefduf saxatilis), yellowfin mojarra (Gerres cinereus), schoolmaster snapper (Lutjanus apodus), gray snapper (Lutjanus griseus), and great barracuda (Sphyraena barracuda). These species were selected for analysis due to their economic and ecologic importance, their potential as environmental indicators, their connectedness to multiple habitats, and their abundance within the available data set. Data were collected using a modified visual ‘belt transect’ method, consisting of 60 m2 transects running parallel to the mangrove shorelines. Data for average length of fish were reconstructed to form standard normal distributions and the resulting lengths were assigned to various age-classes to create species-specific length-frequency distributions. Variations in presence and abundance were examined across three time periods (1998-2009; 2010-2011; 2012-2014), as well as comparisons of length-frequency distributions. Following the January 2010 cold spell, the presence and abundance values for the two years immediately following the event were significantly decreased compared to the years prior to the cold spell for most of the five species at either mainland (ML) or leeward key (LK) locations. Additionally, the presence and abundance estimates typically remained statistically decreased when compared against the remaining years in the available data set. The size structures for the majority of the five species at either location, however, were not consistently significantly different between the three time periods, as was hypothesized. Instead, the analyses showed mixed results, with the size structure typically shifting towards smaller individuals immediately following the event. These findings suggest that drops in water temperature resulting from cold spells are capable of directly impacting mangrove utilizing reef fish species, albeit to varying degrees depending on various factors, such as physiological tolerances, ecological life history strategies, and habitat requirements.