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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Etnoecologia do Peixe-Boi da Amazônia (Trichechus inunguis) na província petrolífera de Urucu, Amazonas, Brasil

Franzini, André Machado 10 October 2008 (has links)
Submitted by Elaine Lucia (lucia.elaine@live.com) on 2015-07-01T19:03:27Z No. of bitstreams: 1 Dissertação - André Machado Franzini.pdf: 2296657 bytes, checksum: 9bea110d8bf19d4a093aeefb9bc70d3a (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-10T14:33:58Z (GMT) No. of bitstreams: 1 Dissertação - André Machado Franzini.pdf: 2296657 bytes, checksum: 9bea110d8bf19d4a093aeefb9bc70d3a (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-07-10T14:38:19Z (GMT) No. of bitstreams: 1 Dissertação - André Machado Franzini.pdf: 2296657 bytes, checksum: 9bea110d8bf19d4a093aeefb9bc70d3a (MD5) / Made available in DSpace on 2015-07-10T14:38:19Z (GMT). No. of bitstreams: 1 Dissertação - André Machado Franzini.pdf: 2296657 bytes, checksum: 9bea110d8bf19d4a093aeefb9bc70d3a (MD5) Previous issue date: 2008-10-10 / CNPQ - Conselho Nacional de Desenvolvimento Científico e Tecnológico / The Amazonian manatee (Trichechus inunguis) is an aquatic mammal, pertaining to Sirenia Order and Trichechidae family. It resides at the biggest tributaries of the Amazonian basin, it’s the only order’s specie that lives exclusively in fresh water. In the past the specie suffered an intense commercial exploration, mainly between 1930 to 1950 decades. In this period is esteemed around 200 thousand animals had been killed. Nowadays the specie has been listed as an animal “vulnerable to the extinction” by IUCN. In the region of Urucu River (Coari city-AM), characteristic area of occurrence and utilization by the specie, a scientific research, was developed between the years of 2006 and 2007, targeting to characterize limnology and to study the habitants traditional knowledge in the areas of Urucu River and in the lakes of Urucu, Aruã, Coari and Coari Grande. To the limnologic characterization the collect of the physical-chemicals parameters was realized: water temperature, depth, transparency, watercourse speed, pH, electric conductive and dissolved oxygen, with three copies to each area, to each hydrologic cycle time (low water, dryness, high water and over flowing). The results are compatible with the others Solimões River dark waters affluent. The Urucu river, even been characterized as a dark water river, shows low transparency and an inclination to white water coloration. The offer of aquatic plants as supplies to the Amazonian Manatee alternates a lot because of the differences between the water levels in the hydrologic time of over flowing and dryness. The dryness and the low water periods are with lower supplies available. Although the productions beginner at large areas of pasture in the region lakes that would serve as supplies to the Amazonian Manatee during all the high water and over flowing periods is watched. The ships traffic in the study area showed a higher intensity around Coari city and around the gas-tube buildings. To obtain the information about the traditional knowledge from the regions habitants about the Amazonian Manatee was realized interviews semistructured that made 74 inhabitants pertaining to 33 communities. To a better quality of data, these interviews were directed to the eldest inhabitants, to the Amazonian Manatee fishermen and to the communities leaders. Between those asked, 14 inhabitants assumed to have already fished at least one Amazonian Manatee at the studied zone. Between the years of 2004 to 2007 were registered a total of 17 abated animals. The harpoon is the equipment used to fish the Amazonian Manatee, but the “malhadeiras” (a kind of Amazonian fishing net) shows risk to accidental captures, mainly for species nestling. Half of the local inhabitants believe that the density of Amazonian Manatee has suffered reduction in the studied zone, mainly because of the fact that is still happening Amazonian Manatee captures. According the inhabitants, the Amazonian Manatee can be almost totally used to consume, taking off just the bones and the hardest leathers parts. The meat trade of Amazonian manatee, even forbidden by law, it is still occurring in the area. About the alimentary habits, the asked mentioned 29 species of aquatic and semi-aquatics plants consumed by Amazonian Manatee. The asked inhabitants showed extensive knowledge about biology, reproduction, alimentary habits and Amazonian Manatee distribution. These informations are considered importants instruments for future conservation works of the specie. / O peixe-boi da Amazônia (Trichechus inunguis) é um mamífero aquático, pertencente à Ordem Sirenia e família Trichechidae. Habita os maiores tributários da bacia Amazônica, sendo a única espécie da ordem exclusivamente de águas doce. No passado a espécie sofreu com a intensa exploração comercial, principalmente entre as décadas de 1930 a 1950. Estimase que neste período tenha sido exterminado cerca de 200 mil animais. Atualmente a espécie encontra-se listada como espécie “vulnerável a extinção” pela IUCN. Na região do rio Urucu (município de Coari-AM), área característica de ocorrência e utilização da espécie, desenvolveu-se entre os anos de 2006 e 2007, uma pesquisa científica com os objetivos de caracterizar limnologicamente e estudar o conhecimento tradicional dos moradores nas áreas do rio Urucu e lagos Urucu, Aruã, Coari e Coari Grande. Para a caracterização limnológica realizou-se a coleta dos parâmetros físico-químicos: temperatura da água, profundidade, transparência, velocidade de correnteza, pH, condutividade elétrica e oxigênio dissolvido, com três réplicas para cada área, para cada época do ciclo hidrológico (vazante, seca, enchente e cheia). Os resultados mostraram-se compatíveis com de outros afluentes de água preta do rio Solimões. O rio Urucu, mesmo sendo caracterizado como rio de água preta, apresenta baixa transparência e a coloração que tende a água branca. A oferta de plantas aquáticas como alimento para o peixe-boi varia muito em função das diferenças nos níveis das águas entre as estações hidrológicas de cheia e seca. A seca e a vazante são os períodos com menor disponibilidade alimentar. Contudo observa-se o início da produção de grandes áreas de capinzal nos lagos da região que servirão de alimento para o peixe-boi por todo o período de enchente e cheia. O tráfego de embarcações na área de estudo apresentou maior intensidade nas áreas próximas do município de Coari e de influência das obras do gasoduto. Para obtenção de informações sobre o conhecimento tradicional dos moradores da área em relação ao peixe-boi, foram realizadas entrevistas semi-estruturadas com um total de 74 moradores pertencentes a 33 comunidades. Para uma melhor qualidade dos dados, estas entrevistas foram direcionadas aos moradores mais antigos, aos pescadores de peixe-boi e as lideranças das comunidades. Dos entrevistados, 14 moradores assumiram já ter pescado pelo menos um peixe-boi na área estudada. Entre os anos de 2004 a 2007 foram registrados um total de 17 animais abatidos. O arpão é o apetrecho utilizado para a pesca do peixe-boi, porém as malhadeiras apresentam risco de capturas acidentais, principalmente para os filhotes da espécie. Metade dos moradores locais acredita que a densidade de peixe-boi na área de estudo está sofrendo uma redução, principalmente pelo fato de ainda ocorrer casos de captura do peixe-boi. Segundo os moradores, o peixe-boi pode ser quase que totalmente aproveitado para o consumo, descartando-se somente os ossos e a parte mais dura do couro. O comércio da carne do peixe-boi, mesmo que proibido por lei, ainda ocorre na área. A respeito dos hábitos alimentares, os entrevistados mencionaram 29 espécies de plantas aquáticas e semi-aquáticas que são consumidas pelo peixe-boi. Os moradores entrevistados apresentaram amplo conhecimento a respeito da biologia, reprodução, hábitos alimentares e distribuição do peixeboi, Essas informações são consideradas importante ferramenta para trabalhos futuros de conservação da espécie.
12

Variações morfológicas e geográficas no sincrânio do peixe-boi da Amazônia Trichechus inunguis (Natterer, 1883)

Valdevino, Gisele de Castro Maciel 04 May 2016 (has links)
Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-12-13T13:42:10Z No. of bitstreams: 1 Dissertação Parcial - Gisele C. M. Valdevino.pdf: 1579242 bytes, checksum: ac97271a24c9541ad8b59f219b0a58d5 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-12-13T13:42:45Z (GMT) No. of bitstreams: 1 Dissertação Parcial - Gisele C. M. Valdevino.pdf: 1579242 bytes, checksum: ac97271a24c9541ad8b59f219b0a58d5 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-12-13T13:43:19Z (GMT) No. of bitstreams: 1 Dissertação Parcial - Gisele C. M. Valdevino.pdf: 1579242 bytes, checksum: ac97271a24c9541ad8b59f219b0a58d5 (MD5) / Made available in DSpace on 2016-12-13T13:43:19Z (GMT). No. of bitstreams: 1 Dissertação Parcial - Gisele C. M. Valdevino.pdf: 1579242 bytes, checksum: ac97271a24c9541ad8b59f219b0a58d5 (MD5) Previous issue date: 2016-05-04 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The Amazonian manatee (Trichechus inunguis) is endemic to the Amazon basin and the only freshwater sirenian. Apomorphies features relative to other Trichechidae derived from its adaptation to freshwater environment and it is distributed from the headwaters of rivers in Ecuador, Peru and Colombia to Amazon River estuary in Brazil. While studies of the morphology of this species, no cranial ontogenetic study was developed over its distribution. Morphological studies in Trichechidae have been conducted through the conventional morphometry, which cannot always describe or represent the variability of form from organisms. Geometric morphometrics is a toolbox that is been widely applied in studies comparing the shape of organisms taking into consideration the biological shapes and analyzing their variation statistically. To understand the ontogeny and morphology of this species, the aim of this study is to analyze the variation in size and shape of the Amazonian manatee skull throughout its ontogeny and morphological variations in sexual and geographic levels. A total of 80 skulls and 102 mandibles were used to collect morphometric geometric data in two and three dimensions. These skulls and mandibles were grouped into three age classes: calves, young and adult according to their origin and then were analyzed geometrically, seeking cranial changes between individuals of age groups and between specimens from different rivers of the Amazon basin. For this skulls and mandibles were scanned and after a geometrical treatment, configurations generated were analyzed statistically by components of shape and size. Amazonian manatee skull presents positive allometry and no sexual dimorphism was observed in this species. The morphological changes were observed in shape of the skull and mandible, which is influenced by size of the structures. The observation of the pattern of closure of supraoccipital - exoccipital synchondrosis and the classification proposed by Amaral et al. (unpublished data) were used to determine three age classes from shape of skulls and jaws. Specimens from white water rivers presented themselves different from other rivers from black and clear water. Within the group of specimens from different rivers of white water, the group originating from Japurá river presents different from the other groups, which are: Amazon, Solimões and Javari rivers. / peixe-boi-da-Amazônia (Trichechus inunguis) é endêmico da bacia Amazônica e exclusivo de água doce. Apresenta apomorfias em relação aos outros triquequídeos, derivadas de sua adaptação ao ambiente dulcícola e distribui-se desde as cabeceiras de rios no Equador, Peru e Colômbia até o estuário do Rio Amazonas, no Brasil. Apesar dos estudos sobre a morfologia desta espécie, nenhum estudo ontogenético sincraniano foi desenvolvido ao longo de sua distribuição. Estudos morfológicos em triquequídeos vêm sendo realizados através da morfometria convencional, que nem sempre consegue descrever ou representar a variabilidade de forma dos organismos. A morfometria geométrica é uma técnica de comparação da forma dos organismos e leva em consideração a geometria das formas biológicas, analisando estatisticamente sua variação. Visando compreender a ontogenia e morfologia desta espécie, o objetivo deste estudo é analisar as variações de forma e tamanho do sincrânio do peixe-boi-da- Amazônia ao longo de sua ontogenia e das variações morfológicas sincranianas a níveis sexual e geográfico. Um total de 80 crânios e 102 mandíbulas foram utilizados para a coleta de dados geométricos morfométricos em duas e três dimensões. Estes crânios e mandíbulas foram agrupados em três classes etárias: filhote, jovem e adulto e de acordo com sua proveniência e então foram analisados geometricamente, buscando alterações cranianas entre indivíduos das classes etárias e entre os exemplares provenientes de diferentes rios da bacia amazônica. Para isso os crânios e mandíbulas foram digitalizados e após um tratamento geométrico as configurações geradas foram analisadas estatisticamente, por meio de seus componentes de forma e tamanho. O sincrânio de Trichechus inunguis apresenta alometria positiva e não foi observado dimorfismo sexual nesta espécie. As variações morfológicas foram observadas na forma do crânio e mandíbulas, sendo esta influenciada pelo tamanho das estruturas. A observação do padrão de fechamento da sincondrose supraoccipital - exoccipital e a classificação proposta por Amaral et al. (dados não publicados) foram utilizadas para a determinação das três classes etárias a partir da forma dos crânios e mandíbulas. Os exemplares provenientes de rios de água branca apresentaram-se diferentes dos demais oriundos de rios de água preta e clara. Dentro do grupo de exemplares provenientes dos diferentes rios de água branca, o grupo oriundo do rio Japurá apresenta-se diferente dos demais grupos, sendo estes: rio Amazonas, Solimões e Javari.
13

Aspectos relacionados à conservação do Peixe-boi-amazônico Trichechus inunguis (Natterer, 1883) e da Ariranha Pteronura brasiliensis (Zimmerman, 1780) no rio Iruá, Parque Nacional do Viruá, Roraima

Diana Marcela Rojas Rojas 28 September 2009 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este estudo relaciona aspectos sobre conservação de peixes-boi (Trichechus inunguis) e ariranhas (Pteronura brasiliensis) no baixo rio Branco, Parque Nacional do Viruá, Roraima. O objetivo geral foi verificar o estado de conservação e saber se existem ameaças em contra destas espécies. O estudo foi desenhado em duas partes: entrevistas aos antigos moradores e pescadores da região e verificação destes dados num transecto de 53 km pelo rio Iruá. Quanto às entrevistas foram utilizados testes de qui-quadrado para saber se há homogeneidade nas respostas. Os resultados mostram que as pessoas têm um bom conhecimento sobre os locais de uso, e alguns comportamentos das espécies. Ressacas, lagos e remansos foram os locais mais mencionados para o peixe-boi, assim como barrancos e igapós para as ariranhas. Rastros de consumo em Ciperáceas subaquáticas são os sinais de presença mais fortes no rio iruá da ocorrência do peixe-boi. Tocas latrinas e paradouros distribuídos em barrancos e igapós mostram que ariranhas utilizam bem o canal do rio, tendo uma ocupação de 23% delas. São discutidos aspectos relacionados à Unidade de Conservação e ao entorno dela. Por enquanto, peixes-boi e ariranhas não estão ameaçadas na área de estudo, mas, devem ser intensificadas as ações de controle e fiscalização, apoiados os estudos in situ com estas espécies, e divulgados programas de educação ambiental e sensibilização tanto a nível local como do estado de Roraima.
14

Call Categorization and Vocal Behavior of the Florida Manatee (Trichechus manatus latirostris)

Unknown Date (has links)
Florida manatees are semisocial marine mammals that vocalize when interacting with conspecifics and to maintain contact with offspring. While many aspects of their biology have been studied, there is a dearth of information on the diversity and complexity of vocal behavior during social, nonsocial, and stressful situations. Investigations of vocal communication repertoires which define, categorize, and correlate varied call types with behavior are needed in order to understand the behavioral and social function of associated calls. Arguably the most important social bond in manatees is the period of cow/calf dependency and empirical evidence indicates cows recognize the vocalizations of offspring. Exploration of individually distinctive vocal features can provide insight on which parameters might be salient to facilitate recognition between cows/calves. This study is focused on vocal communication in Florida manatees, how calls are structured, utilized and function while animals are distressed and during social interactions in their shallow water habitats. Hydrophones recorded vocalizations from individual calves and manatees in different behavioral contexts and varying size aggregations. Analysis of the vocal repertoire indicated manatee vocalizations can be parsed into five broadly defined call types which include the hill-shaped high squeak, tonal squeak, noisy squeal, two toned chirp, and the combinatorial squeak-squeal. Furthermore, the high squeak is likely a discrete call whereas the others are graded and do not have strict boundaries between call types (Chapter 2). Broadly defined call types were used to explore call usage with variations in behavior, group size, and group composition (Chapter 3). Manatees vocalized using few call types and altered structural parameters depending on behavioral state. Calls were longer and more frequency modulated when stressed. Vocalizations produced while cavorting were higher in entropy and more frequency modulated than when manatees were resting or feeding. Vocalizations obtained from individual calves suggest that the high squeak is a stereotypical call that is produced by smaller calves. All calves had individually distinctive acoustic features that could potentially be used in recognition (Chapter 4). Lower fundamental frequencies and higher emphasized frequencies from smaller calves suggest that the fundamental frequency may not be a reliable indicator of body size in calves. This research increases our knowledge of the vocal behavior and call characteristics of the Florida manatee. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2020. / FAU Electronic Theses and Dissertations Collection
15

Stabel Isotope Turnover Rates And Diet-tissue Discrimination In The Skin Of West Indian Manatees: Implcations For Evaluating Their Feeding Ecology And Habitat Use

Alves, Christy 01 January 2007 (has links)
The West Indian manatee (Trichechus manatus) is an herbivorous marine mammal that occupies freshwater, estuarine, and marine habitats. Despite being considered endangered, relatively little is known about the feeding ecology of either of the two recognized subspecies, the Florida manatee (T.m. latirostris) and Caribbean or Antillean manatee (T.m. manatus). A better understanding of their respective feeding preferences and habitat use is essential to establish criteria on which conservation plans can be based. The present study expands on previous work on manatee feeding ecology by both assessing the application of stable isotope analysis to manatee tissue and providing critical baseline parameters for accurate isotopic data interpretation. The present study was the first to calculate stable isotope turnover rate in the skin of any marine mammal. Stable carbon and nitrogen isotope ratios were examined over a period of more than one year in the epidermis of rescued Florida manatees that were transitioning from a diet of aquatic forage to terrestrial forage (lettuce) in captivity. Mean half-life for 13C turnover in manatee epidermis was 55 days and mean half-life for 15N turnover was 42 days. Due to these slow turnover rates, carbon and nitrogen stable isotope analysis in manatee epidermis is useful in summarizing average dietary intake over a long period of time rather than assessing recent diet. In addition to turnover rate, a diet-tissue discrimination value of 2.8‰ for 13C was calculated for long-term captive manatees on a lettuce diet. Turnover and diet-tissue discrimination results were subsequently used to interpret carbon and nitrogen stable isotope data in epidermis samples collected from free-ranging manatees in Florida, Belize, and Puerto Rico. This study was the first application of stable isotope analysis to Antillean manatees. Regional differences in stable isotope ratios in manatee skin were consistent with ratios in plant samples collected in those regions. Signatures in the skin of manatees sampled in Belize and Puerto Rico indicated a diet composed mainly of seagrasses, whereas those of Florida manatees exhibited greater variation. Mixing model results indicated manatees sampled from Crystal River and Homosassa Springs had an overall average intake of primarily freshwater vegetation whereas manatees sampled from Big Bend Power Plant, Ten Thousand Islands, and Warm Mineral Springs fed primarily on seagrasses. Possible diet tissue discrimination values for 15N ranged from 1.0 to 1.5‰. Stable isotope analysis can be successfully applied to interpret manatee feeding behavior over a long period of time, specifically the use of freshwater vegetation vs. seagrasses, and can aid in improving conservation efforts.
16

INDICADORES POPULACIONAIS E ECOLÓGICOS DE PEIXES-BOIS-MARINHOS (Trichechus manatus manatus) EM DUAS ÁREAS DE MANGUEZAIS E MARISMAS NO MARANHÃO / POPULATION AND ECOLOGICAL INDEX FOR MANATEES (Trichechus manatus manatus) IN TWO MANGROVES AND SALT-MARSHES AREAS OF MARANHÃO

Alvite, Carolina Mattosinho de Carvalho 28 September 2008 (has links)
Made available in DSpace on 2016-08-19T18:20:37Z (GMT). No. of bitstreams: 1 Carolina Mattosinho de Carvalho Alvite.pdf: 6763080 bytes, checksum: d171930fac0eadfa71fb881a91e48018 (MD5) Previous issue date: 2008-09-28 / INSTITUTO INTERNACIONAL DE EDUCAÇÃO DO BRASIL / The Brazilian north coast has the largest continuous area of mangroves on the planet and hosts large groups of manatees, aquatic mammal critically endangered. This research examines the efforts of fix point methodology of observation of manatees on relevant sites of occurrence, from data collected while on the beach in Guarapiranga (GUA), São José de Ribamar and on Ilha do Gato (IGA), Baía do Tubarão. This article discusses the application of population index for manatees in a ecological-environmental study on IGA (02°31'09, 81"S, 43°37'09,13" W), Mapari estuary, serving as a methodological basis to be replicated in other parts of the coast. From the application of index developed with data from fixed point and the characterization of the environmental area, the study provides evidence to infer the relative abundance of the population and it trends over the years, discussing aspects of spatial and temporal use of estuary. Was characterized: temperature, salinity, pH, conductivity, depth, current speed, tides fluctuations, rainfall, biomass of salt-marsh (Spartina alterniflora), and density of plants/seedlings of mangrove. The region showed a seasonal variation marked by two regimes of water, rain (January-July) and dry (August-December), with annual rainfall of 1,704mm. The oceanographic parameters ranged from tides: salinity (FLOOD=14.8; EBB=1.5), conductivity (FLOOD=27.1; EBB=6.3mS/cm), speed of current (FLOOD=46; EBB=88m/s). The tide height ranged from 0.0-5.4m. Biomass of S. alterniflora ranged from 860g/m2(RAIN) to 430g/m2(DRY) and density of plants/seedlings of 74ind/m2(RAIN) to 21ind/m2(DRY). Variations between rain/dry seasons influenced the availability of fresh water and food resources, important factors in the choice of areas for manatees. The estuary was shown with strong influence of daily tide fluctuations, reflecting changes in salinity, current speed, depth and access to plant resources by manatees. Between 2004/2007, manatees were monitored in 1241 days (GUA = 625, IGA = 616). The population analysis carried out in two sites of Maranhão indicated a trend of reducing population between 2004 and 2006, with stabilization between 2006 and 2007. The IGA had the highest relative abundance and showed to be important site of occurrence of manatees, which used as an area of reproduction, parental care, food and rest. IGA in the number of manatees seems to have relation with the seasons, being sighted in greater numbers in the rainy season. Variations during the tides also shown to influence the pattern of use of the IGA, and the manatees were more frequent in the tides ebb and flood. The main type of human activity in the IGA was not motorized boat and it had no negative influence on the occurrence of fish-horse. Knowledge about characteristics of coastal ecosystems is essential for development of appropriate conservation strategies for manatees in the Brazilian north coast. / O litoral norte do Brasil possui a maior área contínua de manguezais do planeta e abriga importantes grupos de peixes-bois-marinhos, mamífero aquático criticamente ameaçado de extinção. Esta pesquisa analisa o esforço da metodologia de observação de peixes-bois por meio de plataformas fixas em sítios de relevante ocorrência, a partir dos dados coletados simultaneamente na praia de Guarapiranga (GUA), São José de Ribamar, e na barra da Ilha do Gato (IGA), Baía do Tubarão. Também é discutida a aplicação de indicadores populacionais e ecológicos para peixes-bois em estudo de caso na barra da Ilha do Gato (02°31 09,81 S; 43°37 09,13 W), estuário do rio Mapari, servindo de base metodológica para ser replicada em outros pontos da costa. A partir da aplicação dos indicadores elaborados com os dados de ponto fixo e da caracterização ambiental da área, a pesquisa fornece elementos para inferir a abundância relativa da população e como esta se comporta ao longo dos anos, discutindo aspectos da utilização espacial e temporal do estuário. Para caracterização ambiental da IGA, foram levantados os seguintes parâmetros: temperatura (ar-água), salinidade, pH, condutividade, profundidade, velocidade de corrente, amplitude de marés, precipitação pluviométrica, biomassa de marisma (Spartina alterniflora), densidade de plântulas de mangue. A região mostrou uma variação sazonal do regime hidrológico: chuva (janeiro-julho) e seca (agosto-dezembro), com precipitação pluviométrica anual de 1704mm. Os parâmetros oceanográficos médios variaram entre as marés: salinidade (ENCH=14,8, VAZ=1,5), condutividade (ENCH=27,1, VAZ=6,3 mS/cm), velocidade de corrente (ENCH=46; VAZ=88 m/s). A altura da maré variou entre 0,0-5,4m. A biomassa de S. alterniflora variou de 860g/m2(chuva) a 430g/m2(seca) e a densidade de plântulas de 74 ind/m2(chuva) a 21 ind/m2(seca). As variações entre os períodos de seca e chuva influenciaram na disponibilidade de água doce e recursos vegetais, fatores determinantes na escolha de áreas pelos peixes-bois. O estuário mostrou-se com forte influência da variação diária nos regimes de maré, refletindo em mudanças na salinidade, velocidade de corrente, profundidade e acesso aos recursos vegetais pelos peixes-bois. Entre 2004/2007, os peixes-bois foram monitorados em 1.241 dias (GUA=625, IGA=616). As análises populacionais realizadas nos dois sítios do Maranhão indicaram uma tendência de redução populacional entre 2004 e 2006, com estabilização entre 2006 e 2007. A Ilha do Gato apresentou a maior abundância relativa e mostrou ser importante sítio de ocorrência de peixes-bois, sendo utilizada como área de reprodução, cuidado parental, alimentação e repouso. Na IGA o número de peixes-bois parece ter relação com as estações do ano, sendo avistados em maior número no período chuvoso. As variações nas fases de maré também mostraram ter influência no padrão de utilização da IGA, sendo que os peixesbois estiveram mais freqüentes nas marés vazantes e cheias. A ocorrência de embarcações não motorizadas foram a atividade humana com maior freqüência na IGA e não teve influência negativa na ocorrência dos peixes-bois. O conhecimento sobre as características dos ecossistemas costeiros é essencial para a elaboração de estratégias de conservação adequadas para o peixe-boi-marinho na região norte do Brasil.
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DistribuiÃÃo espacial e status do peixe-boi marinho Trichechus manatus manatus, (Sirenia: Trichechidae) no litoral leste do estado do Cearà / Spatial distribution and status of the marine manatee Trichechus manatus manatus (Sirena: Trichechidae) in the eastern coastal state of CearÃ

Alexandra Fernandes Costa 29 March 2006 (has links)
O peixe-boi marinho, Trichechus manatus manatus, à um mamÃfero com dieta herbÃvora, e distribuiÃÃo costeira em rios, estuÃrios e Ãguas litorÃneas da Zona Tropical brasileira. No Estado do Cearà ocorre em duas Ãreas distintas, no extremo dos seus setores leste e oeste. No litoral leste nÃo existe nenhuma Unidade de ConservaÃÃo com abrangÃncia marinha que restrinja os impactos causados ao meio ambiente e à populaÃÃo do peixe-boi, tais como urbanizaÃÃo, turismo e ocupaÃÃo de praias, dunas, falÃsias e manguezais. Sendo considerado pela UniÃo Internacional para ConservaÃÃo da Natureza como âespÃcie vulnerÃvelâ e estando inserido na Lista Oficial de EspÃcies da Fauna Brasileira AmeaÃadas de ExtinÃÃo de acordo com o IBAMA, corre risco de extinÃÃo extremamente alto num futuro prÃximo. Os objetivos desta DissertaÃÃo foram determinar a distribuiÃÃo espacial e padrÃes de uso da Ãrea, escolha da metodologia mais adequada ao monitoramento da populaÃÃo, e realizar levantamento das Ãreas de alimentaÃÃo e fontes e Ãgua doce provavelmente utilizadas pelos animais. A base de dados foi obtida atravÃs de prospecÃÃes aÃrea, realizada de junho/2003 a outubro/2004, totalizando 11 sobrevÃs e 24 horas de esforÃo de monitoramento, e nÃutica, realizada de agosto/2003 a novembro/2004, num total de 10 embarques e 157 horas de esforÃo de monitoramento. Dentre os mÃtodos de prospecÃÃo aÃrea e nÃutica, o primeiro gera erros devido à turbidez da Ãgua, e dificuldades de identificaÃÃo e contagem dos indivÃduos, enquanto o segundo, por sua maior proximidade em relaÃÃo aos animais, mostrou-se mais eficiente. O status da populaÃÃo do peixe-boi marinho foi avaliado atravÃs dos seguintes parÃmetros: (a) conservaÃÃo do habitat, com Ãnfase para a manutenÃÃo do territÃrio; (b) acesso a fontes de Ãgua doce e a Ãreas preferenciais de alimentaÃÃo e reproduÃÃo; (c) geraÃÃo de condiÃÃes ambientais Ãtimas para os cuidados parentais. Os fatores de ameaÃa de extinÃÃo nessa Ãrea estariam relacionados com reduÃÃo das fontes de alimento e Ãgua doce, assoreamento do Rio Jaguaribe, alÃm de captura acidental por aparelhos de pesca. Estes se traduzem nas seguintes conseqÃÃncias: reduÃÃo do habitat; aumento da frequÃncia de encalhes de recÃm-nascidos; aumento da mortalidade de adultos. A regiÃo de Picos, com destaque para o Banco dos Cajuais, foi definida como Zona de Alta Densidade, com padrÃo de distribuiÃÃo âaltamente agregadaâ por causa da abundÃncia de macroalgas e do menor fluxo de barcos motorizados. Dentre as recomendaÃÃes para se minimizar os riscos de extinÃÃo do peixe-boi, destacam-se: (a) desenvolvimento de campanhas educacionais que ressaltem aspectos importantes da conservaÃÃo do ambiente marinho; (b) reintroduÃÃo de espÃcimes em locais onde o declÃnio populacional à evidente; (c) criaÃÃo de unidades de conservaÃÃo com abrangÃncia marinha e aplicaÃÃo e fiscalizaÃÃo da legislaÃÃo pertinente ao habitat do peixe-boi e (d) monitoramento sistemÃtico da populaÃÃo no litoral leste para determinaÃÃo dos padrÃes ambientais que influenciam na ocorrÃncia do peixe-boi no municÃpio de IcapuÃ, litoral leste do CearÃ. / The Antillean manatee, Trichechus manatus manatus, is a mammal with an herbivorous diet and costal distribution in rivers, estuaries and inshore waters of the Brazilian Tropical Zone. In Cearà State, the species may found in the outermost ends of its western and eastern sectors. In the eastern sector there are no Marine Conservation Units to ward off impacts to the environment and the manatee population, such as urban development, tourism and occupation of beaches and mangrove forests. Manatees have been classified by the International Union for Nature Conservation as a âvulnerable speciesâ and included on the Official List of Endangered Species of the Brazilian Fauna. According to the Brazilian Institute for the Environment, it runs an extremely high risk of extinction in the near future. The objectives of this Thesis have been to determine the spatial distribution and patterns of usage of the living area, choice of the most appropriate methodology for population monitoring and mapping of feeding grounds and freshwater sources likely to used by the animals. The database was obtained by means of aerial surveys from June, 2003 to October, 2004, making up a 24-hour monitoring effort during 11 overhead flights, as well as nautical surveys performed from August, 2003 to November, 2004, making up a 157-hour monitoring effort during 10 voyages. Of the two prospecting techniques, the aerial one was less practical because of water turbidity, which made it difficult to identify and count manatee specimens, whereas the nautical one, because of its nearness to the targets, proved to the most efficient. The status of the Antillean manatee population was evaluated through the following parameters: (a) habitat conservation, with emphasis on territory maintenance; (b) access to freshwater sources and areas suitable for feeding and reproduction; (c) yielding of optimum environmental conditions for parental care. The threatened extinction in the studied area is related to factors such as decreasing of food and freshwater sources, silting-up of the Jaguaribe River, by-catch by trawl and gillnet fishing. The worrying outcome of such a scenario is likely to result in a reduction of the habitat size; increase in the straying of newborns plus an increase in adult mortality rates. The Picos region, specially the Cajuais sandbank, was defined as a High Density Zone, which displays a highly aggregate distribution because of seaweed abundance and smaller deployment of fishing boats. Among the suggestions for lowering the extinction risks of the Antillean manatee in Eastern Cearà State, the following ones stand out; (a) development of education campaigns which deal with the main aspects of environment preservation; (b) reintroduction of specimens in zones where population decline is evident; (c) installation of Marine Conservation Units and enforcement of the pertinent management measures and (d) constant monitoring of the population in the known habitat to determine environmental patterns which influence manatees in Icapuà county, eastern Cearà State.
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Diel, Tidal, and Sex Based Differences in Time Spent Feeding by the Florida Manatee (Trichechus manatus latirostris)

Flora, Megan 14 November 2012 (has links)
The feeding behavior of an animal is based on adaptations to the environment and the animal’s body condition. The Florida manatee (Trichechus manatus latirostris) is an example of a marine mammal that may alter its feeding pattern based on diel and tidal cycles. The increased presence of boats during the day could potentially cause manatees to alter their feeding rates, or the time spent feeding per hour, over the diel cycle. Tide levels may cause manatees to be restricted from areas of preferred vegetation. In addition, the differential reproductive investment between males and females may cause differential time dedicated to feeding between the sexes. This study analyzed sound recordings (lasting up to 24 hr) from manatees tagged in southwest Florida with a digital acoustic recording tag (DTAG) between April and September. Distinctive chewing sounds were indicative of feeding activity. Variation in time spent feeding was analyzed in relation to time of day, sex, female reproductive status, and water level as affected by tides. Manatees dedicated 26% of the time (6 hours) to feeding, on average. During the first year of the study, manatees spent 39% of the time feeding (9 hours), on average, over the course of a 24-hour period; during the second year they spent 15% (2 hours) over the course of a 13-hour daytime period. Adult females fed significantly more, on average, than adult males. Females in late-term pregnancy appeared to spend more time foraging than other non-lactating females, but the sample size was too small to be definitive. Manatee time spent feeding was not correlated with time of day. Increases in feeding activity occurred at mid to high tide levels. This may indicate that manatees had greater access to preferred food sources at this time. An understanding of when manatees 5 are most likely to be feeding and which environmental factors influence this activity may suggest ways to reduce impacts on the endangered population.
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The Effects of a New Bridge on Manatee (Trichechus manatus latirostris) Use of the FPL Discharge Canal at Port Everglades, Florida

Viragh, Brea 01 July 2012 (has links)
The Florida manatee (Trichechus manatus latirostris) is an endangered species that migrates to warm water refuges such as natural springs or power plant effluents during the winter months to escape cold water. The Florida Power and Light (FPL) discharge canal in Port Everglades, Ft. Lauderdale, FL., is utilized as a refuge by overwintering manatees. Construction of a new bridge over the FPL effluent canal had a potential effect on manatee usage of the canal. Discharge is often 10-15° C warmer in the winter season than the surrounding waters of the Intracoastal Waterway. Previous data, including age class and cow/calf abundance from pre-bridge winters (2004-2009), were compared with data from winter 2010, during bridge construction and winter 2011, postbridge construction. No manatees were present at the survey sites during winter until surface water temperatures fell below 22° C. Although monthly mean surface water temperatures were not statistically different between 2008-2009, 2009-2010, and 2010-2011 (21.9±0.4° C, 21.8±1.8° C and 21.4±0.6° C respectively), manatee abundance did vary. 2008-2009 had higher monthly mean numbers of manatees per survey from December through March (29.7, 27.3, 48.1, 2 respectively) than 2009-2010 (0, 30, 10.7, 5 respectively) and 2010-2011 (18.7, 6.7, 0.1, 0 respectively). A Poisson distribution analysis showed a significant difference in adult manatee counts among the study years (α < 0.05). No significant differences were found for juveniles and calves. While I cannot decisively state that bridge construction reduced the number of overwintering adult manatees during 2010, there appears to be the potential for an effect.
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Emerging Hotspot Analysis of Florida Manatee (Trichechus manatus latirostris) Mortality (1974-2012)

Bass, Crystal Ann 23 October 2017 (has links)
The Florida manatee (Trichechus manatus latirostris) is a protected species that is vulnerable to both anthropogenic and natural causes of mortality. The ability of wildlife managers to oversee regulation of this species is based on available abundance estimates and mortality data. Using existing manatee mortality data collected by Florida Fish and Wildlife Conservation Commission (FWC) from 1974-2012, this study focuses on identifying significant spatial clusters of high values or “hotspots” of manatee mortality and the temporal patterns of these hotspots using the novel “emerging hotspot analysis” ArcGIS tool. The categories of manatee mortality included in this analysis were watercraft-related, perinatal, cold-stress, and other natural (which includes red tide) and were classified into five hotspot pattern categories. Of interest were the locations where consecutive or new hotspot patterns were identified among the four categories of manatee mortality included in this analysis. Consecutive hotspot clusters were found near Tampa Bay (which includes parts of Pinellas, Hillsborough, and Manatee Counties) and in the counties of Hernando/Pasco, Monroe, Palm Beach/Broward/Miami-Dade, St. Johns/Flagler, and Citrus. New hotspot clusters were found in Tampa Bay (which includes parts of Pinellas, Hillsborough, and Manatee Counties) and in the counties of Nassau, Wakulla, Charlotte/Lee, St. Lucie/Martin, Levy, Duval, Dixie, Volusia/Seminole, and Citrus. These mortality hotspots frequently overlapped areas of higher manatee and human population densities. These hotspot clusters indicate emerging patterns that highlight areas to focus future research by wildlife managers; specifically, on the relationship between human population density and concentration of watercraft activities in coastal areas, as well as the influence coastal development has on the vital resources utilized by manatees.

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