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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.
1

Distribution and ecology of soft-bottom Sipuncula from the western Mediterranean Sea / Distribución y ecología de los sipuncúlidos de fondos blandos del mar Mediterráneo occidental

Ferrero-Vicente, Luis Miguel 10 October 2014 (has links)
No description available.
2

Poliquetas associados a bancos de mitilídeos de fundos não consolidados um uma região subtropical / Polychaetes of soft-bottom mussel beds in a subtropical area

Silva, Camila Fernanda, 1984- 22 August 2018 (has links)
Orientador: Antonia Cecília Zacagnini Amaral / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-22T03:18:37Z (GMT). No. of bitstreams: 1 Silva_CamilaFernandada_M.pdf: 2054287 bytes, checksum: 3eb2bbba7d82fc1653b87868f315280a (MD5) Previous issue date: 2013 / Resumo: Os bancos de mitilídeos consistem de uma matriz física de indivíduos vivos e mortos e fragmentos de concha, interconectados por um emaranhado de filamentos do bisso. O estudo da caracterização estrutural de dois bancos de mitilídeos (Mytella charruana) foi realizado entre abril de 2006 e fevereiro de 2007, nas praias Camaroeiro e Cidade (costa norte do Estado de São Paulo). Amostras mensais foram obtidas com o auxílio de um delimitador de 0,04 m2 de área, até 20 cm de profundidade, em três níveis do banco (inferior médio e superior). Foi analisada a densidade de M. charruana, bem como os parâmetros perfil praial, salinidade da água intersticial, temperaturas do ar e do sedimento, conteúdo de calcário e matéria orgânica do sedimento e granulometria. A densidade média mensal de M. charruana do banco Camaroeiro variou de 13,66 inds/0,04 m2 (dp = 12,09) a 46 inds/0,04 m2 (dp = 11,53), e a do banco Cidade, de 57,33 inds/0,04 m2 (dp = 54) a 156 inds/0,04 m2 (dp = 43,31). O perfil da Praia do Camaroeiro permitiu classificá-la como dissipativa e, o da Cidade, como intermediária do tipo terraço de baixamar. A salinidade média da água intersticial do Camaroeiro variou de 26,33 (dp = 4,04) a 33,33 (dp = 1,15) e a da Cidade, de 27,5 (dp = 3,53) a 33,33 (dp = 1,15). A temperatura média do ar variou de 17ºC (dp =0) a 30,5ºC (dp =0) e a do sedimento, de 18ºC (dp =0) a 29ºC (dp = 0), em ambos os bancos. O conteúdo médio de calcário e matéria orgânica oscilou entre 6,73% (dp = 2,58) e 10,59% (dp = 1,53) e entre 2,17% (dp = 1,26) e 6,07% (dp = 2,07), respectivamente, no Camaroeiro e entre 8,39% (dp = 2,53) e 12,13% (dp = 1,91) e entre 3,56% (dp = 0,22) e 6,11% (dp = 0,48) na Cidade. A fração do sedimento predominante em ambos os bancos foi a de areia muito fina, com algumas variações ao longo do ano, e classificada principalmente como pobre a moderadamente selecionada. Ao final do período de estudo, os bancos de mitilídeos desapareceram, mas devem surgir novamente ao longo do tempo. Esse fato ocorre devido à dinâmica populacional e/ou reprodutiva de Mytella charruana, organismo estruturador dos bancos, e também à morfodinâmica praial dessa região / Abstract: Mussel beds are aggregations of live and dead mussels, shell fragments and byssus thread. The structural characterization of two soft-bottom mussel beds of Mytella charruana was studied between April 2006 and February 2007 at Camaroeiro and Cidade beaches (northern coast of São Paulo State). Mensal samples were taken with a 0,04 m2 corer, until a depth of 20 cm, in the lower, middle and upper levels of the beds and analyzed the density of M. charruana, beach slope, interstitial salinity, sediment and air temperatures, calcareous and organic matter content of the sediment and granulometry. The mean density of M. charruana ranged between 13,66 inds/0,04 m2 (sd = 12,09) and 46 inds/0,04 m2 (sd = 11,53) at Camaroeiro, and between 57,33 inds/0,04 m2 (sd = 54) and 156 inds/0,04 m2 (sd = 43,31) at Cidade. The Camaroeiro beach slope enabled the classification of the beach as a dissipative state while the Cidade beach slope, as a low-tide terrace. The mean Camaroeiro interstitial salinity ranged between 26,33 (sd = 4,04) and 33,33 (sd = 1,15); and the mean Cidade interstitial salinity ranged between 27,5 (sd = 3,53) and 33,33 (sd = 1,15). Mean air temperature ranged between 17ºC (sd = 0) and 30,5ºC (sd = 0) and mean sediment temperature, between 18ºC (sd = 0) and 29ºC (sd = 0), in both mussel beds. Mean calcareous and organic matter contents ranged, respectively, from 6,73% (sd = 2,58) to 10,59% (sd = 1,53) and from 2,17% (sd = 1,26) to 6,07% (sd = 2,07) at Camaroeiro and ranged, respectively, from 8,39% (sd = 2,53) to 12,13% (sd = 1,91) and from 3,56% (sd = 0,22) to 6,11% (sd = 0,48) at Cidade. The granulometric composition of both mussel beds was very similar, with a predominance of moderate and poorly-sorted fine sand. At the end of the study period, the mussel beds disappeared, but must appear again with time. This can happen due to the population and/or reproductive dynamic of Mytella charruana, the organism who structures the mussel beds, and also due to the beach morphodynamic of the area / Mestrado / Ecologia / Mestra em Ecologia
3

Associações de Polychaeta na Baía do Araçá, São Sebastião, litoral norte do Estado de São Paulo / Polychaete associations at Araçá Bay, São Sebastião, northern coast of São Paulo State

Checon, Helio Herminio, 1987- 22 August 2018 (has links)
Orientador: Antonia Cecília Zacagnini Amaral / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-22T03:21:23Z (GMT). No. of bitstreams: 1 Checon_HelioHerminio_M.pdf: 9773867 bytes, checksum: 60c5bdd061a149ba1cfa98b82f4d43fd (MD5) Previous issue date: 2013 / Resumo: O resumo poderá ser visualizado no texto completo da tese digital / Abstract: The abstract is available with the full electronic document / Mestrado / Ecologia / Mestre em Ecologia
4

The importance of biodiversity for ecosystem processes in sediments : experimental examples from the Baltic Sea / Betydelsen av biologisk mångfald för ekosystemprocesser i sediment : experimentella exempel från Östersjön

Näslund, Johan January 2010 (has links)
Aquatic sediments are, by surface, the largest habitat on Earth. A wide diversity of organisms inhabit these sediments and by their actions they have a large influence on and also mediate many ecosystem processes. Several of these processes, such as decomposition and remineralisation of organic matter are important on a global scale and are essential to sustain life on Earth. The main aim of this thesis was to use an experimental ecosystem ecology approach in order to study some of these ecosystem processes in marine sediments and how they are linked to biodiversity. Paper I and II found that an increased species richness of sediment deposit feeders increases the processing of organic matter from phytoplankton settled on the sea-floor, and that species-rich communities have a more efficient resource utilization of deposited organic matter. The results in paper IV and V also suggest that there is a link between microbial diversity in sediments and the degradation of organic contaminants. Paper V also shows that antibiotic pollution is a potential threat to natural microbial diversity and microbially mediated ecosystem services. The introduction of invasive species to ecosystems is another major threat to biodiversity and was studied in Paper II and III, by investigating the ecology of Marenzelleria arctia, a polychaete worm recently introduced in the Baltic Sea. Paper II suggests that M. arctia mainly utilize food resources not used by native deposit feeders, thus potentially increasing the benthic production in the Baltic Sea by increasing resource use efficiency. Paper III, however, show that M. arctia is protected from predation by the native benthic invertebrate predators, due to its ability to burrow deep in the sediment, suggesting that predation on M. arctia by higher trophic levels is restricted, thereby limiting trophic transfer. In conclusion, this thesis gives some examples of the importance of marine biodiversity for the generation of a few key ecosystem processes, such as organic matter processing and the degradation of harmful contaminants. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript. Paper 4: In press.

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