Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-02-16T13:44:43Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação BCTG_Digital.pdf: 7436148 bytes, checksum: 8202bd7e2553a94e29e709b92f260072 (MD5) / Made available in DSpace on 2017-02-16T13:44:43Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação BCTG_Digital.pdf: 7436148 bytes, checksum: 8202bd7e2553a94e29e709b92f260072 (MD5) Previous issue date: 2016-06-29 / FACEPE / Material particulado em suspensão (séston) em ecossistemas aquáticos contém dois compartimentos: organismos (plâncton) e partículas. Conhecimento sobre a contribuição das partículas para o séston é essencial para a compreensão da dinâmica de fluxos tróficos em ecossistemas marinhos. Este estudo tem como objetivo medir a biomassa sestônica úmida total e avaliar as contribuições relativas do mesozooplâncton e das partículas em suspensão em amostras de plâncton. As amostras foram obtidas no estuário do Rio Formoso e na Baía de Tamandaré (Pernambuco, Brasil). Arrastos subsuperficiais horizontais foram realizados durante dois anos (junho / 2013 a maio / 2015) em intervalos bimestrais com redes de plâncton (malhas: 200 e 300 µm) durante as estações seca e chuvosa. Um total de 155 amostras foram analisadas para estimar a biomassa sestônica úmida total e posterior identificação e estimativa de densidade e volume do zooplâncton e das partículas usando o equipamento ZooScan. Foram detectados, identificados, quantificados e medidos 26 grupos taxonômicos do zooplâncton. Dentre estes os grupos mais abundantes foram Copepoda (Calanoida e Cyclopoida), zoeas de Brachyura, outros decápodes, apendiculárias e náuplios de crustáceos. Foram detectadas 15 categorias de partículas, entre elas, as partículas opacas, transparentes e escuras, fibras vegetais, e exúvias de copépodos foram as mais abundantes. O ambiente estuarino apresentou os maiores valores de biomassa sestônica úmida, densidade e volume, e, também apresentou as maiores concentrações de partículas e contribuições relativas em termos de volume (72% e 59% do volume, para as malhas de 200 e 300 micrômetros, respectivamente). No entanto, o ambiente marinho também mostrou concentrações e volumes de partículas muito elevadas (32% e 44% do volume, para as malhas de 200 e 300 micrômetros, respectivamente). Zooplâncton e partículas mostraram maiores densidades durante o período seco. A comparação entre os volumes totais obtidos com medidas semi-automáticas de imagens digitalizadas e a biomassa sestônica úmida revelou uma relação linear significativa (R² = 0,73; p <0,0001). Este estudo confirma a importância de mesopartículas (maiores do que 200 micrômetros) na estrutura do séston em áreas costeiras tropicais. / Suspended particulate matter (seston) in aquatic ecosystems contains two compartments: organisms (plankton) and particles. Knowledge on the contribution of particles to the seston is essential in understanding the dynamics of trophic energy flows in marine ecosystems. This study aims to measure the total wet seston biomass (wet weight) and to assess the relative contributions of zooplankton and particles to plankton net samples. The samples were obtained in the Rio Formoso estuary and in Tamandaré Bay (Pernambuco State, Brazil). Subsurface horizontal tows were performed during two years (June / 2013 to May / 2015) at bimonthly intervals with plankton nets (meshes: 200 and 300 µm) during dry and rainy seasons. 155 samples were analyzed to estimate the total wet seston biomass and subsequent identification and estimation of density and zooplankton volume and particle volume using a ZooScan equipment. 26 taxonomic groups of zooplankton were detected, identified, quantified, and measured. The most abundant were Copepoda (Calanoida and Cyclopoida), brachyuran zoea, other decapods, appendicularians and crustacean nauplius. 15 categories of particles were detected, among these, opaque, transparent and dark particles, plant fibers, and copepod exuviae were the most abundant. The estuarine environment showed the highest values of wet seston biomass, density and volume and also had the highest particle concentrations and relative volume contributions, (72% and 59% volume, for 200 and 300 µm mesh nets, respectively). However, the marine environment also showed very high concentrations and volumes of particles (32% and 44% volume, for 200 and 300 µm mesh nets, respectively). Zooplankton and particles showed highest densities during the dry period. The comparison between total volumes obtained with semi-automatic measurements of scanned images with wet seston biomass revealed a significant linear relationship (R² = 0.73; p < 0.0001). This study underlines the importance of particles (greater than 200 micrometers) in the structure of the seston in tropical coastal areas.

Coastal areas in Grenada and the Caribbean are experiencing an abundance of stranded macroalgae. Climate change and eutrophication are probable causes of this inconvenience. This leads to logistic and economic dilemmas for the Caribbean societies. Research of methods to benefit from the algal bloom is therefore valuable for a sustainable future in these countries. Studies of biogas and fertilizer production are initiated around the world, but a large scale production is absent. Therefore, this thesis scrutinize the requirements for producing biofertilizer from biogas by examine the content of macroalgae and the conditions in Grenada. To achieve this, a literature study and a miniature biogas experiment were conducted. Grenada would presumably benefit from substituting synthetic fertilizer with biofertilizer from macroalgae utilized in biogas production. The positive aspects includes the recirculation of nutrients, development of renewable energy and autonomous fertilizer production. Further research of the definite macroalgae content is essential to determine the exact extent and conditions of the fertilizer utilization. / Kustområden i Grenada och Karibien är drabbat av större mängder strandade makroalger. Klimatförändringar och övergödning är de huvudsakliga orsakerna till denna olägenhet. Detta leder till logistiska och ekonomiska problem för samhällen i Karibien. Det är därför av värde att forska på metoder för att försöka nyttja algblomningen, för en hållbar framtid i dessa länder. Studier på biogasproduktion och gödselmedelstillverkning av makroalger har utvecklats på senare tid, men en storskalig produktion är fortfarande frånvarande. Därför ska denna avhandling granska kriterierna för att använda biogödsel från biogasproduktion genom att undersöka makroalgernas innehåll, och Grenadas förutsättningar för att genomföra detta. För att uppnå detta så har en litteraturstudie och ett mindre biogasexperiment genomförts. Grenada skulle förmodligen dra fördel av att byta ut syntetiskt gödningsmedel med biogödningsmedel från biogasproduktion med makroalger. De positiva aspekterna av detta är recirkulationen av näringsämnen, etablering av förnyelsebara energikällor, samt självständig gödselproduktion. Vidare forskning på det exakta innehållet i makroalger är väsentligt för att kunna bestämma utsträckningen och förhållandena för gödselmedelsanvändningen.