DSpace Coleção: Mestrado

Avaliação das águas superficiais da bacia hidrográfica do baixo tocantis, Pará, Brasil: Um panorama no espaço e no tempo

2026-05-22T00:00:00Z

Título: Avaliação das águas superficiais da bacia hidrográfica do baixo tocantis, Pará, Brasil: Um panorama no espaço e no tempo Autor(es): MELO http://lattes.cnpq.br/3542869559542094, Adriana da cruz; banca 1 ALVES JÚNIOR http://lattes.cnpq.br/2566643607928091, Flavio de Almeida; banca 2 LIMA http://lattes.cnpq.br/8021186707342335, Mauricio Willians de https://orcid.org/0000-0001-9092-8731; banca 3 CHAGAS http://lattes.cnpq.br/9393899936340805, Rafael Anaisce das https://orcid.org/0000-0002-1555-6154 Abstract: Preserving water quality is essential for human survival and environmental conservation. Despite Brazil possessing the largest amount of freshwater in the world, it faces a water crisis throughout its territory due to problems such as lack of sanitation, pollution from agriculture, and lack of water reuse. The Tocantins-Araguaia River basin, the second largest in the country, encompasses a vast area with 430 municipalities distributed across the states of Pará, Maranhão, Tocantins, Goiás, and Mato Grosso. This study focuses on the Lower Tocantins region in northeastern Pará, where abiotic and biotic water parameters will be evaluated to understand the environmental dynamics. Factors such as land use, anthropogenic actions, and periods of intense rainfall influence water quality, increasing turbidity and nutrient levels, such as nitrogen and phosphorus, which can lead to eutrophication. CONAMA Resolution 357/2005 is a fundamental instrument for monitoring water quality standards in Brazil, contributing to the sustainable use of this vital resource. This study aimed to evaluate environmental parameters, calculate the Trophic State Index (TSI), and analyze the influence of seasonality, focusing on eleven points distributed across seven municipalities in Pará state, in order to support the planning of water preservation actions in the region. The results show the influence of seasonality on water quality, with higher values of electrical conductivity in the less rainy period (79 μS cm⁻¹) compared to the rainy period (65 μS cm⁻¹), indicating a higher concentration of dissolved ions. Chlorophyll a was also higher in the less rainy period (12.2 μg L⁻¹) compared to the rainy period (9.8 μg L⁻¹), suggesting a greater supply of nutrients. Turbidity was higher during the less rainy period (97 NTU), while dissolved oxygen remained close to 6.4 mg L⁻¹ in both periods. The Trophic State Index ranged from 51.32 to 52.11, indicating a mesotrophic condition and the influence of seasonality on the limnological dynamics of the region.

Decifrando os desembarques de grandes bagres migradores: Como as características operacionais e sazonais moldam a pesca no estuário Amazônico?

2026-01-01T00:00:00Z

Título: Decifrando os desembarques de grandes bagres migradores: Como as características operacionais e sazonais moldam a pesca no estuário Amazônico? Autor(es): COSTA, Izabelle Tavares da Abstract: Fishery resources play an important role in the global economy. In the Amazon, fishing is a traditional and economically significant activity that provides both income and food security. Amazonian fish production is dominated by large migratory catfish species, such as piramutaba, dourada, and filhote, which depend on extensive migrations to complete their life cycle. Analyzing fishery activity data is an indirect approach to assessing fish populations. This study aimed to investigate the operational, spatial, and temporal characteristics that influence the occurrence and intensity of catches of B. rousseauxii, B. vaillantii, and B. filamentosum at the mouth of the Amazon River. Using advanced statistical tools, we evaluated the relationship between the CPUE of B. rousseauxii, B. vaillantii, and B. filamentosum as a function of seasonality and fishery operational characteristics, such as fishing area and vessel fishing power in the Amazon estuary. To account for zero-inflated data, a Hurdle model was applied, allowing a two-part structure: a binary component indicating the absence of CPUE and a continuous component modeling positive CPUE values. The CPUE of dourada is influenced by vessel classification and by the interaction between area and period. The CPUE of piramutaba varies with fishing area and period, and the effect of the period changes depending on the area. The CPUE of filhote varies with vessel type, area, and period, and the effect of the period also changes according to the area. These findings underscore the need for management strategies that incorporate the seasonality and spatial heterogeneity of fishing in the Amazon estuary.

Produção de plântulas de ipê-rosa (Handroanthus heptaphyllus (Vell.) Mattos) em sistema de aquaponia com tambaqui (Colossoma macropomum, Cuvier, 1818.

2026-02-12T00:00:00Z

Título: Produção de plântulas de ipê-rosa (Handroanthus heptaphyllus (Vell.) Mattos) em sistema de aquaponia com tambaqui (Colossoma macropomum, Cuvier, 1818. Autor(es): LOPES, Priscila Caroline Alves Abstract: Integrated production systems, like aquaponics systems, combine agricultural and aquaculture activities to promote sustainable practices. The present study assessed the growth of pink trumpet tree ((Handroanthus heptaphyllus (Vell.) Mattos) seedlings in aquaponic systems with various planting trays and cell models, alongside, tambaqui (Colossoma macropomum, Cuvier, 1818) cultivation. Five aquaponic systems were set up with different treatments for pink trumpet tree growth, using tubes tray, hydroponic cups, commercial seedling bags, polystyrene seedbeds, and açai seed substrate in the hydroponic beds. Additionally, a control treatment with conventional seedling bags was included outside the aquaponic system. The experiment lasted for 33 days. Water quality variables, fish growth performance, and pink trumpet tree growth were evaluated at the end of the experimental period. There were significant differences (p < 0.05) in water quality among the treatments. Dissolved oxygen levels were significantly lower (p < 0.05) in the açai seed substrate treatment (7.36 ± 0.06 mg L–1) compared to the seedbed (7.62 ± 0.02 mg L–1), hydroponic cup (7.65 ± 0.03 mg L–1), and seedling bags (7.57 ± 0.03 mg L–1) treatments, but similar to the seedling tubes treatment (7.49 ± 0.04 mg L–1). The different planting bed models did not significantly (p > 0.05) impact tambaqui growth performance in pink trumpet tree. The polystyrene seedbed treatment showed a significant increase (p < 0.05) in total length, aerial part length, and root length of the pink trumpet tree compared to other treatments. Total fresh mass was significantly higher (p < 0.05) in the polystyrene seedbed treatment compared to other treatments. Leaf area significantly increased (p < 0.05) in the polystyrene seedbed treatment. Dickson indices were significantly higher (p < 0.05) in the cup tray treatment compared to other treatments. The aquaponic system with tambaqui was effective in producing pink trumpet tree seedlings.

Dinâmica espaço-temporal do microfitoplâncton em viveiro de cultivo de LITOPENAEUS VANNAMEI (boone, 1931) e sua área de influência em um estuário amazônico.

2026-01-29T00:00:00Z

Título: Dinâmica espaço-temporal do microfitoplâncton em viveiro de cultivo de LITOPENAEUS VANNAMEI (boone, 1931) e sua área de influência em um estuário amazônico. Autor(es): RIBEIRO, Denise Cristina de Souza Abstract: In order to formulate a better use of aquatic ecosystems it is necessary to evaluate the body of water, integrating and interacting simultaneously with the terrestrial environment, thus, in aquaculture activity is of extreme importance the study of the planktonic community, pointeding the phytoplankton, that representes an important role as a primary producer in aquatic ecosystems. The objective of this work was to characterize the structure of the microphytoplankton community of a marine shrimp nursery Litopenaeus vannamei and its adjacent area, during two periods, relating the abiotic and biotic factors that influence the spatiotemporal variation of microphytoplankton. For qualitative and quantitative analyzes, five points were collected delimited, using a plankton net (64μm) and was collected 200 mL of water directly from the water surface. The datas were submitted a treatment non-parametric tests (Mann-Whitney and Kruskal-Wallis, p<0,05). The indicator species were determined using the method (IndVal) and to evaluate the influence of the abiotic variables about microphytoplankton community, a RDA was performed. The microphytoplankton community contributed a total of 205 taxa (194 in the estuary and 107 in the nursery) Bacillariophyta with higher contribution mainly in the estuary. The environments were different in relation to the total density, once that the estuary presented higher density compared with nursery.