Dissertações em Oceanografia (Mestrado) - PPGOC/IG

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Acesso aberto (Open Access)
Análise ecológica da ostracofauna (crustacea) e meiofauna bentônica associada como bioindicadores ambientais na ilha de Cotijuba, Belém (PA), Amazônia
(Universidade Federal do Pará, 2025-02-27) BRITO, Maurício de Souza; PEREIRA, Ana Paula Linhares; http://lattes.cnpq.br/8369046011837903
The uncontrolled occupation of environmental protection areas (APA) in Belém-PA and candidates for APA, such as Cotijuba Island, has intensified the environmental impacts in the region. To mitigate these effects, Conservation Paleobiology integrates historical data on the distribution of fauna and flora, connecting past, present, and future. In turn, ostracods, small crustaceans sensitive to environmental variations, which are part of the benthic meiofauna, provide information about changes in ecosystems through the analysis of their communities and shells, formed from the calcium carbonate in the water. In this way, the survey of the ostracofauna and associated meiofauna on the island of Cotijuba allowed the use of these groups as bioindicators. The research was conducted during the rainy, transitional, and less rainy seasons, at two beaches: Flexeira, less impacted, and Farol, more influenced by human activities. During the campaigns, surface samples were collected in the inframarine, intertidal and supramarine zones, as well as sediment cores, physico-chemical water measurements, and beach profiles. The results showed Farol beach as reflective and Flexeira beach as dissipative, in addition to physical-chemical parameters with low influence on the organisms. The benthic meiofauna recorded 10 distinct classes: Oligochaeta, Polychaeta, Insecta (Diptera and Trichoptera), Malacostraca (Amphipoda), Arachnida, Ostracoda, Hydrozoa, Gastropoda, Bivalvia, and Rhabditophora. Approximately 84% of the specimens are from Flexeira beach, with this proportion being higher when only ostracods are analyzed (89%). Despite the lower abundance at Farol beach, a large number of cocoons of Trichoptera pupae were observed, known for their sensitivity to pollution and environmental changes, indicating a relatively healthy environment. However, a low abundance of ostracods was observed, which may be related to abiotic factors, such as the type of beach and coarse sediments. Moreover, the overall abundance of meiofauna in Cotijuba was also considered low, even without indications of significant anthropogenic intervention, which suggests a relationship between the low number of specimens and hydrodynamic conditions that intensify erosive and depositional processes. The record of a new species is highlighted: Cyprideis cotijubensis sp. nov., as a potential bioindicator of recent ostracofauna in river estuaries in the Amazon. The project also resulted in the digital book “Cartilha Digital Preserva Amazônia”, aimed at raising awareness about the conservation of the Amazon.
Acesso aberto (Open Access)
Análise multitemporal (1991-2021) da linha de costa (trecho Calçoene - Cabo Norte), costa atlântica do estado do Amapá.
(Universidade Federal do Pará, 2023-08-21) SILVA, Rhuan Rodrigo Pereira e; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217
The coastline (LC) is highly dynamic due to its geographic position adjacent to the mouth of the Amazon River estuary. This region is characterized by meteorological forcings, such as a semihumid equatorial climate, high rainfall (> 2,600 mm. year-1), winds (3 to 9 m. s-1), and extreme events (El Nino - 1997/1998 and 2015/2016; La Nina - 1999/2000 and 2010/2011). It is also influenced by hydrological forcings, including water and solid discharge from the Amazon River (175,000 m³ s-1 and 1,200 Mt. year-1, respectively), and oceanographic forcings, such as hyper-tides (up to 12 m), tidal currents (2 m. s-1), waves (up to 3 m in height), and currents (up to 3 m. s-1). This study aims to analyze the multitemporal variation of the LC between the mouths of the Calçoene and Sucuriju rivers, and at the Maracá-Jipioca Ecological Station, from 1991 to 2021. The methodology includes a literature review, acquisition of LANDSAT satellite images (1991, 2000, 2008, 2014, and 2021), LC vectorization, and the application of DSAS to quantify accretion (m) and erosion areas (m) of the LC, determine retreat and advance rates (m/year and m²/year) between the mouths of the Calçoene and Sucuriju rivers, and create change polygons at the Maracá-Jipioca Ecological Station. The study area experienced predominant erosive dynamics, with an average LC retreat of 12 m. year-1 and 1.4 km² of erosion in the Calçoene-Sucuriju stretch, and 2 km² of erosion at the Maracá-Jipioca Ecological Station with an annual average retreat of approximately 18 m. Due to erosive dynamics, the study area requires special attention from public managers to prevent any type of anthropic interference that could intensify this process.
Acesso aberto (Open Access)
Análise multitemporal da linha de costa e indicadores de erosão na praia da Ponta D’Areia, ilha do Maranhão: diagnóstico dos impactos de obras costeiras
(Universidade Federal do Pará, 2024-08-29) SANTOS, Alessandro Ferreira dos; LIMA, Leonardo Gonçalves de; http://lattes.cnpq.br/5984899472616752; RANIERI, Leilanhe Almeida; http://lattes.cnpq.br/3129401501809850; https://orcid.org/0000-0002-9870-4879
The coastal zone is defined as the geographical transition space between the ocean and the continent. In the state of Maranhão, it comprises five sectors, including the Maranhão Golfão. Ponta D’Areia beach is located northwest of the Maranhão Island, making up this sector where tides can reach up to 7.2 meters in height. The beach is approximately 2.5 km long, bounded by the Anil River and São Marcos Beach. In 2014, the construction of a coastal groin was completed at Ponta D’Areia beach, aimed at containing erosion and preventing sedimentation towards the Anil River. In this context, the research addressed the following questions: (a) How did the shoreline change over 27 years? (b) What are the erosional, depositional, and stable sectors from a morphodynamic perspective, considering the period before and after the construction of the coastal groin at the beach? It was believed that the rigid engineering structure was intended to stop the sedimentation at the mouth of the Anil river, which did not occur. As a result, it was necessary to extend the groin to an "L" shape to attempt to curb sedimentation, but this led to continued erosional activity at the northeastern end of the beach. Therefore, the objective of this research was to conduct a multitemporal analysis of the Ponta D’Areia shoreline from 1996 to 2022 and assess its current vulnerability to erosion. The methodology included: (1) on-site observational analysis to fill out pre-defined tables related to coastal erosion geoindicators and collection of surface beach sediments in November 2022 and April 2023, during the dry and rainy seasons, respectively; (2) beach topography survey and orthophoto acquisition through drone flights in April 2023; (3) multitemporal shoreline analysis from 1996 to 2022 using Landsat satellite images, ArcGIS software, and the Digital Shoreline Analysis System (DSAS) extension, as well as shoreline projections for 10 and 20 years into the future; (4) application of the Coastal Erosion Vulnerability Index (CEVI) in three coastal sectors, through the evaluation of natural and anthropogenic parameters; and (5) assessment of the impacts of coastal engineering works on Ponta D’Areia beach. Results showed variations in the shoreline from -64.63 meters (-3.46 m/year: erosion) to 32.15 meters (2.39 m/year: acretion) from 1996 to 2022, with a projected advance of 157.76 meters (4.94 m/year) and retreat of -123.26 meters (-3.68 m/year) by 2032, and a projected advance of 101.93 meters (1.48 m/year) and retreat of -141.35 meters (-1.63 m/year) by 2042. The morphodynamic state of the beach was identified as dissipative through topographic mapping with a drone, and moderate vulnerability to coastal erosion in Sector I, the marina sector, which had the lowest CEVI of 4. Sector II, the groin sector, had CEVI of 6.37 (moderate vulnerability), while Sector III, the Lighthouse sector, had a CEVI of 6.8, indicating high vulnerability to coastal erosion. It was possible to observe how meteo-oceanographic processes (waves, littoral drift, tidal currents, winds, and estuarine discharge) are influencing shoreline variation, as well as human interventions (coastal occupation and construction of rigid structures). Coastal accretion intensified at the beach after the anthropogenic intervention with the groin construction. It is concluded that the multitemporal analysis of the shoreline in the study area between 1996 and 2022 revealed significant variations influenced by natural and anthropogenic factors. Even with human interventions to alter the resulting sedimentation caused by meteo-oceanographic agents, these natural processes continue to intensely shape the region's coastal dynamics and are mainly responsible for variations in the shoreline.
Acesso aberto (Open Access)
Aplicabilidade de um sistema de baixo custo para o monitoramento de dados meteoceanográficos na zona costeira Amazônica
(Universidade Federal do Pará, 2025-04-23) SOTÃO, Daniel da Silva; ROSÁRIO, Renan Peixoto; http://lattes.cnpq.br/8003860457518342; https://orcid.org/0000-0003-2913-0514
This study aimed to develop, implement, and validate a low-cost Continuous Monitoring Prototype (CMP) to collect meteoceanographic data in the Amazon Coastal Zone (ACZ), a region vulnerable to climate change and lacking environmental data. The system, built with an ESP32 microcontroller, integrates sensors for air temperature and relative humidity (HDC1080 and AM2302), atmospheric pressure (BMP280 and MS5611), water temperature (DS18B20), tide level (HC-SR04), precipitation, and wind speed and direction. Sensor validation was performed by comparing the collected data with reference equipment: a CICLUS PRO weather station (CWS) and a Sonlist Levelogger 5 LTC recorder (CTDlog). The CMP conducted four joint test campaigns with the CWS and CTDlog, totaling 56,221 records. Linear regression was applied to develop calibration equations for each sensor. Calibration quality was assessed using the coefficient of determination (R²), root mean square error (RMSE), Pearson correlation coefficient, and residual analysis. The HDC1080 and AM2302 sensors showed excellent performance for temperature measurement, with R² > 0.9, RMSE < 0.2 °C, mean absolute residual (MAE) < 0.12 °C, and very strong Pearson correlation (r ≥ 0.9). However, they exhibited instability in relative humidity measurements (R² ≈ 0.64; RMSE ≈ 3.46%; MAE ≈ 2.52%). The performance of the BMP280 and MS5611 pressure sensors was initially affected by internal heating, but after thermal compensation, they achieved R² values between 0.88 and 0.99, RMSE from 0.17 to 0.45 hPa, and MAE from 0.11 to 0.34 hPa, with the BMP280 showing superior performance. The DS18B20 water temperature sensor showed very strong correlation, with R² ≈ 0.94, RMSE ≈ 0.036 °C, and MAE ≈ 0.021 °C, proving highly promising. The HCSR04 sensor stood out as the most accurate, with R² ≈ 0.99, RMSE ≈ 2.6 cm, and MAE ≈ 1.9 cm. Precipitation and wind sensors presented inconsistencies and require further testing. The total production cost of the CMP was BRL 952.75, representing savings of 86.19% compared to the CWS (BRL 6,897.00) and 96.14% compared to the CTDlog (BRL 24,677.29). When compared to equivalent equipment, the CMP achieved at least 66.33% cost reduction compared to basic stations and 87.3% compared to lower-cost temperature and water level recorders. The CMP proved to be a viable, economical, and replicable solution for continuous environmental monitoring in the ACZ, with the potential to fill existing gaps in observation networks, although improvements are still needed to enhance its long-term performance.
Acesso aberto (Open Access)
Caracterização dos padrões morfodinâmicos em cristas de praias na costa amazônica
(Universidade Federal do Pará, 2023-09-29) ROSÁRIO, Edineuza dos Santos; SANTOS, Valdenira Ferreira dos; http://lattes.cnpq.br/1395198888623953; HTTPS://ORCID.ORG/0000-0002-5038-4191; RANIERI, Leilanhe Almeida; http://lattes.cnpq.br/3129401501809850; https://orcid.org/0000-0002-9870-4879
Knowledge of beach environments requires an integrated morphodynamic approach using different spatio-temporal scales, in order to understand the role of coastal and marine processes in modifying beach morphology. There are some important peculiarities about these processes on the beaches of the Amazon region, such as the large hydro-sedimentary discharge from the estuaries, high rainfall rates and the high amplitude and intensity of the tidal currents, which shape the often complex beach systems, such as beach ridges. The objective of this research was to analyze the morphological dynamics of a beach ridge segment located north of the mouth of the Amazon River, in Goiabal (city of Calçoene), in the coastal ocean sector of the state of Amapá.The hypothesis is that the morphological changes in the segment of beach crest under study are influenced by the hydrosedimentary dynamics of the Amazon River. The research methodology was based on three stages: (1) determining the morphology of beach ridges and their changes (beach profile variation, sedimentary deposits and beach classification); (2) analysis of morphosedimentary processes (physical coastal agents such as tides, waves and currents, and sediment supply such as sediment plumes; (3) data integration (correlation between the processes analyzed in stage one and two). The results indicate significant average variations in the morphosedimentation of the Goiabal beach ridge system, with seasonal migration (~24 to ~42 meters) towards the mainland. Erosion and deposition on the ridges and subsequent channels averaged less than 0.30 m along the beach profiles during the seasonal cycle. The oceanographic parameters indicate an average wave height of 0.25 m and an average tidal range of 5 m. Coastal currents are directed west-southwest and there is a predominance of ebb tide currents during the rainy season. The sediment plume of the Amazon River was closer to the study area during the rainy season (~15 to 25 km), with a predominance of ebb tide currents. Thus, it can be concluded that the segment of beach crest studied has a greater influence from the Amazon River sediment plume during the rainy season, intensifying the deposition of fine sediments. The displacement of beach ridges and the supply of sediment have a strong relationship with tidal dynamics in the region.
Acesso aberto (Open Access)
Desenvolvimento de modelo matemático para simulação de transporte de resíduo plástico em estuário amazônico.
(Universidade Federal do Pará, 2024-05-28) SANTIAGO, Matheus Pamplona; BORBA, Thaís Angélica da Costa; http://lattes.cnpq.br/6210073723678433; https://orcid.org/0000-0001-8084-3128; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471; https://orcid.org/0000-0002-8601-1514
The increasing use of plastics has raised environmental concerns due to the persistence of these materials in marine ecosystems. It is estimated that trillions of pieces of plastic debris are currently in the oceans, with millions of additional tons entering annually through rivers and other terrestrial sources. There is a gap between models of plastic input to the oceans and field observations, indicating the need for more accurate approaches and simulations based on in-situ data. The Amazon Coastal Zone (ACZ) emerges as a hotspot for the accumulation of plastic waste, especially in vegetated areas close to large urban centers. Although several numerical models have been developed for the ACZ, none have addressed the transport of plastic waste to date. This pioneering study implemented the first mathematical simulation for plastic transport in an urban estuary on the Amazon coast, specifically in the Guajará Bay, using the urban river (Tamandaré river) as a release site due to the availability of in-situ data for plastic parameterization. The hydrodynamic model (D-Flow), validated by the LAPMAR environmental modeling group, and the water quality module (D-Waq), were implemented using the Delft-3D software. The results show that Guajará Bay is more sensitive to plastic contamination during the dry period, characterized by slow transport of water masses and a reduced capacity for renewal. In contrast, during the rainy season, the tendency is to export plastics, due to the system's greater capacity for renewal. The residence time of the waters of the Tamandaré River in the bay varies from approximately 8.28 days in the period of greatest discharge to 31.76 days in the period of lowest discharge, allowing us to estimate that the waste released by the Tamandaré can reach the Tropical Atlantic Ocean in a range of 36 to 63 days, depending on the seasonal season. The study concludes that Amazon estuaries dominated by positive asymmetric tides favor the import of waste during periods of lower flow and increase exports during periods of higher flow. Temporary plastic retention zones were observed in both seasonal periods for marginal regions of low energy and atypical morphology, such as the coastline close to the port of Belém (BG1) and the mouth of the Guamá River (RG). These retention zones are intensified in the dry season and attenuated in the rainy season, depending on local hydrodynamic variability. Although the study analyzed the dynamics resulting from the input of plastics in a single ebb tide, it did not consider the continuous flow and potential accumulation of plastics over time. This work represents an important initial step towards improving the understanding and methodology of plastics transport in the ACZ.
Acesso aberto (Open Access)
Detecção das mudanças costeiras na margem leste do estuário do Rio Pará: uma análise multitemporal (1987-2019) utilizando sensoriamento remoto.
(Universidade Federal do Pará, 2022-05-24) GUIMARÃES, Diandra Karina Martins; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217; ROSÁRIO, Renan Peixoto; http://lattes.cnpq.br/8003860457518342; https://orcid.org/0000-0003-2913-0514
In the Coastal and Estuarine Zone of Pará (ZCEP) occurs a complex dynamics influenced by meteorological forces (rainfall, winds, extreme events), fluvial (flow) and marine (tides, currents, waves). The forcings affect the coastline (CL) of the estuaries margins causing changes that depend on the degree of exposure of the area and the intensity of the forcings. Therefore, the detection of the places that happen the processes of erosion and/or accretion of the coastline becomes interesting to observe the changes in the surroundings of the islands and municipalities of the eastern margin of the Pará River Estuary. The work area is located on the eastern margin of the Pará river estuary, in the section: Mosqueiro island, Santo Antônio do Tauá, Colares island (edge of the middle estuary), Vigia and São Caetano de Odivelas (edge of the lower estuary). To achieve the results, LANDSAT satellite images were acquired (1987; 1993; 1999; 2004; 2008; 2013 and 2019) and the Digital Shoreline Analysis System (DSAS) was used to more accurately identify and calculate the rates of variation of changes in erosion and accretion areas in the LC. NSM, LRR and EPR parameters were applied on the east margin of the Pará river estuary (117 km) in the 32-year period of analysis, with a total of 1130 transects generated. In the middle estuary, the tendency to erosion was higher, predominating in Mosqueiro Island with an average erosion rate of -38m and an average accretion rate of 22.97m, related to the average rates of variation of -0.58m/year (EPR) and -0.54m/year (LRR) and in Santo Antônio do Tauá with LRR and EPR parameters identifying average rates of change of -1.67m/year (LRR) and -1.55m/year (EPR). Only on the Colares island there was a tendency to accretion, with an average erosion rate of -96.29m and an average accretion rate of 116.49m, where the maximum accretion and erosion rates are 405.61m and -396.87m, respectively. While in the lower estuary there was a greater tendency to accretion, where in Vigia there was an average rate of change of 1.26 m/year and a maximum rate of accretion of 10.06 m/year in the EPR, and an average rate of change of 0.64 m/year and maximum accretion rate of 7.22 in the LRR. In São Caetano de Odivelas, the average rate of change in the EPR parameter was 0.40 m/year and in the LRR parameter it was 0.25 m/year and in the NSM it was 13.09 m. Comparing the margins of the Estuary, the east margin is under the influence of a low hydrodynamics, while the west margin is under a high hydrodynamics where erosion predominates, demonstrating that in the same estuary the processes occur in a different way, where the areas of high erosion are related to the morphology of the site and location of the area being more exposed to forcing.
Acesso aberto (Open Access)
Especiação do fósforo em rios urbanos: um estudo de caso dos rios Tucunduba e Tamandaré, Belém/Pará
(Universidade Federal do Pará, 2023-05-24) COIMBRA, Marcus Vinicius Rodrigues; MONTEIRO, Sury de Moura; http://lattes.cnpq.br/4309806566068586; https://orcid.org/0000-0001-9449-7043
Phosphorus (P) is a bioliminating macronutrient that plays an essential role in regulating ecosystem functions and primary productivity in marine and coastal environments. However, when in excessive concentrations, P assumes the role of a pollutant, negatively influencing the ecosystem and causing eutrophication. In Brazil, the problem is maximized in urban centers cut by canals, where there is an intensification of the process of changing the natural conditions of the environment. The speciation of P associated with hydrodynamic processes and the type of urbanization of the environment allows identifying the eutrophication status of these environments. Therefore, the present study seeks to promote understanding of the dynamics of P speciation in two urban rivers, the Tucunduba and Tamandaré rivers, located in the metropolitan region of Belém (Northern Brazil), with the objective of evaluating whether there is variation in P speciation. phosphorus in urban rivers at different time scales. To this end, samples of suspended particulate matter (SPM) were carried out using two different methodologies: the horizontal flow trap (portable traps) and the vertical flow trap (fixed traps). For the extraction of P, the sequential extraction method SEDEX was adopted, which allowed the extraction of five forms: P-Ex, P-Fe, P-Au, PDe and P-Org, in addition to P-Bio. In the Tucunduba river, Total-P concentrations ranged from 20.52 to 100.78 μmol.g-1, with predominance of the P-Fe fraction. In the Tamandaré River, concentrations ranged from 42.36 to 173.88 μmol.g-1 with P-Au predominance. Thus, it was possible to verify that the urban rivers Tucunduba and Tamandaré have high concentrations of P and its species. With these data, it is clear the need to deepen this type of study in these rivers and other urban rivers present in Belém, as well as the need for policies aimed at the recovery and preservation of these, in order to mitigate the problem involving phosphorus and restore the capacity ecosystems of these environments.
Acesso aberto (Open Access)
Especiação do fósforo em rios urbanos: um estudo de caso dos rios Tucunduba e Tamandaré, Belém/Pará.
(Universidade Federal do Pará, 2023-05-24) COIMBRA, Marcus Vinicius Rodrigues; MONTEIRO, Sury de Moura; http://lattes.cnpq.br/4309806566068586; https://orcid.org/0000-0001-9449-7043
Phosphorus (P) is a bioliminating macronutrient that plays an essential role in regulating ecosystem functions and primary productivity in marine and coastal environments. However, when in excessive concentrations, P assumes the role of a pollutant, negatively influencing the ecosystem and causing eutrophication. In Brazil, the problem is maximized in urban centers cut by canals, where there is an intensification of the process of changing the natural conditions of the environment. The speciation of P associated with hydrodynamic processes and the type of urbanization of the environment allows identifying the eutrophication status of these environments. Therefore, the present study seeks to promote understanding of the dynamics of P speciation in two urban rivers, the Tucunduba and Tamandaré rivers, located in the metropolitan region of Belém (Northern Brazil), with the objective of evaluating whether there is variation in P speciation. phosphorus in urban rivers at different time scales. To this end, samples of suspended particulate matter (SPM) were carried out using two different methodologies: the horizontal flow trap (portable traps) and the vertical flow trap (fixed traps). For the extraction of P, the sequential extraction method SEDEX was adopted, which allowed the extraction of five forms: P-Ex, P-Fe, P-Au, PDe and P-Org, in addition to P-Bio. In the Tucunduba river, Total-P concentrations ranged from 20.52 to 100.78 μmol.g-1, with predominance of the P-Fe fraction. In the Tamandaré River, concentrations ranged from 42.36 to 173.88 μmol.g-1 with P-Au predominance. Thus, it was possible to verify that the urban rivers Tucunduba and Tamandaré have high concentrations of P and its species. With these data, it is clear the need to deepen this type of study in these rivers and other urban rivers present in Belém, as well as the need for policies aimed at the recovery and preservation of these, in order to mitigate the problem involving phosphorus and restore the capacity ecosystems of these environments.
Acesso aberto (Open Access)
Evolução multitemporal (2010-2024) do canal de acesso do estuário do rio Amazonas (canal Norte - baía de Macapá - margem ocidental)
(Universidade Federal do Pará, 2025-02-27) SILVA, Eduardo Pantoja da; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217
The Amazon River, the world’s largest by water volume, has an average discharge of approximately 209,000 m³/s and exhibits a semidiurnal tidal range that varies from 0.3 m to 4 m during spring tides. Its vast watershed profoundly shapes the geomorphology of the Amazon Basin, driving sedimentary processes and directly affecting navigability. The economic importance of navigation within its estuary contrasts sharply with the challenges posed by both natural and anthropogenic alterations, which compromise the long-term stability of the channel. This dissertation analyzes the geomorphological evolution of the Amazon River’s northern channel and Macapá Bay from 2010 to 2024. It assesses the impacts of sedimentary dynamics on navigability and port management. The research methodology encompassed the analysis of bathymetric data, 38 Sentinel-1 radar scenes (captured between 2016 and 2024) processed via the Google Earth Engine platform, and historical hydrological records. Bathymetric processing was carried out in SURFER using the kriging method, while spatial analyses were performed with geostatistical tools in Python and QGIS. This included the delineation of sandbanks and the calculation of modification areas to identify erosion and deposition patterns. The study area is highly dynamic, influenced by tidal forces, river discharge, and sedimentation. These interacting processes drive the formation and migration of sandbanks and unstable channels, which directly affect bed depth and navigational safety. The findings indicate a reduction in the northern channel’s average depth from 26 m to 22 m, along with a noticeable east-northeastward migration. This shift is evidenced by erosion along the left bank and simultaneous deposition on the right bank. Three-dimensional analysis revealed that while the bed morphology was relatively homogeneous in 2011, by 2024 it had become more compartmentalized, reflecting a rate of change of 0.307 m per year. The study also highlights significant variations in the spatial extent of emerged areas within Macapá Bay. During El Niño years (2016, 2018, 2023), average accretion reached 8,326.93 km², whereas La Niña years (2017, 2020, 2021, 2022) experienced average erosion of -13,941.27 km². Linear regression analysis produced an adjusted R² value of 0.163, indicating that hydrological variability and human activity influence the region’s sedimentary dynamics. The observed geomorphological changes directly affect waterway management and the Santana port complex, underscoring the need for effective strategies to ensure ongoing navigability. Remote sensing has proven invaluable for monitoring these dynamic transformations, offering strategic insights to enhance port infrastructure planning and ensure the long-term sustainability of navigation in the region. This research reinforces the necessity of continuous monitoring and integrated hydrodynamic planning to maintain navigational safety and logistical efficiency. The combined use of geoprocessing and bathymetric techniques enables more accurate planning and the implementation of measures to mitigate sedimentation impacts, thereby preserving the viability of inland waterway transport. Ultimately, the results provide essential support for managing navigation in the Amazon River’s northern channel, promoting enhanced efficiency and safety.
Acesso aberto (Open Access)
Evolução multitemporal da linha de costa (1972-2040) do município de Soure, Ilha do Marajó (Amazônia - Brasil)
(Universidade Federal do Pará, 2021-11-11) MENEZES, Rafael Alexandre Alves; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217
Exogenous agents that act in the Coastal Zone (ZC) act as morphological modelers of the CoastLine (LC) and this action modifies the erosive and accretive scenario of the LC over time. To assess these temporal changes in the ZC, remote sensing (SR), from orbital remote sensors, is an opening that makes it possible to identify these variations, where the main objective around the world is the management and protection of these coastal areas. Thus, the present composition aims to present the evolution of the LC line during the period 1972-2020 (48 years) and estimate the evolution of the LC for the years 2030 and 2040 in the ZC of the Soure municipality, located in the northeastern part (NE) of the Marajó island (Pará-Eastern Amazon), inserted in the Pará Estuarine Coastal Zone (ZCEP), conditioned by the hydrodynamics of the South channel of the Amazon River and by the estuary of the Pará River. A set of 6 images from a time series of the satellite were acquired: Landsat 1 (MSS) from 1972 and 1994 (bands 7.6.5 and 5.4.3, respectively), Landsat 5 (TM) from 1985, 2004, 2009 ( bands 5.4.3), with a spatial resolution of 30m, and Landsat 8 (OLI) 2020 (bands 6.5.4.8), with a spatial resolution of 15 m after the fusion of band 8 (panchromatic), being obtained from the USGS (United States Geological Survey) site, all already georeferenced and geoprocessing techniques for: a) LC delimitation: where it was created from semi-automatic methods combined with manual methods, using the normalized water difference index (NDWI) technique; b) DSAS version 5.0 (v5.0), being used to compose the LC analysis hrough this tool: NSM, EPR and LRR, version v5 brings the Kalman Filter, which was used to calculate the future estimate in the LC for the years 2030 and 2040. As a result, it was identified that in sectors I and II (southern channel of the Amazon River), accretion predominates, in sector III (Maguari Cape) it is where it obtained the highest accretion rates, and in sector IV the accretion process predominates with a tendency erosive, sector V erosion predominates. These data are linked to the total number of 654 transects comprising an average distance of 214.4 m, where the mean retreat is indicated with a negative rate of - 179.5 m and a positive rate of 451.9 m. For the years 2030 and 2040, the trend is that this process will continue, where the greatest coastal retraction, around 271.46 m, will be in the Northeast (NE) (sector II), and a CL advance of 625.26 m in sector III.
Acesso aberto (Open Access)
Gestão de resíduos por atividades turísticas na área de preservação ambiental (APA) em ilha metropolitana da Amazônia
(Universidade Federal do Pará, 2025-02-27) ELLERES, Igor Diniz; MONTEIRO, Sury de Moura; http://lattes.cnpq.br/4309806566068586; HTTPS://ORCID.ORG/0000-0001-9449-7043; SAMPAIO, Dionisio de Souza; http://lattes.cnpq.br/2193736281754259; https://orcid.org/0000-0002-2688-6001
Solid waste management on Combu Island, in Belém (PA), reflects the logistical and structural challenges faced by Amazonian riverside communities in the context of growing urbanization and tourism. This study focused on waste management and the various stakeholders involved, who play a crucial role in the collection and disposal of discarded materials. Interviews and observations were conducted to understand the practices adopted by restaurants regarding waste disposal and the perceptions of waste pickers about the impact of this activity on the environment and their livelihood. The results indicated that although restaurants generate significant volumes of waste—around 4.8 tons per year—the lack of proper infrastructure, such as selective collection and regular transportation, leads to improper disposal. This issue is partially mitigated by the work of waste pickers, who collect recyclables such as glass bottles and plastics, turning them into a source of income. However, waste pickers face precarious working conditions, with low recognition and little integration into public policies or environmental education initiatives. The research also revealed that restaurant managers recognize the importance of improving their practices and developing them based on the Sustainable Development Goals (SDGs 14 and 15), but often encounter logistical difficulties and a lack of incentives or specific regulations. It is concluded that promoting integrated actions between restaurants, waste pickers, and public authorities, along with environmental education strategies, can enhance the efficiency of solid waste management, reduce socio-environmental impacts, and value the stakeholders involved.
Acesso aberto (Open Access)
Investigação da influência antrópica na concentração de nutrientes inorgânicos dissolvidos no entorno da cidade de Belém-PA
(Universidade Federal do Pará, 2022-08-30) PORTO, Yuri Paixão Santa Rosa; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471; https://orcid.org/0000-0002-8601-1514
Water is one of the most important natural resources, especially in the Amazon context. The disorderly population increase and consequent mismanagement of this resource causes worrying environmental changes in terms of its quality. According to the National Sanitation Information System - SNIS, the northern region of the country treats about 22.0% of the sewage generated and in the Metropolitan Region of Belém, below the national average, with 11.3% of sewage collection. The study area encompasses Guajará Bay and adjacent areas such as the Guamá and Acará rivers. Water collections were carried out during the rainy season (May), in 4 sections divided into left bank (ME), middle (M) and right bank (MD) with surface and bottom collections, every 4 hours for 13 hours to analyze the entire tidal cycle. Parameters were analyzed in situ (Temperature, pH, Eh, electrical conductivity, turbidity, OD, %OD and total dissolved solids) and in the laboratory (Silicate, phosphate, nitrate and nitrite), in addition to determining the intensity, speed and direction of the current. with the aid of an ADCP to obtain the flow and calculate the nutrient flow. The study area has some more remote places with little or no human influence throughout its extension, and others with untreated domestic and industrial effluent discharge points. The objective of this work is to investigate a possible anthropic contribution in the flow of dissolved inorganic nutrients from the water bodies that bathe the city of Belém-PA and surroundings. The Guamá River near the “alça viária” showed the lowest values of dissolved inorganic nutrients, unlike the Acará River which, despite its geographical distance from the RMB, showed the highest values of nutrient concentration. The mouth of the Guamá river had higher nutrient values on its right bank and the Guajará bay in its central portion, due to the influence of domestic and industrial waste. The Guamá river near the “alça viária” is relatively preserved, with a low concentration of dissolved inorganic nutrients, increasing only near its mouth, while the Acará presented higher values mainly due to the intense agricultural activity in the surroundings of its basin. The Guajará Bay, despite receiving discharges from the Acará and Guamá rivers, has lower nutrient values than the two locations, demonstrating its capacity for self-purification and dilution.
Acesso aberto (Open Access)
Modelagem tridimensional da hidrodinâmica e transporte sedimentar de um lago amazônico urbano
(Universidade Federal do Pará, 2025-04-17) CALLADO, Marco Antônio Vieira; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471; https://orcid.org/0000-0002-8601-1514
Lakes are critical environments for sustaining human well-being, as they regulate local climate conditions, supply potable water, and underpin a wide range of ecosystem services. The continuous monitoring of these systems is essential for elucidating their metabolic processes and for informing effective management strategies for natural resources. This study aims to develop an environmental diagnosis and prognosis for a shallow Amazonian lake located in an urban area—Lago Água Preta—through the application of a three-dimensional numerical model of hydrodynamics and sediment transport. Numerical simulations were performed using the Delft3D-FLOW model, encompassing the region’s seasonal periods: wet and dry seasons. The simulations were driven meteorological variables and physical parameters of the lake, such as air temperature, humidity, cloud cover, solar radiation, bathymetry, water temperature, current velocity, and the inflow/outflow rates. This comprehensive dataset allowed for the construction of a computational environment capable of accurately representing the hydro-sedimentary processes within the lake Model calibration was performed using a one-month time series of water temperature from February (wet season), while validation was carried out with current data and vertical temperature profiles over four months (December, February, April, and June). The simulations presented good statistical indicators, demonstrating the model's reliability. The greatest discrepancies between simulation and observation occurred at points closer to the urban center. These differences are associated with the influence of anthropogenic activities, such as the discharge of domestic effluents, or with the narrow morphology of the lake in these areas, which can generate thermal shadow zones. The analysis of circulation and temperature patterns between seasonal periods revealed relatively small differences. Notably, there was an average increase of up to 2 °C in water temperature and approximately 0.02 m/s in current velocity during the warmer period. The most significant differences in average temperature occurred in the lake's daily cycle, varying by about 3°C, with a maximum variation of up to 10°C. Since the lake is fed by an artificial water inflow, this inflow is characterized by an intense discharge with a high sediment load. As it is a shallow lake with a maximum depth of up to 4 meters, this discharge is capable of influencing the lake’s entire metabolism by promoting the resuspension of bottom sediments and redistributing nutrients into the water column. Upon entering the lake, the inflow currents are rapidly decelerated, intensifying sedimentation near the inflow point. This process increases water turbidity and alters the local biotic dynamics, resulting in an environment dominated by phytoplankton and prone to eutrophication processes, which consequently reduce water quality. Therefore, based on the diagnosis provided by the modeling of Lago Água Preta, this study highlights the need for ongoing monitoring and control of anthropogenic influences to prevent the progressive degradation of the lake's metabolism. It also underscores the importance of lakes in general, especially when located in urban contexts.
Acesso aberto (Open Access)
Monitoramento meteorológico e hidrodinâmico de um ambiente lêntico em uma região metropolitana amazônica
(Universidade Federal do Pará, 2025-04-25) GOMES, João Vitor da Silva; ROSÁRIO, Renan Peixoto; http://lattes.cnpq.br/8003860457518342; https://orcid.org/0000-0003-2913-0514
The increasing urbanization and the resulting pressure on water resources have intensified the need to monitor and manage aquatic ecosystems. The Utinga State Park, located in Belém, Pará, is home to an important lake that plays a crucial role in supplying water to the region. However, the lack of urban planning and the disorderly population growth have jeopardized both the quality and quantity of this water resource. In light of this scenario, the present study aimed to evaluate the hydrodynamic and meteorological conditions of Água Preta Lake, with the goal of contributing to its conservation and sustainable management. Meteorological parameters were measured using a weather station over a 12-month period, with data made available at 60- minute intervals. Hydrodynamic data were collected using instruments such as the ADCP, which measures current intensity and direction at 50 cm intervals along the water column; an electromagnetic current meter, used for 48-hour measurements during both dry and rainy seasons to validate the lake's hydrodynamic patterns; and a CTD profiler, which measured the vertical temperature profile. Additionally, levelogger pressure sensors were deployed at strategic locations. After analysis, it was found that the lake's current velocity is low. Meteorological factors remained within the ranges reported by other authors, confirming the consistency of the collected data with previous studies. The hydrodynamic analysis revealed restricted circulation patterns, with limited water movement, especially near the bottom. The main driving force of the system is the operation of pumps that supply the lake with water from the Guamá River. Surface water movement is also limited, as wind speeds are low, hindering circulation in this environment. These results highlight the importance of continuous monitoring for the efficient management of the lake, especially in the context of growing environmental pressure caused by unplanned urbanization. The information obtained provides a solid foundation for future conservation actions, contributing to the preservation of biodiversity and the sustainability of the region's water supply.
Acesso aberto (Open Access)
Mudanças morfológicas em praias da costa Leste da ilha do Marajó e os níveis de vulnerabilidade à erosão
(Universidade Federal do Pará, 2021-06-29) SOUSA, Maria Bárbara Pereira de; RANIERI, Leilanhe Almeida; http://lattes.cnpq.br/3129401501809850; https://orcid.org/0000-0002-9870-4879
The coastal zone is a transition area between the sea and the continent, being one of the most vulnerable geographic spaces on the planet. In view of this, the assessment of morphological changes and coastal vulnerability to erosion is essential, as it contributes to the planning of protective and mitigating actions against impacts that occur on the environment, whether natural or anthropic. Thus, the work aims to verify the morphological changes in beaches on the east coast of Ilha de Marajó/PA and their levels of vulnerability to erosion at different time scales. For this purpose, two field campaigns (dry and rainy seasons) were carried out at Barra Velha beach (municipality of Soure) and Praia Grande (municipality of Salvaterra). The methodology consisted of a semi-quantitative analysis, determined by parameters of human and natural occupation evaluated on the beaches. Remote sensing techniques (medium period data) and in situ data collection (short period data) were used. According to the results obtained, Barra Velha beach was classified as dissipative in the two periods studied and most profiles topographic showed an erosive trend from the dry to the rainy period. Praia Grande showed behavior of intermediate to reflective beaches in both the dry and rainy seasons. The sedimentary accretion phase of this beach occurred during the rainy season, reflecting an atypical pattern for beach morphodynamics. Barra Velha beach exhibited moderate erosion vulnerability in the northwest sector and high vulnerability in the southeast sector, mainly due to the high erosion rate over the 16 years studied. Praia Grande, on the other hand, presented a moderate degree of vulnerability to erosion, being considered a more stable beach, combined with coastal protection works. On both beaches, the coastal risk was low due to the low level of occupation close to the coastline. It is believed that the results of this research can contribute to future studies on the theme of vulnerability to erosion in areas that are little or very anthropized and, for possible actions of coastal management in the Amazon region, considering their environmental particularities.
Acesso aberto (Open Access)
Sedimentação recente e palinologia do Talude Continental Superior Amazônico-Maranhão
(Universidade Federal do Pará, 2025-04-24) AZEVEDO, Gabriela Miranda de; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429; https://orcid.org/0000-0001-7850-1217
The continental slope off the Amazonas, coast of Pará is a geologically complex region, influenced by tectonic phenomena and sedimentary processes associated with the proximity of the Amazon River mouth. The Amazon River discharges approximately 5.7 × 10¹² m³ of water per year and 1.2 × 10³ m³·s⁻¹ of solid load. The continental slope displays a diverse sedimentary cover distribution, which varies regionally depending on the origin of the sediment sources. Few studies (in sedimentology, palynology, and paleontology) have been conducted on the continental slope of the northern region. The main objective of this study is to analyze the sedimentological characteristics (grain size distribution, calcium carbonate content/CaCO₃, organic matter/OM, and organic carbonate/OC) and investigate the occurrence of fertile sediments in the sediment cover of the upper continental slope off Pará, based on two core samples (T66 and T144). The methodology involved: (1) Bibliographic research on scientific databases; (2) Acquisition of sub-surface core samples using a piston corer; (3) Macroscopic description of cores (color, stratigraphic arrangement, and sediment analysis) and core subsampling; (4) Grain size analysis of the sampled layers, including separation of the silt/clay fraction; (5) Quantification of OM and CaCO₃ contents; (6) Selection of fertile samples for palynological analysis. The results indicate that the sediments are predominantly muddy, with a dominance of coarse silt fraction. They are mostly well-sorted, with approximately symmetrical skewness and platykurtic kurtosis. OM content in the cores ranged from 10.64% to 24.42%, with an average of 16.39% (T66) and 10.64% to 24.42% with an average of 16.39% (T144). Preliminary palynological investigation confirms the presence of pollen grains in the samples. The sediments from the continental slope off Pará consist of a mixture of allochthonous and autochthonous material, with the occurrence of palynomorphs.
Acesso aberto (Open Access)
Variabilidade sazonal e espacial da qualidade de água em dois lagos amazônicos: Água Preta e Bolonha, Belém, Pará, Brasil
(Universidade Federal do Pará, 2025-04-04) ROMÃO, Cryssia da Costa; ROLLNIC, Marcelo; http://lattes.cnpq.br/6585442266149471; https://orcid.org/0000-0002-8601-1514
Located in the Utinga State Park (PEUt), the Bolonha and Água Preta lakes are the main bodies of water that supply the Metropolitan Region of Belém (RMB) with drinking water through the Companhia de Saneamento do Pará (COSANPA), which is responsible for 75% of the supply to this population. Studying and understanding the hydrochemistry of these lakes is of fundamental importance, as environmental conditions and ecosystem services are directly related to the quality of the water in the lakes. The sources of input, such as pumping from the Guamá River, in natura effluent discharges and continental runoff from rainfall, require an enhanced sampling effort throughout the system. Therefore, the aim of this study was to analyze the water quality of the Bolonha and Água Preta lakes in order to identify sources of contamination and their effects on the ecosystem and public health. In order to understand and identify the physical-chemical processes and their interactions with anthropogenic activities, hydrodynamics and climate, monthly measurements were taken over 12 months at 20 points in Água Preta Lake and 4 points in Bolonha Lake. Samples were taken at 2 depths (surface and bottom) to obtain water temperature, pH, electrical conductivity, dissolved oxygen (DO), turbidity and total dissolved solids (TDS) using a HORIBA multi-parameter probe. Aliquots were separated for laboratory determination of the following parameters: ammonium, nitrite, nitrate, phosphate, nitrogen and total phosphorus, biochemical oxygen demand, thermotolerant coliforms, chlorophyll-a and total alkalinity. The measured data was statistically analyzed between points and seasonal stations, and the Trophic State Index (TSI) and Water Quality Index (WQI) were calculated.
Acesso aberto (Open Access)
Variação interanual e sazonal das massas d’água sobre a Plataforma Continental Norte do Brasil
(Universidade Federal do Pará, 2021-12-20) MEDEIROS, Paula Renata Lobato de; ROSÁRIO, Renan Peixoto; http://lattes.cnpq.br/8003860457518342; https://orcid.org/0000-0003-2913-0514
This study aimed to analyze the spatial and temporal variability of water masses over the Northern Continental Shelf of Brazil (PCNB), relating it to local dynamics and freshwater inputs. The PCNB extends from Cape Orange to the Bay of São Marcos and is characterized as highly energetic, due to the combined action of the north current of Brazil (CNB), trade winds, waves, tides and the water discharge from the Amazon rivers and Pará. Temperature, salinity and density data for the interannual analysis were obtained from the Brazilian Navy's national database (BNDO), during six oceanographic cruises: Amasseds I, II and III, North Ocean I, MCT VII and CBO in different years: 1989, 1990, 2001, 2016 and for the seasonal analysis, five months of the Costa Norte Project were used: March, July, November, December 2018 and January 2019. The TS parameters were intended to characterize and identify the water masses that occurred on the platform over the years, as well as observe the existing interannual and seasonal variability. The PCNB showed large variations in TS over the years and periods analyzed, and it is possible to observe the occurrence of four types of water bodies interannually: Pluma Estuarina (PE), Coastal Water (AC), Central Water of the South Atlantic (ACAS) and Tropical Water (AT) and seasonally, five water bodies were identified as occurring: AF (front water), AC, AT, ACAS and Pluma etuarina (PE). From the analysis of the TS diagrams it was possible to identify a thermohaline index for the estuarine plume and its metrics over time, where it occurred in March - 2018 and January - 2019, and their respective thermohaline indices were 27.5 °C to 28 °C and 0 g/kg to 33 g/kg.

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