Navegando por Assunto "Amazon coast"

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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)
Petrechos de pesca como resíduo praial em uma área de proteção ambiental na costa paraense
(Universidade Federal do Pará, 2024-02-29) SILVA, Elaine Simone da Cruz Silva; LOREIRO, Sarita Nunes; http://lattes.cnpq.br/1473112723704086; MONTEIRO, Sury de Moura; http://lattes.cnpq.br/4309806566068586; https://orcid.org/0000-0001-9449-7043
Abandoned, Lost or otherwise Discarded Fishing Gear (ALDFG) during fishing activities represent a global problem. This equipment corresponds to at least 640,000 tons of waste that accumulates annually in the oceans and causes impacts on aquatic fauna such as entanglement, ingestion, injuries, ghost fishing and can also act as vectors of chemical substances. This is the first quantification of ALDFG on beaches in Northern Brazil. The study was carried out on beaches on Algodoal Island, which is an Environmental Protection Area (APA), with the aim of evaluating whether there is spatial and temporal variation in ALDFG on different beaches (Caixa d´água, Farol, Princesa and Cação), considering their different environmental characteristics, and check whether there is the occurrence of organisms associated with ALDFG. The ALDFG were collected in the rainy and dry seasons (2022), in quadrants of 100m² in 30 transects containing three points: high tide line, intermediate and low tide line. The density of ALDFG and an Environmental Impact Factor (FIA) were calculated, considering the type of ALDFG, its mass and the environment where it was found. In total, 459 ALDFG items were collected (248 in the dry season and 211 in the rainy season), totaling 13.14 kg, among which the main ones were fragments, electrical cables, ropes and fishing nets, with emphasis on the nylon type material and blue color. Overall, the beaches had an average density of 0.023 items/m² and 0.755 g/m² in the rainy season and 0.028 items/m² and 0.704 g/m² in the dry season, with a low environmental impact (FIA between 0-1). But points with high impacts were also observed (FIA = 10 and FIA = 9), in points with the presence of rocky outcrops and vegetation, respectively. On Caixa d'água beach there is the presence of juvenile mangroves in the intertidal environment and rocky outcrops, as well as, it is located close to the port for fishing vessels, therefore, it was the beach that presented the largest quantity of ALDFG (274 items), the highest mass (6.35 kg), the highest density (2.74 items/m² and 63.52 g/m²), and consequently the highest Environmental Impact Factor (FIA = 10). Furthermore, associated with the ALDFG, 1,543 organisms were recorded (1,380 in the rainy season and 163 in the dry season) belonging to the following groups, barnacles, bivalves, paguros, crabs, isopods, polychaetes, gastropods, anemones and sea fleas, the majority of which were found associated with ropes and polystyrene buoys. Fishing is a recognized source of ALDFG and the presence of these residues in an APA can cause several impacts to this ecosystem.
Acesso aberto (Open Access)
Variação temporal do fitoplâncton e dos parâmetros hidrológicos da zona de arrebentação da Ilha Canela (Bragança, Pará, Brasil)
(Sociedade Botânica do Brasil, 2009-12) SOUSA, Eliane Brabo de; COSTA, Vanessa Bandeira da; PEREIRA, Luci Cajueiro Carneiro; COSTA, Rauquírio André Albuquerque Marinho da
Seasonal and nyctemeral variations of the phytoplankton and hydrological parameters were studied at a fixed station (00º46'37.2"S-046º43'24.5"W) situated in Canela Island (Bragança-Pará) in September and December, 2004 and in March and June, 2005. Subsurface water samples were taken for qualitative and quantitative phytoplankton studies and to determine chlorophyll a concentrations. Simultaneously physical and chemical parameters were measured: salinity, temperature, pH, dissolved oxygen and percent of oxygen saturation. A total of 64 taxa belonging to Cyanophyta (one taxon), Bacillariophyta (54 taxa) and Dinophyta (nine taxa) were identified. Chlorophyll a concentrations ranged from 4.67 mg m-3 (dry season), to 5.44 mg m-3 (rainy season) and follow phytoplankton densities, which were higher during the rainy period (mean values of 1,870 x 103 cell L-1). Phytoflagellates quantitatively dominated the local phytoplanktonic community followed by diatoms. Dimeregramma minor and Skeletonema sp. were abundant and ve