Navegando por Assunto "Rio Marapanim - PA"

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Acesso aberto (Open Access)
Análise morfoestratigráfica do estuário do Rio Marapanim - NE do Pará
(Universidade Federal do Pará, 1998-12-20) SILVA, Cléa Araújo da; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
The estuary of Marapanim River is developed on tertiary-quaternary sediments of Barreiras and Pós-Barreiras Formation. It is inserted on "Littoral of Rias" of Pará northeast, which from High Pleistocene was submitted to marine transgression that drowned coastal paleolines and, in the maximum of Holocene Transgression, reached the coastal plateau. This portion of coast is strongly influenced by dynamic macrotides (5,3m) and salt wedge with mear salinity of 8%0 (high tide — Marudazinho) and 3%0 (low tide — Marapanim). So that, on outer funnel (Marudá) the salinity is 35°/00, representing no influente of mouth river discharge. Geomorphology of the area is subdivided in three morphologic domains: (1) Coastal Plain, constituted by strand plain, paleodune, coastal dune, salt marsh, tidal flat (sand flat and mangrove swamp), recurved spit, lake and palco tidal creek; (2) Estuarine Plain, constituted by estuarine channel (subdivided in estuarine funnel segment, sinuous meandering segment, cuspidate meandering segment and upstream channel), tidal creek and floodplain (salt marsh and fresh water marsh) and; (3) Alluvial Plain constituted by meandering channel (chute cutoff), channel deposits (channel lag deposits), overbank deposits (natural levee, crevasse-splay deposits and floodplain) and channel-fill deposits. Fourteen morphostratigraphic units was identified: floodplain, levee, chute cutoff, fresh water marsh, mudflat, channel bar, point bar, strand plain, paleodune, coastal dune, recurved spit, sand flat and salt marsh. Six stratigraphic facies are also present: point bar sand and mud, marine sands, estuarine sand and mud, estuarine muds, fluvial sands and motled sand. Stratigraphical analysis permitted recognize stratigraphic sequences: Basal Marine Transgressive (Si) with fluvial, salt marsh and shoreface environments; Marine Regressive (S2) with fluvial, fresh water marsh, tidal flat, salt marsh and strand plain environments and; Recent Marine Transgressive (S3) with estuarine (channel bar and point bar) and littoral environments (recurved spit, strand plain and coastal dune). Geological evolution of the estuary of Marapanim River is associated with sea levei oscillations that occurred during progradation and regressive cycles on Later Holocene, which in the maximum of the Holocenic Transgression eroded the highland (coastal plateau). In stillstand sea levei conditions occurred marine regressive and mud flat progradation over marine sand deposits. In present time, sand sheets are deposited over mud ilat providing partia! filling in the mouth of estuary by sand bars.
Acesso aberto (Open Access)
Functional trophic composition of the ichthyofauna of forest streams in eastern Brazilian Amazon
(2013-06) BREJÃO, Gabriel Lourenço; GERHARD, Pedro; ZUANON, Jansen Alfredo Sampaio
This study aimed to describe the functional organization of the ichthyofauna of forest streams from northeastern Pará State, Brazil, based on behavioral observation of species' feeding tactics. Seven streams were sampled between June and November, 2010, during snorkeling sessions, totaling 91h 51min of visual censuses at day, dusk, and night periods. Seventy three species distributed in six orders, 26 families and 63 genera were observed, with dominance of Characiformes, followed by Siluriformes. From information gathered by ad libitum observations, each species was included in one of 18 functional trophic groups (FTGs), according to two main characteristics: (1) its most frequently observed feeding tactic; and (2) its spatial distribution in the stream environment, considering their horizontal (margins or main channel) and vertical (water column) dimensions. The most frequent FTGs observed were Nocturnal invertebrate pickers (9 species), Diurnal channel drift feeders (8 spp.), Diurnal surface pickers (7 spp.), and Ambush and stalking predators (6 spp.). The FTGs herein defined enable a comparative analysis of the structure and composition of ichthyofauna in different basins and environmental conditions, which presents an alternative approach to the use of taxonomic structure in ecological studies. The ichthyofauna classification based in FTGs proposed in this study is compared to three other classifications, proposed by Sazima (1986), Sabino & Zuanon (1998) and Casatti et al. (2001).
Acesso aberto (Open Access)
Mineralogia e geoquímica de sedimentos de manguezais da costa amazônica: o exemplo do estuário do rio Marapanim (Pará)
(2008-03) BERRÊDO, José Francisco; COSTA, Marcondes Lima da; VILHENA, Maria do Perpétuo Socorro Progene; SANTOS, Josiana Torres dos
The mangroves of the Para state represents an important segment of the Brazilian north coast on the ones which little it is known of the geological characteristics and it relationships with source areas. This research was accomplished in the Marapanim river estuary, in the Para coast, to demonstrate the contribution of continental sediments for the constititution of the mangrove's sediments. The mangrove's sediments and the Barreiras Formation sediments and soils (main continental sources) were collected. In the mangrove's sediments grain size, determination of the carbon (C%), pH and Eh measures and interstitial salinity was made. The mineralogical determination and the multi-elementary geochemistry was made in the sediments muddy and terrigenous adjacents sediments for comparisons. The mangrove's sediments are clayey silty (> 90%), with the carbon values among 0,75 to 3,5%. The main mineralogy is composed by quartz, goethita, hematite, kaolinite, illite, besides zircon, tourmaline, staurolite and cianite as accessories, what indicates contribution of the Barreiras Formation sediments and sediments muddy. It is common the occurrence in these mangroves the neoformated minerals as: smectite, K-felspars, pyrite, halite, gipsum and jarosite. The enrichment in SiO2, Al2O3, Fe2O3 and TiO2 in the mangroves and the low tenors in trace metals reflects the tropical climate and the mineralogical composition of the source area, enriched in quartz and caulinite, with low tenors in K2O, Na2O, MgO and CaO. The chemical composition associated to the organic matter, abundant diatoms besides Fe, S and the marine contributions of Cl-, Na+, K+, Ca++ and Mg++, identify the deposicional ambient and the autigenics minerals. The concentrations and the geochemical behaviour of the trace metals in the mangroves corroborates the outstanding contribution of the continental source area. Those sediments presents the prevalence of the Light Rare Earth Elements (LREE) on the Heavy Rare Earth Elements (HREE) with high reasons of Th/Co; La/Th; La/Sc; La/Co and Zr/Sc and Th/Sc and Ba/Co, elements present in the felsic igneous rocks that originated the continental sediments.
Acesso aberto (Open Access)
Pesca, alimentação e ecologia reprodutiva e embrionária de carataí (Pseudauchenipterus nodosus) (Siluriformes, Auchenipteridae) no rio Marapanim, Marapanim, Pará
(Universidade Federal do Pará, 2000-10) ASSUNÇÃO, Maria Ivaneide da Silva; BARTHEM, Ronaldo Borges; http://lattes.cnpq.br/4192105831997326
This study presents information on the fisheries, diet, reproduction and embryonic development of carataí fish, Pseudauchenipterus nodosus (Siluriformes, Auchenipteridae), based on data collected between December 1998 and April 1999 in Marapanim River, Pará State, Brazil. Daily and biweekly samplings were collected by means of weirs and pound nets at four sites along the river: the bay, the estuarine funnel, mid-river and the upper portion. It was confirmed that fishing took place during the reproductive period of the species, and that its features varied according to the different sites. Most of the fishermen’s yield was sold in neighboring districts. Catch data along the river pointed the upper portion (33%) and mid-river (44%) as the most productive sites and indicated that carataí performs a biweekly ascending movement. The species ingested larger amounts of food in turbid waters, mainly in tide streams: its diet included annelids, arthropods, mollusks and fishes. Local observations and frequency distributions of ovaries at mature, reproductive and spent stages respectively indicated that carataí spawns in places with fresh and clean waters, on river and creek shores, under a canopy of undisturbed forests. Spawning occurred during the last peaks of the highest waters of spring tides, and following their retraction the eggs were incubated in the soil for about 11 days until the coming syzygy, under temperatures of 22 to 27.5 °C. After hatching, the embryos either remained enclosed within the egg shell until flooded by the tide, or got out of the shell and onto the ground, where they could survive for a couple of hours. Those latter embryos had the ability of taking up exogenous food as they hatched, while those incubated in water would tend to hatch prematurely and show little perception of the surrounding environment. Intervention in the annual recruitment of carataí in Marapanim River seemed to be more dependent on local rain distribution and on the integrity of the forest than on fishing activities.
Acesso aberto (Open Access)
Segregação espaço-temporal das assembléias de peixes em ambientes de entremaré não vegetado e canal subtidal de um estuário de macromaré no norte do Brasil
(Universidade Federal do Pará, 2012-02-28) LOUREIRO, Sarita Nunes; GIARRIZZO, Tommaso; http://lattes.cnpq.br/5889416127858884
Various estuarine environments are hydrologically and ecologically connected and provide vital functions to several aquatic organisms. Spatial and temporal segregation were observed in fish assemblages structure (average biomass) in the subtidal channel and intertidal nonvegetated environments in the estuary of the Marapanim River, North Brazil. Monthly fish sampling were carried out between August 2006 and July 2007 at the subtidal channel and intertidal non-vegetated environments using a beam trawl and beach seine, respectively. A total of 41,496 individuals belonging to 29 families and 76 species was collected. Species richness in the subtidal channel (71 species) was higher than in the intertidal non-vegetated environments (51 species). Different associations in the composition of the species and functional guilds were observed between the subtidal channel and the intertidal non-vegetated environments, through the Detrended Correspondence Analysis. Significant differences in fish fauna composition were found between environments, seasons and zones, through Analysis of similarities (ANOSIM). The fine sediments (silt-clay), sand and salinity were the most important factors structuring the fish assemblages. In summary, these results can be associated to the fish tolerance to environmental factors, and to different feeding type.