Influence of river discharge on phytoplankton structure and nutrient concentrations in four tropical semiarid estuaries

Barroso, Hortência de Sousa; Becker, Helena; Melo, Vânia Maria Maciel

doi:10.1590/s1679-87592016101406401

Cited by 28 publications

(4 citation statements)

References 37 publications

(53 reference statements)

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“…In these cases, high salinities may also adversely affect the activity of different iron-oxidizing bacteria and the Fe(II) oxidation enzymes (see Bongoua-Devisme et al 2012;Sadeghieh et al 2020). This reasoning is supported by the results of a recent study in several Brazilian semiarid mangrove forests which evidenced sharp increase in salinities (2 psu to 37 psu; Barroso et al, 2016) from the rainy season to the dry season.…”

Section: Iron Biogeochemistry In Northeast Mangrovesmentioning

confidence: 85%

Windsock behavior: climatic control on iron biogeochemistry in tropical mangroves

et al. 2021

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Iron is one of the most abundant elements on the planet and a micronutrient for most organisms. In many coastal regions worldwide, mangrove forests affect the dynamics and mobility of different elements to the oceans especially through their soils. The biogeochemistry of mangrove soils responds to numerous factors that vary within different spatial and time scales. In this sense, seasonality can be crucial in determining the role of these ecosystems towards the iron biogeochemical cycle. Thus, the main goal of the present study was to assess the effects of contrasting climatic conditions on iron biogeochemistry in different mangrove forests along the Brazilian coast. We studied the soils (n = 435) of 14 different mangrove forests distributed along two contrasting climate regions: the semi-arid Northeast and the humid Southeast coasts of Brazil. In the SE region, water surplus and lower temperatures in both seasons did not cause significant changes in iron concentrations (wet season: 216 lmol g -1 ; dry season: 230 lmol g -1 ) where oxyhydroxides and pyrite immobilize iron in the mangrove soils. In contrast, in the semi-arid mangroves, a marked water deficit during the dry season caused both pyrite oxidation and iron reprecipitation as oxyhydroxides. Contrarily,

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Section: Iron Biogeochemistry In Northeast Mangrovesmentioning

confidence: 85%

Windsock behavior: climatic control on iron biogeochemistry in tropical mangroves

et al. 2021

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“…However, the short rainy season has a highly variable intensity, influenced by the temperatures in the Atlantic Ocean. The countryside of Ceará is a semi-arid region, with rainfall intensity decreasing each year and temperatures reaching 40°C ( Barroso et al 2016 ). Therefore, the building of dams for water storage is common.…”

Section: Discussionmentioning

confidence: 99%

Natural environmental water sources in endemic regions of northeastern Brazil are potential reservoirs of viable Mycobacterium leprae

Arraes

Holanda

Lima

et al. 2017

Mem. Inst. Oswaldo Cruz

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BACKGROUNDThe detection of live Mycobacterium leprae in soil and animals other than humans suggests that the environment plays a role in the transmission of leprosy.OBJECTIVEThe objective of this study was to investigate the presence of viable M. leprae in natural water sources used by the local population in five municipalities in the state of Ceará, northeastern Brazil.METHODSSamples were collected from 30 different sources. Viable bacilli were identified by reverse transcriptase polymerase chain reaction (PCR) of the M. leprae gyrA gene and sequencing of the PCR products. Physicochemical properties of each water source were also assessed.FINDINGS M. leprae gyrA mRNA was found in 23 (76.7%) of the water sources. No association was found between depth of the water and sample positivity, nor was there any association between the type of water used by the population and sample positivity. An association between viable M. leprae and temperature and pH was found. Georeferencing showed a relation between the residences of leprosy cases and water source containing the bacterium.MAIN CONCLUSIONSThe finding of viable M. leprae in natural water sources associated with human contact suggests that the environment plays an important role in maintaining endemic leprosy in the study region.

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“…Estuaries are among the most diverse and productive marine environments, they assimilate and process most of the river discharges and coastal basins, and have a unique position among coastal systems allowing a relatively simplistic view of water inflows and outflows (Pino et al, 1999;Tudurí et al, 2018;Grasso & Le Hir, 2019). The degree of fluvial influence (as a result of precipitation in the drainage basin) affects not only sediment composition and distribution, but also controls salinity, nutrients, pollutants and biota distribution (Barroso et al, 2016;Costa et al, 2018).…”

Section: Introductionmentioning

confidence: 99%

Spatial and temporal variations of sediments in a subtropical microtidal estuary

et al. 2021

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Sediment dynamics are determined by the synergy between the hydrodynamic condition and sediment properties. This study analyzed, between the years 2015-2017, the spatial and temporal changes in sediment texture of a shallow embayment in the Patos Lagoon estuary (Southern Brazil), and the influence of environmental parameters in these variations. Two areas were selected: an area more exposed to the estuary main channel dynamics and NE winds, and the other protected from them by islands. Each area was divided in shallow (mean depth <2m) and deeper zones (mean depth ≥2 m). The organic matter content presented a spatial and temporal variation, with maximum values higher than previously reported. Due to elevated rainfall rates during the winter and spring of 2015, higher values of fine sediments and organic matter were recorded, mainly at deeper zones. The protected area presented smaller grain sizes and their variability was correlated with wind speed and direction. While in the exposed area the water depth has a higher influence in the granulometric variations, decreasing grain sizes with depth increases. The higher seasonality in the granulometric variation was observed in the deeper zones, which presented the smaller grain sizes and lower values of asymmetry, decreasing these values in winter and spring. In conclusion, few centimeters in water depth may cause large changes in bottom types (or in the relative amount of sand, silt and clay) of shallow estuarine areas. From the environmental variables measured, wind, rainfall and bathymetry were the most influential in the temporal variation of the sediments, while hydrodynamic exposure on the spatial differences.

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Influence of river discharge on phytoplankton structure and nutrient concentrations in four tropical semiarid estuaries

Cited by 28 publications

References 37 publications

Windsock behavior: climatic control on iron biogeochemistry in tropical mangroves

Windsock behavior: climatic control on iron biogeochemistry in tropical mangroves

Natural environmental water sources in endemic regions of northeastern Brazil are potential reservoirs of viable Mycobacterium leprae

Spatial and temporal variations of sediments in a subtropical microtidal estuary

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