Influência das características físico-químicas dos solos no ciclo hidrobiogeoquímico do mercúrio na região do Rio Aracá - AM

Oliveira, Luciana Camargo de; Botero, Wander Gustavo; Santos, Ademir dos; Cordovil, Mirela Cristina de Oliveira; Rocha, Júlio César; Silva, Heliandro Cordovil da

doi:10.1590/s0100-40422011000800002

Cited by 13 publications

(7 citation statements)

References 12 publications

(14 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The study was carried out in the Aracá and Demeni rivers, two tributaries of the middle Negro River, in the northern portion of the Amazon Basin (Figure 1), whose headwaters are in the Guiana Plateau. The Aracá River is formed by black waters that have recent deposition of organic matter on the surface, followed by a sandy layer which has a low organic matter content (<0.03%; Oliveira et al., 2011). However, the Demeni River is limnologically distinct with white waters and a low sediment load (Aguiar‐Santos et al., 2018; Sioli, 1984).…”

Section: Methodsmentioning

confidence: 99%

Length‐weight relationship of 16 fish species from the Negro River basin (Amazonas state, Brazil)

et al. 2020

View full text Add to dashboard Cite

Summary This study aimed to estimate the parameters of length‐weight relationship for 16 freshwater fish species that inhabit the Aracá and Demeni Rivers, which are two tributaries of the Negro River (Amazonas state, Brazil). The fishes were sampled using gillnets (15 × 2 m, mesh size 30–120 mm between opposite knots), during 6 days each year, in April 2016, November 2018 and April 2019. The gillnets were placed in the river twice each day; in the morning (5–9 a.m.) and in the evening (5–9 p.m.), with a standardized time of 4 hr. Measurements were taken for standard length (SL – 0.1 cm precision) and total weight (TW – 0.01 g precision). The parameters a and b of the equation WT = a.LTb were estimated. This study also provides new data on of maximum lengths for six species, namely, Argonectes longiceps, Hemiodus atranalis, Chalceus erythrurus, Astrodoras asterifrons, Trachydoras steindachneri and Acarichthys heckelii.

show abstract

Section: Methodsmentioning

confidence: 99%

Length‐weight relationship of 16 fish species from the Negro River basin (Amazonas state, Brazil)

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The positive correlation between the finer portion of sediments (silt and clay) and Hg contents (Figure 3) is due to the larger surface area of fine particles, increasing their adsorption capacity (Oliveira et al, 2011;Cembranel et al, 2017b). Thus, clay is considered an important factor for Hg adsorption in soils and sediments (Araujo et al, 2015).…”

Section: Resultsmentioning

confidence: 99%

Mercury in the Sediment of Pelotas River Basin, Brazil

et al. 2018

View full text Add to dashboard Cite

Many studies have determined the concentration of trace elements in river sediments in Brazil. Notwithstanding, mercury assessments are scarce, especially because of exclusive extraction techniques and expensive analysis techniques. Still, this element is known for its toxicity, persistence, and bioaccumulation, making its presence in the environment an important factor for biota and human health. For this reason, the objective of this study was to determine the mercury concentration in the sediment of the Pelotas River basin, located on the border of the states of Santa Catarina and Rio Grande do Sul. The sediment was collected at eight locations of the Pelotas basin and, after drying, the mercury was quantified by atomic absorption spectrometry based on the Zeeman-background correction, coupled to a pyrolysis reactor. The mercury concentrations in the sediments of the Pelotas River varied from 40.5 ng g-1 to 62.0 ng g-1 and presented a positive correlation with the fraction of silt and clay. The concentrations of mercury found in sediments of the Pelotas River basin have a low probability of negatively affecting the biota. Nonetheless, given the persistence and bioaccumulation potential of this element, the aforementioned region needs further studies to quantify the risks it may cause on the local biota and human health.

show abstract

“…In the rainy season, its waters can become cloudy due to increased suspended material in the water column. Clear rivers have low conductivity (~ 10.0 μS/cm) and pH values that are slightly acid (De Oliveira et al, 2011;Sioli, 1984). The Aracá River is a typical blackwater river, with a low concentration of nutrients, acidic pH and high concentrations of humic and organic acids (Goulding et al, 1988;Ríos-Villamizar et al, 2022).…”

Section: Study Areamentioning

confidence: 99%

Influence of abiotic factors on the composition of fish assemblages in the Aracá-Demeni sub-basin of the middle Negro River

Sambora,

Aguiar-Santos,

Siqueira-Souza

et al. 2023

Braz. J. Biol.

View full text Add to dashboard Cite

We evaluated the influence of flooding and receding comparison and spatial variation on the composition and structure of fish assemblages in blackwater and clearwater rivers of the Aracá-Demeni sub-basin in the middle Negro River, Amazonas state, Brazil. The collections were carried out during the falling-water period (November 2018) and the rising-water period (April 2019) using gillnets with meshes ranging from 30 to 120mm stretched mesh size. Ecological estimates of richness, equitability, the Shannon-Wiener diversity index, and the Berger-Parker index showed no significant differences between the periods. The composition of the ichthyofauna showed variations between the falling-water and rising-water periods. Beta diversity in the Aracá-Demeni sub-basin is almost completely caused by species substitution, with spatial turnover accounting for most of the estimate. The identification of these patterns and of the responsible factors are fundamental for the definition of conservation strategies, especially in an ecosystem whose dynamics can be influenced by climate change through changes in the intensity of the flood pulse and connectivity.

show abstract

Influência das características físico-químicas dos solos no ciclo hidrobiogeoquímico do mercúrio na região do Rio Aracá - AM

Cited by 13 publications

References 12 publications

Length‐weight relationship of 16 fish species from the Negro River basin (Amazonas state, Brazil)

Length‐weight relationship of 16 fish species from the Negro River basin (Amazonas state, Brazil)

Mercury in the Sediment of Pelotas River Basin, Brazil

Influence of abiotic factors on the composition of fish assemblages in the Aracá-Demeni sub-basin of the middle Negro River

Contact Info

Product

Resources

About