Baseline Study of Trace Element Concentrations in Sediments of the Intertidal Zone of Amazonian Oceanic Beaches

Abstract

Analyzing the presence and quantifying trace elements is of paramount importance to understand natural environmental processes and monitor the degree of anthropogenic disturbance to mitigate impacts already caused. Here, we aimed to establish a baseline of the trace elements profile and concentrations in sandy sediments of intertidal areas of three Amazonian beaches (Brazil). For each beach, sediments were collected from three different sectors (south, center, and north) and five shoreline distance levels (from the high- to the low-water mark), totalizing 15 samples per beach. The concentration of the different trace elements (Mg, Al, P, S, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Br, Rb, Sr, Y, Zr, Cd, Sn, I, Hg, and Pb) was determined by Total reflection X-ray Fluorescence spectrometry. Sediment was also characterized for its grain size, organic matter, and pH. To assess possible enrichment due to anthropogenic activities we compared trace element levels with the values for the Earth’s crust and calculated pollution indexes: geoaccumulation index (Igeo), ecological risk index (RI), contamination factor (CF), pollution load index (PLI), and sediment quality guideline (SQG), threshold effects level (TEL) and probable effects level (PEL). Individual trace metal concentrations did not vary significantly between beaches, sectors, or sample levels, evidencing a homogeneity of trace elements composition and concentrations across this environment. Igeo indicated 62.2% of the sampling stations uncontaminated, 20.0% from uncontaminated to moderately contaminated, and 4.44% (two sampling stations) strongly contaminated, the same two areas classified as high ecological risk by RI. Most of the sampling points presented low CF. Cadmium and Hg were the only elements that showed moderate to very high values of CF. According to the SQGs, 77.7 and 8.8% of the sampling points presented values above the moderate threshold effect level (SQG-TEL) and probable effect level (SQG-PEL), respectively. All points were classified as non-polluted according to the PLI. Our results show that the three beaches present safe levels of almost of the elements demonstrating the good state of preservation. Most of the indexes classified the sampling points as non-polluted, except for Cd and Hg in a few specific sampling points.

Rainfall Influences the Patterns of Diversity and Species Distribution in Sandy Beaches of the Amazon Coast

“…Similarly, Santos et al [19] recorded a total of 46 species in the intertidal area of Atalaia, Farol-Velho, and Corvina Beaches, all sites also located on the Pará coast. Given that (i) macrotidal dissipative beaches are expected to host a larger number of species and individuals among beach types [46,47] and (ii) that the study area is not subject to a high degree of anthropic influence, such as urbanization, tourism, or trace element contamination [7,28], factors often associated with decreased macrobenthic diversity [48][49][50][51], our results are unexpected and suggest this overall low diversity is not a regional but rather an intrinsic feature of local beaches. Similarly, Jourde et al [52] found low macrobenthic diversity (H' means ranging from 0.17 to 1.74) on mudflats of Guiana.…”

“…Sampling was performed during spring tides at the eastern section of Goiabal Beach (2°31′02.2 N; 50°49′33.8 W), and the western section of Nazaré (2°29′32.3 N; 50°47′23.2 W) and Samaúma Beaches (2°48′23.0 N; 50°55′40.9 W) (Figure 1). The three sites are tidedominated flats with a predominance of very fine sands [28]. The width of the sandy intertidal zone changes across the arc, shorter eastwards, where the stream sediment is responsible for muddy lower levels.…”

Spatial distribution of trace elements and potential contamination sources for surface sediments of the North-Western Black Sea, Romania

“…Accumulation of TEs in marine sediments depends on various factors, e.g., water depth, water physicochemical properties (pH, salinity, temperature, dissolved oxygen and organic matter content), sediment composition and texture, intensity/direction of winds, waves, and currents, fluvial, atmospheric, and other natural or anthropogenic inputs (Oros, 2019;Constantinescu et al, 2023). Multivariate analysis, especially PCA, is widely used to identify the main factors affecting the concentration of TEs in sediments and possible pollution sources/transport pathways (Martins et al, 2012;Kahal et al, 2018;Remeikaite-Nikienėet al, 2018;El-Sorogy et al, 2020;Perumal et al, 2021;Vilhena et al, 2021;Wang et al, 2021;Kubra et al, 2022;Zhou et al, 2022).…”

Unravelling the Portuguese Coastal and Transitional Waters’ Microbial Resistome as a Biomarker of Differential Anthropogenic Impact

“…Despite this reduction in the anthropogenic input of classic contaminants, these are still frequently persistent in the environment, with the added threat of newly emerging contaminants such as microplastics, pharmaceuticals and personal care products [ 3 ]. The prevalence and consequent significant mobility of these contaminants in the ecosystems [ 4 ] can even be detected in remote uninhabited locations, with an unexpected presence in key trophic compartments such as the planktonic microbial community [ 5 , 6 ]. Beyond the necessary environmental risk assessment (ERA) approaches, to evaluate the possible impacts of these contaminants in the different biotic compartments [ 7 ], it is also essential to understand how these xenobiotics interact with the organisms and what are the molecular implications of these interactions.…”