Natural light driven plastic leaching effects on carbon chemistry in the tropical coastal waters of eastern Arabian sea: An experimental study.

This study examined the effects of solar light driven plastic degradation on carbon chemistry in the coastal waters of eastern Arabian Sea along the west coast of India. The research was conducted through experimental incubations exposed to natural sunlight at multiple locations between December 2023-February 2024. Photodegradation induced a significant pH decrease (up to 0.

Implications of ocean acidification on micronutrient elements-iron, copper and zinc, and their primary biological impacts: A review.

This review has been undertaken to understand the effectiveness of ocean acidification on oceanic micronutrient metal cycles (iron, copper and zinc) and its potential impacts on marine biota. Ocean acidification will slow down the oxidation of Fe(II) thereby retarding Fe(III) formation and subsequent hydrolysis/precipitation leading to an increase in iron bioavailability. Further, the increased primary production sustains enzymatic bacteria assisted Fe(III) reduction and subsequently the binding of weaker ligands favours the dissociation of free Fe(II) ions, thus increasing the bioavailability.

Iron and phosphorus geochemistry in the core sediments of an urbanized mangrove ecosystem, Southwest coast of India.

This study has been carried out to understand the geochemistry of elements namely, iron (Fe) and phosphorus (P) in the core sediments of an urbanized tropical mangrove ecosystem along the Southwest coast of India. The study revealed the coupling of iron and phosphorus in which the reductive conditions induced reductive dissolution and upward transport of Fe, causing surface coprecipitation of phosphorus incorporated Fe oxyhydroxides. The accumulation and transformation of phosphorus were significantly influenced by processes viz.

Trace metals enrichment and potential ecological risk in sediments of the Sepetiba Bay (Rio de Janeiro, SE Brazil).

The Sepetiba Bay (SB; SE Brazil) has been severely affected by growing of urbanization and industrial activity. This work aims to analyze the evolution of contamination by metals of sediments in SB. The results show a marked increasing trend in the concentrations of potentially toxic elements (PTEs), which is consistent with the rapid populational and industrial growth, mostly since 1970 CE.

Trace metal distribution and ecological risk assessment in the core sediments of a highly urbanized tropical mangrove ecosystem, Southwest coast of India.

Distribution and ecological risk assessment of trace metals were carried out in the core sediments of a highly urbanized tropical mangrove ecosystem along the Southwest coast of India. The metal distribution pattern was as follows: Co, Cu, Ni and Pb adsorbed onto Fe oxyhydroxides and fine grained sediments; Cd and Zn preferential adsorption by organic matter and Cr scavenging by Mn oxyhydroxides. Cd, Pb and Zn were significantly enriched in upper sediments, while Cd, Ni and Zn were present in metal exchangeable fractions.

Amino acids as indicators to elucidate organic matter degradation profile in the Cochin estuarine sediments, Southwest coast of India.

Surface sediments from three zones (fresh water, estuarine, and riverine/industrial zones) of the Cochin estuary, Southwest coast of India, were seasonally analyzed to understand the nature and degradation status of organic matter. Amino acid-based indices such as total hydrolyzable amino acids (THAAs), percentage contributions of amino acid carbon to total organic carbon (THAA-C%) and those of amino acid nitrogen to total nitrogen (THAA-N%), and degradation index (DI) were calculated. Elevated levels of amino acids in the sediments of the estuary were attributed to river runoff, autochthonous production, allochthonous inputs, and industrial and domestic effluent discharges.

Heavy metal distribution and contamination status in the sedimentary environment of Cochin estuary.

Heavy metals (Fe, Mn, Cr, Zn, Ni, Pb, Cu, Co and Cd) in the surface sediments of Cochin estuary, Southwest coast of India were analyzed to understand the spatio-temporal variation and contamination status via six sampling campaigns. Pollution indices like enrichment factor, geoaccumulation index and pollution load index inferred that the sediments of the northern arm of the estuary exhibited severe trace metal accumulation. Numerical sediment quality guidelines were applied to assess adverse biological effects of the trace metals, suggesting that occasional biological effect may occur due to Cr, Cu, Ni and Pb.

Heavy metal concentrations in some gastropods and bivalves collected from the fishing zone of South India.

The present study investigates heavy metal concentrations in gastropods and bivalves collected from major fishing centers in South India. Three gastropods, Bursa spinosa, Tibia curta, and Murex trapa, and two bivalves, Perna viridis and Villoritta cyprinoids, were collected for the analysis of heavy metals. The metals in the present study followed the order Mg>Ca>Zn>Fe>Cu>Mn>Cr>Pb>Ni>Co>Cd.

Trace metal enrichment and organic matter sources in the surface sediments of Arabian Sea along southwest India (Kerala coast).

The geochemical distribution and enrichment of trace metals (Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn) were determined in the surface sediments of Arabian Sea, along southwest India, Kerala coast. The results of geochemical indices indicated that surficial sediments of five transects are uncontaminated with respect to Mn, Zn and Cu, uncontaminated to moderately contaminated with Co and Ni, and moderately to strongly contaminated with Pb. The deposition of trace elements exhibited three different patterns i) Cd and Zn enhanced with settling biodetritus from the upwelled waters, ii) Pb, Co and Ni show higher enrichment, evidenced by the association through adsorption of iron-manganese nodules onto clay minerals and iii) Cu enrichment observed close to major urban sectors, initiated by the precipitation as Cu sulfides.