Bioaccumulation and health risk of metal contamination from different tiers of food chain in Ennore estuary, Southeast coast of India.

The concentration and bioaccumulation of heavy metals were investigated in four distinct components (water, sediment, benthic organisms, and fish) in the Ennore estuary. The average concentration of studied metals in water is 2-5 times higher in the sediment. The geoaccumulation index in the sediment, particularly for Cd, 55 folds greater than WHO and USEPS standards. The indices like MI, Cdeg, PLI, and PERI demonstrated low contamination levels, whereas Igeo and Cf revealed elevated levels of cadmium (Cd), signifying a moderate degree of contamination. Human health indices like Target Hazard Quotation (THQ) values generally fell within permissible limits (<1), except for lead (Pb) and iron (Fe). However, HI values exceeded 1, indicating a non-carcinogenic health risk for consumers. The Target Risk for lead (TRPb) value for Oreochromis urolepis was 1.0 × 10-5, suggesting a significant cancer risk and may leads to other fish species in future if carcinogenic metals bioaccumulation.

Assessment of metal contaminants along the Bay of Bengal - Multivariate pollution indices.

The spatial concentration of heavy metals (Mn, Ni, Cu, Co, Zn, Cd, and Pb) was studied in coastal areas (n = 9) including water (n = 27) and sediment (n = 27) in the Palk Bay, India to understand the metal pollution due to prevailing natural and anthropogenic activities. Pollution indices like metal index (MI), geoaccumulation index (Igeo), contamination factor (CF), pollution load index (PLI) and potential ecological risk (PER) were calculated based on the background/reference value. The values of MI index indicated that water was free of metals, whereas Igeo, CF, PLI and PER indicated moderate contamination of sediment in monsoon. Cadmium concentrations were the highest irrespective of the indices (Igeo: 0.04-1.42, Cf: 0.36-0.74, PLI: 0.36-0.74, and PER: 76.89-143.36) indicating moderate pollution. The Principal Component Analysis (PCA) affirmed that Cd was positively correlated with stations indicating anthropogenic sources of Cd contamination.

Adsorption isotherm, kinetics and response surface methodology optimization of cadmium (Cd) removal from aqueous solution by chitosan biopolymers from cephalopod waste.

The present investigation was aimed to explore the cadmium removal efficiency, mechanism and characterization of Chitosan biopolymers from cephalopods waste. The extracted chitosan has showed good yield of 32% and with high minerals, ash and moisture content. In the Fourier-transform infrared spectroscopy (FT-IR) analysis multiple active functional groups of Amine, Amine, Hydroxyl were found between 612 and 3424 cm-1 and the sugar signals such as N-acetyl glucosamine (GlcNAc) and H-1 [GlcN (H-1D), GlcNAc (H-1A)] were identified in Chitosan by 1H Nuclear Magnetic Resonance (NMR). The Crystalline, rough surface, micropores characters were observed in Chitosan surface by Scanning Electron Microscope (SEM) analysis and the pores played a key role in adsorption process. The Cd ions removal was performed by batch experiment and the results were revealed that the pH, temperature, time and dosage highly influenced the process and the optimum condition was discovered through RSM for pH 7, temperature 42.5 °C, time 220 min and dosage of sorbent 1 g/L respectively. The kinetics models of the Cd removal were carried out and the results revealed that the Pseudo-second order is more suitable and fit for removal than Pseudo-first order model. Chitosan surface characters and functional groups played a big role in adsorption process and Chitosan can be alternative eco-friendly, low cost and highly efficient sorbent for heavy metal removal in effluent treatment plants.

A preliminary investigation of marine litter pollution along Mandvi beach, Kachchh, Gujarat.

Marine debris is a global issue with adverse impacts on marine organisms, ecological processes, aesthetics, and economies of nations. Several studies have been conducted to quantify the plastic debris along Indian beaches. This baseline study describes the results of a survey conducted on the types of plastic litters and their quantification during January to March 2020 along Mandvi beach in Gujarat. A quadrate having 10 × 10 m size was used for sampling the plastic litter on the shoreline. A total of 10 quadrates along the shore was considered for quantification of the plastic materials based on their density, color, and weight. The plastic material observed includes gutkha pouches, food wrappers, and fragments, along with plastic straws, cutleries, and fragments of various dimensions and thickness. The major contributing factors for the debris abundance in Mandvi beach are land-based sources and recreational activities. The results suggest that similar long-term projects covering extensive areas should be undertaken for accurate quantification of available debris and their impacts on coastal habitats of Gujarat.

DNA barcoding of macrofauna act as a tool for assessing marine ecosystem.

Nowadays, marine ecosystem monitoring and assessment are increasingly depending on variety of molecular tools. With these background, DNA barcoding play a key role in species identification with increasing speed and accuracy, and although the suitability for developing genetic tools like genomic AMBI (gAMBI). Presently we have submitted 13 benthic polychaete species using mtCOI to GenBank. Of these, nine species were newly submitted, and hence they act as a benchmark and reference organism for identifying respective polychaete species worldwide in the near future. Based on that, our study results tend to be helpful for motivating among the researcher in order to implementing the genomic AMBI (gAMBI).

AMBI indices and multivariate approach to assess the ecological health of Vellar-Coleroon estuarine system undergoing various human activities.

Estuaries receive a considerable amount of pollutants from various sources. Presently an attempt has been made to assess whether the aquaculture discharges and dredging activities alter the ecological conditions of Vellar-Coleroon estuarine complex. The European Water Framework Directive (WFD) established a framework for the protection of marine waters. In this commission, a variety of indices were used, among them, AMBI (AZTI Marine Biotic Index) indices along with multivariate statistical approach is unique, to assess the ecological status by using macrobenthic communities. Keeping this in view, stations VE-1 and VE-4 in Vellar; CE-6 and CE-7 in Coleroon estuaries showed moderately disturbed with the AMBI values ranging between 3.45 and 3.72. The above said stations were situated near the shrimp farm discharge point and sites of dredging activities. The present study proves that various statistical and biotic indices have great potential in assessing the nature of the ecosystem undergoing various human pressures.