Polycyclic Aromatic Hydrocarbons (PAHs) in aquatic ecosystem exposed to the 2020 Baghjan oil spill in upper Assam, India: Short-term toxicity and ecological risk assessment.

This study focuses on the short-term contamination and associated risks arising from the release of Polycyclic Aromatic Hydrocarbons (PAHs) due to the 2020 Baghjan oil blowout in upper Assam, India. Shortly after the Baghjan oil blowout, samples were collected from water, sediment, and fish species and examined for PAHs contents. The results of the analysis revealed ΣPAHs concentrations ranged between 0.21-691.31 µg L-1 (water); 37.6-395.8 µg Kg-1 (sediment); 104.3-7829.6 µg Kg-1 (fish). The prevalence of 3-4 ring low molecular weight PAHs compounds in water (87.17%), sediment (100%), and fish samples (93.17%) validate the petrogenic source of origin (oil spill). The geographic vicinity of the oil blowout is rich in wildlife; thus, leading to a significant mass mortality of several eco-sensitive species like fish, plants, microbes, reptiles, amphibians, birds and mammals including the Gangetic River dolphin. The initial ecological risk assessment suggested moderate to high-risk values (RQ >1) of majority PAHs concerning fish, daphnia, and algae species. This study highlights the need for recognizing the potential for short-term exposure to local species. To safeguard local ecosystems from potential future environmental disasters, it is imperative for the government to adopt a precautionary strategy.

Pingers are effective in reducing net entanglement of river dolphins.

Ganges River dolphins echolocate, but this mechanism is inadequate for poor sonar-echoing objects such as the monofilament gillnets, causing considerable net entanglement related mortalities. Net entanglement related deaths are one of the major causes of cetacean population decline around the world. Experiments were carried out to understand the use of pingers-an acoustic deterrent, in aiding the deterrence of dolphins from fishing nets. Based on the dolphin clicks recorded, in an experimental setup spanning 36 days, a 90% deterrence was found; 22.87 ± 0.71 SE dolphin detection positive minutes per hour near non-pingered nets versus 2.20 ± 0.33 SE per hour near pingered net. Within 30 m radii of nets, visual encounters of non-calf reduced by 52% and calf by 9%, in the presence of pingers. No evidence of habituation to pingers, habitat avoidance in dolphins after pinger removal or a change in fish catch in nets because of pingers was found during the study. While the effectiveness of pingers on calves and fish catch needs further experimentation, the use of pingers to minimize net entanglement mortalities in the Ganges River dolphins seems to be the most promising solution currently available. These results have critical implications for the conservation of other species of river dolphins around the world.

rbcL, a potential candidate DNA barcode loci for aconites: conservation of himalayan aconites.

BACKGROUND: Aconitum heterophyllum Wall. ex Royle and Aconitum balfourii Stapf, are two highly important, threatened medicinal plants of the Indian Himalayan Region. Root-tubers of Aconites have occupied an important place in Indian pharmacopoeia from very ancient times. India is a hub of the wild-collected medicinal herbs industry in Asia and these two aconites are known to have been heavily traded from the region in illicit manner. Prosecution of these illegal trading crimes is hampered by lack of pharma-forensic expertise and tools. METHODS AND RESULTS: Present study was conducted to evaluate the discriminatory potential of rbcL, a Chloroplast based DNA barcode marker for the authentication of these two Himalayan Aconites. Fresh plant samples were collected from their natural distributional range as well as raw materials were procured from herbal market and a total of 32 sequences were generated for the rbcL region. Analysis demonstrated that rbcL region can successfully be used for authentication and importantly, both the aconites, were successfully discriminated by rbcL locus with high bootstrap support (> 50%). CONCLUSION: Molecular markers could certainly be relied upon morphological and chemical markers being tissue specific, having a higher discriminatory power and not age dependent. Phylogenetic analysis using Maximum Likelihood Method revealed that the rbcL gene could successfully discriminate Himalayan Aconites to species level and have potential to be used in pharma-forensic applications as well as to curb illicit trade of these invaluable medicinal plants.

Chloroplast-based DNA barcode analysis indicates high discriminatory potential of matK locus in Himalayan temperate bamboos.

The study was conducted to evaluate the discriminatory potential of selected chloroplast-based DNA barcode regions for identifying and resolving phylogeny of the Indian bamboos. Among 11 chloroplast markers screened, only four, namely matK, rbcL, psbK-I and rps16-trnQ showed successful amplification in 88 genotypes of 30 Indian bamboo taxa under Bambuseae and Arundinarieae tribes. A total of 244 sequences were generated for the four chloroplast regions. Tree-based analysis demonstrated that none of the tested regions successfully discriminated the taxa under Bambuseae tribe. Importantly, our highly concerned Himalayan temperate bamboo species under Arundinarieae tribe, were successfully discriminated by matK locus with high bootstrap support (>60%). Sequence comparisons revealed that the discriminatory power demonstrated by matK region actually lies in the few unique fixed nucleotides (UFNs) despite the overall DNA polymorphism. Although, rps16-trnQ region was found to be the most polymorphic and revealed high genetic divergence among different taxonomic levels, it could not successfully discriminated the taxa with strong statistical support. In a taxonomically difficult plant group like bamboos, whose genome is relatively more complex and has a slow rate of molecular evolution, it is difficult to get a universal marker. Further, highly variable barcode regions utilized in other species may not be informative, and thus, the development of DNA barcodes for different taxonomic levels, such as lineages or tribes could be a viable approach.