Trophic transfer and their impact of microplastics on estuarine food chain model.

Microplastic contamination in marine ecosystems, and its negative effects through trophic transfer among marine organisms, remains a growing concern. Our study investigates the trophic transfer and individual impacts of polystyrene microplastics (MPs) in an estuarine food chain model, comprising Artemia salina as primary organism, Litopenaeus vanamei as secondary organism, and Oreochromis niloticus as tertiary organism. A. salina were exposed to 1 µm polystyrene microplastics (106 particles/ml), further it was fed to L.vannamei, which, in turn, were fed to O.niloticus. MPs transfer was studied over 24 and 48 h. Fluorescence microscopy confirmed MPs presence in the gut and fecal matter of all the test organisms. Histopathology revealed MPs in the gut epithelium, but did not translocate to other tissues of the test species. MPs exposed A.salina had a bioconcentration factor of 0.0029 ± 0.0008 (24 h) and 0.0000941 ± 0.0000721 (48 h). Whereas, the bioaccumulation factor values for L. vanamei were 0.00012143 ± 0.000009 (24 h) and 0.0025899 ± 0.0024101 (48 h), and for O.niloticus were 0.154992 ± 0.007695 (24 h) and 0.00972577 ± 0.00589923 (48 h). Despite low MPs transfer among trophic levels, the induced stress was evident through biochemical responses in all the test species. This implies the potential risk of MPs ultimately reaching humans via the food chain.

Bioremediation by oil degrading marine bacteria: An overview of supplements and pathways in key processes.

Oil spillage is one of the most common pollutants which brings greater economic loss and damage to the environment. The intensity and amount of the damage may vary depending on factors such as the type of oil, the location of the spill, and the climatic parameters in the area. As for any pollution management, the guidelines are Reduce, Re-use, Recover and Disposal. Amongst the other remediation processes, Bioremediation is amongst the most significant environmentally friendly and cost-effective approaches for marine biological restoration because it allows complex petroleum hydrocarbons in spilt oil to decompose completely into harmless compounds. Mainly, the necessity and essence of bioremediation were talked about. This review discussed the bacteria identified which are capable of degrading various oil related pollutants and their components. Also, it covered the various media components used for screening and growing the oil degrading bacteria and the pathways that are associated with oil degradation. This article also reviewed the recent research carried out related to the oil degrading bacteria.

Risk assessment of potential toxicity induced by bio and synthetic plastic microspheres in Lates calcarifer.

Plastic pollution is a serious issue in the aquatic environments. This concerning issue of negative impacts of synthetic plastic debris particles in the aquatic ecosystem give rise to the bioplastic materials. These bioplastics are synthesized from biological organisms, retaining same structural and functional ability as synthetic plastics. However, their degradability and toxicity in natural environment is still unknown. So, in this study we have focused on to elucidate the toxicity caused by Bacillus subtilis synthesized biopolymer - polyhydroxybutyrate (PHB) microspheres and compare their effects with synthetic plastic. The effect of Synthetic plastic (Polystyrene microspheres) and bioplastic (PHB microspheres) were studied on acute exposure to in-vitro and in-vivo model of Lates calcarifer. PHB microspheres were characterized and confirmed using Flurospectrophotometer, Fourier-Transform infrared spectroscopy (FTIR), Particle size analyzer (PSA), Zeta potential and Scanning electron Microscope (SEM). Histopathology assessment for in-vivo model and MTT assay for in-vitro model were performed. The results of fish exposed to 0.5 µg/ml and 1 µg/ml of both microspheres have shown significant necrosis and alteration in muscle, gill and heart tissues. The increased cytotoxicity observed in spleen cell line of Lates calcarifer on exposure to 0.5 µg and 1 µg of both microspheres. Bioplastics are needs specific times for degradation into the aquatic environment. In these results suggest, that even bioplastic have the risk of inducing toxicity similar to the synthetic plastic.