No abstract

Background: Fishing activity is a major source of marine litter on beaches, but most studies focus on recreational beaches. In this study, we assessed the abundance, composition, source and spatial distribution of marine litter on ten fishing beaches along Palk Bay, on the southeast coast of India. We also used social media to collect data on the impact of fishing litter on marine animals in the study area. Results: A total of 4,227 marine litter and their average density of 0.70 items/m2 were collected. Plastic (84.54%) is the most abundant in the study area, followed by cloths (7.46%), glass (5.19%), and rubber (3.47%). From the result, the value of CCI ranges from 6.26 to 25.7 indicating that the coast is "moderately clean" to "extremely dirty". The majority of the marine litter collected originated from fishing activity. The most common are string and cord, fishing lines, fishing gear, floats and buoys. Conclusion: The presence of this type of marine litter can produce serious environmental issues, such as ghost fishing, that impacts a large variety of marine species. A total of 25 of the olive ridley turtles (Lepidochelys olivacea) were entangled in fishing litter between 2018 and 2020. Most of the reported entanglements were due to discarded or lost fishing gear, which shows the importance of managing this type of litter in India. It is important to manage the litter related to the fishing activity by educating fishermen and organizing clean-up campaigns.

Background The Thondi coast is rich in valuable natural marine resources and socio-economically significant activities like agriculture, aquaculture, and fishing. The area receives an excess of untreated solid and liquid waste as a result of these activities. The study focuses on the abundance, distribution, and status of the Clean-Coast Index (CCI) of marine debris from the Thondi coast, Palk Bay, Southeast coast of India. This is the first research work focused on assessing the type and quantity of marine debris on the Thondi coast. Results A total of 1636 marine debris items/m2 and their 4.09 concentration of the items/m2 were determined in the marine debris: plastics (77.49%), cotton swabs (8.62%), cigarette butts (10.15%), and food containers (3.73%). From the result, the CCI had ranged between 4.25 (clean) and 20.4 (extremely dirty) with a mean of 8.92 (moderate) in the Thondi coast assessed. Conclusion This study was conducted for the first time in this region. Finally, the high CCI value of 20.4 on the coast indicated that the marine debris pollution levels were high at the time of sampling in the middle part of the Thondi coast (most of the beaches are covered with plastic) due to land-based marine debris (62.45%), sea-originated marine debris (21.14%), and unknown sources (16.41%) of the items. Our findings served as a baseline for potential evaluations of the marine environment. Input prevention should be the goal of management efforts, including proper waste management, plastic recycling, and stringent penalties for illegal waste dumping.

No abstract

Crabs are economically important crustaceans as they are essential delicacies consumed worldwide and are also an excellent environmental indicator. Portunus reticulatus, the blue swimming crab, is a highly valued seafood throughout Asia. The invertebrates protect themselves from invading pathogens by the innate immune response, and lectins play an essential role in recognizing non–self‐agents. The present study was aimed at purification and bacterial agglutinating properties of lectin from the serum of P. reticulatus. Initially, the species identity was confirmed using the mitochondrial cytochrome oxidase I (mtCOI) region and accessions were submitted to the NCBI and BOLD. Then, the lectin (PrLec) was purified using a chitosan‐based affinity column chosen based on the preliminary characterization consisting of haemagglutination (HA), cross‐adsorption, carbohydrate‐binding specificity and physicochemical parameters. The PrLec showed the highest HA titre value of 64 against Human A and buffalo erythrocytes and greater affinity towards N‐acetyl‐D‐glucosamine. The divalent cations and EDTA did not alter the PrLec activity. The molecular weight of the PrLec was 126 kDa (heterodimers of 66 and 60 kDa). Bacterial agglutination activity of the PrLec was examined with Gram‐negative bacteria, Escherichia coli and Gram‐positive bacteria, Micrococcus luteus. The lectin agglutinated both the bacterial strains efficiently.