Indian Council of Agricultural Research
CENTRAL MARINE FISHERIES RESEARCH INSTITUTE
CENTRAL MARINE FISHERIES RESEARCH INSTITUTE
India’s National Policy on Marine Fisheries (2017) has stressed on the need for seaward expansion of fishing to harness the potential of the deep sea and oceanic waters, given that the fishery resources from the near-shore waters are almost fully utilized. Against this backdrop, this paper undertakes a socio-economic analysis of offshore fishing being carried out by the artisanal fishing community based at Thoothoor on the Southwest coast of India. This is juxtaposed with an overview of India’s offshore and deep sea resource potential as well as the policy and infrastructural context. The findings points to the need for strengthening small-scale fishers’ capacity in exploring the offshore areas of the country with due regard to safety and sustainability concerns.
Chennai Fishing Harbour, Southeast coast of India. The trawl bycatch consists of 45,527 ichthyofauna individuals collected fortnightly during the period June 2018 to April 2019. The recorded ichthyofaunal diversity includes 156 species belonging to 2 classes, 14 orders, 66 families, and 119 genera. The order Perciformes dominantes with 74 species (47%) followed by Scorpaeniformes (12%; 19 species) and Tetraodontiformes (11%; 18 species). Temporal diversity analysis revealed that the maximum species diversity was observed during the North-east monsoon (123 species) while the minimum was observed during the post-monsoon (107 species) period.
Studies on the quantum of non-edible biota (NEB) discarded during the trawl fishing operations hardly exist in literature. The limited availability of baseline data on this specific area of research has resulted in an inadequate assessment of the ecological implications of plant and animal species caught and discarded during trawl operation. In this context, an attempt was made to document the marine faunal diversity and biomass of NEB destroyed and discarded by trawl operations along the Thoothukudi coast, Gulf of Mannar Marine Biosphere Reserve (GoMMBR), India.
Impact of microplastic pollution on the marine environment and its biota is a major concern globally. Gulf of Mannar (GoM) and Palk Bay (PB) are two important biodiversity hotspots along the south-east coast of India. However, in the recent years the intense tourism and fishery activities have made the ecosystem and biota of these two ecologically significant coastal zones vulnerable to microplastic contamination. Hence, a comparative study on the seasonal distribution of microplastics in the surface waters, sediments, and in commercially important fishes were conducted to evaluate the threats imposed by microplastics on the environment and biota of both these coastal ecosystems. Microplastic distribution in the surface waters and sediments of GoM and PB exhibited conspicuous seasonal variation and showed positive correlation with the seasonal current patterns. In the surface waters of GoM, microplastics were abundant during the South West Monsoon whereas in PB it was high during the Early Winter Monsoon period. In the sediments of PB, microplastics was more during Spring Inter-monsoonand South West Monsoon whereas in GoM it was high during Late Winter Monsoon. Fragments, of size 1 to 5 mm formed the abundant microplastic type in the surface waters whereas in the sediments, fragments of size < 1 mm dominated. Of the gut content of the 613 fishes belonging to 12 families examined, microplastics were more in pelagic than demersal fishes with higher incidences in the family Clupeidae (42%). Among the fishes studied, microplastic ingestion was more in Selaroides leptolepis (27.77%), Sphyraena sp. (14.28%), Pelates quadrilineatus (12%), Caranx sp. (10.34%), and Sphyraena barracuda (10%).
New dolabellanes {6-methoxy-dolabella-8(17),12-diene-10?,18-diol (1), 3-methoxy-dolabella-12(18)-ene-4?-ol (2), 3-methoxy-dolabella-10,18(19)-diene-5?,8?-diol (3)} and dolastanes {2,7-dimethoxy-14?-hydroxy-dolasta-1(15),9-diene (4) and 4,7-dimethoxy-9?,14?-dihydroxy-dolasta-1-ene (5)} were identified from brown seaweed Padina tetrastromatica (family Dictyotaceae), collected from the southeast coast of India. Compounds 1–3 were found to possess dolabellane skeleton with [9.3.0] cyclotetradecane framework whereas, 4–5 were composed of tricyclic diterpenes with linear arrangement of six-seven-five fused alicyclic rings. Compounds 3 and 5 registered greater antioxidative activities (IC50 ?0.63?mg/mL) than other analogues (IC50 ?0.65?mg/mL), whereas their attenuating potentials against carbolytics ?-amylase and ?-glucosidase (IC50 ?0.12–0.14?mg/mL) were comparable with those displayed by acarbose (IC50 0.14-0.12?mg/mL). Bioactive potentials of titled compounds were assessed by electronic and lipophilic parameters. The lesser binding energies of 3 (?9.71?kcal/mol) and 5 (?8.59?kcal/mol) through molecular docking demonstrated their effective hydrogen bonding interactions with ?-amylase. Thus, dolabellanes and dolastanes might be used as anti-diabetic and antioxidant leads to reduce the risk of hyperglycaemia.
Mangrove sediment-associated bacteria are of significantly important in the field of medicine and pharmaceuticals as new promising sources of biologically active pharmacophores due to the extreme conditions, such as high salt concentration and soil anoxia. The sediment bacteria associated with Acanthus ilicifolius and Avicennia officinalis collected from the Mangalavanam mangrove ecosystem of the Kerala State of India were evaluated using various in vitro models for the assessment of their pharmacological properties. The bacteria exhibiting significant antioxidant and antimicrobial activities were isolated, identified, and characterized by the integrated microbiological, biochemical, and 16S rRNA sequencing. Among the varied bacteria isolated from mangrove sediments, Bacillus amyloliquefaciens MBMS5 (GenBank accession number MK765025) exhibited significant antimicrobial activities against various pathogenic bacteria, such as Aeromonas caviae, Vibrio parahemolyticus, and methicillin-resistant Staphylococcus aureus. The extracellular extracts of B. amyloliquefaciens MBMS5 exhibited potential antioxidant activity against free radical species coupled with anti-inflammatory property as displayed by the attenuation activity against pro-inflammatory 5-lipoxygenase.
