Charybdis lucifera, a seafood delicacy in many parts of the world, are discarded from commercial fishery operations of Karnataka coast (India), since it is not used for consumption in the region. Globally, in light of reports on overfishing and reduction in fishery, reducing the fishing pressure on many conventional species are becoming a priority. To meet the probable reduction in availability of seafood, due to the regulations on the fishery of conventional species, there is need to bring in more non-conventional species to commercial status.
The tropical cyclone Ockhi which hit the Kerala and Tamil Nadu coasts of the Indian subcontinent in December 2017, was an unusual cyclone, with its rapid intensification and unpredictable path. An analysis of the impact of Ockhi on the losses in man-days, catch, and revenue indicated that in Kerala and Tamil Nadu, the estimated revenue losses due to the loss in fishing days were $15.17 and 1.85 million, respectively.
An isochroman derived polyketide, salmachroman characterized as methyl 153 (11-(10-hydroxy-12-oxo-6-pent-63 -en-61 -yl)isochroman-10-yl)-13-oxotetrahydrofuran-15-yl was isolated from the organic extract of the Echinodermata sea urchin Salmacis bicolor (family Temnopleuridae) through chromatographic fractionation. The structure of the compound was identified by detailed spectroscopic techniques. Salmachroman demonstrated significant duel inhibition potential against pro-inflammatory enzymes, cyclooxygense-2 (IC50 1.29 mM) and 5-lipoxygenase (IC50 1.39 mM). The compound exhibited significantly greater anti-inflammatory selectivity index (1.03) than that displayed by the anti-inflammatory agent ibuprofen (0.43). The isochroman analogue exhibited greater antioxidant activities against 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (IC50 1.19 mM) and 2,2-diphenyl-1-picrylhydrazyl (IC50 1.24 mM) than the standard antioxidative agent a-tocopherol (IC50 > 1.50 mM). The binding properties of the compound with the active site of cyclooxygense-2 and 5-lipoxygenase enzymes, combined with its higher electronic parameters as attributed by the structure-activity relationship accounted for its significant anti-inflammatory properties.
Taking advantage of published data on life-history traits and short-term information on fishery parameters from 3132 records for 644 fish stocks along the coast of India, we calculated resilience (R) and vulnerability (V). Further, we developed an Index of Resilience and Vulnerability (IRV) for 133 species of tropical finfishes, crustaceans, and molluscs. Using 7 resilience and 6 vulnerability attributes, two-dimensional scatter plots of the resilience and vulnerability scores were generated and the Euclidean distance and angle from the origin to each point were calculated to determine IRV and the effect of fishing on fish species. By ranking the species, the top 10 highly resilient, highly vulnerable, and high-risk species (low IRV) were identified. While small-sized species with fast growth rate and low trophic level were among the highly resilient species, large predatory species such as sharks and barracudas were among the highly vulnerable and high-risk species. More than 100 of the 133 species were resilient-yet-vulnerable, and most crustaceans showed high resilience. Differences in IRV scores among species within the same family were discernible, indicating the differences in the biological characteristics and response to fishing. Sensitivity analysis indicated that an abridged IRV with 6 attributes works similar to 13 attributes and can be used in data-deficient situations. Comparison of R and V of IRV with other assessments showed different results because of divergences in the objectives, number and types of attributes, and thresholds used. These assessments do not convey the same information and therefore great care must be taken for reproducing these frameworks to other fisheries. The results of IRV analysis can be useful for stock assessments and in developing effective management measures in combination with other complementary information.
A biomass dynamics modelling study to derive biological reference points and management requirements of 223 commercially important fish stocks in different maritime states of India was conducted. Two decades (1997–2016) of fishery-related data on the harvest of resources by different types of fishing fleets formed the input. The multigear nature of the fishery situation was solved by introducing a gear standardization parameter into the biomass dynamics model. The relative positions of the fish stocks were depicted through Kobe plots generated for the ten maritime states/union territory, and the fish stocks were categorized, based on the status, into sustainable, overfished, recovering, and overfishing. The results indicate that 34.1% of the assessed fish stocks in the country are sustainable, 36.3% are overfished, 26.5% are recovering, and 3.1% are in the overfishing status. Regionally, the percentage of sustainable fish stocks were high along the southwest coast (51.6%), overfished stocks were high along the northwest coast (54.2%), and recovering fish stocks were high along the northeast coast (47.8%). The national mean B/BMSY was estimated as 0.86, which is a strong reason for strengthening fisheries management. Fishing fleets harvesting overfished stocks were examined for each maritime state, and recommendations regarding reduction in annual fishing hours are made.
Angiotensin-I converting enzyme catalyses the rate-determined step of the conversion of angiotensin-I to angiotensin-II that narrows the blood vessels, and angiotensin-I converting enzyme inhibitors were recognised as important medications for hypertension-related diseases. Chemical investigation of angiotensin-I converting enzyme inhibitors from marine demospongiae Clathria (Thalysias) vulpina (family Microcionidae), resulted in a previously undescribed 22-membered macrocyclic lactone derivative, named as clathriolide. The studied compound showed potential angiotensin converting enzyme attenuation property (IC50 0.41 mM), which was comparable with the standard captopril (IC50 0.36 mM). Clathriolide revealed significantly greater antioxidant potentials against free radical species (IC50 < 1 mM) in comparison with the standard a-tocopherol (IC50 > 1.5 mM). Superior electronic characteristics (topological polar surface area > 100) coupled with relatively smaller binding energy and docking score of clathriolide with the aminoacyl residues of angiotensin-I converting enzyme (–11.5 and –12.2 kcal/mol, respectively) described its potential inhibitory property against angiotensin-I converting enzyme.