Peer Reviewed Journal Articles (Inter.) (FT)
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- ItemReproductive potential and stock status of the anadromous shad, Tenualosa ilisha (Hamilton, 1822): Implications for managing its declining fisheries in northern Bay of Bengal bordering India(Elsevier, 2021-03-20)The anadromous shad, Tenualosa ilisha is a fish of high economic importance in countries flanking the Bay of Bengal (BoB). Its fishery in the northern BoB bordering India and the associated Bhagirathi– Hooghly river system has been declining. Scientific explanations on the existing fishery management recommendations, especially the length at first maturity (Lm50), minimum legal size (MLS), minimum mesh size for fishing nets and stock status were limited, raising serious concerns on the sustainability of its fisheries. Through the examination of its reproductive cycle, using histological maturity identifiers, the Lm50 of males and females were redefined at 265 mm TL/ 1.0 year age and 305 mm TL/ 1.2 year age, respectively. The size-based fecundity, sex ratio and abundance revealed that females of 281–360 mm TL/ 1.0–1.6 year of age have maximum reproductive potential. In the catch, 45%– 65% of males and females were below Lm50. The temporal progression of mean length in the catch (MLC) and female length at maturity showed declining trend. Application of length-based indicators (LBI) and stock assessment models showed the fishery in near full exploitation, less optimal and undergoing multi-generation, indiscriminate, size-selective overfishing. The spawning stock biomass (SSB) has declined to 26.8% of the virgin SSB, while the yearly spawning potential ratio (SPR) ranged from 0.04 to 0.29, which is lower than the SPR threshold (0.3) suggested for sustaining a fishery. The species is both growth and recruitment overfished. Though the mean annual catch is marginally lower than the estimated maximum sustainable yield (MSY) of 32,953 t, any increase in fishing effort would further impact the SSB. Based on the results, a MLS of 360 mm TL, minimum mesh size of 110 mm for fishing gear and a precautionary annual catch limit of 30,000 t suggested for management, and the potential impact of implementing these on fishers’ catches discussed.
- ItemSeasonal Changes of the Major Fouling Organisms in Cochin Harbour(Ocean Research, 1998)Biofouling census in Cochin Harbour, the rank correlation coefficients between the members of the fouling community and their dependence on environmental perturbations are reported. The affinity/ coexistance between major taxa of foulers is examined by cluster analysis through coefficient of correlation . Maximum correlation is observed between polyzoans and tube-dwelling worms. Modiolus sp.. barnacles and oysters ranked next in their order of coexistence-. The higher fouling biomass observed is attributed to the profusion of species. their fastcr growth and attainment of sexual maturity at an early date in the tropics.
- ItemMicroplastics in the Edible and Inedible Tissues 1 of Pelagic Fishes 2 Sold for Human Consumption in Kerala, India(Elsevier, 2020)Microplastics in commercially important seafood species is an emerging area of food safety 9 concern. While there have been reports of plastic particles in the gastrointestinal tract of 10 several species, presence of microplastics in edible fish tissues has not yet been reported from 11 India. This study examined the presence of microplastics in the edible (muscle and skin) and 12 inedible (gill and viscera) tissues of nine commercially important pelagic fish species from 13 Kerala, India. A total of 163 particles consisting mainly of fragments (58%) were isolated. 14 Out of 270 fishes analysed (n = 30 per species), 41.1% of the fishes had microplastics in their nedible tissues while only 7% of fishes had microplastics in their edible tissues. The quantity of microplastics in inedible tissue was significantly larger in filter feeders than, that in visual 17 predators (p< 0.05). The average abundance of microplastics in edible tissues was 0.07 ± 0.26 items/fish (i.e., 0.005 ± 0.02 items/g) and was 0.53 ± 0.77 items/fish (i.e., 0.054 ± 0.098 items/g) in inedible tissues. The results suggest the possibility of human intake of microplastics by the consumption of pelagic fishes from this region, albeit in small quantities.
- ItemAbundance, characteristics and seasonal variation of microplastics in Indian wgite Shrimps (Fenneropenaeus indicus) from coastal water off Cochin,Kerala,India(Elsevier, 2020)The microplastic contamination of seafood species is increasingly becoming a global concern due to its potential influence on food safety and human health. This study investigated the presence and seasonal variation of microplastics in a commercially important marine shrimp species, Fenneropenaeus indicus, from the coastal waters of Cochin, India. The soft tissues of 330 shrimps were examined over a period of 12 months, from March 2018 to February 2019. A total of 128 microplastics were detected, of which 83% were fibres. An average (mean ± SD) of 0.39 ± 0.6 microplastics/shrimp (0.04 ± 0.07 microplastics /g wet weight) was obtained from the shrimps sampled. Microplastic contamination was significantly higher in July-August (Monsoon season) compared with other months. This study reports microplastic contamination in F. indicus for the first time. Results also suggest that consumption of peeled but undeveined or whole dried white shrimps can be one of the ways of the human uptake of microplastics, especially during the monsoon season.
- ItemOccurrence of Alpheus euphrozyne deman,1897 from the Southeastern Arabian Sea, India(Indian Journal of Geo Marine Sciences, 2019)The present study reports the occurrence of pistol shrimp Alpheus Euphrozyne from the South Eastern Arabian Sea. Identification of species was based on morphological and molecular examination.