Effect of air flow on tubular solar still efficiency

BACKGROUND: An experimental work was reported to estimate the increase in distillate yield for a compound parabolic concentrator-concentric tubular solar still (CPC-CTSS). The CPC dramatically increases the heating of the saline water. A novel idea was proposed to study the characteristic features of CPC for desalination to produce a large quantity of distillate yield. A rectangular basin of dimension 2 m × 0.025 m × 0.02 m was fabricated of copper and was placed at the focus of the CPC. This basin is covered by two cylindrical glass tubes of length 2 m with two different diameters of 0.02 m and 0.03 m. The experimental study was operated with two modes: without and with air flow between inner and outer tubes. The rate of air flow was fixed throughout the experiment at 4.5 m/s. On the basis of performance results, the water collection rate was 1445 ml/day without air flow and 2020 ml/day with air flow and the efficiencies were 16.2% and 18.9%, respectively. FINDINGS: The experimental study was operated with two modes: without and with air flow between inner and outer tubes. The rate of air flow was fixed throughout the experiment at 4.5 m/s. CONCLUSIONS: On the basis of performance results, the water collection rate was 1445 ml/day without air flow and 2020 ml/day with air flow and the efficiencies were 16.2% and 18.9%, respectively

Neoplasia in oil sardine from Palk Bay

During a routine fishery survey programme at Irumeni fishing village, Palk Bay on 03rd December 2016, a single specimen of oil sardine Sardinella longiceps with neoplasia, measuring 163 mm in total length (TL) and weighing 119 gram was collected from the gillnet landings. The specimen was a female with empty stomach

NUMERICAL INVESTIGATION OF FLOWTHROUGH CONICAL DIFFUSER WITH SWIRLGENERATOR

Swirlisatangentialvelocitycomponentofthefluidflowandisoftenpresentintheconicaldiffuserasaresultofrotatingmachineryintheupstream section. The present experimental work isdedicated to study theeffectof moderate swirlonwide angle conicaldiffuser performanceandflow development. The numerical investigation were performed in ansyssoftware. Thereare two different diffusers having a cone angle ofand 21°(with area ratio 4.2) were selectedfor this investigation. The results showedthat the moderate swirl can significantly improvethe stalled diffuser(21°coneangle)performance;however,ithasalittleeffectonthediffuser(13°cone angle) havingincipient turbulent boundary layer separation. It wasconfirmed that the introduction ofmoderate swirl reduces the chances offlowseparationinwideangle conical diffusers

Histomorphology and immunohistochemistry of adenocarcinoma and fibroma in Indian oil sardine (Sardinella longiceps Valenciennes, 1847) from Palk Bay, Southeast coast of India

A single specimen of Indian oil sardine Sardinella longiceps was observed with wart-like appearances in three different regions of the fish: one on the premaxillary part, and other two on the skin and at the vent region respectively. Mucosal tissues were expunged and preserved in 10 % neutral phosphate-buffered formalin for histological examination. Based on the histopathological analysis, lesions were identified as adenocarcinoma and fibroma on the premaxillary part and skin, respectively. Based on the immunohistochemistry, vimentin and cytokeratin-like proteins were demonstrated, suggesting that the wart-like extrusions were fibroma and adenocarcinoma respectively

Integrative taxonomic approach to the systematics of the genus Pampus

In capture fisheries management, fish populations play a critical role in deciding management units employed. Projects like FishPopTrace have been employed in Europe, facilitating use of genetic data and morphological markers, including otoliths for this purpose. Multispecies, multi-gear fisheries landing closely resembling species mixes found in a common ecosystem or fishing ground is widespread in the Indian EEZ. Pomfrets are a low -volume, high value marine fishery in India and an important targeted fishery resource in the Indian Ocean region. However, the taxonomy of the genus Pampus has remained complex till date, with literature indicating several cryptic species leading to misidentification and nomenclature issues. This has serious ramifications for traceability concerns in seafood trade and supply chains as well to address sustainability concerns while preparing species specific fisheries management plans. A recent study involving an integrative taxonomic approach with conventional taxonomy tools as well as genetic data and otolith structure, has helped to clarify the taxonomic status of the genus Pampus in the Indian EEZ and the new findings with a global outlook is summarized below

Course Manual on Marine Fisheries & Mariculture Prepared for the Training programme for B.F.Sc students of Central Agricultural University (CAU), Tripura

The undergraduate Fisheries Science students are required to know about the inland and marine fisheries. The students from landlocked area are getting rare opportunity to understand the marine fisheries and mariculture activities. Hence, based on the request of the Central Agricultural University (CAU), Tripura as a part of their academic activities, the Director, ICAR-CMFRI, has kindly approved a 10 days in-plant training for B.F.Sc. final year students at the ICAR-Central Marine Fisheries Research Institute (CMFRI), Mandapam Regional Centre. The training was organized in collaboration with Agricultural Technology Information Centre (ATIC), ICAR-CMFRI, Kochi. A total of 27 B.F.Sc students and a faculty of Central Agricultural University (CAU), Tripura participated in the training programme during 17th to 26th January, 2020. The training emphasized on the skill development of students through hands on training on mariculture activities and field visits to fish landing centres. A course manual was prepared covering the major topics on marine capture fisheries and mariculture. I congratulate all those who have put in their sincere efforts to bring out this manual

Note on mass mortality of Bloch’s gizzard shad at Dhanushkodi lagoon, Tamil Nadu

Mass mortality of Bloch’s gizzard shad, Nematalosa nasus (Bloch, 1795) was observed around 5 km shore area of the lagoon from Ottathalai to Thavukadu near near the Kothandaramar Temple, Dhanushkodi, Ramanathapuram District, Tamil Nadu on 19th October 2019. An estimated 3 tonnes of Nematalosa nasus were washed ashore and water samples collected from the site were analysed indicated Dissolved oxygen (2.17ppm), pH (7.83ppm), salinity (40ppt), temperature (30.6oC), ammonia, nitrite and nitrate (0.1, 0.2 and 0.43 ppm respectively)

Fishery and stock dynamics of ribbonfish Trichiurus lepturus (Linnaeus, 1758) in the Indian Exclusive Economic Zone

The fishery and stock dynamics of Trichiurus lepturus (Linnaeus, 1758) were studied in the Indian Exclusive Economic Zone (EEZ) for the period 2014-2019. The average annual landing was 2,09,285 t and varied from 1,77,259 to 2,39,355 t. Trawl nets were the major gear, contributing more than 85% with an average annual catch rate of 4.56 kg h-1. The annual catch rate decreased over the years from 5.40 to 3.85 kg h-1. Landings (23,155-40,354 t) and catch rates (4.24-8.67 kg h-1) were highest during the post-monsoon months (September-December). Around 63% of the landings (1,32,072 t) were from the north-west coast, with Gujarat alone contributing three-fourth (98,296 t) of it, followed by the south-west coast (17%, 36,017 t), the south-east coast (12%, 25,322 t) and the north-east coast (8%, 15,875 t). The von Bertalanffy’s growth equation was Lt = 143.8 [1-e–0.48 (t + 0.03285)]. Natural mortality, Exploitation ratio and Maximum Sustainable Yield (MSY) were 0.76; 0.65 and 1,59,504 t respectively. Recruitment was substantial throughout the year with a single modal peak during June-October. With lower lengths at first capture and recruitment and with exploitation above the maximum permissible level and landings higher than MSY; the species appears to be overexploited along the Indian coasts. The present study is the first holistic report on the population parameters and stock status of T. lepturus from the Indian EEZ

Bycatch in Indian trawl fisheries and some suggestions for trawl bycatch mitigation

Globally, trawl is the major fishing gear used in marine fisheries and in India, it contributes to more than onethird of the marine fish production. Trawl fishing has been critically evaluated from a sustainability perspective, especially analysing its bycatch composition. Most of the bycatch from trawlers contains valuable edible species with high market demand. However, a portion of the bycatch which does not have such demand in the edible fish market, known as low-value bycatch (LVB), continues to be a matter of concern from an ecological and economic perspective. During 2017–19, 30–60% of trawl landing in India was constituted by LVB, which was mainly used for fishmeal preparation. To enhance the value and utility of LVB, this study explores the possibility of converting waste from LVB into edible resources using pufferfish and triggerfish. It also highlights the positive impact of efforts by different Government agencies for bycatch mitigation like the implementation of minimum legal size in reducing the juvenile component in bycatch, with a social survey-based account of fisher’s perceptions and suggestions on successful bycatch mitigation