2012

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Browsing 2012 by Author "Boopendranath, M.R."

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    Bycatch Characterization of Shrimp Trawl Landings off Southwest Coast of India
    (Society of Fisheries Technologists (India), Cochin, 2012) Gibinkumar, T.R.; Sabu, S.; Pravin, P.; Boopendranath, M.R.
    Bycatch and discards are common and pernicious problems faced by all fisheries globally. It is recognized as unavoidable in any kind of fishing but the quantity varies according to the gear operated. In tropical countries like India, bycatch issue is more complex due to the multi-species and multi-gear nature of the fisheries. Among the different fishing gears, trawling accounts for a higher rate of bycatch, due to comparatively low selectivity of the gear. A study was conducted during 2004 to 2006 using shrimp trawl in the traditional trawling grounds off Cochin in the southwest coast of India to reveal the quality, quantity and monthly variations of bycatch generated by trawlers. Mean monthly bycatch generated by shrimp trawling off Cochin ranged from 1.14 to 38.64 kg h-1, in different months with an overall average of 12.85±1.97 (SE, n=12) kg h-1. Shrimpbycatch ratio ranged from 1:0.6 to 1:6908, during different months. The study identified 281 species including juveniles of commercially important fishes and shellfishes from the shrimp trawl bycatch.
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    Energy Analysis of the Ring Seine Operations, off Cochin, Kerala
    (Society of Fisheries Technologists (India), Cochin, 2012) Boopendranath, M.R.; Hameed, M.S.
    Ring seines are lightly constructed purse seines adapted for operation in the traditional sector. Fish production and energy requirement in the ring seine operations, off Cochin, Kerala, India are discussed in this paper, based on data collected during 1997- 1998. The results reflect the Gross Energy Requirement (GER) situation that existed during 1997-1998. Mean catch per ring seiner per year worked out to be 211.9 t of which sardines (Sardinella spp.) constituted 44.3%, followed by Indian mackerel (Rastrelliger kanagurta) 29.7%, carangids 11.4%, penaeid prawns 2.2%, pomfrets 1.1% and miscellaneous fish 11.3%. Total energy inputs into the ring seine operations were estimated to be 1300.8 GJ. Output by way of fish production was determined to be 931.85 GJ. GER is the sum of all non-renewable energy resources consumed in making available a product or service and is a measure of intensity of non-renewable resource use. GER per tonne of fish landed by ring seiners was estimated to be 6.14. Among the operational inputs, kerosene constituted 73.4% of the GER, followed by petrol (12.7%), diesel (6.7%) and lubricating oil (2.4%). Fishing gear contributed 3.8%, engine 0.8% and fishing craft 0.3% of the GER. Energy ratio for ring seining was 0.72 and energy intensity 1.40.
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    Trawl codend selectivity in respect of silver pomfret pampus argenteus (Euphrasen, 1788)
    (Society of Fisheries Technologists (India), Cochin, 2012) Boopendranath, M.R.; Pravin, P.; Remesan, M.P.; Thomas, S.N.; Edwin, L.
    The silver pomfret Pampus argenteus (Euphrasen, 1788) belonging to the family Stromateidae is an important resource exploited by trawlers in India and is one of the most sought after marine food fish worldwide. Information on trawl selectivity is required in biological investigations, fish stock assessment, fisheries management and fishing gear design and development. The size selectivity for this species in 100 mm diamond mesh codend was estimated using covered codend method and the selectivity parameters were estimated using the software CC 2000 (ConStat, Denmark). The L50, selection range and selection factor were determined as 144.8 mm, 27.3 mm and 1.45 respectively. The optimum mesh size estimated based on the highest reported value of length at first maturity for silver pomfret in Indian waters and the selection factor determined through trawl selectivity experiments was 150 mm, for conventional diamond mesh codends.
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    Waste minimisation in fishing operations
    (Society of Fisheries Technologists (India), Cochin, 2012) Boopendranath, M.R.
    Sources of wastes in fishing operations mainly include bycatch discards; processing wastes where catch is processed onboard; plastic wastes due to abandoned, lost and discarded fishing gear; bilges and other wastes from the vessel operations. Fishing systems in general have an associated catch of nontargeted organisms known as bycatch. Non-selective fishing gear that is not modified or equipped to exclude non-targeted organisms, may take a significant quantity of bycatch of non-targeted finfish, juvenile fish, benthic animals, marine mammals, marine birds and vulnerable or endangered species that are often discarded. Average annual global discards, has been estimated to be 7.3 million t, based on a weighted discard rate of 8%, during 1992-2001 period. Trawl fisheries for shrimp and demersal finfish account for over 50% of the total estimated global discards. Plastic materials are extensively used in fisheries, owing to their durability and other desirable properties, contributing to the efficiency and catchability of the fishing gear. However, plastics biodegrade at an extremely slow rate compared to other organic materials. Abandoned, lost or otherwise discarded fishing gear (ALDFG) and related marine debris have been recognized as a critical problem in the marine environment and for living marine resources. Prevention of excess fishing capacity by appropriate management measures could lead to enormous savings in terms of fuel consumption, emissions and bycatch discards from the excess fishing fleet, capital and operational investments and labour deployment in capture fisheries, with significant economic gains. In this paper, wastes originating from fishing operations are reviewed, along with their environmental impacts and possible mitigation measures.