Research Interests:
Research Interests:
Research Interests: Engineering and INFLIBNET
Research Interests:
The present study was conducted in the Dal lake of Kashmir using two types of cast net viz., polyamide (PA) multifilament stringless with fixed pockets and polyamide (PA) multifilament stringed cast net to assess the catch composition and... more
The present study was conducted in the Dal lake of Kashmir using two types of cast net viz., polyamide (PA) multifilament stringless with fixed pockets and polyamide (PA) multifilament stringed cast net to assess the catch composition and length weight distribution of fishes caught in the nets and to compare their catching efficiency in this lake. The study was based on 50 operations by each type of gear. A total of 9 species of fishes were caught in the study period. It was observed that Schizothorax labiatus (20.7%), Schizothorax niger (17.7%) and Cyprinus carpio communis (12.2%) dominated the catches. The average number and weight of fish caught was 2 and 126 g in PA multifilament stringless with fixed pockets cast net.
Research Interests:
Research Interests:
Knowledge on initial bioadhesion and composition of micro and macro nutrients within the biofilm matrix are recognised as essential for understanding the formation of biofilms. This communication highlights the heavy metal accumulation... more
Knowledge on initial bioadhesion and composition of micro and macro nutrients within the biofilm matrix are recognised as essential for understanding the formation of biofilms. This communication highlights the heavy metal accumulation pattern in biofilms, influenced by the substrate and seasons. Natural biofilms were simultaneously grown on aluminium and steel panels for 72 hours by exposing them in the aquatic environment. Accumulation of toxic and nutrient metals in biofilms on different substrates and its seasonal variation were studied. Biofilms grown within 24 hours had shown significantly (p < 0.05) higher concentrations of trace metals in both the metal substrates. Trace metals accumulated over the substrates varied in different seasons. Among the metals, the accumulation of zinc was more during all the seasons. Biofilms grown on steel, concentrated more metals than on aluminium
Research Interests:
Research Interests:
The term ‘non target’ is usually used for fish caught unintentionally in a fishery while intending to catch other fish. Bycatch is of different species and undersized individuals of the target species or juveniles (Alsayes et al., 2009).... more
The term ‘non target’ is usually used for fish caught unintentionally in a fishery while intending to catch other fish. Bycatch is of different species and undersized individuals of the target species or juveniles (Alsayes et al., 2009). These are either kept to be sold or discarded. Reduction of wastage in fisheries is a major goal of most fisheries organizations. However, there is a paucity of information available on bycatch associated with gillnet fisheries and what data is available is inconsistent in India (MRAG, 2012). More than fish and shell fish there are reports that gillnets accounted 76.5% accidental catch of turtles along the Indian coast during 1985-1995 (Rajagopal et al., 1996). Compared to trawl nets, in gillnets, the capture of non target species is lesser (Thomas et al., 2005). In India, the bycatch problem is more due to the multispecies nature of the tropical fisheries. So there is a need to assess bycatch impacts of fishery on stocks and ecosystems to identify ...
Mechanisation brings about major developments in fishing systems. Main fishing gear operated in Odisha state targeting large pelagics are drift gillnets. Odisha coast is an ecologically sensitive area having one of the four significant... more
Mechanisation brings about major developments in fishing systems. Main fishing gear operated in Odisha state targeting large pelagics are drift gillnets. Odisha coast is an ecologically sensitive area having one of the four significant arribada beaches of Olive Ridley turtle, with three mass nesting beaches. Large mesh drift gillnets are reported to be the main gear contributing to incidental catch of turtles. The gillnet fishing sector has undergone many changes during the last few decades in terms of size of craft and gear, area of operation and trip duration. This paper deals with design and general features of mechanised gillnet fishing system operated in the coastal waters of Odisha. Presently mechanised gillnetters of 8-19 m LOA with 70 to 140 hp inboard engines go for voyage fishing of up to 30 days. Drift gillnets of the states are made of Polyamide (PA) and High Density Polyethylene (HDPE) having mesh size ranging from 80-380 mm. Total fleet size of the net increased substa...
Research Interests:
The effect of preservative treatment on a secondary species of wood, Adina cordifolia (Haldu) was studied. Panels were impregnated with creosote, an oil borne preservative, and copper-chrome- arsenic (CCA), a water borne preservative,... more
The effect of preservative treatment on a secondary species of wood, Adina cordifolia (Haldu) was studied. Panels were impregnated with creosote, an oil borne preservative, and copper-chrome- arsenic (CCA), a water borne preservative, through immersion treatment. The compressive stress parallel to grain of panels at various preservative retention levels was assessed to find out the change in mechanical strength. An average reduction of 14% compressive stress was noticed in CCA treated haldu panels and slight increase of 2 - 6% was observed in creosote treated panels.
Research Interests:
Length frequency of sardine, Sardinella longiceps (Valenciennes), caught in gill nets with mesh size of 32, 34, 36, 38 and 40 mm operated off Cochin (Kerala) was recorded. Using this, the selectivity parameters of the nets of these mesh... more
Length frequency of sardine, Sardinella longiceps (Valenciennes), caught in gill nets with mesh size of 32, 34, 36, 38 and 40 mm operated off Cochin (Kerala) was recorded. Using this, the selectivity parameters of the nets of these mesh sizes were assessed. The size range of S. longiceps caught was 12 to 20 cm. The estimated selection factors ranged from 4.56 to 4.67 and the selection lengths ranged from 14.7 to 18.7 cm. Gill nets with mesh size less than 34 mm did not facilitate the escapement of S. longiceps which had not attained the stage of first maturity.
Research Interests:
ABSTRACT
Research Interests:
The torpedo scad, Megalaspis cordyla (Linnaeus, 1758) is a moderately large marine fish belonging to family Carangidae. The largest recorded individual is 80 cm long (TL). The torpedo scad is distributed throughout the tropical and... more
The torpedo scad, Megalaspis cordyla (Linnaeus, 1758) is a moderately large marine fish belonging to family Carangidae. The largest recorded individual is 80 cm long (TL). The torpedo scad is distributed throughout the tropical and subtropical waters of the Indian and west Pacific Oceans. Results of selectivity studies in respect of torpedo scad using covered codend method carried out with a 18 m semi-pelagic trawl, fitted with 65 mm diamond mesh codend and 30 mm mesh codend cover, off Cochin, India, are presented in this research note. According to the selectivity studies, the L25, L50 and L75 values for torpedo scad were 231, 294 and 357 mm respectively. Based on size at first maturity (Lm) of torpedo scad reported as 250 mm (TL; unsexed), the codend mesh size that can be recommended to harvest the mature torpedo scad is estimated as 55 mm, for conventional diamond mesh codends.
Research Interests:
Corrosion of fishing hooks is a major problem faced by hook and line fishing industry. This communication presents the results of a study taken up to asses the corrosion resistance of round bent, flatted hook no. 7 with two different... more
Corrosion of fishing hooks is a major problem faced by hook and line fishing industry. This communication presents the results of a study taken up to asses the corrosion resistance of round bent, flatted hook no. 7 with two different surface coatings; viz., tinned and blued. The hooks were exposed to 300 h of salt spray as per ASTM B117. The tinned hooks exhibited excellent performance in salt spray exposure in comparison to the blued fishing hooks. The exposure of the hooks to salt spray resulted in an appreciable weight loss viz., the tinned hooks incurred a loss of 5.37% from the initial weight while the blued hooks lost 20.54% of weight. The corrosion rate of the tinned and blued hooks were found to be 26.934 mpy (mills per year) and 106.298 mpy respectively.
Research Interests:
ABSTRACT 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... more
ABSTRACT 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.
Research Interests:
Research Interests:
Gill nets are one of the predominantly used fishing gears of Assam in the rivers and flood plain wet lands ( beels ). Results of a study on the gill nets of Assam undertaken during 2004-2006 are reported in this paper. Gill nets of... more
Gill nets are one of the predominantly used fishing gears of Assam in the rivers and flood plain wet lands ( beels ). Results of a study on the gill nets of Assam undertaken during 2004-2006 are reported in this paper. Gill nets of different mesh sizes ranging from 20 to 320 mm targeted at different groups of fishes are prevalent in Assam. The technical specifications, salient features and operational aspects of different gill nets are discussed. The nets are classified into groups based on the mode of operation, species of fish caught and materials used for construction. Synthetic materials like polyamide has almost completely replaced the natural fibres in gill nets and polyamide monofilament yarn of 0.16 to 0.20 mm dia are being widely used in the state.
Research Interests:
Corrosion of fishing hooks is a major problem faced by hook and line fishing industry. This communication presents the results of a study taken up to assess the corrosion resistance of round bent, flatted hook no. 7 with two different... more
Corrosion of fishing hooks is a major problem faced by hook and line fishing industry. This communication presents the results of a study taken up to assess the corrosion resistance of round bent, flatted hook no. 7 with two different surface coatings; viz., tinned and blued. The hooks were exposed to 300 h of salt spray as per ASTM B 117. The tinned hooks exhibited excellent performance in salt spray exposure in comparison to the blued fishing hooks. The exposure of the hooks to salt spray resulted in an appreciable weight loss viz., the tinned hooks incurred a loss of 5.37% from the initial weight while the blued hooks lost 20.54% of w eight. The corrosion rates of the tinned and blued hooks were found to be 26.934 mpy (mills per year) and 106.298 mpy respectively.
Research Interests:
Based on the level of technology adopted and species targeted, four sub-sectorswere identified within the gill net sector viz., non motorised small mesh,motorised small mesh, motorized large mesh and mechanised large mesh sectors.The... more
Based on the level of technology adopted and species targeted, four sub-sectorswere identified within the gill net sector viz., non motorised small mesh,motorised small mesh, motorized large mesh and mechanised large mesh sectors.The technical and economic efficiency of operation of these four sub-sectors wereanalyzed. The technical efficiency with reference to fishing effort and productivityindicated that there is a direct relationship in terms of fishing effort with thelevel of technology but no such direct relationship was observed in terms ofproductivity.IntroductionBetter technologies obviously have abetter access to fishery resources; butthese generally involve higher cost. Thetechno-economic efficiency of differentfishing systems is an important factor inthe allocation of scarce resources such ascapital. The sustainable development offishing through the co-existence ofdifferent sectors needs basic informationon their comparative efficiency. Thecomparative technical and econo...
Research Interests:
Hooking rate, hooking location and severity of wound were assessed during 163 experimental handline operation, targeted for fishes like tilapia, pearlspot and snapper. Two barbed hook types viz., circle hook (non-offset size 9/0) and... more
Hooking rate, hooking location and severity of wound were assessed during 163 experimental handline operation, targeted for fishes like tilapia, pearlspot and snapper. Two barbed hook types viz., circle hook (non-offset size 9/0) and J-hook (0° offset size 6) were deployed in an alternative fashion using natural dead baits viz., oil sardine and chicken waste. Circle hook had significantly lower (p<0.05) hooking rate than J-hook. Type of hook affected hooking location as 78% of the fish caught by circle hook were lip hooked, 22% deep hooked and there was no foul hooking. With J-hook, 50% fishes were lip hooked, 43% deep hooked and 7% foul hooked. The difference in severity of wounds in the two types of hooks was statistically significant (p<0.05). In fishes caught by circle hooks, 67% had minor injuries, 22% had moderate injuries and 11% suffered severe injuries. In contrast, 43% fishes caught by J-hook had severe injuries, 36% moderate injuries and 21% had minor injuries. Resu...
Research Interests:
The wood from the rubber tree ( Hevea brasiliensis ) comes as a by-product from the commercial plantations. The highly perishable nature of the wood makes it unsuitable for use such as boat building without chemical preservative... more
The wood from the rubber tree ( Hevea brasiliensis ) comes as a by-product from the commercial plantations. The highly perishable nature of the wood makes it unsuitable for use such as boat building without chemical preservative treatment. This communication deals with the chemical preservative treatment of rubber wood with copper- chrome- arsenic (CCA), a water borne preservative and creosote an oil borne preservative through immersion in an open tank for the purpose of fishing canoe construction. The fabrication of the canoes was as per the method of construction of plank built canoes. Two canoes were made, one for use in brackish water and the other for use in the sea. The cost of construction was found to be lower than that of the conventional canoe. The performance monitoring shows that the canoes are free from physical damage and deterioration caused due to weathering and biological agencies.
Research Interests:
The results of experimental and pre-commercial fishing operations conducted at Agatti Island during 2003-2006 with large mesh high density polyethylene (HDPE) and polyamide (PA) drift gill nets are presented in the paper. Gill nets can be... more
The results of experimental and pre-commercial fishing operations conducted at Agatti Island during 2003-2006 with large mesh high density polyethylene (HDPE) and polyamide (PA) drift gill nets are presented in the paper. Gill nets can be used effectively in the islands as a diversified fishing method to harvest the vast untapped resources like Thunnus albacares (yellowfin tuna), Thunnus obesus (bigeye tuna), Istiophorus platypterus (sailfish), Makaira spp (marlin) and other large pelagics. Results indicated that large mesh drift gillnets were effective in harvesting large pelagic fishes which are not being exploited by the existing pole and line fishing. This can be taken up successfully in a commercial scale in the Lakshadweep islands.
Research Interests:
Food is lost during all stages along supply chains of capture fishery products, during capture operations, post-harvest handling and processing, storage, distribution and consumption. Reducing food loss increases the sustainable... more
Food is lost during all stages along supply chains of capture fishery products, during capture operations, post-harvest handling and processing, storage, distribution and consumption. Reducing food loss increases the sustainable production of fishery resources, supporting the long-term capacity to provide food, and increases economic opportunities for the capture fisheries sector. Gillnets and trammel nets are main fishing gears used in tropical fisheries associated with significant loss of fishery resources and food during fishing operations. The Indian Council for Agricultural Research – Central Institute of Fisheries Technology (ICAR-CIFT) and Food and Agriculture Organization of the United Nations (FAO) convened the Expert Workshop on Estimating Food Loss and Wasted Resources from Gillnet and Trammel Net Fishing Operations in Cochin, India, from 8 to 10 April 2015. Sixteen experts from 9 countries participated. FAO’s Fishing Operations and Technology Branch prepared a background...
Research Interests:
Research Interests:
The origin of gillnetting cannot be traced back exactly, but reports of its commercial existence dated back to 11th and 12th centuries. This fishing methodwithstood the technological and other transitional changes, the sector passed... more
The origin of gillnetting cannot be traced back exactly, but reports of its commercial existence dated back to 11th and 12th centuries. This fishing methodwithstood the technological and other transitional changes, the sector passed through such as introduction of bulk catching methods like purse seining and trawling. From a simple 20-30 m long piece of netting tied across a rivulet, it transformed to huge walls of netting running to 100 km and above in length and >50 m depth , with automated setting, hauling and catch removal.
Research Interests:
The studywas conducted to evaluate the accumulation of heavymetals in barnacle shells and tissues in different seasons of the year. Heavy metal concentration was monitored in barnacle tissues and shells on a long term and short term... more
The studywas conducted to evaluate the accumulation of heavymetals in barnacle shells and tissues in different seasons of the year. Heavy metal concentration was monitored in barnacle tissues and shells on a long term and short term (monthly) basis by exposing glass panels in Cochin estuary. Short term panels gave a clear idea of the dynamics of heavy metal accumulation in barnacles. Accumulation of chromium and cadmiumwasmaximum in the tissues and shell during themonsoon season whereas lead and nickel was maximum in pre monsoon period. Selenium varied irregularly and arsenicwas detected only in one sample. Higher levels of copper andmanganese were observed in shells during both high and low salinity season (pre monsoon and monsoon). Manganese and iron uptake was significantly higher in the initial stages of growth and is mainly utilized for shell formation. Zinc was maximum during monsoon in short term panels whereas in soft tissues of long term panels it was detected during monsoo...
Research Interests:
The present study is aimed at investigating the electrochemical characteristics of aluminium due to the incorporation of nano metre and micro metre sized cerium oxide mixture. Treated aluminium exhibits higher corrosion resistance as... more
The present study is aimed at investigating the electrochemical characteristics of aluminium due to the incorporation of nano metre and micro metre sized cerium oxide mixture. Treated aluminium exhibits higher corrosion resistance as evidenced by lower corrosion current density and corrosion rate and improved morphologies. Impedance spectra of aluminium subjected to long term exposure to 3.5% NaCl (w/v) show that the corrosion resistance of surface and internal matrix increases significantly and the corrosion is occurred in the β spaces of the aluminium. Smaller grain size and increased electronic conductivity improve the corrosion resistance of aluminium.
Research Interests:
Fishing hooks stand out among the simplest and the oldest of such devices. They are not well studied, and the available studies are out dated due to emergence of new models materials and technologies. Methods of numbering of hooks are not... more
Fishing hooks stand out among the simplest and the oldest of such devices. They are not well studied, and the available studies are out dated due to emergence of new models materials and technologies. Methods of numbering of hooks are not standardized. This review dwells into their history and evolution, terminology, properties, classification, numbering, testing procedure and hooking efficiency. The study points to the need for a comparative study of hooks in terms of their relative properties and also as a conservation tool for sustainable development of recreational fishing
Research Interests:
Research Interests:
Netting yarns/twines forms the main part of majority of fishing gears. Apart from giving structure and shape to the gear, materials play a substantial role in resource and energy conservation. Netting materials for fabrication of fishing... more
Netting yarns/twines forms the main part of majority of fishing gears. Apart from giving structure and shape to the gear, materials play a substantial role in resource and energy conservation. Netting materials for fabrication of fishing gear are either of textile or non-textile origin. Textile materials comprise of netting, twine and rope while floats, sinkers, hooks etc constitute non-textile origin materials. The raw material for fish netting consists of fibres which can be distinguished into two groups: natural fibres and man-made fibres. Different kinds of fibres originating from plant and animal body parts have been used for production of textiles and other products are termed as natural fibres. Traditional fishing gears used earlier, till 1950s were mainly with natural fibres such as cotton, manila, sisal, jute and coir.
Very few studies have been conducted to analyse physical and mechanical properties of fishing hooks. The present work is an account of a study carried out on five major brands of number seven round bent fishing hooks available in India,... more
Very few studies have been conducted to analyse physical and mechanical properties of fishing hooks. The present work is an account of a study carried out on five major brands of number seven round bent fishing hooks available in India, which are used to harvest tuna and medium sized fish resources. We have selected three imported and two indigenous brands of fishing hooks. The dimensional characteristics and unbending force as tensile load for deformation of the hook bend equal to its bite length were investigated. The mechanical strengths of the fishing hooks studied were highly varied and brand IB-1 recorded the highest unbending force of 275.9 N. It was found that the unbending test method employed to analyse the mechanical strength of fishing hook in this study is in agreement with the actual performance by the fishing hooks in the field and this test could be effectively used to evaluate mechanical strength of fishing hooks. © 2007 Elsevier B.V. All rights reserved.
Research Interests:
Research Interests:
A cage is a space enclosed with some type of mesh forming a container for aquatic animals to grow. It is typically box-shaped or tube like structure with a rope system which supports the netting material, gives shape and allows for tying... more
A cage is a space enclosed with some type of mesh forming a container for aquatic animals to grow. It is typically box-shaped or tube like structure with a rope system which supports the netting material, gives shape and allows for tying to the raft unit. In box type cages, the cage is constructed of four panels at the sides and one bottom panel. Anti-predator nets are deployed around the cage to prevent entrance of predators such as sharks and sea lions into the cages. An additional net would be provided on top of the cage to prevent bird predation.
Research Interests:
Gill net is a highly selective and passive gear accounting for 20% of all the fishing methods of the world. The simplicity of its design, construction, operation and its low energy requirement make the gear very popular in all the sectors... more
Gill net is a highly selective and passive gear accounting for 20% of all the fishing methods of the world. The simplicity of its design, construction, operation and its low energy requirement make the gear very popular in all the sectors especially in the traditional sector. It is a highly selective gear and the use of this gear in a responsible way ensures resource conservation. The gear is a vertical wall of netting, which is kept erect in water by means of floats and sinkers. The gear is mostly rectangular in shape whose upper end is mounted to a float line (head rope) and the lower end to a sinker line (foot rope).
Polyamide (PA) multifilament continues to be the material for gill nets for large pelagics in Kerala despite its replacement by PA monofilament and polyethylene (PE) multifilament in many other states of the country. The cost of the gear... more
Polyamide (PA) multifilament continues to be the material for gill nets for large pelagics in Kerala despite its replacement by PA monofilament and polyethylene (PE) multifilament in many other states of the country. The cost of the gear contributes significantly to the total investment of the fishing unit viz., around 19% in the mechanised sector and 50% in the motorised sector. Results of a study on replacement of costly PA multifilament by cheaper PE without compromising on the production efficiency are discussed in the present communication. Fishing trials using nets of PE of 1.25 mm dia in comparison to PA 210 dx6x3 (R 455 tex) showed no significant difference in catch and the species composition was similar in both the nets. PE net was found to be cost effective than the PA net, the PE net costing only 52.4% of the PA net. Results indicated that PE twisted monofilament of 1.25 mm dia can be considered for replacement of PAR 455 tex in gill nets for seer and tuna.
Research Interests:
A total of 19 different fish and shell fish species were landed by nonmotorised gillnetters at Mahim of Mumbai coast. The Catfishes contributed 16.69% of the total landing. Among three groups, pelagic fishes shared 49.61%, demersal fishes... more
A total of 19 different fish and shell fish species were landed by nonmotorised gillnetters at Mahim of Mumbai coast. The Catfishes contributed 16.69% of the total landing. Among three groups, pelagic fishes shared 49.61%, demersal fishes 43.81% while crustacean contributed only 7.59% of the total landings. Among the total pelagic catch, oil sardine contributed 32.40% while in demersal fin fishes, catfishes contributed maximum of 38.10% and in crustacean group only crabs were observed with a share of 7.59%. The fish species and their percentage contribution varied from month to month. Maximum landing was observed in September contributing 15.52% of the total annual catch.
Longline fishing is a fuel efficient and selectivefishing method with low environmental impact. Thelongline fishing methods of Kerala, Tamil Nadu andAndhra Pradesh are discussed in this paper, basedon the studies conducted during... more
Longline fishing is a fuel efficient and selectivefishing method with low environmental impact. Thelongline fishing methods of Kerala, Tamil Nadu andAndhra Pradesh are discussed in this paper, basedon the studies conducted during 2012-2013. Mecha-nized vessels of L OA 9.5 to 20 m with 97-250 hpengines are used for longline fishing in this region.Fishing is normally multiday extending from 5 to40 days. The longline vessel has a crew complementof 6 to 15. Some of the vessels use mechanical orhydraulic winches for hauling the line. The totallength of the main line ranged from 15 - 25 km.Longline vessels target commercially importanthigh value species like tuna, marlin, sailfish,seerfish, shark and rays. Structural and operationalchanges in longline fishing which happened duringthe last few decades have also been documented.Keywords: Longline fishing, structural and opera-tional changes, Kerala, T amil Nadu, Andhra Pradesh Received 18 September 2013; Revised 15 March 2014;Accepted 18 Ma...