Catch trend of the commercial trawl fisheries of Rameswaram

The present report summarises the catch details of some of the commercially important fishes landed by the trawlers operating from Rameswaram during the years 1980 and 1981. The silverbellies, formed the major group, indicating the availability of silverbellies in large quantities throughout the year, followed by Elasmobranchs and Penaeid prawns in the landings. Quarterrwise landings of trawlnets and monthwise landings of prawns and other groups were portrayed

Large-scale exploitation of sacred chank Xancus pyrum using modified trawl net along Rameswaram Coast, Tamil Nadu

The sacred chank, Xancus pynim is a gregarious, large gastropod and its habitat forms distinct chank bed. Homell as early as 1922 described the chank beds in depths of 10 to 20 metres in the Gulf of Mannar and are considered as the most important ones in the country although there are other chank beds along the Gulf of Kutch and the southwest coast of India

Dorab fishery of Gulf of Mannar waters and population characteristics of the species Chirocentrus dorab (Forsskal, 1775) and Chirocentrus nudus Swainson, 1839

Dorab (wolf-herrings) fishery of Gulf of Mannar and species diversity, biology as well as population characteristics of the species, Chirocentrus dorab (Forsskal, 1775) and Chirocentrus nudus Swainson, 1839 were studied to understand the dynamics of the resource, evaluate extent of their exploitation and to propose appropriate strategies for sustaining the stock and yield. Almost all gears operating along the coast exploit dorabs. About 1,142 t dorabs were landed annually during the period. Fishery was supported by two species dominated by C. dorab. Growth estimates indicated that both species grow much faster than the earlier estimates from the same region. Stock assessment shows that both species were under heavy fishing pressure and subjected to overexploitation resulting in low production below the MSY level. Strategies for enhancing stock and yield are discussed

Snake mackerel fishery of the Tuticorin coast of Gulf of Mannar with emphasis on population characteristics of the sackfish, Neoepinnula orientalis (Gilchrist & von Bonde 1924)

Snake mackerels form by-catch in deep sea trawls and gillnets with an annual average production of 106 t during 2004 - 2006 in Tuticorin area. Fishery occurred almost round the year with peak during November - March. Fishery and biology of the dominant species, Neoepinnula orientalis was monitored during 2004 - 2005. Peak spawning and recruitment of the species was during December - March period. Growth parameters, L∝ and K are estimated as 31.6 cm and 0.68/year respectively. K value indicates that fish growth is relatively slow. Natural mortality estimate (M) is 1.38, total mortality (Z) 1.59 and fishing mortality (F) 0.21. The exploitation ratio (E) is low being 0.132. These estimates indicate that the stock is at its early stage of exploitation and have large scope for future commercial exploitation. As a preliminary step in this direction, the extent of stock abundance, biomass and distribution of the stock needs to be assessed. Being a slow growing species in cold habitat, considerably long time is required for stock multiplication. These factors have to be taken into consideration while planning for exploitation of snake mackerels in future

Sardines of the Gulf of Mannar ecosystem - fishery and resource characteristics of major species

Fishery, species diversity and resource characteristics of exploited sardine resources of the genera Sardinella were studied during 2000-2008. Sardines were exploited by sardine gillnets, trawls and shore seine. Annual average production for the period was 20,249 t. They formed about one fourth of the total marine fish production (77,443 t) of the region. Fishery was supported by eight species dominated by Sardinella gibbosa, followed by S. sirm, S. albella and S. longiceps. Fishery fluctuated widely with declining trend over the years mainly due to reduction in the fishing effort following destruction of traditional crafts and gears during the Tsunami in 2004. Oilsardine in the fishery registered an increasing trend with wide annual fluctuation during the period. Stock assessment studies show that the exploitation rate of major species ranged between 0.45 and 0.62, against the EMSY value of 0.72 and 0.86. This indicated that sardine resource as a whole is under-exploited, offering considerable scope for enhancing their yield. Despite contributing a higher share to marine fish production, sardines, along with other small pelagics, play a vital ecological role in sustaining the stock and fishery of other predatory groups especially large pelagics by providing them a major share of their forage. They support 46 to 87% of the total food of pelagic predators and 14 to 29% of demersal predators

मान्नार की खाडी में टूटिकोरिन तट पर सागरी जलक्षेत्रों में फीतामीन ट्राइक्यूरस लेप्टुयूरस किशोरों का जमाव और गभीर सागर आनायकों द्वारा इसका लक्षित विदोहन

कृपया पूरा लेखा पढ

Studies on Poly(propylene fumarate-co-caprolactone diol) Thermoset Composites towards the Development of Biodegradable Bone Fixation Devices

The effect of reinforcement in the cross-linked poly(propylene fumarate-co-caprolactone diol) thermoset composites based on Kevlar fibres and hydroxyapatite was studied. Cross-linked poly(propylene fumarate-co-caprolactone diol) was also studied without any reinforcement for comparison. The reinforcing fibre acts as a barrier for the curing reaction leading to longer setting time and lesser cross-link density. The fibre and HA reinforced composites have almost the same compressive strength. Nonreinforced material undergoes greater degree of swelling. Among the reinforced materials, the hydroxyapatite reinforced composite has a much higher swelling percentage than the fibre reinforced one. The studies on in vitro degradation of the cured materials reveal hydrolytic degradation in Ringer's solution and PBS medium during aging. All the three materials are found to swell initially in Ringer's solution and PBS medium during aging and then undergo gradual degradation. Compression properties of these cross-linked composites increase with aging; HA reinforced composite has the highest compressive strength and compressive modulus, whereas the aged fibre-reinforced composite has the least compressive strength and modulus

Ranching of clams in the Ashtamudi lake

Ranching of clams in the Ashtamudi lak

Feeding congregation of ribbonfish, Trichiurus lepturus juveniles in oceanic waters and their targeted exploitation by deepsea trawlers along the Tuticorin coast in Gulf of Mannar

Ribbonfishes supported commercial fishery at Tuticorin prior to nineteen nineties. But reports suggested that their stock and fishery declined considerably thereafter. Their fishery during 2000- 2006 was represented by occasional landings of small quantity of ribbonfish by trawls. Average production by trawls at Tuticorin fishing harbour during the period was 250 t. They represent about 0.7% of the total fish catch of the period

Emergence of triggerfishes (Family: Balistidae) as an alternate lucrative target fishery for trawls along the Tuticorin coast in Gulf of Mannar

Fishes of the family Balistidae are commonly known as trigger fishes. Globally the family is represented by about 40 species belonging to 11 genera. The name triggerfish arose as the second dorsal spine act as a trigger to the first dorsal fin. Locally they are known as ‘Kilathi’ in Tamil. Though they used to occur in trawl catch of Tuticorin coast from time immemorial, they were thrown back into the sea by fishermen mainly due to lack of market demand and also for want of onboard storage space. Trawlers used to avoid areas of their congregation as they considered it a menace leading to wastage of energy and time