Indian Tuna Resources: Distribution, Commercial Exploitation, Utilization and Trade

Tuna and tuna-like fishes are important both from global demand and economic view points. They include 40 species occurring in the Atlantic, Indo-Pacific Oceans and in the Mediterranean Sea. Archaeological evidence showed that, tunas being harvested by early Europeans in the area around Sweden, by Native Americans near British Columbia and by the peoples of the Joman culture near Japan. However, industrial fishing for tunas began in the 1950’s and global production has tended to increase continuously from 0.6 million tons in 1950 to over 6 million tons in 2008. Catch of principal market tuna species was estimated as four million tons in 2008, which represented about 67 per cent of the total catch of all tuna and tuna-like fishes. Most of these catches were taken from the Pacific Ocean (70.2 per cent), with the Indian Ocean contributing 20.4 per cent with an estimated catch of 870,000 tonnes and the rest by Atlantic Ocean and the Mediterranean Sea (9.5 per cent). Major contributors to the global tuna production are skipjack tuna (57.5 per cent), followed by yellowfin tuna (27.1 per cent), bigeye tuna (9.6 per cent), albacore tuna (4.7 per cent) and the rest (10.7 per cent) by other species. According to assessments carried out during 2010 by ICCAT, IOTC, IATTC and WCPFC the international organizations responsible for management of the tuna stocks of in the world Oceans, many tuna stocks are heavily exploited, some unsustainably, and the catches in many cases are declining

Age determination in fishes

Fisheries management relies on the proper understanding the fish population dynamic. It includes determining the biological parameters, including size at maturity, duration of spawning season, mortality estimates, age and growth. Accurate information on age of fish is an important pre-requisite for extracting precise information on growth, mortality, recruitment and other fundamental population parameters of fishes for stock assessment. The outcome of conventional age estimates using length frequency data depends upon the sample quality, selectivity of the fishing gear etc. The stock assessment results may therefore be affected and sometimes give results which is having no bearing on reality. The hard parts of the fishes also grow with the fish and the growth process may left some inscription on such parts and if that can be interpreted properly, will get precise idea on growth. These inscriptions may result from either changes in the environment which the fish inhabits, or food availability, or physiological states of the fish. However, free swimming fishes always lives in ideal conditions and do not leave any environment related markings in their skeletal structures. So interpretation of hard part inscriptions need utmost care

Common Pelagic Finfish Families and their Identification

Bony fishes are distinguished by the presence of bony endoskeleton. Their second noteworthy character is the presence of a swim bladder or lungs, which helps the fish to maintain its body density equivalent to that of its surrounding medium. The skin of bony fish is normally covered with overlapping scale, which are either cycloid or ctenoid. In some it become obsolete and in others it is modified by calcification to an ossified dermal covering in complete bony coating

Emigration dynamics of three species of penaeid prawn from backwaters and tidal ponds of Cochin, India

Emigration of three species of penaeid prawn from backwaters and tidal ponds were studied. Considerable diel, tidal, lunar and seasonal fluctuations were observed in emigration process, which was almost nocturnal. Rate of emigration and composition of emigrants varied with time of migration

Pelagic fin fishery resources of India

India is endowed with a long coastline of 8129 km. Being tropical country, the marine ecosystem bordering Indian sub-continent contain large number of species adapted to wide range of habitats, from mangrove swamps, estuaries, saline lagoons, sea grass meadows, sandy/ muddy/rocky coasts, coral reefs, oceanic islands to deep oceanic realms. Theses resources are supporting the marine fishery of the country. The water spread of continental shelf is 0.5 million sq. km and of EEZ is 2.02 million sq. km. The annual catchable marine fishery potential of the EEZ is 4.42 million tonnes. India is one of the leading nation of the world in marine fish production and export

Peningkatan Aktivitas Pembelajaran IPA dengan Menggunakan Metode Eksperimen di Mis

The problem in this study is science learning How to use experimental methods to increase the activity of students in class V Mis - Righteous Ketapang Ash ? " . means of collecting data and interviewing techniques initial observations of classroom action research . The method used is descriptive nature of the research is a collaboration by following the action research procedures , including planning , implementation , observation , and reflection . Research subject is a class V student Mis - Righteous Ash Ketapang District , amounting to 24 people in the second semester of the school year 2013/2014 and Mis Ash - Righteous teachers as teacher collaboration . This research was conducted by 2 cycles . The results obtained by the research that has been done on improving science learning activities using an experimental method in Class V student Mis - Righteous Ash as follows . With the use of experimental methods to increase the physical activity of the first cycle was 70 % and cycle 2 was 89 % . With the use of experimental methods to increase mental activity first cycle was 35 % and cycle 2 was 58 % with the use of experimental methods , can increase the emotional activity of the first cycle was 73 % and cycle 2 was 88

മത്തി എന്ന മത്സ്യ സമസ്യ

മത്തി എന്ന മത്സ്യ സമസ്

Occurrence of Indian Ruff, Psenopsis cyanea in shallow waters along Kakinada coast, an indication of upwelling

Psenopsis cyanea usually occurs in deeper waters between 250 to 300 m depth in schools. They are irregularly and west distributed off the east coasts of India and off Sacotra and the mouth of the Gulf of Aden. The normal pattern of landings and species composition along the Kakinada coast changed complete by during the period due to the sizeable contribution of deep sea species in the catch. P.cyanea appeared in large shoals along the shallow coastal waters of 5-15 m depth along with the other deep water species such as Priacanthus sp. Decapterus tabl and Upeneus sp. and were caught in large quantities by trawls and gillnets. The landing of deepwater groups lasted for about 12 days. P. cyanea and other species which usually occur in the deep cold water areas might have moved towards the shallow coastal region due to upwelling of the cold deeper water towards the surface, where they were caught by trawls and glllnets

On the juvenile fishery of Euthynnus affinis and Sarda orientalis along the Tuticorin Coast in Gulf of Mannar

An estimated 2882 t of tuna were landed by gillnets and hook and line at Tuticorin duringthe year 2006. They were exploited by smallmeshed gillnets locally known as podivalai with 3.3 to 7.5 cm mesh size, large meshed gillnets known as paruvalai with 8-16 cmmesh size and hooks and line operated from mechanized boats and motorized vallams.Small meshed gillnets operate in shallow waters within 10-15 m depth and land tunas along with other medium sized pelagics.Podivalai accounted for 8.3% tuna landings.Large meshed gillnets and hooks and line operate in 50-150 m depth zone beyond 10 km from the coast and land large tunas and pelagics. Large meshed gillnets contributed 90.3% of the total tuna catch

मान्नार की खाडी में टूटिकोरिन तट पर यूथिनस अफिनिस (कान्टर) और सार्डा ओरिएन्टालिस (टेम्मिंक और शीयगल) की किशोर मात्स्यिकी

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