tuna, Thunnus albacares in Lakshadweep Islands
M.S. SAYED ISMAIL KOYA1, A.I. MUHSIN1*, PRATHIBHA ROHIT2 AND K. HASSAN1
1Department of Science and Technology, U.T. of Lakshadweep, Kavaratti
2Mangalore Research Centre of Central Marine Fisheries Research Institute, Post Box 244, Bolar, Mangalore-575 001, Karnataka, India
*e-mail : [email protected]
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akshadweep Islands scattered in the Arabian Sea between 800 N - 120 30’ N latitudes and 710 E - 740 E longitudes are known for their rich tuna fishery. The existing pole & line fishing has mainly focussed on exploiting skipjack tuna.Other tunas such as yellowfin, kawakawa and frigate tunas formed part of the by-catch.
Targeted fishing for yellowfin tuna, Thunnus albacares using pole & line is an emerging fishery in Lakshadweep and has gained popularity since 2010. The design and operation of the pole & line generally used for fishing tunas have been suitably modified so as to catch large sized yellowfin tunas. The modified version has two bamboo poles which are joined with a nylon rope so as to maintain a distance of around half a meter between the two poles. A monofilament nylon line with a barbless hook on the distal end is tied to the centre of the nylon rope. Two to four persons are involved in handling one such modified set of the poles & line. The fishermen from Kavaratti Island pioneered this type of fishing by introducing a Maldivian boat model along with the local Pablo boats. The Maldivian boat
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models are bigger (45-48" OAL) as compared to the Pablo boat (35-38") and have better endurance out at sea with a fish hold capacity up to 5 t. Fishing is mostly carried out around Agatti Island. Presently it is estimated that there are 16 units (2 Maldivian models and 14 Pablo boats) with the crew mainly from Agatti and Kavaratti involved in exploiting yellowfin tuna using the modified poles and line fishing technique.
The fishing operation consists of two stages -the first to collect suitable bait fishes and -the second to exploit yellowfin tunas. Bait fishes are collected from the lagoons either early in the morning of the fishing day or the previous
evening. Apogonids are the main baits used and when there is a shortage of Apogonids, Caesionids and Clupeids (sprats) are used.
Though distribution of yellowfin tuna has been reported throughout the island systems, fishing on a commercial scale using the modified pole
& line is presently carried out mostly near Bangaram and Agatti islands. Exploitation on a commercial scale is now slowly spreading towards Kavaratti, Amini and Kadmat islands. The existing pole and line has been suitably modified to exploit only larger sized yellowfin tunas (>10-30 kg). A brief account of the emerging fishery for large sized yellowfin tunas along with the advantages over the existing type of fishing in Lakshadweep is described.
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Development of cobia, Rachycentron canadum and pompano, Trachinotus blochii aquaculture in India – the way forward
G. GOPAKUMAR1*, G. SYDA RAO2, A.K. A. NAZAR1, R. JAYAKUMAR1, G. TAMILMANI1, C. KALIDAS1, M. SAKTHIVEL1 AND P. RAMESHKUMAR1
1Mandapam Regional Centre of CMFRI, Marine Fisheries Post, Mandapam, Camp - 623 520, Tamil Nadu, India
2Central Marine Fisheries Research Institute, P.B. No. 1603, Ernakulam North P. O., Kochi - 682 018, Kerala, India
*e-mail : [email protected]
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obia Rachycentron canadum and silver pompano Trachinotus blochii are two marine finfish species with very high potential for aquaculture in India. Fast growth rate, adaptability for captive breeding, lowest cost of production, good meat quality and high market demand especially for sashimi industry are some of the attributes that makes cobia an excellent species for aquaculture. In recent years, seed production and farming of cobia is rapidly gaining momentum in many Asian countries. Envisaging the prospects of cobia farming in India, broodstock development was initiated at the Mandapam Regional Centre of Central Marine Fisheries Research Institute in sea cages during 2008 and the first successful induced breeding and seed production was achieved in March – April 2010.Trials on sea cage farming carried out at Mandapam showed that the fishes attained an average weight of 2.5 kg in six months and 7.3 kg in twelve months. The species can be grown in low salinity and experiments revealed that upto 15 ppt the growth and survival is comparable to that in seawater. These results point out the possibility of developing a lucrative cobia aquaculture enterprise in the country. However, standardization of technologies for seed production and farming of cobia to suit our environmental conditions have to be further pursued on a priority basis so that India can also emerge as a contributor for cobia production in the near future. Similarly, among the many high value marine tropical finfish that could be farmed in India, the silver pompano is also one of the topmost, mainly due to its fast growth rate, good
meat quality and high market demand. The species is able to acclimatize and grow well even at a lower salinity of about 10 ppt and hence is suitable for farming in the vast low saline waters of our country besides its potential for sea cage farming. At Mandapam Regional Centre of CMFRI, successful broodstock development, induction of spawning and fingering production of silver pompano was achieved during July 2011 for the first time in India. Subsequently two more seed production experiments were also done successfully and now farming trials are progressing. This can be considered as a milestone towards the development of pompano aquaculture in the country. The current achievements in cobia and pompano can be considered as the first step towards the aquaculture development of the two species. The establishment of biosecure broodstock centres, standardisation of breeding, larviculture and nursery rearing protocols and farming demonstrations in pond and sea cages are the steps to the way forward. Hence it is required to invest and establish infrastructure for the different phases from seed to product development viz.
required broodstock facility for the production of viable fertilised eggs throughout the year (ii) hatchery facility for meeting the seed requirements (iii) grow out facilities and (iv) product processing and distribution system. It is felt that both cobia and pompano are potential aquaculture giants having vast domestic and global business prospects.
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