तिरुवनंतपुरम के विषिंजम तट में तटीय टूयूना मात्स्यिकी की स्थिति - अस्सी के दशक में

कृपया पूरा लेखा पढ

Fishery and bionomics of tunas at Vizhinjam

Vizhinjam (76°59'E, 8°22'N) is an important fish landing centre owing mainly to its location which affords facilities for operation of boats even during the monsoon season and accessibility to the nearby markets. With the Fisheries Harbour construction underway, the fisheries importance of this area is bound to increase further. Details of common nets employed in the centre and the modes of their operations were described earlier by Nayar (1958), Bennet (1967) and Luther et al. (1982). Rao (1964) described the ripe ovaries of some Indian tunas from Vizhinjam and summarised that E. affinis, A. thazard and S. orientalis spawn in the local waters from April to September and possibly in other months of the year. According to him, the spawn ripe individuals of the above three species indicate the existence of an important spawning ground for them off Vizhinjam

Resource characteristics of the ribbonfish Trichiurus lepturus Linnaeus at Vizhinjam, southwest coast of India

The annual landings of the ribbon fish Trichiurus leptwus at Vizhinjam during 1979-81 fluctuated between 5831 and 34291 with an average at 21241 forming 43 % of the total fish catch. The active fishery season was from June to October with peak landings during July and August/September. Boatseinecontributed96%ofthecatch with a maximum CPUE of 111.5 kg. Hooks andline, shore seine and gill net accounted for the rest of the catch. The size and maturity distribution and sex-ratio of T. leptwus in the catches are given along with its food and feeding habits. The disposal and utilisa* tion of the catch are also briefly described

Present status of coastal tuna fishery at Vizhinjam, Trivandrum coast

The coastal tuna fishery of Kerala, which has been yielding about 6,000 tonnes annually in recent years, constitutes 32% of the total tuna landings of the country. A district-wise analysis of the tuna production during 1979-'81 indicated that 70% of the total tuna landings in the state was from the coasital fishery along Trivandrum district. At Vizhinjam, where fishing goes on all through the year, coastal tunas constitute a major pelagic fish resource accounting for 20% of the total marine fish landings. Since the prime requirement of tuna fishery developmsnt in the area seems to be the improvement of the existing small-scale fishery sector, knowledge on the present status of the fishery appears to be a basic necessity for the planning of further development in this sector. In addition, when the fishery harbour under construction at Vizhinjam becomes operational, mechanised fishing for tunas is bound to increase in the area and this also requires information on the catch trend and seasons of abundance of various species for the management of fishing fleet

Motorization of traditional craft and its effect on the exploitation of tuna and whitebait anchovy resources

The impact of motorization of traditional craft on two fisheries resources, viz. tunas and whitebait anchovies, was studied. A conspicuous increase in the annual tuna catch was seen from 1984 due to the increased effort expended by the motorized craft by using more units of drift nets, hooks and lines than non-motorized craft. The tuna landing increased from 361 tonnes during the pre-motorization period to 1976 tonnes during the motorization period. On the contrary, the anchovy landing came down from 580 tonnes during the pre-motorization period to 386 tonnes on motorization. A decline was noticed in the effort expended for whitebait anchovies but the catch rate did not show a steep decline which indicated that the reduction of effort was not due to the decrease in the catch rate. The shifting over of motorized units to drift net and hooks and lines operation seems to be the major reason for the decline in the effort of boat siene and nelholi vala which are the main gears for whitebait anchovies. Indian Journal of Fisheries 41 (2): 92-9, June 1994 The motorization of traditional craft was initiated in central Kerala by 1980. It spread to northern and southern areas by 1983 (Balan et al. 1989). At Vizhinjam, the most important fish landing centre in Trivandrum, the motorization was initiated during the middle of 1982. A substantial increase in the effort from the motorized craft was recorded from A 984 which resulted in an immediate increase in the total fish catch at Vizhinjam. An account of the traditional fishery in the area has been given by Luther et al. (1982) and Nair et al. (1988) and the initiation of motorization of traditional craft in the area has been reported by Gopakumar et al. (1986). The increase in Present address: 'Scientist (SG), technical Officer, Technical Assistant the catch and catch rate of tunas and mackerel as a result of motorization has also been pointed out by Gopakumar and Sarma (1989) and Gopakumar et al. (1991). The chief gears operated by the motorized craft at Vizhinjam are hooks and lines and drift net. Motorization has extended the fishing areas of traditional craft to relatively more distant grounds and has increased the yield of certain resources like tunas which are caught chiefly by drift net and hooks and lines. This has resulted in a reduction in the operation of non-motorized units and a simultaneous decrease in the yield of certain other resources like whitebait anchovies which are caught by boat seine, shore seine and netholi vala. To analyse this aspect, the trends offish landing with particular reference to two resources, viz. 9

Observations on the catches of the mechanised Boats at Neendakara

The catch data of the mechanised boats for the period from August 1969 to July 1971 revealed that the area off Neendakara is a potential trawling ground for prawns and other ground fish, with an estimated annual total catch of 12,079 tonnes. Observations also indicate the area off Neendakara to be a potential fishing ground for quality fishes such as seer fishes and tunas which are caught in surface gill nets. Trawl catch formed the main bulk of the landings constituting 92.8% and gill-net catch formed the cest. Details of the catch rates by trawl and gill nets, and of biological aspects such as size range, maturity, sex ratio and food and feeding habits of the important species of fish in the trawl catches are also presented in a chart

First record of spotted chub mackerel Scomber australasicus Cuvier (scombridae : pisces) off Vizhinjam, Southwest Coast of India

The occurrence of spotted chub mackerel Scomber australaslcus Cuvier, 1831 off Vizhinjam, southwest coast of India is reported. This is the first record of the species from the Indian Coast. The diagnostic characters, description, distinguishing characters from the other closely related species and distribution of this species are briefly given

Comparative assessment of the impact of motorisation on the artisanal fisheries at Vizhinajam

The fishery statistics collected from Vizhinjam fish landing centre for seven years from 1986 to 1992 was utilised as the data for the motorisation period. The fishery data during the pre-motorisation period is taken from Luther et cd. (1982) for presenting the comparative assessment of the impact of motorisation. An Increase in the total fish catch as well as in the catch per unit effort is evident during themotorisation period. The fast accessibility to the distant fishing grounds by the motorlsed crafts, the increased number of fishing hands employed in the motorlsed units and the avEiilability of more time for actual fishing due to the time saved for rowing seem to be the major reasons for the higher catch and catch rate in the motorlsed units

Tuna fisheries in India: Recent trends

Tuna is one of the least exploited resources of the Indian seas accounting for 0.98 % of the total marine fish catch of India at the 1978 level. On the other hand tuna resources have been exploited by countries such as Japan, Korea and Taiwan from the Indian Ocean. Relevant portions of the recommendations of the 'Symposium on scombroid fishes' held at Mandapam camp. The authorities involved with the planning of the Indian Ocean Expedition give due consideration to gathering and collating the information which should be useful in aiding the development of high seas fisheries for scombroid fishes in the Indian Ocean. In the context of these developments and the need for efficient utilisation of the resources of the Exclusive Economic Zone, a brief account on the trend in the tuna fisheries in the country is presented here

Marine Fish Calendar 9. Vizhinjam

Vizhinjam, an important fish landing centre in the fishery zone extending from Kollangode in the south to Valiaveli in the north spreading over a distance of 50 km on the southwest coast of India. Data collected over a period of five years, from 1981 to 1985, from the landing centre at Vizhinjam have been analysed to draw up a general fishery calendar suitable for this centre elucidating the cyclic changes in the abundance and dominance of the commercially important species/ groups of fish within a year. The data show that the annual marine fish landings (fin fish alone) at Vizhinjam ranged from 5,207.01 t in 1981 to 9,726.2 t in 1985 with the annual average landings at 6,374.41 t