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Longline fishery for yellowfin tuna in Iran EEZ was initiated in 1992 with an industrial Taiwanese style longliner owned by Iranian company. Artisanal longline fishery in Iranian EEZ in Oman Sea has been experienced in recent 3 years by local fisherman through the operation on trials and errors. So, this preliminary study is the first in which the information on the artisanal tuna longliners in Iran are observed in terms of gears and catch data. Data on technical parameters of the gear and fishing operation were provided by the logbooks distributed to the local fishermen, in which totally 359 line sets were available. In this paper, the features of artisanal longliner and the gear configuration are shown in details. Fishing ground is limited to the narrow area in EEZ waters, but it needs be confirmed by more data from the field. Average nominal CPUE were estimated to be at 104.6 fish/100 h and 2.36 fish/100 h for the target species, i.e. yellowfin tuna (Thunnus albacares). This value in comparable to those of longline fisheries in Indian Ocean. CPUEs trend also revealed a clear trend by season, which has to be investigated further in future work. Catch composition in number showed that yellowfin tuna accounted for 79.7%, Common dolphinfish (Coryphaena hippurus) 10.2%, marline 3.2%, sea turtle 2.4%, ray fish 2%, sharks 0.1% and miscellaneous fishes 2.4% of the total catch. A comparison of length frequency of yellowfin tuna between longline and drift gillnet fishery was made, on which a significant difference was observed between the both fisheries; for gillnets, the size distribution varied between 37-170 cm with three dominant modes of 55cm, 85 cm and 133 cm and for longline, the length distribution ranged from 90-175 cm, peaking at one mode of 130 cm. The issue of feeding and spawning migration is discussed for the larger yellowfin tuna in EEZ waters.
Artisanal longline fish is still the first step in the process, and needs to be mechanized to the technical parameters of gears and equipment with the aim at improving the catch quantity and quality.
