Longlines are passive fishing gears which are meant to catch sparsely distributed large pelagic fishes like tunas, billfishes and sharks. This fishing method is considered as highly energy efficient, eco-friendly and species and size selective compared to other fishing methods such as trawling and purse seining. Skipjack tuna are the major group of tuna species landed from the world oceans in terms of quantity and the major portion utilized for canning. Skipjack and yellowfin tunas contributed nearly 80% of the tuna landed from the Indian Ocean waters and are the major tuna species landed in...