Sardine fishery with notes on the biology and stock assessment of oil sardine off Mangalore-Malpe

Abstract

Sardines form an important resource off Mangalore-Malpe and the success/failure of their fishery in a way determined the status of marine fishery landings of this region. They contributed to an annual average (1997-98 to 2001-02) catch of 9,060 t. Since a number of gears are employed, the sardines are landed throughout the year along this coast. The fishery has registered a steep increase with the highest catch being observed in 2001-02. Several species of sardines supported the fishery, however the oil sardine, Sardinella longiceps comprised more than 90% of the catch. Length of S. longiceps varied from 40 mm to 220 mm and the length- weight relationship was estimated as W= .01189L2.s6. Growth parameters estimated separately for the different years as well as for all five years combined showed that the Lm ranged from 212 mm to 228 mm and K from 0.85 to 1.09 yr-'. Total mortality rate ranged from 1.95 to 4.58 and natural mortality rate from 1.77 to 2.06. The exploitation rate ranged from 0.08 to 0.55. The study revealed that oil sardine is presently underexploited (E = 0.34) and the yield can be optimised by increasing the effort by 21%. However, economically remunerative man- agement option would be to increase the size at first capture from the present 0.76 year to 0.97 year.