With the introduction of purse seines in the midseventies the catches of
oil sardine steeply rose from 6,129 t in 1976-77 to 32,629 t in 1979-80. However,
in the subsequent year the landings declined by 6,800 t and with increase
in effort the catch rate only showed a downward trend, obviously because of
the large-scale removal of gravid fish during 1978-79 and 1979-80. The total
instantaneous rate of mortality was found to be high indicating the high rate
of mortality caused by the gear. The adverse effect of purse seiners on traditional
fishery, with special reference to the shore-seine Rampart, is discussed