The purse seine fishery in the Western Indian Ocean is dominated by Spanish
and French vessels that rely heavily on the use of drifting fish aggregation
devices (DFADs) to capture tropical tuna species (skipjack, yellowfin and
bigeye tuna). This study uses local ecological knowledge (LEK) obtained
through standardized interviews of fishing masters to compare and
characterize the body of local ecological knowledge, fishing technology and
fishing strategies of both fleets, with the goal of obtaining useful
information for the management of the fishery. A notable difference between
fleets was the number of DFADs actively monitored per vessel at any given
time, which was much higher for Spanish vessels (ca. 60 versus 20 DFADs).
Spanish vessels also achieved higher vessel CPUE (catch per DFAD set) than
their French counterparts. The use of supply vessels to manage, monitor and
protect productive DFADs, and the latest satellite-based technology to track
and remotely monitor DFAD aggregations is restricted to the Spanish fleet.
The French do not use supply vessels and deploy less sophisticated tracking
buoys. These technological disparities resulted in some fishing strategy
differences between both fleets, but few differences were found in the
knowledge of tuna behavior accumulated by the fishers.