Island ecosystems have rich marine biodiversity and high levels of terrestrial endemism, but are potentially the most vulnerable to climate change and anthropogenic stressors. To effectively manage environments, scholars and conservation practitioners have increasingly turned their attention to local islander knowledge (LK) and practices. To date, much of the literature treats LK definitionally rather than examining its theoretical underpinnings. This review focuses explicitly on the concept of LK and it describes three discernible phases of research marked by conceptual shifts. Over the 20th century, LK underwent a dramatic reversal from something understood as inferior and deficient to something that is valuable and empirically sound. This shift ushered in widespread acceptance of local islander knowledge as a unique, rich corpus of information that could be tapped by Western science to enhance community-based resource management. Over the last several decades, a third phase of LK research has emerged in which a more dynamic framing has developed, emphasizing LK's hybrid and adaptive dimensions, as well as its constitutive entanglements with other social–ecological processes. This has expanded the scope of inquiry into the strategies islanders employ as they adapt to changing social and environmental milieus, and as they attempt to co-produce knowledge with scientists and conservation practitioners.

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.