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To test the hypothesis on connectivity of anchored FADs in the Maldivian 65 skipjack and 57 yellowfin tuna were tagged with acoustic transmitters. Tagging campaigns were within a subsection of the array consisting of 21 AFADs, equipped with acoustic receivers. Only three yellowfin tuna (5.2%) and one skipjack tuna (1.5%) were observed to move from one FAD to another. These four fish were tagged together at the same AFAD during the same tagging campaign, while no fish tagged at the other AFADs moved between FADs. Despite being tagged together, the fish that moved between the AFADs were detected at different AFADs, suggesting that they did not have a specific preference in the direction of movement. Another important result is that fish departing from the same AFAD is detected at different AFADs, suggesting that tuna left the AFAD in multiple schools. The mean continuous residence time at AFADs recorded for all tagged skipjack and yellowfin tuna were 2.03±2.93 days and 4.42±6.72 days, respectively. The few observed inter-AFAD movements of tuna suggest that the AFAD array in the Maldives, with its large inter-AFAD distances, does not act as a network but rather as individual AFADs that locally attract tuna. In contrast to other denser AFAD arrays in the world, it appears that large distances between AFADs minimize any possible AFAD array-effect on tuna movements.
