A comparison of the yields of tropical tunas and vulnerable associated species will be made by vessel and by major spatio-temporal strata according with control indicators related to FADs. These indicators include the total number of FADs deployed per month, the daily number of operational FADs (i.e., tracked, activated and in the water), the number vessel-owned FAD sets or total FAD sets (including vessel-owned, foreign FADs and natural objects). Modelling the relationship between the control indicators and associated catches will provide a range of optimal values for each spatio-temporal stratum.
In parallel, FAD catches, in terms of volume and size by tuna species and by spatio-temporal strata, will be compared to the overall purse seine catches in free schools and to other fishing gear targeting tropical tuna.
Finally, the size distribution of catches for all species and fishing gears, will be compared to the theoretical size distribution of the ecosystem. In the event of a discrepancy, adjustments between fishing gears can be studied to better balance this distribution, so that it is more respectful of the theoretical structure of the ecosystem.