Predicted origins of drifting fish aggregating devices (dFADs) into environmentally sensitive habitats of Hawaiʻi using backwards simulated drift trajectories

This study aims at identifying the origin areas of dFADs that can impact the marine environment by damaging fragile benthic habitats and entangling wildlife. The spatial extent of the simulations included the whole Pacific Ocean, from 120°E to 90°W and from 50°N to 30°S to cover both the Western and Central Pacific Fisheries Commission (WCPFC) and the Inter-American Tropical Tuna Commission (IATTC) convention areas and the Hawaiian Exclusive Economic Zone (EEZ) (Figure 1). We investigated the likely origin of dFADs stranding in Hawaiʻi coastal areas and their connectivity route with the equatorial region where dFADs are deployed and used by purse seiners. The potential origin zones in the equatorial areas were separated into Equatorial Zones (EZ) and dFAD Zone (FZ). This will help determine the probability of the origin of dFADs arriving in key essential habitats over a timescale of five years. We used backward simulated Lagrangian drift trajectories to assess these origin areas with a focus on essential Hawaiʻi coastal habitats and unique ecosystems defined as coastal zones (CZ). Results will also be compared, when possible, with actual reports of dFADs washing ashore in the MHI and the PMNM. The results presented in this report are preliminary.