Iodine, bromine and arsenic uptake, accumulation and efflux in three ecologically important Southern Hemisphere brown algae: Durvillaea antarctica , Macrocystis pyrifera and Lessonia trabeculata

With a few exceptions, knowledge about halogen and arsenic metabolism is limited to Northern Hemisphere taxa. This study explores the uptake, accumulation and efflux of iodine in three of the most common Southern Hemisphere brown algae: Durvillaea antarctica , Macrocystis pyrifera and Lessonia trabeculatα . All three brown algal species investigated here showed measurable iodine uptake in steady state conditions and, conversely, iodine efflux during oxidative stress. The two species of Laminariales, Lessonia (6.7–19 mmol I kg −1 DW) and Macrocystis (6.1–17 mmol I kg −1 DW), both contained more iodine than Durvillaea (0.46–4 mmol I kg −1 DW; Fucales), but all three species contain much less iodine than previously studied Laminaria species. The studied algae also contain bromine and arsenic levels typical of brown algae reported from elsewhere, which are not affected by physiological conditions such as oxidative stress resulting in efflux of iodine.