Institute of Marine Research 1 article published in JoVE Biology Assessing Mineral Availability in Fish Feeds using Complementary Methods Demonstrated with the Example of Zinc in Atlantic Salmon Marta S. Silva1,2, Thea Stewart4, Heidi Amlund1,3, Jens J. Sloth1,3, Pedro Araujo1, Erik-Jan Lock1, Christer Hogstrand4, Robin Ørnsrud1, Rune Waagbø1,2, Antony Jesu Prabhu1 1Institute of Marine Research, 2Department of Biological Sciences, University of Bergen, 3National Food Institute, Technical University of Denmark, 4 This article explains in detail a systematic approach to assess micro-mineral availability in Atlantic salmon. The methodology includes tools and models with increasing biological complexity: (1) chemical speciation analysis, (2) in vitro solubility, (3) uptake studies in cell lines, and (4) in vivo fish studies.