The international fisheries community is deeply saddened and shocked to learn of the untimely passing of Olaf Weyl, Chief Scientist at South African Institute of Aquatic Biodiversity and South African Research Chair in Inland Fisheries and Freshwater Ecology.   Dr. Weyl was universally loved and respected across the fisheries profession.  With over 160 peer-reviewed journal articles, Olaf was a talented and prolific scientist whose research team addressed a wide range of fish ecology problems.  His team addressed conservation and impacts of nonnative fishes on endemic fish communities, and evaluation of factors influencing the quality of recreational fisheries.    Olaf had an infectious laugh and a true passion and curiosity about fisheries and fish ecology.   The outpouring from the international community is a clear sign of his impact on so many lives and on our profession.  He will be deeply missed throughout the world.   A tribute from his home institution can be found at: https://www.saiab.ac.za/features/official-announcement-.htm, and a full obituary will follow in Fisheries.