It is with great sadness that SAIAB announces the passing of Professor Olaf Weyl on Saturday 14th November 2020. Doing what he loved best, Olaf was chasing fish in mountain streams looking for new trout genetics sampling sites.

Fish biology and ecology, particularly on the impact of alien species and the influence of anthropogenic factors on aquatic ecosystems.

Olaf's research focus at SAIAB was geared towards providing information with which to better manage Africa’s aquatic biodiversity. His work on fisheries revolved around developing an inland fisheries policy for South Africa to ensure sustainable resource management. He was particularly interested developing policy and strategies to manage ‘conflict species’ which are valued recreationally or economically but pose conservation risks. To this end his research group will continue work on freshwater ecosystems in several African countries including Mozambique, Malawi, Namibia, Botswana, Zambia and South Africa.

Olaf's interests ranged across fisheries, native fish conservation and alien species invasions. As a result his research was multidisciplinary and included not only research on natural systems and processes but also research on understanding how humans alter and benefit from aquatic systems.

Recent invasive species related projects include assessing the impacts of recreational angling species such as carp and bass on native fish and invertebrate communities; parasitological and ecological research on eels; monitoring the recovery of stream ecosystems after alien fish removal using piscicides; impacts of hybridisation resulting from fish introductions; managing fish invasions in protected areas and assessing the role that alien fish play in subsistence and recreational fisheries in South Africa; and investigating impacts of the spread of invasive freshwater crayfish species beyond their indigenous ranges.

Olaf also provided policy support with regards to inland fisheries and legislation on alien fish management and was active in the development of decision making tools used by provincial nature conservation departments to assess invasion risks through fish introductions.

He was editorial board member of African Zoology, African Journal of Aquatic Science and Journal of Fish Biology and provided expert advice for several organisations including the Endangered Wildlife Trust and the World Wildlife Fund.

Follow Olaf's Research at SAIAB on Facebook