# South African sardine mortality event > Live situation record from CLSTR: https://clstr.news/situations/south-african-sardine-mortality-event > Updated: 2026-08-23T08:49:34.000Z. Sources: 6. Developments: 2. Following a mass mortality event of sardines along South Africa’s West Coast, laboratory sequencing confirmed the presence of pilchard herpesvirus (PHV) genetic material. Initial investigations by the Department of Forestry, Fisheries and the Environment (DFFE) noted that while PHV was detected in both dead and healthy fish, the virus might not have been the sole cause, prompting research into environmental stressors like low oxygen or harmful algae. Subsequent testing by the South African Institute for Aquatic Biodiversity and Rhodes University identified PHV as the likely cause of the deaths. Researchers found high viral levels in samples collected from the mortality event, with the identified sequence showing a “99.7% match to an Australian PHV gene.” While environmental factors such as unusually cold water and low-oxygen conditions were observed, investigations into toxins from harmful algae have not identified them as the primary drivers of the event. ## Timeline ### 2026-08-23: Pilchard herpesvirus identified as likely cause of South African sardine deaths South African authorities identify pilchard herpesvirus (PHV) as the leading cause of recent mass sardine deaths, following testing that showed high viral levels in affected fish. 2 sources. https://clstr.news/cluster/pilchard-herpesvirus-identified-as-likely-cause-of-south-african-sardine-deaths ### 2026-08-14: Pilchard herpesvirus detected in South African sardine mortality event Scientists have detected pilchard herpesvirus in sardines following mass deaths on South Africa’s West Coast, though environmental stressors are also being investigated as potential causes. 4 sources. https://clstr.news/cluster/pilchard-herpesvirus-detected-in-south-african-sardine-mortality-event --- Cite as: South African sardine mortality event. CLSTR, https://clstr.news/situations/south-african-sardine-mortality-event