Pilchard herpesvirus confirmed in sardines as cause of mass deaths remains under investigation

Laboratory sequencing has confirmed pilchard herpesvirus genetic material in sardines linked to recent mortalities along the West Coast.

Laboratory sequencing has confirmed the presence of pilchard herpesvirus (PHV) genetic material in sardines sampled following recent mass mortalities along South Africa’s West Coast.

The Department of Forestry, Fisheries and the Environment (DFFE) said PHV was detected in both dead sardines and, at lower levels, in some apparently healthy fish.

The finding suggests that the presence of the virus alone may not be sufficient to cause mass mortality, and scientists are investigating whether environmental stressors may have triggered or intensified the event.

These include harmful algae, low oxygen levels and unusual oceanographic conditions. However, the department stressed that this remains a hypothesis requiring further evidence.