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

Laboratory tests have confirmed the presence of pilchard herpesvirus (PHV) genetic material in sardines following a recent mass mortality event along South Africa's West Coast. However, it remains unclear whether the virus alone caused the mass mortality, as environmental stressors like harmful algae, low oxygen levels, and unusual oceanographic conditions are being investigated.

Tests found no paralytic toxins linked to harmful algal blooms in Saldanha Bay, but detected low levels of domoic acid and yessotoxin. The Department of Forestry, Fisheries and the Environment (DFFE) is convening an urgent briefing with fishing industry stakeholders and establishing a task team to formulate a coordinated response plan for PHV-associated sardine mortality.

Disease surveillance is being expanded along South Africa's coasts, and routine hydroacoustic biomass surveys will assess the impact on the sardine population. The virus is not known to infect humans or other animals, and there is no evidence that PHV makes healthy sardines unsafe for commercial or canned use. However, monitoring and food-safety controls should continue, and the public has been advised not to collect or consume dead or dying fish.