DFFE: Govt Continues Investigations Into Sardine Deaths, PHV Implicated

• The Department of Forestry, Fisheries and the Environment continues to investigate recent sardine deaths, with no new mass-mortality incidents reported since August 16, 2026.
• Pilchard herpesvirus (PHV) genetic material has been detected in 15 initially examined fish, with high viral levels found in 10 fish from the mortality event.
• The viral sequence shows a 99.7% match to an Australian PHV gene, and confirmatory testing for PHV is ongoing across additional samples.
• Investigations have largely ruled out harmful algae and broad environmental conditions as primary causes, though environmental stressors are not entirely excluded.
• A high-level task team has agreed on a coordinated response plan, and PHV is confirmed to pose no known risk to human health or the safety of commercially caught sardines.

The DFFE has reiterated that PHV is exclusively a fish virus and poses no known risk to human health, emphasizing that there is no evidence it can infect or cause disease in people.

The Department of Forestry, Fisheries and the Environment (DFFE) has confirmed that the government continues investigations into sardine deaths following a recent mass mortality event. While no new large-scale incidents have been reported since Sunday, August 16, 2026, suggesting a potential easing of the acute phase, comprehensive monitoring and testing efforts remain ongoing. This sustained governmental oversight aims to fully understand the causes behind the significant loss of marine life.

Initial findings from the DFFE's extensive testing program have focused heavily on the pilchard herpesvirus (PHV). Approximately 75 sardines have been incorporated into the PHV testing initiative to date. Early examinations conducted by the South African Institute for Aquatic Biodiversity and Rhodes University successfully identified PHV genetic material in 15 fish that were initially scrutinized.

Further analysis of these initial samples revealed consistently high viral levels in 10 fish collected directly from the mortality event. In contrast, viral levels varied among five fish that were caught alive and appeared healthy at the time of collection, suggesting a potential correlation between high viral load and the observed deaths. The genetic sequence of the detected virus showed a 99.7% match to an Australian PHV gene, indicating a strong similarity to known strains.

Beyond the initial cohort, the DFFE has processed an additional 60 samples for PHV screening. Preliminary results from roughly half of these samples also indicate elevated PHV levels. Confirmatory testing is currently underway, alongside pathological examinations of approximately 40 more samples. These examinations aim to determine if the fish exhibit characteristic gill inflammation and damage, which are typically associated with active PHV disease, providing crucial evidence for its causal role.

Investigations into other potential environmental factors have largely ruled them out as primary causes. Harmful algae, for instance, were not found to be a significant factor; paralytic shellfish toxins were undetectable, and domoic acid and yessotoxin appeared only at low concentrations, with the highest levels even found in an apparently healthy comparison sample. Furthermore, analyses of stomach contents and material rinsed from gills did not reveal harmful algae at densities sufficient to cause the observed mortality. While unusually cold water and low-oxygen conditions were noted along parts of the West Coast, these were broadly similar to conditions recorded during a prior pelagic recruitment survey when no dead or dying sardines were observed. The department highlighted that low oxygen periodically occurs in the region without previously leading to sardine mortality on this scale, making a general environmental cause less likely, though environmental conditions cannot be entirely dismissed as contributing stressors.

The accumulating evidence increasingly points towards PHV as the leading explanation for the sardine deaths, although its definitive causal role awaits confirmation from ongoing pathological and wider surveillance results. In response to the crisis, a high-level task team has been established, bringing together the DFFE, affected municipalities, management authorities, the fishing industry, and other relevant stakeholders. This task team has already convened its first meeting and successfully agreed upon a coordinated response plan.

The comprehensive plan outlines several key actions, including expanded surveillance and testing protocols to better track the situation. It also addresses the practical aspects of the event by providing clearer guidance on the proper disposal of dead fish. Public health communication forms another critical component, alongside an assessment of the potential long-term impact on the sardine resource. The DFFE has reiterated that PHV is exclusively a fish virus and poses no known risk to human health, emphasizing that there is no evidence it can infect or cause disease in people. Consequently, the detection of PHV does not render healthy commercially caught sardines or canned sardine products unsafe for consumption.

Despite the reassurances regarding human health, the public has been strongly advised against collecting, consuming, or feeding dead or dying sardines to pets. This precautionary measure is crucial while investigations continue and the full scope of the event is being understood. The DFFE has committed to providing further updates to the public as confirmed results become available, ensuring transparency throughout the ongoing inquiry. The apparent restriction of the mortality event specifically to sardines further supports the hypothesis of a targeted biological agent like PHV, rather than a broad environmental catastrophe, though environmental factors are still being considered as potential exacerbating elements.

Source: Original reporting via DFFE