Sardine herpesvirus in South Africa raises concerns over Morocco’s fisheries

Wednesday 09 September 2026 - 08:08

By: Azzat Manal

Sardine herpesvirus in South Africa raises concerns over Morocco’s fisheries

The detection of a herpesvirus linked to unusual sardine deaths along parts of South Africa’s coastline has raised concerns among Moroccan fisheries professionals, who are calling for increased scientific and environmental monitoring. South African authorities, however, say the phenomenon remains localized and that there is currently no evidence that the virus has spread beyond the affected area or poses a risk to human health.

Unusual sardine strandings and mortality events began appearing along sections of the South African coast in early August. On August 14, authorities reported detecting genetic material associated with sardine herpesvirus, known as PHV, in samples collected for laboratory analysis.

Scientists have yet to establish conclusively whether PHV is the sole cause of the fish deaths. Investigations are continuing to determine the role of the virus and whether other environmental or biological factors may have contributed to the unusual mortality events.

Available scientific information indicates that PHV is associated with sardines and that there is currently no evidence that it can infect humans or spread to other animal species. Based on the information available, commercially caught sardines and canned sardine products are not considered a human health risk linked to this virus.

South African authorities have not recommended suspending sardine fishing, processing or commercial activities. Morocco has also not reported any detection of PHV so far, meaning that there is currently no specific indication of a health risk associated with sardine consumption in the country.

Laboratory testing has so far examined around 75 sardines, with 15 samples initially testing positive for the viral genetic material. The highest concentrations were detected in 10 fish directly associated with mortality events.

Genetic analysis also identified a sequence showing approximately 99.7% similarity to a virus previously detected in Australia during the 1990s. Australia experienced significant sardine mortality events, including episodes recorded in 1995 and between 1998 and 1999. However, scientists caution that these historical cases do not demonstrate that the same pattern will occur in South Africa or Morocco, nor do they establish that the virus can naturally spread between distant geographic regions.

The discovery nevertheless highlights the importance of monitoring marine ecosystems, particularly because sardines are an economically important species in several coastal countries. Changes in fish populations can have broader consequences for fisheries, processing industries, food supplies and coastal communities.

For Morocco, where the fishing sector plays an important role in the coastal economy, continued surveillance of marine diseases and unusual mortality events could help authorities identify potential threats at an early stage. Scientific cooperation and the exchange of information between countries could also contribute to a better understanding of the virus and its possible environmental implications.

Experts stress that the current evidence does not justify assuming that the virus represents an imminent threat to Moroccan fisheries. The key issue is to determine whether PHV is actually responsible for the South African sardine deaths and to understand its biological behavior before drawing conclusions about possible regional risks.

Further testing, larger-scale monitoring and longer-term observations will therefore be needed. Until more evidence becomes available, scientists and fisheries authorities are expected to maintain a cautious approach while continuing to monitor sardine populations and the health of marine ecosystems.