There have been renewed reports of sardines washing up along Cape Town beaches this weekend, as the Department of Forestry, Fisheries and the Environment urges people not to consume the sardines or feed them to pets.

Multiple accounts on social media posted pictures of sardines, commonly known as pilchards, washed up on Milnerton, Sunset Beach and Blouberg beaches. The Department confirmed that it is aware of sardines washing up on these local beaches.

The Department first alerted the public to this widespread sardine mortality incident on 3 August, after thousands of them washed up along the West Coast, including Saldanha and Gansbaai.

On Friday, 14 August, the Department issued a follow-up statement, saying that after laboratory tests, it was confirmed that pilchard herpesvirus (PHV) genetic material is present in sampled sardines.

“Its role in the recent sardine mortality remains under investigation. PHV was detected in both dead sardines and, at lower levels, in some apparently healthy sardines collected from the West Coast. This suggests that the presence of the virus alone may not be sufficient to cause mass mortality.”

 

The Department’s Zolile Nqayi said scientists are also investigating whether an environmental stressor, such as harmful algae, low oxygen or unusual oceanographic conditions, may have triggered or intensified the event.

“Tests for toxins in sardines collected off Saldanha Bay, the Cape Canyon and Gansbaai, together with an apparently healthy comparison sample from St Helena Bay, found none of the paralytic toxins associated with a harmful algal bloom in Saldanha Bay. Two other algal toxins, domoic acid and yessotoxin, were detected at low levels, with the highest levels found in the apparently healthy comparison sample. No other toxins included in the screening were detected.”

 

Nqayi says these findings suggest that the toxins tested for were unlikely to have been the primary cause of the sardine deaths. However, they do not entirely rule out harmful algae or environmental conditions as factors that may have placed additional stress on the fish.

An urgent briefing with small pelagic fishing industry stakeholders has since been convened, and a task team will be established to formulate a high-level coordinated response plan for PHV-associated sardine mortality in South African waters.

Disease surveillance along the West, South and East coasts has been increased, while further investigations continue.

“PHV has not previously been reported in South African sardines. It was associated with two large-scale sardine mortality events in Australasia during the 1990s. However, the virus was subsequently detected in apparently healthy Australian populations without causing continuous mortality.”

 

PHV is a virus associated with sardines, also known as pilchards, and there is no evidence that it infects people or other animals.

“The PHV finding alone does not indicate that healthy sardines caught commercially or canned products are unsafe, and does not currently justify a general suspension of fishing or canning. The biotoxin results are also reassuring, although they do not constitute a general clearance of all commercial catches. Monitoring and normal food-safety controls should therefore continue.”

 

Members of the public have been urged not to collect or consume dead or dying fish. They should also not feed dead or dying fish to pets.