By Lehlohonolo Lehana.
A mass sardine die-off that spread along the South African coast has eased, with no new deaths reported since 3 September 2026, according to Department of Forestry, Fisheries and the Environment (DFFE).
This comes as the department continues to probe widespread sardine mortality reported along the South African coast and similar strandings in Namibia.
The mortality event, which began in the Western Cape in late July, spread along the coast to the northern Wild Coast.
The department said it has received no further reports of dead or dying sardines since 3 September 2026, while no strandings have been reported along the KwaZulu-Natal coast.
It noted that sardines moving northwards during the annual sardine run typically occur in pockets of cooler nearshore water.
“The relatively warm inshore conditions along the KwaZulu-Natal coast may therefore have limited the further northward movement of affected shoals, although this remains a plausible oceanographic interpretation rather than a confirmed barrier to the mortality event. Monitoring is continuing, and the event cannot yet be regarded as concluded,” the department said in a statement on Sunday.
Laboratory testing has confirmed pilchard herpesvirus (PHV) in affected sardines from both the Western Cape and Gqeberha, supporting a link between the Eastern Cape mortality and the earlier PHV-associated event in the Western Cape.
“Taken together, the consistent detection of high levels of PHV in affected sardines, its confirmation in Western and Eastern Cape samples, and the observed mortality pattern indicate that PHV is the most likely primary cause,” the department said.
The department said the investigation has not supported harmful algae or the marine biotoxins screened for as the primary cause, although oceanographic and other environmental conditions could not yet be excluded as contributing stressors.
Laboratory, pathological and epidemiological investigations are continuing.
“A small sample of sardines collected off the KwaZulu-Natal coast in June and July 2026, before any mortalities were reported, tested negative for PHV. However, because the sample was small and limited in space and time, this does not establish that PHV was absent from the wider sardine population at that time, but it provides a useful pre-event comparison,” the department explained.
Testing of other comparison samples is continuing.
“There is currently no evidence identifying when or how the virus reached South African waters, and no basis for attributing its origin to a particular country, company or product,” it said.
During a meeting on 4 September 2026, the DFFE’s Small Pelagic Scientific Working Group (SWG-PEL) considered available scientific information, including diagnostic results, mortality observations and estimates, observer information and fishing data.
Preliminary mortality estimates were scenario-based and highly uncertain, as they depended on assumptions about fish density in visible patches, the width and continuity of affected coastal areas, and the extent to which local observations could be extrapolated.
“There is also no reliable estimate of the number of fish that may have sunk to the seabed.”
While the magnitude of the mortality remains uncertain, available evidence did not indicate that it has caused a sufficiently large reduction in the sardine population to warrant a complete closure of the fishery.
“The SWG-PEL nevertheless recommended a temporary precautionary limitation on catches while further information is obtained. The DFFE has decided to implement the recommendations by the SWG-PEL.”
The SWG-PEL also considered comparisons with PHV-associated mortality events in Australia.
“These provide an important warning and useful scientific context, but Australian mortality estimates and percentage population reductions cannot be applied directly to South Africa because the survey methods, spatial coverage, coastline, oceanographic conditions, fish distribution and stock context differ,” the department said.