A virus detected in sardines in South Africa raises concerns as far as Morocco
A virus previously known mainly in Australia has been detected in dead sardines in South Africa. As the die-offs spread, the episode is attracting attention in Morocco, where sardine stocks are already weakened. No cases have nevertheless been detected there.
The alert began in early August along the South African coast. Thousands of dead or dying sardines were observed between Saldanha Bay and Gansbaai, with some floating several kilometres offshore. Authorities initially considered several possible causes, including toxic algae, a lack of oxygen or unusual ocean conditions.
Analyses subsequently revealed the presence of Pilchard herpesvirus (PHV). On 14 August, the South African Department of Forestry, Fisheries and the Environment confirmed that the virus’s genetic material had been found both in dead sardines and, at lower concentrations, in some fish caught alive. The South African ministry nevertheless stressed that the presence of the virus alone did not yet explain all the mortalities.
On Bladi.net : Sardines Move Away as Fuel Prices Soar: Moroccan Fishers Face a Double Trap
Investigations have since strengthened this theory. All 15 of the first fish analysed by the South African Institute for Aquatic Biodiversity and Rhodes University tested positive for PHV. Ten sardines taken directly from the die-off had high viral loads. The sequence identified corresponds by 99.7% to a gene from the virus already known in Australia, according to a new official update published on 23 August.
The matter did not end there. On 27 August, new dead sardines were found around Gqeberha, in the south of the country. Strandings were also reported in Namibia, whose authorities are expected to send samples for analysis. PHV is now considered by Pretoria to be the main explanation for the episode observed in the Western Cape, although its role in the new mortalities still needs to be confirmed.
At this stage, no cases of PHV detected in Morocco
The South African episode is nevertheless beginning to raise questions in Morocco. Le Matin has notably examined the consequences that the emergence of such a pathogen could have for a Moroccan industry already facing a sharp decline in its catches.
But no available data currently makes it possible to assert that PHV has reached Moroccan waters. There is also an important difference between the populations concerned: the mortalities studied in South Africa affect the South African pilchard, Sardinops sagax, while the sardines caught off Morocco are mainly Sardina pilchardus, as recalled by the Food and Agriculture Organization of the United Nations (FAO).
It has therefore not been established that the virus detected in southern Africa can cause the same phenomenon in Moroccan sardines. Its spread is nevertheless being monitored more closely since the appearance of new mortalities and strandings farther north of the area initially affected.
This vigilance comes amid an already difficult context. Sardine landings in Morocco fell from approximately 965,000 tonnes in 2022 to 525,000 tonnes in 2024, a drop of nearly 46%. Morocco has also suspended exports of frozen sardines since February in order to prioritise the domestic market.
On Bladi.net : Morocco Keeps Its Sardines, German Shelves Are Emptying
The scarcity of the resource is already beginning to have effects abroad, particularly in Europe, where some retailers are experiencing supply difficulties. Any additional health pressure on sardine populations would therefore be closely monitored.