While government departments are still investigating the cause of the mass sardine die-off along the South African coastline, conservationists fear that the main food supply of the critically endangered African Penguin is disappearing.
As reports of dead and dying sardines spread along the Eastern Cape coast, experts in Nelson Mandela Bay have voiced their concerns over the impact this could have on dwindling African Penguin numbers.
And while the Department of Forestry, Fisheries and the Environment (DFFE) are still awaiting test results to confirm the exact cause of the mass mortality among these fish in recent weeks, the Algoa Bay Conservation group believes the department’s surveys in October or November to determine the scale of sardine losses should be brought forward to preserve the penguin population.
Meanwhile, reports of sardines washing ashore seem to be steadily spreading further west, with the latest report coming from the Wild Coast and Buffalo City Municipality, and officials warning residents not to pick up or consume the dead fish.
The department’s investigation into the mass mortality incident began early last month after it received reports of large numbers of dead sardines washing ashore along the West Coast, between Saldanha and Gansbaai.
This came after dead sardines from the Namibian coast were sent to South Africa to test for pilchard herpesvirus (PHV). This is currently believed to be the cause of the mass mortality after some of the samples tested positive for the disease. Other possible environmental factors are also being investigated.
In the following weeks, more sardines were found along the coast near Tsitsikamma, and last week beaches in Nelson Mandela Bay were littered with thousands of dead fish.
Over the past weekend, the Buffalo City Municipality also issued a notice for residents to avoid masses of dead sardines on their beaches.
“The DFFE recognises the concerns raised by conservation organisations. The Small Pelagic Scientific Working Group will meet on 4 September to review the latest findings and consider their implications for fisheries management. This assessment will inform advice on whether additional management measures are warranted. The scale of mortality remains uncertain, and the October/November hydroacoustic survey will provide essential information on the post-event sardine stock status,” the department said in its latest statement.
However, environmental scientist and director of Algoa Bay Conservation (ABC) Ronelle Friend says the penguin population in Nelson Mandela Bay cannot wait for the department’s surveys and has called for more urgent action.
“We have seen thousands of sardines wash up on the shore all over the country, and the ones we see are just the tip of the iceberg. How many more are dead and floating around in the ocean that we don’t know about?”
An ABC statement said marine scientists and pathologists were increasingly confident that PHV was the leading cause of the mass mortalities. Alternative explanations, including cold shock, toxic algal blooms, acute chemical pollution or severe hypoxia were far less likely, but could be contributing factors.
The group said the local PHV had a 99.7% match with an Australian strain that wiped out close to 70% of that region’s adult sardine biomass between 1995 and 1999, placing severe pressure on the marine food chain.
Friend said the annual Sardine Run, one of the largest fish migratory events along the South African coast, sees billions of fish come through Algoa Bay and make their way up the East Coast. This is a crucial event for the African Penguin population nesting on St Croix Island.
Her concern is that the loss of such a massive feeding event could have a further negative impact on the already dwindling penguin colony.
Almost a decade ago, St Croix was home to one of the largest colonies of African Penguins in South Africa, boasting upwards of 7,000 breeding pairs.
Through the use of specialised, non-invasive monitoring systems, scientists have been able to monitor penguin populations and health. This includes an automated weighbridge on Bird Island, along the penguins’ natural pathways, which determines colony weights and their direction of movement.
Various environmental and human factors, including increased ship activity around the ports of Nelson Mandela Bay, have played a part in the shrinking of the colony in recent years. In 2023, ABC estimated only 700 breeding pairs of the critically endangered species were still on the island.
“Taking into account the number of fish we have seen wash ashore, the breeding cycle of sardines, and their short lifespan, we are looking at a potential ecological catastrophe, not only for the penguins, but for seals, birds and other fish that rely on the sardines for survival,” Friend said.
Fellow director at ABC and environmentalist Thomas Stone said another factor threatening the African Penguin is its limited range and mobility.
“These are not birds that can simply fly away and look for other food. A drop in their food supply could be detrimental.”
Stone and Friend said a large area around St Croix was recently named as a marine protected area in an effort to limit fishing and allow penguins a better chance to feed, but further and more urgent government intervention was needed.
“We cannot wait another two to three months for the department’s survey to determine sardine numbers. Perhaps fishermen could be incentivised not to fish in a broader area, even if it is only for a limited period.
“Hopefully that could give the penguins a better chance of feeding on the limited numbers still available. At least until we can figure out how to address the sardine crisis,” Stone said. DM
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