Penguins continue to die en masse

Bird flu continues to take a heavy toll on the African penguin colony on Halifax Island off Lüderitz.

The latest official count shows that 345 penguins, mostly adults, have died, but scientists estimate that more than 500 could have died since December.

In a desperate effort to curb infection, local scientists this week consulted widely with veterinarians and virologists to address a possible source of the avian influenza (H5N8) virus on the island.

“We have noticed that most affected penguins are clustered around colony two on the south side of the island, and in particular near a muddy wet patch adjoining this colony,” a Facebook post shared by scientists on the Lüderitz Marine Research group said yesterday.

The scientists wondered whether the muddy patch might be a factor in the continuing mortality, as it is crossed daily by adult penguins returning from sea.

The H5N8 virus is known to survive for a lengthy period in a wet environment.

Following consultations with veterinarians and virologists, ministry of fisheries employees spread buckets of salt over the mud patch before covering it with beach sand, based on the fact that the virus apparently does not survive well in a high-salinity environment.

Twenty more adult penguin carcasses, in addition to two juveniles and two chicks, were burnt to curb the spread of the disease.



Tragic consequences

The long-term impact of the outbreak on the endangered penguin species is a cause for concern.

“Halifax Island is one of the few localities across the African penguin's distribution where penguin numbers have been increasing over the last few years,” the scientists said.

In comparison, South African populations continue to plummet.

Before the outbreak, the island was home to about 7 000 adult penguins, including roughly 1 400 breeding pairs.

The bird flu has killed mostly adult penguins, of which the majority were breeders, “which makes the loss even more tragic”.

African penguins only start breeding at the age of five years and they form lifelong, monogamous pairings.

“It will take some time to replace these breeding pairs in the population,” the scientists said.

Earlier this year, when the mass deaths became obvious but the cause was still unknown, the scientists said they were seeing “decades of conservation efforts and rehabilitation work vanishing before our eyes”.

Too long

Official confirmation by the state veterinary laboratory that the mass mortality was caused by the H5N8 virus only became available last week.

Critics said the “unnecessary” delay in identifying the disease first noticed in December had weakened their ability to respond sooner. But the Lüderitz Marine Research group admitted that “frustratingly little” could be done to stop the spread of the virus besides monitoring the situation, incinerating carcasses and adhering to strict biosafety protocols.

A visit by local scientists to Halifax Island on 16 January made it “immediately clear that a mass mortality was happening”.

A fisheries ministry team was dispatched the next day to collect samples for analysis by the Central Veterinary Laboratory.

After a lengthy wait for feedback from the lab, additional samples were taken on 2 February and another 11 days passed before an official statement was issued.

JANA-MARI SMITH