Cape Town - Increased aggression in Cape fur seals that has led to attacks on humans at Cape Town beaches, has been directly linked to the presence of rabies.
This is among the findings by City marine mammal experts, veterinarians, marine scientists and various government departments who attended a two-day workshop in Cape Town, focused on investigating the possible causes of the increase in the frequency of unusual and unprovoked Cape fur seal bites and aggression.
The “unusual” seal attacks around the coast in recent months have led to questions around suspicious seal behaviour.
In a latest incident in March, a seal attacked and bit divers along the Atlantic Seaboard near Oudekraal, wounding a Portuguese tourist and a South African.
Last year, a video of a young seal exhibiting unusually aggressive behaviour at Clifton 4th Beach went viral, showing the seal attacking a child and other beachgoers frolicking in the surf.
The City noted that experts at the workshop found that while aggression in seals was normal, the increased aggression could be directly linked to the spread of rabies.
“Some levels of aggression in seals should be considered normal and may arise from various causes including territorial behaviour, maternal protectiveness, pain or distress, as well as from poor health condition caused by various disease states.
“However, excessive aggression associated with unusual behaviour that is being documented in multiple cases is not normal and is directly linked to the now confirmed presence of the rabies virus in some individual Cape fur seals.
“Rabies appears to be well-established in the Cape fur seal population and is unlikely to be eradicable and should now be considered endemic requiring ongoing and long-term management by coastal authorities,” the City said.
Initial indications were that rabies was transmitted to seals from another wildlife population and not from local domestic dogs.
The experts highlighted that the effect of rabies on the seal population remained unknown, but in other animals, rabies typically flared and declined, rather than resulting in mass mortalities.
Coastal authorities in partnership with the State Vet, veterinary experts, researchers, marine mammal experts and animal welfare organisations will continue to implement ongoing proactive measures to manage the rabies outbreak, the City said.
“Questions however remain about the differences between seals – highly gregarious animals living in very large colonies – and other terrestrial animals in which rabies occurs. Given that this is the first documented rabies infection in a marine mammal population there are many unknowns,” the City said.
Cape Argus