According to authorities, rabies appears to be well-established in the Cape Fur Seal population and should be considered endemic. PHOTO: Supplied
- A scientific workshop determined that the unusual and unprovoked aggression of Cape Fur Seals in the Western Cape is due to the rabies virus.
- The virus is now considered endemic in the seal population, requiring ongoing management by coastal authorities.
- Experts recommended vaccination trials for seals regularly in contact with humans, though eradication of the virus from the entire population is not feasible.
A scientific workshop, to determine the cause of unusual and unprovoked Cape Fur Seal bites and aggression in the Western Cape, found rabies to be considered endemic and well-established in the seal population.
Marine mammal experts, veterinarians, marine scientists and various government departments from South Africa and worldwide attended the two-day workshop from Tuesday 23 to Wednesday 24 July.
Experts from the City in partnership with the Department of Forestry, Fisheries and Environment (DFFE), the Two Oceans Aquarium Foundation and Sea Search, attended the workshop which focused on the possible causes for the increase and frequency of any unusual and unprovoked Cape Fur Seal bites.
In a statement, the City said the workshop was to look at ways to manage the rabies virus in the Cape Fur Seal.
“With the recent confirmation of rabies in the Cape Fur Seal population, the workshop included discussions about the implications of and appropriate management responses to the rabies virus in the Cape Fur Seal population,” the statement read.
Months of headlines
In a recent incident on Sunday 26 May, a juvenile Cape Fur Seal bit several surfers participating in a longboard surfing competition at the eastern end of Muizenberg.
However, reports of aggressive seals and attacks on humans emerged as far back as October 2022 and January 2023 (“Keep distance from sea animals,” People’s Post, 17 January 2023).
In January last year, a video clip of a seal pup chasing and biting a child and woman in the swash at Clifton Fourth Beach went viral on social media. A day later, the NSRI indicated similar incidents involving aggressive seals in Hout Bay, Yzerfontein and Noordhoek.
In September 2022, a woman was chased and grabbed by the leg in a seal attack on Fish Hoek Beach.
At the time, Brett Glasby, wildlife management programme coordinator at Two Oceans Aquarium, said the behaviour exhibited by these seals was far from normal.
“I have been rescuing seals on Cape Town beaches for 14 years and have never experienced this kind of behaviour. Normally, when seals are encountered and feel harassed, they return to the water and escape. Animals that are weak or sick and unable to escape sadly die from the stress of human interaction.”
According to the City, the workshop looked at possible causes and aggression of Cape Fur Seals.
“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,” the statement read.
However, excessive aggression associated with unusual behaviour is not normal and is likely directly linked to the confirmed presence of the rabies virus in some individual Cape Fur Seals.
Well-established
The City added that it was unlikely to eradicate the virus/ seals as it was found to be well-established in the Cape Fur Seal population.
“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 findings also concluded that rabies was not transmitted from domestic dogs as previously believed.
“The effect on the seal population remains unknown, but in other animals, rabies typically pursues a ‘slow burn’ course of flares and declines, rather than resulting in mass mortalities.”
Authorities have meanwhile implemented proactive measures to responsibly manage the rabies outbreak among the Cape Fur Seal population of two million.
“Coastal authorities in partnership with the State Vet, veterinary experts, researchers, marine mammal experts and animal welfare organisations will need to continue to implement ongoing proactive measures to manage the rabies outbreak.”
Reporting, surveillance
Ongoing management actions include the reporting of all suspected or confirmed rabies, ongoing surveillance of the seal colony and euthanasia.
“A definitive diagnosis of rabies can only be done post-mortem, as such in cases where the presentation includes unprovoked or extreme aggression a poor prognosis is likely irrespective of the cause,” the statement read.
“Given the high risk posed by a potentially rabid individual that meets the case definition, immediate euthanasia of the affected animal is a justified and necessary response, in the interest of the seal itself, the seal population and as a protective measure for people.”
With over two million Cape Fur Seals spread between Southern Angola and the Eastern Cape, vaccination of the wild population is not considered viable or possible.
Experts recommended a trialled vaccination period focusing on seals that come into regular contact with people.
“Although the efficacy of rabies vaccines in seals is not yet known, there is no reason to expect adverse outcomes and it was strongly recommended that vaccination be trialled with a focus on animals that come into regular contact with humans.”
Natasha Bezuidenhout
www.news24.com
