Unprecedented rabies outbreak in Cape fur seals raises marine pandemic fears

The South African coastline is witnessing an alarming first: a rabies outbreak spreading through its Cape fur seal population. This unprecedented situation has raised concerns about a potential far-reaching marine pandemic, as rabies has only been observed in seals once before, in a single case in Norway back in 1980.

As the Cape fur seals – approximately two million strong across colonies from the South African tip to Namibia and Angola – grapple with the effects of the virus, symptoms such as heightened aggression and disorientation lead to imminent death within 10 to 14 days of exposure. “What is unfolding along the South African coastline is unprecedented,” asserted Debby Querido, Programme Director of Animal Survival International (ASI). She cautioned about the underestimation of the threat this outbreak poses not just to seals, but to the entire marine ecosystem.

Researchers suspect that black-backed jackals, which prey on seal pups, are the likely carriers of the rabies virus. The implications of rabies transmission are profound and troubling, given that the outbreak could spread rapidly among other local marine mammals, particularly in the confined natural spaces imperilled by human encroachment.

Infected seals have been reported to attack not only each other but also humans and domestic animals. While confirmation of attacks on other marine mammals in the wild remains uncertain, experts do not dismiss the possibility. Savannah Anderson, ASI Campaigner and Researcher, warned, “While the outbreak is devastating for local seal populations, the fear is that the virus could jump species, possibly infecting orcas, dolphins, and even whales.” With creatures such as orcas capable of traversing vast distances, the outbreak could threaten marine mammals as far afield as Australia and the Americas.

Efforts are underway among South Africa’s scientific and animal welfare communities to address this urgent situation. Given that the only definitive method to confirm rabies involves sampling brain tissue, veterinarians are learning to identify affected seals through observable clinical signs. SeaSearch, a marine-focused NGO, is at the forefront of monitoring seal colonies, conducting autopsies, and tracking potential in-utero transmission among seal pups. Dr Tess Gridley, Principal Scientist of SeaSearch, articulated the pressing nature of the situation: “We need to stop it at the colonies before it comes more to the coast.”

Additionally, Cape Town’s Two Oceans Aquarium has initiated a novel vaccination trial for seals in high-risk areas where human-seal interactions are common. Vaccination efforts are expanded to itinerant seal species like elephant and leopard seals to prevent further spread among different colonised areas.

The public is urged to remain vigilant. As experts advise, seals should be treated with caution, especially in popular recreational areas such as beaches and swimming spots. Infected seals may exhibit unprovoked aggression, and anyone who interacts with them should ensure they are vaccinated against rabies with their pets’ vaccinations also up to date.

In the unfortunate event of a bite from a suspected rabid seal, immediate action is crucial: thoroughly cleanse the wound with soap and water and seek emergency treatment at the nearest hospital. Furthermore, individuals should promptly notify local animal welfare authorities to prevent possible attacks on people or other animals.

The management of this outbreak lies in the hands of qualified professionals; individuals are discouraged from attempting to harm or cull seals. Reporting suspected rabid seals to relevant authorities is vital for ensuring the safety of both humans and marine life alike.