When a smell so foul that locals called it “unimaginable” wafted over Cape Town this week, a search for the source of the stench choking the scenic South African tourist destination led to the city’s harbor.
Nearly a mile from the dock on Monday morning, Terence van der Walt, a local wine distributor, was stuck in traffic when the odor, made worse by the hot summer weather, began to drift into his car. With a smell so enveloping, rolling up his windows felt pointless.
“It was so putrid,” Mr. van der Walt said on Tuesday, describing his experience. “It would have been green if this were a cartoon.”
After the smell hovered over Cape Town for several hours, a team from the local environmental health department discovered the source: a 623-foot-long livestock carrier registered in Kuwait — with 19,000 cows onboard.
The carrier, Al Kuwait, had docked in Cape Town’s busy harbor on Sunday to replenish the feeding stocks during its journey to Iraq from the Port of Rio Grande in Brazil, according to shipping data. The animals had been onboard for more than two weeks.
It was the ship’s first time docking in South Africa, said Jacques Peacock, a spokesman for the national Society for the Prevention of Cruelty to Animals. So the organization had obtained a court order before the vessel’s arrival that allowed inspectors from the group to board the ship and inspect its cargo.
Onboard, they found a buildup of feces and ammonia in the animals’ cramped holding pens across several decks. It had created an “unimaginable” odor, the group said on Monday in a statement. On Tuesday, after inspectors had spent several hours onboard, the organization released images of cows with their coats caked in waste. Veterinarians found several dead and injured cows, and euthanized eight animals, the group said.
“This smell is indicative of the awful conditions the animals endure,” it said.
The group has campaigned in South Africa against the transportation of live animals by sea, and has lobbied the country’s government to ban the practice in its waters. Such vessels often have poor ventilation and unhygienic conditions, the group said, adding that the animals risk being trampled or injured in voyages over rough seas, and the ships rarely have an onboard veterinarian.
Although the South African government issued new guidelines last year regarding animals exported from the country, Mr. Peacock said that the S.P.C.A. now planned to seek stricter guidelines for ships coming from other livestock-exporting nations.
The ship is owned by the Kuwait-based Al Mawashi company, which specializes in livestock trade and transportation, with branches in Dubai, South Africa and Australia.
The vessel had been chartered by a client, and Al Mawashi knew nothing of the shipment of 19,000 cows or the conditions they were kept in, said Sithembele Qomoyi, a spokesman for the group’s South African division. The Al Kuwait complied with animal welfare regulations, he added. The carrier had recently passed inspection in Australia, where Al Mawashi also does business.
In South Africa, the Society for the Prevention of Cruelty to Animals are locked in an ongoing court challenge with the livestock trading company over the export of live farm animals.
Mr. Qomoyi said the society “regards any vessel transporting live stock by sea as a ‘death ship.’”
The carrier remained at the port on Tuesday and was expected to leave South African waters by Wednesday.
Officials have instructed the local authority that runs the port to ensure that the ship does not pump any waste into the harbor. Mr. van der Walt, for his part, said that he had been swimming in the ocean on Tuesday and found the water to be clear.
In the meantime, although the smell was coming from outside the city, it was a worrying reminder to locals who have been dealing with another source of foul matter: the city’s crumbling sanitation infrastructure.
Councilors in the mayor’s office moved quickly to assure residents that the latest noxious smell was not emanating from raw sewage, as happened just weeks before when a water pump collapsed in a northeastern suburb.
Last fall, heavy rains had damaged pipes in another suburb, sending sewage into rivers and wetlands, said Caroline Marx, a director of Rethink the Stink, a water activism group in Cape Town. And since then, the area has experienced about a dozen sewage spills, she said.
Despite the city having increased its sanitation budget, Ms. Marx said, Cape Town has been struggling to keep up with rapid urbanization. Away from its luxury hotels and affluent suburbs, residents in mushrooming shack settlements without basic services often share a water pump and portable chemical toilets.
“The city is years behind where they would like to be,” Ms. Marx said.