Multiple shark sightings off KuGompo City's shores have forced the temporary closures of Nahoon and this week Gonubie beach following a shark attack which took the life of an openwater swimmer off Orient Beach last month.
Gonubie Beach was closed on Tuesday afternoon after several sharks were spotted feeding on a whale carcass near the shore.
This came a week after two separate shark sightings at Nahoon Beach, following the fatal attack on Janine Lochrenberg.
It is unclear when Gonubie Beach will reopen.
Principal scientist at the East London Museum and environmentalist Kevin Cole said sharks were present throughout the year, but their numbers and visibility increased during seasonal periods such as the sardine run.
The sardine run usually starts around April or May.
However, a heavy influx of dead sardines in September raised concerns that scavengers and predators, including sharks, would be drawn closer to shore.
Cole had warned at the time that more sharks could move closer to the coastline, saying scavenging was normal behaviour.
"Sharks are a regular, year-round presence off KuGompo City with clear seasonal peaks, especially during the sardine run, when larger numbers of great whites and bronze whalers become more visible near the coast," Cole said.
"The numbers of sharks and different species change with the seasons.
"This coast supports a mix of large predatory species and smaller coastal sharks.
"Sharks are opportunistic so if there is a whale carcass floating at sea, they will predate on it but will not necessarily stay in the area when the food source has been depleted.
"Once the accessible flesh and blubber of the carcass has been largely depleted, or the carcass sinks or breaks up and drifts away, the sharks will typically disperse," he said.
Buffalo City municipal spokesperson Luzuko Buko confirmed the closure, saying several sharks had been seen feeding on a whale carcass reported by Gonubie residents.
"The whale carcass was spotted on Monday at Black Rock, which is not far from Gonubie Beach," Buko said.
"This led to the closure of the beach as a precautionary measure.
"Although the carcass cannot be seen currently, that does not mean the beach is safe for swimmers.
"Maintaining the current beach closure poses significantly less risk to the public.
"Reopening prematurely creates an unnecessary safety hazard.
"The beach will be monitored closely by BCM lifeguards, who will maintain heightened vigilance regarding any shark activities."
Nahoon Beach was also closed on October 24 and 25, prompting the municipality to extend lifeguards' operating hours ahead of the festive season.
Four separate shark-sighting incidents have been reported since the October attack.
Surfing guru and Dispatch columnist Nick Pike said surfing in the city had been affected for several years by the presence of sharks.
"Local surfing has been under pressure for some years now due to push-and-pull events on our great white sharks," he said.
"In my limited understanding and experience, orcas and demersal fishing helped push the great whites out of Cape Town.
"Upwelling, deep water and cold water in the KuGompo area along with well-stocked marine reserves full of fish and demersal to eat, contribute to a surge in great whites here."
Cole said the presence of a whale carcass could continue to attract sharks, depending on its condition and location.
If it was still floating, authorities could assess whether it should be moved or whether beaches should remain closed.
"The amount of predation by sharks and the size of the carcass will determine whether it sinks or remains on the surface," he said.
"To the best of my knowledge, no-one has examined the carcass," Cole said.
"The whale carcass, if still floating close to the coast and still attracting sharks, will require caution for bathers should it be near a bathing beach.
"It is unlikely any cause of death can be postulated from the remains as decomposition and predation will make any interpretation of the cause of death extremely difficult."
The Dispatch team did not see any evidence of a whale carcass along Gonubie Beach when visiting the area on Wednesday.
Buku said the municipality would begin assessments on Thursday to determine when the beaches could reopen.
Daily Dispatch