The National Council of SPCAs (NSPCA) has threatened to institute prosecutions for whales that are caught in octopus traps as bycatch.
This comes after reports of drowned whales as a result of the traps.
"We have issued a warning to the trap owner and DEFF (Department of Environment, Forestry and Fisheries) has put a moratorium on this particular fisheries permit," NSPCA spokesperson Meg Wilson told News24 on Monday.
The use of octopus traps are a particular risk to the whales as they get caught in the long ropes.
"The National Council of SPCAs (NSPCA) is disturbed at the suffering caused by octopus traps being used at False Bay in the Western Cape. This is in light of the most recent three whales that were caught in these traps - two of which succumbed to death," said Wilson.
The threat comes after a whale was freed from octopus lines on Monday morning after it became stuck on Sunday.
"SAWDN (the South African Whale Disentanglement Network) successfully rescued the whale this morning," Gregg Oelofse, City of Cape Town manager of coastal management in the environmental management department, told News24 on Monday.
According to the City of Cape Town, the former Department of Agriculture, Forestry and Fisheries (DAFF) issued an exploratory octopus permit 17 years ago and in 2017, the City called on DAFF to set limits as part of the conditions for the permit.
"We argue that the national department should, after nearly two decades, be able to fully comprehend the impact and risks associated with the exploratory fishing. Clearly, there is an urgent need to design fishing gear that would not lead to the drowning of whales," said mayoral committee member for spatial planning and environment, Marian Nieuwoudt.
The NSPCA explained that it had recently been informed of the deaths of whales as a result of the traps.
"It's only been brought to our attention now. The bycatch, the octopi are kept in traps for days - if you lay a trap, you have to clear that trap within 24 hours," said Wilson.
"The NSPCA enforces the Animals Protection Act and we need to stand up for any animal where the law is contravened."
The City of Cape Town has also modified the way it deals with dead whales.
"When a whale carcass washed ashore we would go and remove it - it was a difficult job because these whales can easily weigh 30 tons," said Oelofse.
"In moving that whale, we were actually causing a lot of damage so now, when we are alerted to a floating whale, we tow it to a slipway and that makes it much easier to remove it."
He said that the carcasses are taken to the Vissershok landfill site near Table View where they are buried in a specific part of the site. There is also a dedicated team to clean up the area where the whale was removed from the ocean.
"It's a big operation and it costs a lot of money and a lot of staff," Oelofse added.
According to Oelofse's experience, large whales seldom beach alive and whales, such as humpback and southern right whales, usually die from ship strikes, being caught in the traps, or natural causes.
"Over the last five years, it (entanglements and traps) only accounts for 5% of deaths. We've removed about six whale carcasses so far this year."
Oelofse added that 10% of whale deaths can be attributed to ship strikes and the rest to natural or unknown causes.
Environmental organisation Greenpeace called for urgent action to prevent more whale deaths.
"We cannot sit back and just allow these senseless and gruesome whale deaths to continue. Endangered whales have many obstacles to face today - the climate crisis, pollution, ocean acidification, and overfishing, which threatens their food supply," said Melita Steele, senior climate and energy campaign manager for Greenpeace Africa.
The International Whaling Commission's report on the risk to Western Grey Whales (WGW) as a result of entanglement concluded that a serious effort should be made to minimise fishing along whale migratory routes.
"As a general point, it is clear that for WGWs to recover throughout their historical range, accidental mortality and serious injury in fishing gear must be minimised to the fullest extent possible. Authorities, as well as fishermen and fishing companies, in all of the range states need to be made aware of and acknowledge the risks that fisheries represent to these animals," reads the report from 2017.
According a report from the Western Australian government, Effectiveness of mitigation measures to reduce interactions between commercial fishing gear and whales , adapting the fishing gear could prevent whale deaths.
"Costs of gear modifications were assessed relative to the 'standard' current fishing gear configuration over the whale migration period. Incorporating biodegradable rope into a fisher's standard fishing gear would add no further costs - both being priced at approximately $44 per rig," reads the report.
For its part, the NSPCA urged members of the public to report all cases of animal cruelty.