Martine Viljoen, Two Oceans Aquarium Foundation: Over the past 20 years we've had a population of wild Cape Crest whales 4making use ofour harbour, acting as an 5extension of our oceans and to them I really think they believe this to be their home. It's a stop of point or a safe space. They're not 6habituated but they move in and out as they please.

CNN Narrator: 7Aside from playing the part of waterfront attraction, they also 8play a vital role within the 9marine ecosystem.

Martine Viljoen: They help balance everything out from being a 10prey source to being a 11predator themselves. They indicate how the health of the ocean is doing and they give us a valuable 12insight how the bigger picture of our ocean health.

CNN Narrator: Once heavily 13hunted, Cape Fur seals are now a 14protected species in South Africa, and it's 15estimated that around 2 million 16inhabit the coasts of southern Africa. Still, they 17face 18significant challenges with climate change, human-wildlife 19conflict, and more recently, 20rabies, all areas of concern. Here on the waterfront, a team from the nearby Two Oceans Aquarium 21looks after them.

Brett Glasby, Two Oceans Aquarium Foundation: The program that we run here, the Marine Wildlife Management Program, is unique. It's the first of its kind in the world where we are essentially reducing conflict between humans and animals within the space of a working harbor/tourist destination. We are the 22buffer.

CNN Narrator: But one of the most widespread and 23tangible threats facing these curious creatures is plastic pollution.