WATCH: Killer whales spotted off iSimangaliso coast

A video of the sighting has been posted on social media.

iSimangaliso shared the clip from its official Facebook page, saying how lucky the visitors were to see the species.

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"iSimangaliso's marine protected area has a very long list of marine species that call it home, or occasionally just pass through. The latest seasonal group of visitors is a pod of orcas (killer whales)," said the organisation.

"What an amazing experience for guests on the St Lucia Tours Charters Safaris whale watching boat today off St Lucia!"

In the description of the clip, credited to www.advantagetours.co.za, St Lucia Tours Charters Safaris says a pod of orcas moved into the area where the visitors had been watching humpback whales.

The pod then preyed on a humpback whale calf.

"A bit sad, but such is nature, carnivores have to eat," read the post.

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The iSimangaliso Wetland Park on the extreme north coast of KwaZulu-Natal is home to thousands of different species in unique wetland environments, the Indian Ocean and protected game reserves.

The park, transcending land and water, allows lucky visitors the chance to view the largest land mammals (African elephants) and the whales in its different protected areas.

The beaches are also world world-renowned for their turtle nesting sites. People also flock to the area to view crocodiles and hippos in their natural environment in Lake St Lucia.

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And if you're into birding, there are some 530 different bird species living in the area.