When you think about scuba diving, usually the first image that comes to mind is diving in warm tropical waters, hovering over coral reefs. But have you considered there might be an even more colourful dive site out there, teaming with life?
Along Cape Town’s shores, there lives a world beneath the waves. From the surface, kelp forests just look like floating, slimy plants, but once you submerge underneath, you will see an alien landscape come to life. In these kelp forests live over 14 000 documented species of marine animals.
Cape Town is one of the largest cities in South Africa and among the most multicultural in the world. It’s uniquely situated on the tip of Southern Africa, surrounded by the Atlantic and Indian Oceans. The Atlantic Ocean brings cold water upwards from the icy poles. In contrast, the Indian Ocean brings down warm water from the Mozambique channel. The meeting of these warm and cold-water masses has resulted in a vast diversity of life underwater.
Kelp (Ecklonia maxima), also known as sea bamboo, form underwater forests rising up to 15 m from the sea floor. They create a unique habitat to explore, acting as a refuge for smaller species of reef fish and shysharks.
Tips for marine life-spotting
You have all the gear ready, your mask, snorkel, fins and wetsuit packed. Now what? Here are some tips for learning how to spot the kelp forest locals.
- Check the diving conditions — Just like we experience different weather days on land, the ocean is the same. Using weather apps like windy.com will help make predictions on the best days to go explore.
- Research your dive site — With such a great diversity of life underneath the waters of Cape Town, you can expect to find them in various habitats! From cold water corals, being home to over 80 species of described nudibranchs to the thick kelp, hosting shelter to the 13+ species of sharks in our waters.
- Pick up a field guide — It’s always worth browsing the common species in an area before taking the plunge. Field guides are excellent, as they also tell you which habitats particular creatures are found in. This will help you know where to start looking. My favourite is the Two Oceans Guide.
- The kelp forest is home to numerous camouflaged critters, including some of the most interesting in the ocean, but spotting them can feel like a game of Where’s Waldo. Make sure to slow down. The slower you swim, the better chance you’ll have of spotting those camouflaged creatures waiting for you to pass by.
- Get low — Swimming close to the bottom and scanning the top of the reef line is a good way to spot sneaky fellows, such as octopuses, as they attempt to slink away unnoticed.
- Ask a local divemaster, they often know the locations of resident critters. Mention what you hope to see; chances are, the divemaster can take you right to it. You’ll also be helping to support local eco-tourism this way!
Editor’s note: You can get more marine life tips and inspiration from Danel on her Instagram page!
Common endemic marine life found in Cape Town
Cape Town’s underwater world is teaming with life. On a single dive, you can spot a great diversity of species, including octopi, crustaceans, sea fans, sponges, feather stars, brittle stars and interesting fish, like the klipfish (34 species have been described in Cape Town, most of them endemic). The Kelp forest is also home to several small sharks, including catshark and shyshark species, which use the kelp as a refuge from larger predators.
Cartilaginous fish (aka the sharks and rays)
Cartilaginous fish are fish that have a skeleton made of cartilage instead of bone! Sharks and rays are some of the most common of this type.
The pyjama catshark is a small but mighty shark found in the kelp forests and rocky reefs around Cape Town. This shark is named for its distinctive striped pattern, which resembles a pair of cosy pyjamas. But don’t let its cute appearance fool you – the pyjama catshark is a skilled hunter that can use its sharp teeth to prey on various small fish and invertebrates.
One of its unique adaptations is the ability to curl up its long, slender tail into a doughnut-shaped ball, which helps it hide from predators and squeeze into tight spaces.
The puffadder shyshark is a master of camouflage, blending in perfectly with the rocky reefs and kelp forests where it lives. Their unusual markings – golden brown with reddish-brown saddles – resemble that of their namesake, the puffadder snake, an aggressive species also found in South Africa. But unlike their reptilian counterpart, the puffadder shyshark is pretty non-confrontational; they curl up into a doughnut when threatened!
The short-tail stingray is a large and impressive ray found in shallow waters around Cape Town. This ray has a flattened, disc-like body that helps it blend in with the sandy seafloor and avoid detection by predators. One of its most unique features is its venomous barb, which it uses to defend itself from predators or to stun prey. But don’t worry – the short-tail stingray is generally not aggressive toward humans and would rather swim away than use its weapon.
There are hundreds of bony fish species found in the temperate waters of Cape Town. I just included my three favourites, which are all quite awkward and unique in their own way. To see some more common fish, check out this blog post on the 20 common bony fish of False Bay and how to ID them.
The red roman is a vibrant and colourful fish found in the rocky reefs and kelp forests around Cape Town. This fish has a distinctive red body with white spots and is often sought after by anglers for its delicious flesh. But the red roman is also an important predator in the marine ecosystem, feeding on various small fish and invertebrates. One of its unique features is its sharp teeth, which it uses to crush the hard shells of crustaceans and molluscs.
These fish are listed as ‘orange’ on the WWF SASSI endangered fish list. It’s better to think twice before purchasing a red roman at your local market.
Image by Two Oceans Aquarium
The galjoen is a tough and adaptable fish well-suited to the South African coast’s rocky shoreline and turbulent waters. This fish is not only an important food source for coastal communities, but it is also a cultural icon — it was officially declared South Africa’s national fish in 2010. One of its most distinctive features is the ability to change colour depending on its surroundings, which helps it blend in with the rocky reef environment.
This small and delicate fish, measuring only up to 20cm in length, possesses a long, thin snout perfect for hunting small crustaceans and invertebrates. It’s often mistaken for a seahorse due to its similar appearance, but it has a much slimmer body and a straighter posture than a seahorse.
As with seahorses, it’s the male longsnout pipefish that carries and incubates the eggs until they hatch. However, unlike seahorses, they do not have a pouch, instead, they use their tail to wrap around the eggs to protect and nurture them. One of the longsnout pipefish’s remarkable features is its ability to change colour and pattern to match its surroundings, providing excellent camouflage that makes it almost invisible to predators and prey.
The diversity of large marine mammals in South African waters is remarkable, with over 40 species that depend on our rich coastal and open ocean ecosystems. The seas near Cape Town support the widest diversity, including five species of dolphin and three species of baleen whale, as it is the boundary between the cold Benguela ecosystem and the warmer Agulhas Current. The close continental shelf around Cape Town also means that some deep-water species, like pilot whales, are occasionally seen.
For more information about whale and dolphin research in South Africa, visit Sea Search.
Cape fur seal
Cape fur seals are a common sight along the coast of Cape Town, and their playful antics and barking calls are a delight to watch and listen to. These intelligent and social animals spend most of their lives in the water, where they are agile and graceful swimmers.
October and November is the primary breeding season for Cape fur seals, when the massive bulls come ashore on Seal Island and collect harems of about 20 females. The seal population grows to over 74,000 seals over the mating period, including about 20,000 adorable pups. Uniquely, Cape fur seals mate only 6 days after giving birth and fall pregnant 4 months later – a process known as delayed implantation.
Common dolphins are one of the ocean’s most playful and social animals. They are known for their striking colouration, with a distinct hourglass pattern on their sides and a dark back that fades into a light belly. These dolphins are fast swimmers and often swim alongside boats, showing off their acrobatic skills with somersaults, jumps, and tail slaps. They are also known for their synchronized swimming, often seen in large groups or pods of up to 1000 individuals. Common dolphins feed on various fish and squid. They can be found in the Atlantic and Pacific Oceans, including off the coast of Cape Town.
Humpback whales are some of the most fascinating creatures that call the ocean home. These giants are easily identified by their long white flippers, which can measure up to nearly one-third of the entire length of their body.
Despite their massive size, humpback whales are known as the ocean’s acrobats for their playful activity. They aren’t afraid to breach – jump out of the water completely – or lobtail – slap their tail on the water. Another one of their tricks is to ‘spy hop’, which is when the whale sticks its head out of the water.
Humpback whales measure around 13.5 m and weigh up to 50 tons. Large super-pods of humpback whales feed off the coast offshore of Cape Town to Yzerfontein on their annual migration from the tropics to Antarctica. These are the largest groups of humpbacks known on Earth.
Southern Right whale
Image by Tomas Kotouc | Shutterstock
The Southern Right Whale is a majestic creature with a unique mouth feature. Its upper jaw contains 200-270 fine plates that hang downwards and act as a filter for its food, making it a baleen whale. These giants of the deep can measure between 15-17m in length and weigh between 20 and 40 tons.
Every year, from June to November, the Western Cape’s coastline becomes a playground for these whales as they migrate from their feeding grounds in the Southern Ocean to the warmer waters of the Atlantic for mating and birthing. Their presence is a fantastic sight, considering the fact that just a century ago, they were driven to the brink of extinction by whaling ships.
Southern Right Whales are known for their elegant acrobatic displays, and the abundance of shallow, protected bays in the area offers the perfect stage for these performances. Whale watchers are often treated to a show of breaching, tail slapping, and spy hopping.
Despite their protected status since 1935, remnants of whaling stations can still be seen along the Western Cape coastline.
Best places to see the Southern Right Whales
- False Bay absolutely teems with whales during the months of August, September and October. While you will undoubtedly be treated to magnificent sightings from anywhere along the coastline, Boyes Drive offers a delightfully elevated view, as does Clarence Drive on the opposite side of the Bay. However, if you want to get a slightly closer view, head out into the water with Simon’s Town Boat Company.
- Hermanus is known as the whale-watching capital of South Africa, offering particularly good land-based viewing from its famous Cliff Path.
- If spotting whale calves is what you’re after, make a beeline for Witsand/Cape Infanta in the southern Cape anytime between July to November. Known as the whale nursery of South Africa, you will get to see moms and babies frolicking in the shallow, protected Bay. If you like your whale watching with a bit of a challenge on the side, be sure to make a booking for De Hoop Nature Reserve’s ever-so-popular five-day Whale Trail.
The dusky dolphin is a small oceanic dolphin found in coastal waters near Cape Town. They are characterized by their distinctive black and grey coloration, reaching a length of 1.8 – 2 meters and weighing between 70 and 100 kg. They are highly social and live in pods of up to 100 individuals, often displaying acrobatic behavior such as leaping, somersaulting and tail-slapping.
Their diet mainly consists of small fish and squid, and they are known to dive to depths of up to 200 meters in search of prey. Despite being popular for dolphin-watching tourism, the dusky dolphin is currently classified as “Data Deficient” by the IUCN, and their population status is unclear.
Invertebrates are animals that lack a backbone or vertebral column, and include a vast array of species such as insects, spiders, worms, mollusks, and crustaceans. In fact, they make up the majority of the animal kingdom! Marine invertebrates play important roles in marine ecosystems, serving as food for other animals, providing shelter and habitat, and contributing to nutrient cycling and oceanic productivity.
West Coast rock lobster
The West Coast Rock Lobster, also known as the crayfish, is a beloved delicacy in South Africa. They prefer rocky areas and kelp forests where they can hide and forage for food. These lobsters can grow up to 60cm in length and weigh up to 4kg.
An interesting fact about the West Coast Rock Lobster is that they have been known to walk out of the ocean and onto the shore during harmful red tides caused by an overgrowth of algae. The lobsters are trying to escape the low-oxygen waters and can be seen walking along the beach in search of safer waters.
You can’t have whales in an article about common marine species without including the key reason these lovable megafauna are present — their food!
Krill are tiny crustaceans that are essential to the marine food chain. They are found in all of the world’s oceans and are a vital food source for many marine species, including whales, seals, penguins, and fish. These tiny creatures are only a few centimetres long and have transparent bodies with a red, orange or yellow colouration.
Krill feed on phytoplankton and are a critical link between the primary producers and the larger animals that depend on them for survival. Despite their small size, krill exist in massive swarms, and some species can be found in densities of up to 10,000 individuals per cubic meter. Krill are also a significant source of omega-3 fatty acids and are harvested for use in nutritional supplements and animal feed.
Imagine having eight arms, nine brains, and blue blood running through your veins. Sounds like a creature from another planet, right? But it’s not. It’s the common octopus, a fascinating and intelligent creature found in the waters around Cape Town. These cephalopods are highly adaptable and can change their colour and texture to blend into their surroundings.
With the ability to squeeze through incredibly small spaces, the common octopus is a skilled predator, using its powerful beak to break open the shells of its prey. Despite their intelligence, the lifespan of the common octopus is relatively short, with most only living one or two years.
Like their cephalopod cousins, the common cuttlefish can change their colour and texture. Their soft, elongated body is supported by a unique internal shell called a cuttlebone, often washed up on the beach. They have eight arms with two rows of suckers and two longer tentacles for capturing prey. Cuttlefish have three hearts and blue-green blood, making them even more intriguing. These intelligent creatures have a complex nervous system, including a central brain and a second brain surrounding their oesophagus.
Cape Town is home to some of the world’s most stunning nudibranchs, including the Doris, Chromodoris, and Flabellina species. These colourful sea slugs can be found in the shallow waters of kelp forests and rocky reefs, where they prey on small invertebrates. Nudibranchs are known for their striking colours and unique shapes, with some species sporting ornate frills and others resembling flattened worms.
Despite their delicate appearance, they possess a potent defence mechanism – many species store toxins in their bodies, making them unpalatable to predators. Interestingly, nudibranchs are hermaphrodites, meaning they have both male and female reproductive organs.
They range in size from just a few millimetres to a few centimetres. Over 220 species of nudibranchs have been described in Cape Town, with new species still being discovered.
With their round, spiky shells and long, tube-like feet, the Cape urchin is unmistakable in appearance. Unlike some other types of sea urchins, those found in Cape Town are not poisonous to humans and are actually considered a delicacy in some cultures (you might have heard of ‘uni’).
They play an essential role in the ocean’s ecosystem as they feed on algae, while their waste promotes the growth of beneficial microorganisms that recycle nutrients, keeping the underwater environment healthy.
The abalone is a marine mollusk found in oceans all over the world. Its shell is known for its beautiful iridescence, with colors ranging from deep blues and greens to pinks and purples. Abalone meat is a delicacy in many cuisines, and its shell is often used in jewelry and decorative arts.
Despite their popularity, abalones are facing a serious threat due to overfishing and poaching. In many areas, abalones have been harvested to the point of near extinction, and illegal poaching continues to be a major problem.
Poachers illegally harvest abalone from the wild, often using dangerous and destructive methods that can damage the surrounding habitat and harm other marine life. Poaching also puts a tremendous strain on already endangered populations, making it even more difficult for them to recover.
The demand for abalone is driven largely by the Asian market, where it is considered a delicacy and is often used in traditional medicine. Unfortunately, this demand has led to the overexploitation of abalone populations, and many species are now on the brink of extinction. For this reason, it is important that we do not contribute to the problem by consuming abalone or supporting the illegal trade in any way.
Abalone farming can be a sustainable and environmentally responsible way to enjoy this delicious seafood delicacy without contributing to the poaching crisis. By choosing to support abalone farms, you can help protect wild abalone populations and promote sustainable aquaculture practices. Not only does this help to conserve the species, but it also provides a source of income and employment for many communities.
While there are many other sea star species in these waters, I’ve chosen to focus on this particular one because of its striking appearance and ecological importance. The African spiny sea star is a true beauty with its long, spiky arms and vibrant colouration. But it’s not just a pretty sight – it plays a crucial role in keeping our marine environment healthy and thriving.
The African spiny sea star is a voracious predator (our only carnivorous sea star), feeding on various small marine animals such as molluscs, crustaceans, and other sea stars. By controlling the population of these prey species, the African spiny sea star helps maintain a balanced ecosystem in which no species becomes too dominant.
Corals are pretty… amazing. Most South Africans are familiar with the beautiful coral reefs in northern KwaZulu-Natal. In the warm light-infused water of the Indian Ocean, these sunlight-powered communities support an incredible diversity of fishes and a thriving scuba diving industry that is a key aspect of South Africa’s marine tourism economy.
Further South, there are coral reefs thriving in the cold, crispy waters of the Cape. These include a variety of hard corals, such as the blue coral (Heliopora coerulea) and the star coral (Stephanocoenia intersepta). Soft corals, also known as octocorals, are more abundant, with species such as the sea fans (Eunicella spp.) and sea pens (Pennatula spp.) being commonly found in the area.
I highlighted my favourite, the false coral (Alcyonium coralloides). Despite the challenges of rising ocean temperatures and bleaching events, sea fans in Cape Town have shown remarkable resilience. They are a testament to the hardiness of these creatures. Sea fans may be fans of the ocean, but they’re also the ocean’s biggest fans! These delicate and intricate structures provide important habitats for small fish and invertebrates.
Explore the Cape’s marine wildlife
Cape Town is a treasure trove of marine biodiversity. From majestic whales and playful seals to colourful fish and intricate invertebrates, the ocean here is a wonderland waiting to be explored. While we have only highlighted 20 of the most common species, there are countless other marine creatures to discover in the waters around Cape Town.
If you want to explore the marine life of Cape Town, there are many ways to do so. Freediving, snorkelling, and scuba diving are all great options, depending on your comfort level and experience. For those new to the underwater world, we recommend starting with snorkelling or booking a guided dive with a reputable dive center.
Some of the most popular dive centers in Cape Town include:
These centers offer a range of courses, guided dives, and equipment rentals to help you get started on your underwater adventure.
However, it’s important to remember that while the ocean is a source of beauty and wonder, it’s also a fragile ecosystem that needs our protection. To help preserve the marine life of Cape Town, we encourage you to support sustainable tourism practices and do your part in reducing your impact on the ocean. This may look like saying NO to single-use plastic, opting to walk, cycle or use public transport over driving or even something as small as turning light off behind you. Every bit counts!
So grab your wetsuit and dive into the fascinating world of Cape Town’s marine life – you never know what incredible creatures you might encounter beneath the waves.
About the author
My name is Danel Wentzel. I am a marine biologist, wildlife TV presenter, and aspiring underwater filmmaker. I work in various freelance spaces, including social media consulting for the Save Our Seas Foundation Shark Education Centre. With a passion for ocean conservation and exploration, I use my expertise to educate others about the importance of protecting marine life. You can follow my adventures on Instagram at @mermaid_danii