Sandy Shores


Sandy Shores, Strande, Elwandle, ebhishi

Special places to play that also protect our coastal communities

© Peter Chadwick

What are Sandy Shores?

Sandy shores are the coastal sandy connection between land and sea. They are dynamic ecosystems that are constantly moving. Tides, wind and waves move sand from one place to another, sculpting the shape of the shore into different types. These range from steep, narrow reflective beaches with coarse sand, to flat, wide dissipative beaches with fine sand. In between these are a range of intermediate types that are characterised by having sand bars in the surf zone, rip currents, or cusps (small hills on the beach). These different beach types are known as morphodynamic types. Because the dunes, beach and surf zone are so strongly connected, they are called the littoral active zone: the area where sand moves. Animals also move between these three zones, sometimes using one for resting and another for feeding. Therefore, sandy shores refer to the dunes, beach and surf zone as a single sandy unit.

Who lives on Sandy Shores?

Although beaches, dunes and the surf zone are all connected, they are home to different plants and animals that are adapted to the very different habitats in these ecosystem components. Further, the number and variety of organisms living on sandy shores is far more than meets the eye: over 500 different species have been recorded on South African sandy shores. Some are present in such high numbers that for every one-meter strip of beach between the dunes and waves, there are one million individuals of a single species. On average, in South Africa, there are about 100 beach animals bigger than one millimeter in the sand under your beach towel! Many of these species are unique to sandy shores, even unique to sandy shores in South Africa (endemic). This is because the environment is so harsh that the species have to be highly adapted to living where they do, and many species also have limited abilities to spread.

Because of the constantly moving nature of sandy beaches and the ebb and flow of salty tides, plants cannot grow on beaches; instead, they grow on nearby sand dunes where they play an important role in stabilising dunes. These dune plants are adapted for high temperatures, strong winds, salty conditions, low nutrients and minimal freshwater. Many of them are small and hold water in their leaves.

Terrestrial grazers like tortoises, grazing insects and even mammals like grysbok, steenbok and duiker can be spotted visiting healthy dune systems. Other mammals present in dunes include a variety of rodents, bushpigs, genets, porcupines, mongooses and monkeys. Dunes also provide food for interesting predators like caracal and gaboon adders, as well as smaller species, like spiders and beetles. Brown hyaena scavenge on wild beaches of the Atlantic coast although today these animals remain only in Namibia. Scavenging black-backed jackal are present in some South African dunes, e.g., in the Alexandria dunefield in Algoa Bay and at iSimangaliso in KwaZulu-Natal.

Even though it may not seem so, beaches are home to many different kinds of animals. Animals living on beaches either move about above the sand, live buried in the sand, or live in the spaces between the sand grains. Some species are big enough to hold in your hand, like ghost crabs, white mussels, plough shells and pill bugs; others are so tiny that you need a microscope to see them.

Although there are no plants on beaches, some species of algae live in between the sand grains, called microphytobenthos, on which some species feed. However, the amount of primary production from these tiny algal species is not enough to fuel beach foodwebs. Rather, beaches rely on nutrients from external sources, such as washed-up material from the sea or estuaries. When seaweed and kelp are washed ashore, it’s called wrack, and when dead animals are washed ashore, it’s called carrion. As a result, many species are scavengers, such as plough shells, ghost crabs, sand hoppers, beach hoppers and pill bugs. There are many predators too, such as some of the beach worms.

The abundance of invertebrate species on beaches provide food for lots of shorebirds, like gulls, plovers and sanderlings. Other bird species, such as Palm-Nut Vultures in KwaZulu-Natal also scavenge on beaches, and have been seen catching ghost crabs. Beaches and dunes also provide important breeding habitat for some shorebirds, including endemic species like African Black Oystercatchers, and sea turtles. Eggs laid on beaches, especially turtle eggs, are also an important source of food for beach animals.

The surf zone is that section of the shore that is under water and where waves are breaking. Both sand and water are constantly moving in this zone, so the animals that live here, especially where the sea meets the beach, have to be fast movers and able to burrow quickly in between waves. Some, like the white mussels and plough shells, surf with the waves and tides to maintain their position in this beach zone. Filter feeders grab tiny food particles from the water, such as white mussels, clams and other burrowing filter feeders like mole crabs (also known as sea lice). Fish such as moonies, mullet or harder, St Josef sharks and sand sharks also frequent the surf zone, as well as crabs like the three-spot swimming crab.

Phytoplankton in the surf zone also provide an important source of food for beach animals. This is especially on beaches where the phytoplankton, specifically surf diatoms, form accumulations that look like brown patches in the waves. The phytoplankton sticks to the surface of bubbles that form in the waves, where they photosynthesize during the day. They provide food for some species of fish, like mullet, as well as grazing beach mysid shrimps.

Why are Sandy Shores important?

Sandy shores include one of South Africa’s most valuable natural assets … beaches! They are special places to play, learn and are culturally and spiritually important spaces for many South Africans. They can be explored all along the South African coastline, attracting millions of visitors each year. Sandy Shores are also extremely valuable to humans by providing benefits in the form of essential ecosystem services.

Beaches are important for recreation and are a part of our South African way of life. Swimmers, surfers, anglers and families flock to beaches, particularly in summer. Visiting beaches is considered the most popular biodiversity-based tourism activity among both South African and overseas tourists. Investing in healthy beaches is an investment in the South African economy because they support tourism and coastal businesses.

Sandy Shores are critical nesting sites for valuable and threatened animals. Loggerhead and Leatherback turtles make their nests on the warm KwaZulu-Natal beaches. African Black Oystercatchers and sanderlings nest on beaches on all coasts. This provides important recreation, tourism and learning opportunities in the form of turtle tours and birdwatching.

Sandy shores are iconic sites for spiritual, religious and cultural practices and ceremonies. Beaches and saltwater are considered by many South Africans to be a place and product used for cleansing, healing, and spiritual renewal. Many South Africans visit the shore to connect with ancestors believed to reside in the water, and religious baptisms take place in the surf zone too. Visiting the beaches on certain days like New Year’s Day is also an important tradition in some cultures.

The plants and animals living on sandy shores and dunes provide us with food, medicine and materials and there are more than 220 useful plant species growing across the South African coastline. Coastal foragers have harvested dune plants, crabs, shells, and fish for thousands of years as food, traditional medicines and for use in rituals and ceremonies.

Healthy beaches and dunes provide ‘ecological infrastructure’ and are investments in our climate adaptation strategy. These ecosystems protect coastal communities by shielding them from rising seas and increased stronger storms because of climate change. Healthy dunes also protect coastal communities from extreme events like tsunamis.

Ancestral legacy of the Cape Fig (sour fig, Cape fig, ghaukum, ghoenavy, suurvy, ikhambi-lamabulawo, umgongozi)

Carpobrotus edulis

The original inhabitants of the Cape foraged along the coastline harvesting plants growing on dunes for food and medicines. Known as Ghaukum by the Khoi, the legacy and usefulness of the Cape Fig has been passed through generations and the plant is still harvested today. 

© Robyn Adams

In the past, all parts of the plant were used as traditional medicine. The fleshy leaves were used to treat sore throats, stomach cramps and diarrhoea, but could also be cut open and used to treat burns, skin irritations and stings from bluebottles washed up on the shore. 

The fruit of the cape fig plant is eaten by biting off the end of dried fruit and sucking out the tiny seeds inside a sour sticky pulp. These fruits are also used to make delicious jams and preserves.

How do we care for Sandy Shores?

The transitional nature of sandy shores means that they are under pressure from both land and sea-based activities. Human disturbance threatens the health of sandy shores and affects the animals relying on them.

To care for sandy shores we should:

Manage the coastal zone to maintain connections between dunes, beaches and the surf zone – Essential to sustaining healthy sandy shores is maintaining the connections between dunes, beaches and surf zones. To effectively manage sandy shores, these three zones should be managed as a unit. If built too close to the shore, coastaldevelopment can threaten the connections between these parts of the ecosystem and affect their ability to provide food; protect the coast from high waves during storms; or provide beaches for recreational, spiritual and cultural activities. They also reduce the habitat available for beach animals, also impacting bird populations. This is made worse as sea-levels rise because the whole beach area could eventually be lost. Individuals should take care when building near the coast and avoid harming the ability of the ecosystem to function. The National Coastal and Marine Critical Biodiversity Area map should be applied in impact assessment and spatial planning in the coastal zone. Protected areas should include all components of sandy shores (dunes and coastal vegetation, the beach and the surfzone) to effectively protect sandy shores and coastal ecosystems and their processes. Sandy shores are protected in Sixteen Mile Beach in the West Coast National Park, Table Mountain National Park MPA, De Hoop MPA, Robberg MPA and iSimangaliso MPA.

Restore degraded dunes – Dunes provide an important barrier to sea-level rise, storms, and large waves. Where these have been impacted by excessive trampling or inappropriate development, they should be restored to enhance the coastal protection services they provide. Dune restoration programmes should be rolled out in key areas, and people should avoid walking on dunes. Engineers should work with nature and employ creative, soft solutions to avoid beach erosion where possible. 

Reduce and manage pollution – Pollution can pose a serious threat to the animals reliant on sandy shores. Plastics are eaten by mistake and fishing lines can wrap around the bodies of animals. Our individual choices and actions can affect the amount of plastic pollution on the coastline. We should choose to reduce our plastic waste and recycle what we can. Responsible practices by industry and government to curb pollutants on the coastline should be encouraged to maintain the health of ecosystems.

How do we learn more about Sandy Shores?

Sandy shores occur all along the South African coastline and are popular places for recreation, spiritual connection and tourism. We can learn about sandy shores by visiting them. Some famous beaches in South Africa are found along the Diamond Coast in the Northern Cape, the West Coast National Park; the popular tourist beaches on the Atlantic coasts in the Western Cape; the untouched Wild Coast in the Eastern Cape; and the warm golden beaches of KwaZulu- Natal.

Dr Linda Harris

Research Associate, Nelson Mandela University

Studied: Bachelor of Science (University of KwaZulu Natal), Bachelor of Science, Honours ( University of KwaZulu Natal), Master of Science (University of KwaZulu Natal), Doctor of Philosophy (Nelson Mandela University)

What is interesting about the ecosystem you are working in?

Very few people know about the variety and number of beach animals that live buried in the sand. In fact, when you put down your towel on the beach, there can be tens to hundreds of tiny invertebrates in the sand underneath you. It is fascinating to find and learn about these animals, and the clever ways that they have adapted to living in such an ever-changing environment. Some have learnt to use the sun for orientation, others have internal clocks to dictate their behaviour (similar to why we get jetlag when we travel across time zones), and all have different ways of burrowing, jumping, running or surfing to move around and escape being washed away by waves. They perform hidden functions, like recycling nutrients that helps to keep beaches clean and safe for us. It is so interesting to learn that beaches are more than just sand for building sand castles!

What are the challenges with working in your ecosystem?

Beach animals are buried in the sand and most are very small: a few millimeters to a few centimeters big. The only way to find most of them is to dig up a lot of sand and sieve it, which is very physical work. To identify most of the animals, you need a microscope to look for subtle differences in the features that tell the species apart. Most sampling can take place only on spring low tides, so you are constrained in the amount of time you can spend doing the work, and can sample only a few beaches on a sampling trip before having to wait another two weeks before the next spring low tide. There is also very little funding available for sandy beach research. However, it is a lot of fun, and worth all the challenges! to know whether they are actually succeeding in the role that they were established to achieve.

What are you working on and why is it important?

Currently I am working on a spatial design for where is best to conserve sandy beaches (and other coastal and marine ecosystems) in South Africa. I have also been working on assessing the status of biodiversity on our beaches to see which ecosystem types are threatened and in need of more protection or rehabilitation. These activities are important because beaches play a very important role in our lives. They are one of the most popular places for recreation and tourism, and increase our sense of wellbeing. If we want to continue having nice beaches for our fun activities in the future, to conserve the unique set of animals that live on beaches, and maintain the important services they provide us, it is important to make sure that the connection between dunes and beaches is kept intact, especially as the rate of sea-level rise is accelerating in response to global climate change. This also helps to keep a natural barrier between us and large waves that crash into the shore during extreme storms, serving to protect us, our homes, and other buildings.

I also have some citizen science projects running on iNaturalist (Sandy Beaches (s Afr), Seashore Vegetation (s Afr), and Ghost Crab Watch (s Afr) in which anyone can participate. These projects are for collecting data on the distribution of beach animals as a way to increase awareness about beach animals, to help provide data for modelling species’ distributions, and to keep an eye out for shifts or extensions in species’ ranges.

Mzansea: revealing south Africa's marine ecosystems Logo

%d bloggers like this: