Wetland in Addo Elephant Park, South Africa

The Addo Elephant National Park in South Africa was established 94 years ago to protect the last 11 elephants in the Eastern Cape region. Since then, the reserve has expanded to 155,000 hectares and today it’s home to lions, leopards, rhino, buffalo and more than 600 elephants. It also has 16 rivers and 437 wetlands. Freshwater scientists Nancy Job and Dirk Roux were part of a team who co-authored the South African National Parks and South African National Biodiversity Institute’s first ever inventory of the park’s rivers and wetlands. With an inventory in place, the park is better placed to conserve wetlands for South Africa and plan for the future.

What wetlands exist in the Addo Elephant National Park

A wetland is a piece of land that is flooded with salt or fresh water most of the time. There are 437 wetlands of different types in the Addo park. To locate all the wetlands in the park, we conducted field surveys in close collaboration with the park staff. We were blown away by the exceptionally diverse landscapes we found. These ranged from arid inland steep rocky mountains and low-lying plains to higher altitude grassy ridges to sandy shores.

We found wetlands that had never before been documented. These included “dune-slack” coastal wetlands. These are wetlands in low-lying hollows which collect water between coastal dunes. Their overall size is ever-changing as the dunes are shifted by winds.

These wetlands are a window into an underground aquifer of water held within the sand. This water is invisible from the surface, except as glimpsed through these wetlands. They may well support species unique to these dune fields, and are of national significance.

We discovered springs hidden within forested gorges (known locally as “kloofs”) and depression wetlands (shallow, bowl-like ponds that hold water for only a few months in the year) inside areas of thick, bushy vegetation.

These were revealed to us only through the care and guidance of the rangers who know the area so intimately. Memorable findings include a life-giving spring in a dry river bed, and crater-like depression wetlands on the plateaus of a mountainous area.

Why is it important to monitor these wetlands

Rivers and wetlands (together with estuaries) are the most threatened and least protected ecosystem types in the country. They are also poorly documented and small in comparison with wetlands in other countries, making them difficult to detect.

Making an inventory of wetlands provides information about the type, condition, location, size and number of wetlands across an area, and the challenges that they face.

This is a first step towards managing and conserving these ecosystems. With each new inventory, the park contributes to the national knowledge base.

By the end of an inventory project, wetlands are no longer seen as mere wet spots in the landscape, but recognised as distinct ecosystems that support their own plant and animal life. This means the park is better placed to start to plan and monitor for the best outcomes for these ecosystems and the animals they support.

Why are the Addo Elephant National Park wetlands so important

The international treaty that protects wetlands (the Ramsar Convention) recognises the importance and critical ecological functions of small wetlands, such as those in the Addo park. In a dry climate such as South Africa’s, small wetlands play a huge role. They are water sources, and habitats or refuges for animals and people in times of drought or low rainfall.

During our research, the importance and lifeline that wetlands and springs held for historical settlement in the area was obvious. On one occasion, park rangers revealed to us a spring that had been modified, perhaps excavated, and a rock wall built to pond the water for ease of collection. In this very remote location, the spring had clearly supported the people and livestock that once lived there for many years before the area was declared a national park.

What are the major problems affecting the wetlands

About 300 biodiversity scientists come up with a national assessment of South Africa’s biodiversity about every six years. This assessment shows that wetlands are highly threatened, meaning that almost no healthy wetlands remain. This is the case across South Africa, not just in the Addo park.

Wetlands inside national parks are just as threatened as they are outside parks. In the Addo park, this is partly explained by the fact that the park was extended in the early 2000s using land that had previously been commercially farmed.

In those areas, the natural water flow had been diverted into small dams suitable for livestock and crop farming. It was difficult for natural wetlands in the area to recover on their own.

The oldest section of the park, established in 1931, has experienced an ever-increasing elephant population. Elephants have a remarkable ability to transform landscapes – and wetlands. Even in large fenced parks, the movement of elephants is relatively restricted and so more elephants trample through wetlands. This raises an interesting trade-off between the conservation of these animals and that of wetlands.

How can the Addo wetlands be protected as the climate changes

The new inventory is a baseline document for rivers and wetlands in the park. The effects of climate change can be monitored against this baseline in future.

Climate change disrupts weather patterns. It puts a lot of pressure on water resources and freshwater ecosystems. It could mean that wetlands hold water for a shorter time in the future, due to water evaporating more quickly. Wetlands are likely to be affected by climate change with less frequent but more intense rainfall. This causes soil erosion, and less water seeps into the ground to regenerate wetlands.

It will become increasingly important to prevent invasive alien plants from spreading, to monitor the water-holding patterns in reference wetlands, and to monitor soil erosion and the use of water by animals.