Biodiversity under pressure — Western Cape ecosystems at a crossroads

According to CapeNature’s 2025 State of Conservation Report, more than half of the Western Cape’s 350 ecosystem types are now classified as threatened. In a province celebrated globally for its biodiversity, the implications are serious — not just for nature, but for people and livelihoods.

At the heart of the findings is a slow-burning emergency in freshwater and estuarine systems. Estuaries — biologically rich transition zones between rivers and the sea — are among the hardest hit. Forty-four of the Western Cape’s 54 estuaries are listed as threatened, having been battered by altered flows, pollution, invasive species and urban sprawl. River and wetland systems fare no better, with 101 of 138 freshwater ecosystems facing ecological stress.

Six of South Africa’s 22 Strategic Water Source Areas fall entirely within the province. These mountainous zones are effectively the nation’s water towers, feeding rivers that sustain agriculture, cities and rural communities alike. If these systems fail, the ripple effects will be felt in taps and irrigation systems across the country.

The pressures on biodiversity are not limited to the province’s rivers. Marine, shoreline, terrestrial and montane systems are also under siege. The drivers are familiar: habitat loss, changing land use, climate change, fire and the ever-expanding footprint of invasive alien plants. Each threat compounds the next, forming what conservationists increasingly describe as a “polycrisis” for biodiversity.

Silent decline

Unlike the visible drama of a wildfire or a flood, biodiversity loss is often quiet and cumulative. Wetlands dry up, frogs vanish, pollinators retreat, and entire ecological relationships fray unnoticed. By the time the absence is noticed — an empty estuary, a degraded vlei — it may be too late.

The report confirms that wetlands in particular are teetering. Nearly three-quarters of South Africa’s most critically endangered wetland types occur in the Western Cape. More than a third of river types and 40% of wetland types in the province have no formal protection. This lack of legal and physical safeguarding undermines ecosystem resilience just when it’s needed most.

The health of these wetlands is not simply a question of conserving birds or frogs. The systems act as sponges, soaking up floodwaters, filtering pollutants and recharging groundwater. Their degradation threatens agriculture, drinking water supplies and even regional stability in the face of a changing climate.

Biodiversity’s broken shield

CapeNature’s mandate includes protecting the Western Cape’s remarkable biodiversity, much of which is found nowhere else on Earth. The Cape Floristic Region — one of only six floral kingdoms globally — is renowned for its plant diversity and endemic species. Yet even here, the shield is cracking.

The report catalogues a long list of species under pressure: freshwater fish hanging on in shrinking rivers; endemic frogs surviving in isolated mountain pools; critically endangered plants with just a few known individuals left in the wild. Species such as the Table Mountain ghost frog or the blue-tongue orchid live on the edge of extinction, dependent on specific microclimates or pollinators that are themselves disappearing.

One high-profile casualty is the African penguin. Once a common sight along the coast, its breeding population has declined by more than 70% in recent decades, prompting its classification as critically endangered. While charismatic species like penguins attract attention, countless less visible organisms — spiders, amphibians, invertebrates — are disappearing in parallel.

Hope in the highlands

Yet the report has bright spots. Over the past year, CapeNature expanded the province’s protected area network by more than 13,000 hectares, a notable achievement in an era where competing land-use pressures are intense. Much of this gain came through stewardship agreements — innovative partnerships with private landowners to conserve critical biodiversity outside formal reserves.

These efforts are bolstered by new spatial planning tools, including the recently adopted Western Cape Biodiversity Spatial Plan. This blueprint enables conservationists to prioritise high-value, high-threat landscapes and intervene strategically. By layering ecological data, threat assessments and land-use trends, planners can map out where conservation will have the greatest impact.

Another encouraging development is the increased use of real-time monitoring and surveillance. CapeNature’s collaboration with universities, research institutes and citizen scientists has produced detailed inventories of plant and animal populations, helping to guide everything from fire management to species recovery plans.

Still, the gains are incremental and often precarious. As the report makes clear, many species and ecosystems remain one step from collapse. Monitoring can reveal the decline, but cannot halt it without political will, funding and broad societal support.

A tool for action

“This report is more than a reflection of where we stand environmentally,” said Anton Bredell, the Western Cape provincial minister of local government, environmental affairs and development planning, at the report’s launch. “It is also a useful guide for decision-making in a way that strengthens both ecosystems and communities.”

That emphasis on human wellbeing is echoed by CapeNature’s CEO, Dr Ashley Naidoo.

“The resilience of our ecosystems and the services they provide is key to the wellbeing of the people of the Western Cape,” he said.

The message is clear: conservation is not just about scenic beauty or species counts. It is about securing the natural infrastructure on which society depends — clean air, safe water, fertile soil and a stable climate.

Crucially, the report aligns with the national State of Environment Outlook and international commitments under the UN Convention on Biological Diversity. It is part of a broader attempt to not only track biodiversity loss but reverse it — one hectare, one river, one estuary at a time.

Looking ahead, CapeNature and its partners face a difficult balancing act: to expand the conservation estate while simultaneously managing pressures from development, agriculture and climate volatility. The tools are there: adaptive management, targeted restoration, stewardship programmes, spatial planning. What’s needed is urgency.

The report offers not just a snapshot of what’s wrong, but a foundation for action. It shows where life hangs in the balance and where interventions can still tip the scale. The Western Cape’s ecosystems have long shaped its identity, economy and culture. Saving them is not a luxury but a necessity. DM