SA’s biodiversity is at risk despite commendable conservation laws
Johannesburg - Dr Andrew Skowno started his career counting the Clanwilliam cedar, an iconic conifer tree species, found in the Cederberg mountains and nowhere else on earth.
The critically endangered species, which survived the last Ice Age, is being wiped out by climate change.
“It faces increasing pressures as temperatures rise, the environment dries out and fires become more frequent, “ explains Skowno, the lead scientist for the National Biodiversity Assessment (NBA) at the South African National Biodiversity Institute (Sanbi).
“Unfortunately, across our assessments, climate change is emerging as a more apparent threat to our species and ecosystems.”
The NBA is a landmark outlook on the increasingly fragile state of SA’s biodiversity. “We live in a dynamic period of land use change and sea use change, affecting our environment and people, set against the backdrop of dramatic global climate change. To navigate this, we need good information,” says Skowno of the NBA’s importance.
The four-year project was undertaken by 480 scientists from 90 organisations. It reveals how almost half of all SA’s 1021 ecosystem types are threatened with ecological collapse and one in seven of the 23 312 indigenous species assessed are threatened with extinction. Major pressures include habitat loss, changes to freshwater flow, overuse of some species, pollution, climate change and invasive alien species.
However, efforts to protect biodiversity “are showing promising outcomes”, as over two-thirds of ecosystem types and 63% of species assessed are represented in protected areas.
Investing in ecological infrastructure, “is as important as investing in built infrastructure” and safeguarding the delivery of services from ecosystems can support service delivery from all spheres of government,” writes Barbara Creecy, the Minister of Environment, Forestry and Fisheries, in the forward to the NBA’s 214-page synthesis report.
But the report’s authors state that while biodiversity is a national asset and a powerful contributor to inclusive growth and job creation, its protection is, at times, “cast as a hurdle” to socio-economic development.
This is “unfortunate”, the authors assert.
“Every decision taken, whether by the government or individuals, affects the future of biodiversity. By investing in the restoration, protection and management of our biodiversity assets and ecological infrastructure, we enhance social and economic development and contribute to human well-being.”
Skowno adds: “We may not ever know we’ve lost something crucial because we never discovered its particular value. There’s that old argument, that the cure for cancer becomes extinct before we’ve even noticed it ... And nature, too, has its own intrinsic value.”
Biodiversity provides jobs
Jobs directly related to biodiversity total more than 418000 “and this is likely an underestimate”, says the report, detailing how this is comparable to the mining sector. For each job dedicated to protecting biodiversity there are five that depend directly on using biodiversity.
Continued investment in managing and conserving biodiversity is essential. “In a context where employment in traditional sectors such as manufacturing and agriculture is declining, biodiversity-related employment is based on a renewable resource, that, if appropriately managed, can provide the foundation for long-term economic activity and sustainable growth,” says the report.
Healthy ecosystems = water security
Rivers, wetlands and their catchment areas are crucial ecological infrastructure for water security, often complementing built infrastructure, but their benefits are compromised by their poor ecological condition.
This is from the over-extraction of water, pollution from wastewater treatment works, agriculture and stormwater (nutrients, plastics and toxins), invasive alien species, habitat loss and degradation and climate change.
“Pollution of inland aquatic ecosystems from acid mine drainage, mining, industrial and urban wastewater, as well as agricultural return flows, negatively impact water quality. Protection and rehabilitation should be prioritised; particularly the rehabilitation of our malfunctioning wastewater treatment works and the management and eradication of invasive plants in Strategic Water Source Areas (SWSAs).”
SWSAs make up just 10% of SA’s land area but deliver 50% of all surface water, supporting half the population and nearly two-thirds of the economy. Only 12% of their extent fall within protected areas.
Climate change is impacting on people, ecosystems
The impacts are evident “across all realms and within most species groups” but biodiversity provides resilience against the worst effects of climate change.
“Restoring ecosystems and maintaining them in a good ecological condition means they are better able to support natural adaptation and mitigation processes, offering increased protection to human communities and reducing the economic burden of future climate disasters.”
Shifting migration times for species (Palaearctic migrant birds), declines in range sizes (Protea canary) and large-scale plant die-offs (Clanwilliam cedar) are being observed. Significant reductions in 70 species of amphibians’ range sizes are probable early impacts, too, according to the report.
Southern Africa has recorded nearly 500 climatic disasters impacting 140 million people in the past 40 years. Temperature increases of more than 1ºC in the past 50 years have been accompanied by the intensification of extreme events - droughts, heavy rainfall, coastal storm surges, strong winds and wildfires.
“Increases of 2-4°C are predicted for southern Africa by 2050, and confidence is therefore high that climate change will have dramatically escalating impacts on South Africa over the coming decades.”
Impacts are “triggering large-scale spatial, temporal and compositional shifts in biodiversity. Species’ population-level changes are being translated into community-level reorganisations, and even regime shifts (bush encroachment), which can impair ecological function”. Over the last few decades these changes have been noted in SA ecosystems from estuaries, coral communities, open savannas to montane streams, exerting pressure either directly or indirectly on all species within these habitats.
“Climate change is a key threat to sub-Antarctic ecosystems; mean annual air and sea temperatures have increased at twice the mean global rate at our Prince Edward Islands.”
It will not only increase the risks to estuary ecosystems under significant pressure at present “but also to the human communities and associated infrastructure and property surrounding them”.
Climate change, say the authors, is “widely considered as a multiplier of other pressures on biodiversity, both exacerbating the effects of these pressures and altering the frequency, intensity and timing of events.
“Many of these shifts are predicted to benefit the survival of invasive species over native species and increase the outbreak potential and spread of disease.”
Small high-value ecosystem types provide disproportionate benefits
Indigenous forests, inland wetlands, lakes, estuaries, mangroves, dunes, beaches, rocky shores, kelp forests, reef seamounts, pinnacles and islands take up less than 5% of the country’s territory but are “responsible for a disproportionally large number of benefits”, such as water purification, nutrient recycling, carbon storage, storm protection, recreation and harvesting of food directly from nature.
“They should be prioritised for planning, management, and protection and restoration efforts as such efforts will provide a high return on investment, both for biodiversity conservation and for benefits to society.” These ecosystem types are particularly vulnerable to climate change.
Benefits from fishing at risk
Estuarine and marine ecosystems provide food and livelihoods yet many fish stocks are overexploited and many fish species are threatened.
“The benefits provided by fishing, which include providing food for people and fodder for intensive animal farming, as well as thousands of jobs, are at risk from poaching, overfishing, unselective fishing practices (gill netting, trawling), habitat degradation (mining) and declining conditions of fish nursery areas (in estuaries).
“Fisheries stock status is not assessed for 90% of the more than 770 harvested marine taxa, and of those 10% that have been assessed, more than a third are overexploited or collapsed,” says the report.
Estuaries, inland wetland ecosystems highly threatened
About 99% of estuarine area and 88% of wetland area is threatened - less than 2% of their extent is in the well-protected category. They are essential for water security, food security, tourism and recreation and natural disaster risk reduction. “They are also important havens for many endemic species that are threatened. Restoring and protecting these ecosystems will secure the key benefits from these ecosystems and deliver a large return on investment.”
Freshwater fishes are the most threatened of all species groups that have been fully assessed with one in three threatened with extinction. Half of these species are found nowhere else on Earth.
Protected areas safeguard many species
They are generally providing good protection for species, with the proportion of threatened species increasing over the past 30 years for most taxonomic groups assessed.
But when considering threatened species alone, more than 85% of threatened birds, plants, freshwater fishes, amphibians, mammals and butterflies are under protected,” and continued expansion is needed.
While wildlife abundance continues to decline across most of Africa, SA remains a stronghold for mammal conservation, boasting "genuine success stories" that often result from cooperation between the public and private sectors, notes the NBA.
60% of SA’s coastal ecosystem types are threatened
Pressures on coastal biodiversity include unsustainable harvesting of species, inappropriate infrastructure development, mining, decreased freshwater flow into the sea from rivers and pollution.
“Proportionately, the rate of habitat loss in the coastal zone is twice that for the rest of the country,” says Linda Harris, of Nelson Mandela University, who led the coastal assessment. Some beaches are being eroded, putting one of SA’s most popular recreational activities at risk.
Invaders threaten biodiversity, well-being
Over 100 alien species have a severe impact on biodiversity and in some cases, on human well-being, impacting on water and food security. Invasive trees and shrubs reduce surface water resources by 3% to 5%, and threaten up to 30% of the water supply of cities like Cape Town and Port Elizabeth. “Invasive alien plants also reduce the capacity of natural rangelands to support livestock production, threatening rural livelihoods and food production,” states the report.
What needs to be done?
The variety of plant and animal life in the world or in a particular habitat, a high level of which is considered to be important and desirable.
SA’s rich biodiversity
The number of South African animal species is estimated at 67000 and more than 20400 plant species have been described.
Approximately 7% of the world’s vascular plant species, 5% of mammal, 7% of bird, 4% of reptile, 2% of amphibian, 1% of freshwater fish and 16% of shark, skate and ray species are found in the country.
South Africa has nearly 10% of the world coral species and almost a quarter of the global cephalopod species such as octopus, squid, cuttlefish.
Some terrestrial invertebrate groups have high richness relative to global statistics - 13% of the world’s sun spiders and nearly 5% of butterflies occur in the country.
Around half of our species of reptiles, amphibians, butterflies and freshwater fish are endemic.
Almost two-thirds of our plant species are endemic - mostly linked to the unique Cape Floristic Region.
Approximately 40% of South Africa’s estimated 10000 marine animal species are endemic, the vast majority of which are invertebrates.
Did you know?
South Africa is ranked in the top three countries globally when it comes to plant and marine species endemism (species found nowhere else on earth).
The diversity and uniqueness of South Africa’s species and ecosystems makes the country one of the world’s 17 mega diverse nations - countries that together contain more than two-thirds of the world’s biodiversity.
South Africa’s economy is highly dependent on this biodiversity. For example, biodiversity tourism demand generates a direct spend of about R31 billion in the economy annually, and its 2 000 medicinal plant species contribute to the African traditional medicine sector worth around R18bn a year.
How biodiversity benefits people:
-Nearly invisible insect pollinators are essential for the production of nutritious fruits and vegetables.
-South Africa’s plant and animal species are used for food and medicine - Aloe ferox, for example, is 95% wild-harvested and used in over 140 cosmetic and complementary medicine products.
-Healthy estuarine and marine ecosystems support 22 commercial fisheries sectors, about 29 000 small-scale fishers and 700 000 recreational fishers.
-Interacting with nature brings measurable emotional, mental and physical benefits, influences our cultural and spiritual development, and provides R31bn per year to the South African tourism economy.
To help protect biodiversity, here are some things you can do:
-Consider what you eat: consume foods from local sources that are sustainably produced.
-Think before you buy: minimise purchasing of items that have only a single use (plastic straws, food in single-use packaging), and buy locally-made items to reduce your carbon footprint.
-Reduce your waste: recycle all packaging, reduce your energy and water consumption, and make sure you don’t waste them, dispose of any other waste appropriately.
-Become involved: support local initiatives that protect, restore and study nature - like coastal clean-ups, biodiversity citizen science projects, alien plant hacking, and more. Source: SA National Biodiversity Institute