The Disappearing Disa

Global Climate Change and What it means for the Overberg – Part 2

By Whale Coast Conservation Member Professor Michael Orren

The iconic red Disa is under threat. The pride of the Cape, clinging precariously to rock faces dusted by the spray from cascading waterfalls is in danger of extinction from increasing temperatures and decreasing rainfall. Is it soon to be but a memory only seen on the fading hooped jersey of a former Stormers star?

This is the second of two articles on the impact of GCC on the Overberg

Air temperatures are rising and rivers are declining

In the Overberg, changes have already occurred, others continue to occur. Average air temperatures are rising and soil moisture will thus decline on average.

Over the next few decades, rainfall is expected to decline by perhaps 20% below ‘traditional’ averages and this unfortunately translates into about a 40% decline in river run-off, seriously stressing wetlands, agriculture and food supply, and society’s water needs.

It is anticipated that summer thunderstorms will increase both in frequency and intensity, causing flash-flooding and fires, but without significantly topping up water supplies.

Lower soil moisture and less rain leads to desiccated vegetation, while warmer, windier summers mean we can expect a significant increase in both frequency and intensity of bush fires, natural or man-made. We can expect these to wipe out much vegetation and cropland, accelerate erosion and endanger property and lives. Stronger winds now fan bush fires into localised horrific ‘fire storms’ – such as we observed recently in the Palmiet River valley.

In-shore sea temperatures are falling

Contrary to what one would expect, our inshore sea temperatures have cooled. This is because GCC increases both the intensity and the frequency of southerly to easterly winds (“south-easters”) which in turn enhances upwelling of cold water from the deep ocean.  These winds are also causing unwanted beach sand movements in many places, as can be seen in, for example Betty’s Bay and Pringle Bay.

North-westers are likely to decline in frequency and the cold fronts are now passing further south bringing less rain. But the ones we do experience are likely to be more powerful.

GCC is altering huge offshore marine ecosystems, but our inshore ecosystems have altered too.  For example, the increase in rock lobster and the change in marine plants off Betty’s Bay may be due to the increased supply of colder, nutrient-rich water since the 1990’s.

Sea levels are rising

Sea level is rising about 3 mm per year.  This translates into a 3 cm annual ingress into the shoreline. Sea water will slowly but surely infiltrate shore aquifers raising their salinity and affecting our ability to rely on ground water for human consumption. The subtle rise unfortunately becomes most evident when a sea storm coincides with a high Spring tide. Then the waves flood in, irreversibly, where they have never been before, indiscriminately destroying homes and built structures.

The increased sea level also enhances flooding from extreme weather on land by hindering the outflow of swollen rivers.

The Roaring Forties

The now stronger blowing “Roaring Forties” winds, driven by GCC, are creating more energetic swells which speed towards our shore, pounding the coast, accelerating erosion, first undermining and then destroying our existing, now inadequate, shore protection like older seawalls.

GCC has caused the giant Agulhas Current off our east coast both to warm measurably and to increase in flow by nearly half a million tonnes per second every year.

Impact on Fynbos

I am no ecologist but the changes in temperature and rainfall must impact severely on our treasured fynbos. Very many plants are extremely sensitive to moisture and temperature ranges having evolved over millions of years to adapt to specific ecological niches.   These temperature and moisture ranges have changed and continue to change.

Insects, such as plant pollinators, are very temperature dependent and their activities must alter, probably by adjustments in their appearance times, growth, range, and activity.Proteaceae, Asteraceae, and Restionaceae spp. all require multiple insects for pollination. Were these to go out of phase with plant biorhythms severe problems will certainly surface; highly significant range shifts in bees, essential pollinators of flowering plants and most important in speciation, are already documented. Delicate fynbos species (Disas, orchids andGladiolus) love water, a reduction may disrupt their flowering and hence survival. Effects on bird and other wild life, probably already on-going, are likely to continue. Unhappily, extinction looms for some.

Is it too late?

These effects of GCC are not going to ‘go away’. While we must strive to reduce our carbon dioxide emissions, it is regrettable that even moderate, say 10%, reductions by the massively large CO2 emitters (inter alia China, India and the USA) seem most unlikely. The recent Durban climate meeting was named COP-17; what, if anything, happened during the annual COP-1 to COP-16 meetings attended by thousands? The “lag” of some years in the atmosphere/ocean system slows the appearance of the effects of energy increase. This means that change would continue unabated for about another century even if – magically, certainly impossible – all emissions were to cease forthwith. Under present emission scenarios this time is far longer.

Adapting to GCC

Hence we in the Overberg must learn both to live with, and to adapt to, the consequences of GCC. This is not at all an impossible task and one well within our reach – but only if we prepare for it. Science has defined the problem for humanity; it is now up to us to use our considerable skills and accumulated expertise to plan and budget for change and mobilise political will. Alas the latter has been eroded by denialist propaganda. But we need to plan well ahead to try to minimise the inevitable and substantial socio-economic effects.

Professor Michael Orren is a geochemist and oceanographer with a special interest in global climate change. He divides his time between teaching at the University of Belfast in Ireland and enjoying the charms of Bettys Bay.

Posted in General | Tagged , , , | Comments Offon The Disappearing Disa

And So To The End Of Another Summer Season

With summer days becoming shorter and the new school year already in full swing, it might be interesting to look back at another summer season on our three Blue Flag Beaches.

This summer we were blessed with many days of perfect beach weather, except for the few days when the westerly wind reached storm strength and fanned the flames that raged in the Kleinrivier Mountains.

The Overstrand has 3 Blue Flag Beaches – at Grotto, Hawston and Kleinmond. A lot of effort and money is spent on attaining blue flag accreditation. Why are these blue flags so desirable?

According to Jan Schuurman, who was a franchise-holder on two of the beaches, and who canvassed the opinions of beach-goers on a daily basis, they were full of praise for the amenities they found – the cleanliness of the beaches, the spotless ablution facilities, the excellent lifesavers, the quality of the informational material and the excellent security presence. Those visitors who were aware of the quality assurances given by the Blue Flag status, confirmed that this was a factor in their choice of beach and that they found everything as expected and were impressed with the high standard of beach facilities.  And so was the man from WESSA who came to do the quality assessments.

Not only the visitors were impressed – so was Jan. He was full of praise for all those who ensured that the Overstrand achieved the necessary requirements for the blue flag accreditation, and those who were responsible for the smooth running of all the beaches over the sometimes silly season. “The cleaners worked non-stop to keep the facilities spotless, and those lifesavers can really swim!” he enthused.  “But special praise should go to law enforcement and HPP who maintained high visibility and professionalism at all times.  They had to deal with any number of tricky situations: from difficult customers at the parking pay point to bathers who were just a bit too ‘happy’. They approached all these situations with courtesy and tact.”

But the most difficult customers were the few dog owners who insisted on taking their dogs, uncontrolled, over the Blue Flag beach area, where they ran about in excitement, spraying sand over sunbathers and, to add insult to injury, one cocked a leg against the ‘no dogs allowed’ sign. Walking around the designated blue flag area, a mere 25 meters, with the dog on a lead, was not in the stubborn nature of these dog owners.

Blue Flag is an international annual award given to beaches that meet a standard of excellence in the areas of safety, amenities, cleanliness, environmental information and environmental management.  In South Africa, the Blue Flag programme is managed by WESSA (the Wildlife and Environment Society of South Africa) and the participating local authorities.

South Africa was the first country outside Europe to be granted Blue Flag accreditation for its beaches. And Hermanus’ Grotto Beach was awarded the blue flag status in the very first year of the local programme and has retained that status every year for the 12 years since then. This is no mean achievement.

Grotto Beach now also offers a beach wheelchair for the disabled thanks to the efforts of the Hermanus Access for Citizens Committee. This is the only wheelchair of its kind along our coastal route stretching from Cape Town to George and can easily be pushed on sand.

Apart from Blue Flag playing a strong role in promoting environmental education, the programme is also of national significance to tourism in South Africa as the Blue Flag has become a symbol of quality recognised by tourists and tour operators around the world.  As such it is a tremendous boost for the economy of the Overstrand.

It is perhaps not generally known that Whale Coast Conservation (WCC) provides the environmental education component of the Blue Flag requirements. Each year WCC rolls out a programme of lessons and activities to school groups at several of the Overstrand beaches. The environmental education programme includes not only school outings, lessons and activities but also the creation of information boards and anti-litter campaigns which can be seen at the beaches.

The annual International Coastal Clean-up week is also part of the Blue Flag environmental education programme.  Many school and community groups pick up litter which is subsequently sorted and tallied and thus informs us about the types of litter found on our beaches.  This information has led to projects that address the most obvious litter problems. For example, when it was observed that one of the most common litter items was the cigarette butt, receptacles for cigarette butts with appropriate signage, were erected at the Blue Flag beaches.

WCC staff members also do presentations on Blue Flag topics to various special interest groups like beach managers, ‘Working for the Coast’ staff and educators.    The importance of removing invasive alien species is emphasised and illustrated by the alien clearing programme recently commenced near Hawston Beach.

The milkwood forest adjacent to Grotto Beach, locally known as Piet-se-Bos, is another outdoor classroom much used by our educators for lessons on the importance of forests, biodiversity and coastal ecology. The sterling work of the Cliff Path Management Group in caring for this fantastic forest cannot be overemphasised. Their programme of alien clearing and planting of and caring for hundreds of new forest trees over the past 10 years has greatly contributed to the preservation of this iconic Hermanus facility – a cool and shady refuge from the searing sun and wind on the adjacent beach.

The WCC Blue Flag Beach educational programme, including the shark egg case project, was on display at the National Launch of the Blue Flag Beach season which was hosted by the Overstrand Municipality. After the ceremony the Minister of Tourism, Marthinus van Schalkwyk, and Deputy Mayor Pieter Scholtz, congratulated the WCC team on their valuable contribution to environmental awareness and to tourism in the Overstrand.


Written by Dr Anina Lee

Whale Coast Conservation