How ORVs destroy beaches

Misconceptions and misinformation, but mostly lame excuses, justify the controversial activity of off-road vehicles (ORVs) on our beaches, writes Conrad Winterbach of Wavecrest Hotel. Here he explains some of the results of studies done by the University of Massachusetts at Cape Cod and the University of Transkei, as well as observations made by students of Wavecrest Eco-Ventures.

THE affected areas can be divided intoseveral distinct, yet interdependent, eco-systems. Apart from the applicable destruction to each of these eco-systems, it must be emphasised that the effects go far beyond the estimated 4000 creatures crushed per kilometre of travel on a healthy beach. The downstream effects to the various food chains, caused by even light traffic, can be disastrous. A chain, after all, is only as strong as its weakest link.

Intertidal beach

THIS is the area of beach below the high water mark, which is mistakenly touted as the environmentally friendly place to be.

Whilst it is true that each new tide appears to erase the assault on one's senses prompted by ugly tracks desecrating a pristine beach, the damage is no less. Creatures particularly vulnerable are the plough snail, (the beach's essential sanitation system), sand mussel donax, mole crab emerita austroafricana, mysid shrimps gastrosaccus and various isopods.

Birds such as the sanderling, white-fronted plover and many others are dependent on these creatures as well as being themselves dependent on the biome. Fish species such as galjoen, white steenbras and spotted grunter that feed within the intertidal zone cannot survive where the beach has been denuded.

It is known that turtle hatchlings are trapped in vehicle tracks and vulnerable to predation or dehydration above or below the high water mark.

Backshore

THIS is the area between the high tide mark and the dunes. The breeding of oyster catchers (an endangered species ) is severely disrupted by vehicle traffic. Nests are very close to the high water mark. Parents will abandon their nest when a vehicle approaches, permanently if too frequently. Eggs that survive the wheels will simply be fried in the sun.

Less obvious, but possibly more important, is the effect on the organic drift lines that are home to the majority of beach life. The accumulation of debris left by the high tide have bacteria levels more than 1000 times higher than the surrounding beach. They are habitat to countless amphipods, insects, spiders and other organisms.

Of most critical concern is the fact that these organisms are themselves the vital link between detritus caused by decomposing biomass amongst the sand granules and the living population of our oceans.

Dunes

THESE are the majestic mounds of sand that make a number of essential contributions to the marine environment. Dunes are a first line of defence for the canopy forest, not only against the ravages of storms or cyclones, but against the harmful salt spray under normal conditions.

They are a reservoir of ever-recycling sand, replenishing beach erosion caused by wind and high seas.

Regrettably, these fragile systems are extremely vulnerable to destruction by vehicles. Dunes are held together by a closed dune shrub, predominantly the seeplakkie scaevola plumieri. They grow with the dune over a period of 70 years before even modest proportions are achieved. One single track can cause downward displacement of sand and a path through the pioneer covering, thus causing "blow throughs" and consequent erosion, particularly at access points.

Dunes provide important nesting habitat for several bird and animal species including the rare damara tern. Historic middens able to supply an invaluable record of demographic, vegetation and climatic changes over the centuries are likewise possible casualties.

More fragile links

THE areas detailed above comprise the normal beach zone. Once a river mouth or estuary is encountered, even more important and delicate systems are exposed.

Intertidal flats, high marshes, low marshes and salt marshes each make their own unique contributions to what is ultimately the life source of our oceans.

By virtue of the dependence of an entire food chain on each fragile link, relatively minor disturbances can have exponentially spiralling effects

Why should we care?

SO much for the theory. How can we as novices know that's not all just hot air? Why should we care anyway?

We at Wavecrest are gifted with four kilometres of the most magnificent stretch of pristine beach imaginable. The environmental dictator who prosecutes every ORV offender is well known. The result is an almost perfect beach. It is marred only by the occasional hot-head, fuelled with Dutch courage, who runs the gauntlet to torment the custodian. In the sober light of day, he pays the R500 admission of guilt fine rather than accept the invitation to explain his actions to the Kentani Court.

The result is a graphic contrast between two identical environments, one part is protected, the other, around the point and out of view, is open to the ravages of uncontrolled ORV traffic.

One of the many special treats at Wavecrest is a mystical walk on the beach on a full- moon night. It's hard to describe the miracle of life scurrying around between the phosphorescent waves and the imposing shadows of the dunes.

The contrast for those, thus inspired, who round the headland to the open-for-all "racetrack", is dramatic. Nothing lives in the dark sand between the tyre trenches.

So often I hear the same lament from the character profile disposed to the ORV-on-beach activity: "Are kaant unnerstend wire there isn't no more fieshes in the sea enymore?"

I just sigh and shake my head.

* With grateful thanks for the support and input of Mr Shaun Schneier of the Department of Environmental Affairs and Tourism, and Professor Arthur Dye of Unitra.