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Following supersonic whispers across Hakskeenpan

By Betsie Milne and Joh Henschel, SAEON Arid Lands Node
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Hakskeenpan has become synonymous with land speed racing in South Africa.

Since 2010 a British team has been preparing the pan to attempt a new world land speed record over 1 600 km/h in the Bloodhound SSC, a 33 000 horsepower jet- and rocket-powered supersonic car. Dry pans are generally favoured for such events due to their vast, hard, flat surfaces.

The Bloodhound endeavour evoked the unsuccessful attempt of Sir Malcolm Campbell to break the land speed record of 371 km/h in his Bluebird on Verneukpan in 1929. His nemesis - numerous small rocks scattered across the pan’s surface that slashed his tyres.

For this reason, the Bloodhound team left no stone unturned on Hakskeenpan. In fact, 16 000 tonnes of stones have been removed manually to smoothen the 22 million m2 (20 km long and 1.1 km wide) track in preparation for the race that is due to take place later this year. This remarkable task has been applauded as a significant contribution in uplifting the local Mier community.

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The Bloodhound supersonic car (top) and Sir Malcolm Campbell’s Bluebird (above) 


However, what about the actual racetrack itself - the Hakskeenpan wetland?

Bloodhound boasts state-of-the-art science to be used in the race across Hakskeenpan, but no attempt has been made to conduct state-of-the-art research on the wetland and associated biodiversity, despite annual inundation. Pans in the Northern Cape have been shamefully neglected based on the erroneous assumption that their bare surfaces are lifeless when dry, though the Bloodhound team did express appreciation of inundation after rainfall events:

“Having the desert flood like this is very good news for us, as flooding helps to repair the surface from any damage that may have been caused… and it helps to create the best possible surface for land speed record racing.”

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A satellite image of Hakskeenpan, indicating the 20 km track prepared for the Bloodhound event

Studying the ecology of dryland wetlands

In August 2016, Dr Betsie Milne of SAEON’s Arid Lands Node embarked on a project to study the ecology of dryland wetlands in order to determine the ecology and sensitivity of these periodically wet and dry ecosystems and how they may be affected by (and serve as indicators for) global change and land-use changes. At first word that the Kalahari region has received more than the annual rainfall of 200 mm in January this year alone, a number of freshwater specialists keen to partner with SAEON in the pans project, identified Hakskeenpan as a key opportunity for collaborative research.

Betsie Milne and her team (Gariep Bird Club member and photographer Brian Culver as well as Tshililo Ramaswiela and Joh Henschel from the Arid Lands Node) opportunistically journeyed the 650 km to Hakskeenpan to conduct the first-ever survey of aquatic life on the pan. They undertook a follow-up visit in March after more rain had fallen, suspecting that life-cycles and productivity on the pan had advanced in the seven intervening weeks.

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Field technician Tshililo Ramaswiela and Dr Betsie Milne chasing mirages (seen in the background) in search for water across the southern section of Hakskeenpan (Photo: Brian Culver)

Dr Betsie Milne and Tshililo Ramaswiela collecting crust and soil samples, which will be processed for edaphic analyses, hatching experiments and egg bank isolation (Photo: Brian Culver)

It soon transpired that in 2017 the 15 000-ha pan surface was not fully inundated and water primarily accumulated in the north, while the southern section of the pan had remained dry. This offered an opportunity to not only sample the aquatic communities, but to also include a survey of the shore life and other habitats provided by the desiccated surface (see examples in accompanying pictures).

Stones were green with microalgae, as was the clay, and the water writhed with many species of freshwater shrimps, water fleas and aquatic beetles. Likewise, the shore was rich with different flies, frogs, beetles, springtails, spiders and mites.

Remarkably, some of these terrestrial species also lived on and in cracks of dry clay far from any standing water or ground moisture. Furthermore, in the dry clay were millions of eggs and dormant forms of life, waiting for the next inundation. Watch this space for our analyses of this plethora of life.

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Dr Joh Henschel and Brian Culver sampling invertebrates found in the desiccation cracks (Photo: Betsie Milne)

Water birds wading in the northern section of Hakskeenpan where water primarily accumulates after flooding (Photo: Betsie Milne)

Therefore, don’t judge a pan by its cover, imitate Joh Henschel and fasten those knee pads to follow the supersonic whispers of organisms hiding under rocks and in the cracks of Northern Cape pans.

Further reading:

Aquatic life

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Triopsidae (top) and Dytiscidae (below) were the most abundant predaceous invertebrates in the water column

(Photo: Joh Henschel)

Filamentous green algae (top) were common during the initial stages of inundation, while mats of benthic microalgae (below) accumulated on rocks and sediments after prolonged inundation (Photo: Brian Culver & Joh Henschel)

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At least 17 water bird species, including this pair of African Sacred Ibis, flocked to Hakskeenpan to forage, with as much as 482 individuals counted during one survey (Photo: Brian Culver)

Metamorphosing frogs were abundant during the second survey, indicating progression in the wetlands life cycle (Photo: Joh Henschel)

Shore Life

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Three species of Tiger Beetles (Cicindelinae) were of the most conspicuous insects along the shore (Photo: Joh Henschel)

Amphibious wolf spiders (Lycosidae) were the most common spiders encountered on the shore (Photo: Joh Henschel)

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Dragonflies were seen actively breeding along the shore during the initial survey, while numerous nymphs were sampled in the water during the follow-up survey (Photo: Brian Culver)

Pied Avocets used the shoreline for nesting

(Photo: Brian Culver)

Desiccated surface

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Kittlitz's Plovers used small stones to camouflage their eggs in the nest (Photo: Joh Henschel)

Ants were seen taking beetle prey down their burrow (Photo: Joh Henschel)

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Webs of jumping spiders were found underneath the rocks (Photo: Betsie Milne)

Spider cribellar silk was discovered along the edge of dry mud cracks (Photo: Joh Henschel)

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