Would-be frackers of the Karoo‚ beware: scientists are watching you.

Three experts in shallow water ecosystems from Nelson Mandela Metropolitan University say the invertebrate population of dams‚ pans and rivers will be a good indicator of whether fracking damages the environment.

To set a baseline‚ they took samples of macroinvertebrates — creatures bigger than 1mm — from 33 waterbodies. And they say the fact that they found four new species in the process — a creeping water bug‚ a beetle and two mayflies — is evidence of the lack of detailed knowledge in “the proposed epicentre of shale gas extraction activities in South Africa”.

Annah Mabidi‚ Matthew Bird and Renzo Perissinotto made two visits to nine dams‚ 13 pans and 11 rivers between Aberdeen in the west and Tarkastad in the east. They swept the water with nets‚ and writing in the journal PLOSone said the creatures they found were dominated by large branchiopods‚ especially fairy shrimps.

They said macroinvertebrates were excellent indicators of human impacts on freshwater environments‚ and their sensitivity to increases in salinity — one of the possible side-effects of fracking — put them at potential risk.

“Under increasing salinity conditions these organisms are unlikely to hatch optimally and survive until reproduction‚” they said. “This may cause depletion of the resting egg bank and eventually extirpation of local populations‚ thereby affecting the whole wetland community through cascading effects on other floral and faunal components.”