Rhodes University Logo

Mrs Alex Holland

Degree: PhD (Water Resource Science)


Supervisor: Dr Nikite Muller
Degree: PhD (Water Resource Science)
Working title of thesis: A transdisciplinary investigation of water governance in the Lower Sundays River sub-catchment, South Africa

Brief biography:
The use of DDT (Dichloro-Diphenyl-Trichloroethan), a persistent organic pollutant (POP) and one of the twelve chemicals identified for priority action ('dirty dozen') under the Stockholm Convention, was prohibited in South Africa in 1996. Since 2000 DDT has been re-introduced for residual in-house sprayings as a malaria vector control. DDT bioaccumulates up the food chain and is toxic to aquatic invertebrates.

Measuring the stress response to DDT in animals lower in the food chain could provide an early- warning system of consequences from increased DDT concentrations in the environment. One possible indicator of environmental stress through pollutants is the measurement of fluctuating asymmetry (FA) - deviations from the near-perfect symmetry of naturally bilateral-symmetrical characteristics of an individual. Although FA is easy to estimate and inexpensive to measure its use as an indicator for pollutants in aquatic invertebrates has not yet been established.