Action: Use repellents to deter birds from landing on pools polluted by mining
A randomised, replicated and controlled ex situ trial from the USA found that fewer common starlings Sturnus vulgaris consumed contaminated water when it was treated with repellents, compared to untreated water.
If the threat from pollution is not from birds landing on ponds but from consuming the water, then repellents may be a more effective or inexpensive method of reducing harm.
Supporting evidence from individual studies
A randomised, replicated and controlled trial in captivity in Philadelphia, USA (Clark & Shah 1993), found that 36 common starlings Sturnus vulgaris consumed less mine-pond water if it was treated with bird repellents, compared to untreated mine-pond water. The repellents tested were: o-aminoacetophenone (OAP), 2-amino-4,5-dimethoxyacetophenone, methyl anthranilate, 4-ketobenztriazine (4KBT) and veratryl amine, all at concentrations of 0.5% by volume. The most effective repellent was OAP and the least effective 4KBT; there were no significant differences between effectiveness of any of the other chemicals. All repellents were effective for five weeks on water which was pH 10.6 and contained 150 ppm sodium cyanide.