There, the rain has made lakes so acidic, native fish can no longer tolerate the water.

The scientists, however, have suggested animals and plants living in the natural springs have adapted to the toxic conditions.

Exactly how, though, remains unexplained, according to UQ team leader Prof Craig Franklin.

"Would I swim in it? I wouldn’t drink it, let’s put it that way," Prof Franklin told The Cairns Post.

The springs flow into the Wenlock River.

Researchers had observed many of the saltwater crocodiles in the Wenlock with stained and weak-looking teeth.

Prof Franklin said this may be related to the acidic spring water.