The remaining 59.0% was found to be stored in the gravel substratum.

It dwells predominantly in fast flowing streams with sandy and gravel substratum.

A comparison of phosphorus removal efficiency of two large-scale, surface flow wetland systems in Australia which had a gravel substratum to laboratory phosphorus adsorption indicated that for the first two months of wetland operation, the mean phosphorus removal efficiency of system 1 and 2 was 38% and 22%, respectively.