An analysis of the mussel species distribution in the St. Croix had been published:
Hornbach, D.J. 2001. Macrohabitat factors influencing the distribution and abundance of naiads in the St. Croix River, MN and WI, USA, pp. 213-230. In G. Bauer and W. Wächtler [eds] Ecology and Evolutionary Biology of the Freshwater Mussels Unionoidea. Ecological Studies Vol. 145 Springer Verlag: Berlin.
The River:
![River Gradient](http://danhornbach.org/wp-content/uploads/2023/03/rivergradient.gif)
The Distribution of the Subfamilies:
![Subfamilies](http://danhornbach.org/wp-content/uploads/2023/03/subfamilies.gif)
Change in Evenness and Diversity:
![Diversity](http://danhornbach.org/wp-content/uploads/2023/03/diversity.gif)