There is a great site called The Biofresh Blog: A blog on the science, policy and conservation of freshwater ecosystems, run out of the European Union.
BioFresh is a European Union project which is putting together the scattered pieces of information about life in our rivers and lakes, to better understand, manage and protect our freshwaters for generations to come
They are currently running a series on ecosystem services provided by rivers, which includes discussions on a range of topics, including: what rivers do for us, thinking with water, ethics and ecosystem services and does ecosystem services need a radical critique?
I will include a link to their blog on the Link side bar. Well worth a look!