Wrieacher, after so many efforts my partners decided to change the title of the project (instead of focusing only on biodiversity they used the sentence:

Question

Comparative studies on local biodiversity related to water and learning from each other.

I think it's too generic. As you know everything about the project, I urgently need to know your opinion.

( As you know, our French partner doesn't really want to use only English as communication language and their school is not specialized in science but in social studies and cinematique techniques.
Our school and the German one are scientific high schools, instead.)

Answer 1

Maybe the French school needs to study the human costs when aquatic biodiversity takes hits, wherever humans are. They could study the social science effects, while you and your German partner study the scientific status quo and the effects of pollution from all causes. Maybe there will be some French students who realize that the science will help them explain and convince humans to change their habits ... or whatever needs to be done.

Did BOTH of the other schools want this title change? Or only one?

I should think this (in italics below) would fit all three schools' needs, even if you decide to divide up the foci of study: science for German and Italian, social science for French.

Comparative and cooperative studies on local aquatic biodiversity