I wish I could say I liked this, but it looks to me like it doesn't communicate very much. It would be better if there were (say) two cohesive "shoals", one for each species, which bobbed around a bit for "excitement" but stayed overall still and in formation enough that you could visually see the two populations increasing/decreasing. I can't see what purpose the current fish movement serves, and it makes visually seeing patterns difficult. Since they're plotting the "trajectory in state space", it might be informative to plot a dot showing position in state state space corresponding to the currently displayed fish shoals. (There's lots of other stuff that you could do: you could perhaps plot "ghost fish" to get an idea of how the current population relates to the maximum population has been so far, come up with some way of showing the linkage between the two populations, etc.)
I'm sure there's some very impressive technology behind the application, but the "output design" doesn't seem to connect the "entertaining" part of the app with the "educational" part.