In four months, athletes from around the world will descend on the Seine for the Paris Olympics triathlon event, but for now, the only ones enjoying its waters are perch, catfish and some of the forty species of fish that live there, according to fishing enthusiast Bill François. A physicist by day, François practices catch-and-release fishing up to five times a week in Paris "to observe and count the fish" whose increase in number and diversity is, according to him, a sign of improving water quality. IMAGES AND SOUNDBITES ARRANGED IN SEQUENCES N°34LU62Z