Remi Masson / European beaver (Castor fiber) eating branches in the water before approaching the camera, River Rhone, Rhone-Alpes, France, June.

Remi Masson / Group of Barbels (Barbus barbus) spawning, River Rhone, Rhone-Alpes, France, April.

Remi Masson / Group of Black bullhead (Ameiurus melas) shoaling to protect themselves against predators, River Rhone, Rhone-Alpes, France, July.

Remi Masson / Tracking shot of a Eurasian beaver (Castor fiber) swimming underwater, turns to look at camera, River Rhone, Rhone-Alpes, France, June.

Remi Masson / Eurasian beaver (Castor fiber) carrying branches back to lodge, dropping them when alarmed. River Rhone, Rhone-Alpes, France, June.

Remi Masson / Pair of Pumpkinseeds (Lepomis gibbosus) mating, male chasing other individuals away, River Rhone, Rhone-Alpes, France, June.

Remi Masson / Group of Nase (Chondrostoma nasus) and Barbels (Barbus barbus) spawning, River Rhone, Rhone-Alpes, France, April.

Remi Masson / Shoal of Nase (Chondrostoma nasus) spawning, River Ain, Rhone-Alpes, France, April.

Remi Masson / Group of Wels catfish (Silurus glanis) gathered in the River Rhone, France, August.

Remi Masson / European beaver (Castor fiber) swimming underwater and urinating, River Rhone, Rhone-Alpes, France, June.

Bence Mate / Greater flamingos (Phoenicopterus roseus) with necks intertwined, Pont De Gau Park, Rhone River, France. February.

Bence Mate / Great flamingo (Phoenicopterus roseus) group in flight, Pont De Gau Park, Rhone River, France.

Bence Mate / Great flamingo (Phoenicopterus roseus) feeding in sludge at bottom of river, Pont De Gau Park, Rhone River, France.

Bence Mate / Great flamingo (Phoenicopterus roseus) with beak covered in mud after feeding, Pont De Gau Park, Rhone River, France.

David Noton / The Pont St-Benezet, Palais des Papes and Rhone River at dusk, Avignon, Provence, France, October 2012.

Jean E. Roche / Giant mirror in the shape of a woman emerging from river, a public sculpture by Rob Mullholland, Port Saint Louis du Rhone, Camargue, France, May 2013. Editorial Use only. Credit Jean Roche / Le Citro...

Jean E. Roche / Boat deposited on land by flooded River Rhone, Arles, Camargue, France, December 2003

Jean E. Roche / Aerial view of Saintes Maries de la Mer, Camargue, France. September 2019.

Philippe Clement / Pont Saint-Benezet / Pont d'Avignon over the river Rhône, Avignon, Vaucluse, Provence-Alpes-Cote d'Azur, France. September 2018

Mike Read / River Bourne and surrounding deciduous woodland. Gorges de la Bourne, Vercors Regional Natural Park, Rhone-Alpes, France. June 2018.

Remi Masson / Group of Wels catfish (Silurus glanis) gathering on the bottom of the River Rhone, France. June.

Remi Masson / Group of Wels catfish (Silurus glanis) gathering on the bottom of the River Rhone, France. June.

Remi Masson / Wels catfish (Silurus glanis) swimming in the river Rhone, France.

Remi Masson / Wels catfish (Silurus glanis) on the bottom of the River Rhone, France. June.

Remi Masson / Group of Tench (Tinca tinca) swimming in the River Rhone, Rhone-Alpes, France, February.

Remi Masson / European beaver (Castor fiber) swimming under submerged branches outside of its lodge, knocks into camera, River Rhone, Rhone-Alpes, France, July.

Remi Masson / European beaver (Castor fiber) returning to its lodge, River Rhone, Rhone-Alpes, France, June.

Remi Masson / Group of Wels catfish (Silurus glanis) swimming in the River Rhone, with one swimming into the camera, France, July.

Remi Masson / Group of Wels catfish (Silurus glanis) swimming in the River Rhone, France, June.

Remi Masson / Albino Wels catfish (Silurus glanis) swimming in the River Rhone, France, November.

Jean E. Roche / Fishermen carrying net of live Eels (Anguilla anguilla) Camargue, France, November.

Jean E. Roche / Fishermen carrying net of live Eels (Anguilla anguilla) Camargue, France, November.

Remi Masson / European beaver (Castor fiber) entering lodge, River Rhone, Rhone-Alpes, France, June.

Remi Masson / European beaver (Castor fiber) swimming underwater, above branches and foliage stored for eating later. River Rhone, Rhone-Alpes, France, June.

Remi Masson / European beaver (Castor fiber) swimming underwater, above branches and foliage stored for eating later. River Rhone, Rhone-Alpes, France, June.

Remi Masson / European beaver (Castor fiber) swimming at the surface, seen from underwater. River Rhone, Rhone-Alpes, France, June.

Remi Masson / Shoal of Nase (Chondrostoma nasus) spawning, River Ain, Rhone-Alpes, France, April.

Remi Masson / Group of Wels catfish (Silurus glanis) rubbing against each other, with very large individual over two metres long, River Rhone, Rhone-Alpes, France, September.

Remi Masson / Eurasian beaver (Castor fiber) swimming underwater amongst aquatic plants, River Rhone, Rhone-Alpes, France, June.

Remi Masson / Male Zander (Sander lucioperca) protecting eggs in nest, Rhone-Alpes, France, April.

Remi Masson / Wels catfish (Silurus glanis) hiding between two rocks, approaching with curiosity and sensing with barbels, River Rhone, Rhone-Alpes, France, November.

Remi Masson / Wels catfish (Silurus glanis) swimming, curious about camera, River Rhone, Rhone-Alpes, France, November.

Remi Masson / Group of Wels catfish (Silurus glanis) gathered in the River Rhone, Rhone-Alpes, France, September.

Remi Masson / Tracking shot of a Eurasian beaver (Castor fiber) swimming underwater, River Rhone, Rhone-Alpes, France, June.

Jean E. Roche / European eel (Anguilla anguilla) portrait, Camargue, France.

Jean E. Roche / Trapping European eels (Anguila anguilla) in the Camargue, for scientific research by the biological research station of Tour du Vala.

Jean E. Roche / European eels (Anguilla anguilla) released after scientific research, La Gacholle, Camargue, France. April.

Jean E. Roche / Scientists releasing European eel (Anguilla anguilla) after they were caught during research, La Gacholle, Camargue, France. April.