Luiz Claudio Marigo / "Igapó" Amazon flooded rainforest near the left bank of Negro River during the 2007 flood. Negro River, Amazonas State, Northern Brazil.

Sumio Harada / Mountain Goat (Oreamnos americanus) pair fighting for salt rights, male at left threatens female at right who lowers her rump in defense, Walton Goat Lick, Glacier National Park, Montana

Sumio Harada / Mountain Goat (Oreamnos americanus) pair fighting for salt rights, male at left threatens female at right, Walton Goat Lick, Glacier National Park, Montana

Will Watson / River Bug, looking upstream, left bank Ukraine, right bank Poland, proposed location for the E40 inland waterway, Ukraine/Poland border. May, 2016.

Will Watson / River Bug, looking downstream, left bank Poland, right bank Ukraine, proposed location for the E40 inland waterway, Ukraine/Poland border. May, 2016.

Alan Williams / Salmon ladder on left next to the weir on the River (Afon) Ogwen at Ogwen Bank near Bethesda North Wales, UK, October 2019.

Karine Aigner / Luilaka River with clouds reflected in the surface of the water, Salonga National Park is on the left bank. Democratic Republic of the Congo.

Karine Aigner / Evening on the Luilaka River. Salonga National Park is on the left bank, and the village of Mankoto on the right. Democratic Republic of Congo.