SCOTLAND: The Big Picture / Stream in spate in native oak woodland in summer, Clonaig, Kintyre, Argyll, Scotland, UK, July 2015.

Nick Upton / Tilt shot of a dam constructed by Eurasian beavers (Castor fiber) on a section of the River Otter, Devon, England, UK, June 2018.

Brian Bevan / Slow motion clip of a male Kingfisher (Alcedo atthis) eating a fish, Bedfordshire, England, UK, July.

Kerstin Hinze / Dipper (Cinclus cinclus) foraging in a stream, Harz National Park, Saxony-Anhalt, Germany, March.

Philippe Clement / European dipper (Cinclus cinclus) perched on rock in stream and looking around, Luxembourg, April.

Philippe Clement / European dipper (Cinclus cinclus) perched on a rock at the base of a waterfall and bobbing, Luxembourg, April.

Dave Bevan / Male Blackbird (Turdus merula) catching European eel (Anguilla anguilla) elvers as they migrate up a waterfall, Ceredigion, Wales, UK, July.

Dave Bevan / Male Blackbird (Turdus merula) catching European eel (Anguilla anguilla) elvers as they migrate up a waterfall, Ceredigion, Wales, UK, July.

Dave Bevan / European eel (Anguilla anguilla) elvers migrating up a wet rock next to a waterfall, Ceredigion, Wales, UK, July.

Guy Edwardes / Golitha Falls, River Fowey, Bodmin Moor, Cornwall, England, UK. May 2010.

Guy Edwardes / River Fowey at Golitha Falls, Bodmin Moor, Cornwall, England, UK. May 2010.

Guy Edwardes / River Fowey flowing through Beech (Fagus sylvatica) woodland, Golitha Falls, Bodmin Moor, Cornwall, England, UK. May 2010.

Bernard Castelein / Beech tree (Fagus sylvatica) showing roots, Peerdsbos, Brasschaat, Belgium

Michel Roggo / Water hyacinth (Eichhornia sp.) in a clear stream of the Pantanal, Brazil. Photographed for The Freshwater Project. Finalist in the Wildlife Photographer of the Year Awards (WPOY) Competition 2017.

Theo Bosboom / Underwater view of bubbles in the mountain stream. La Hoegne, Belgian Ardennes/High Fenn near Hockai, Belgium

Theo Bosboom / Autum leaves and grass in the current of mountain stream La Hoegne, Belgium.

Theo Bosboom / Underwater view of bubbles in water and trees on land, La Hoegne mountain stream, Belgium.

Theo Bosboom / Maple leaf in autumn, viewed from underwater with bubbles and foam of mountain stream, La Hoegne, Ardennes, Belgium.

Theo Bosboom / Autumn foliage including Beech and Oak leaves and Rowan berries floating in the current of a mountain stream, La Hoegne, Ardennes, Belgium.

Theo Bosboom / Underwater view of autumn leaves in stream current, La Hoegne, Ardennes, Belgium.

Theo Bosboom / Underwater view of bubbles and Beech (Fagus sylvatica) leaves Hoegne, Belgium.

Theo Bosboom / Autumn leaves stuck behind branches in the water, Leuvenumse beek, the Netherlands.

Theo Bosboom / Autumn leaves from Beech trees, Oak trees and Birch trees floating under water in the current of a mountain stream, La Hoegne, Ardennes, Belgium.

Theo Bosboom / Underwater view of autumn leaves stuck behind a fallen tree, Leuvenumse beek, the Netherlands.

Theo Bosboom / Autumn leaves seen underwater, Ardennes, La Hoegne, Belgium.

Theo Bosboom / Autumn leaves from Beech, Oak and Birch trees floating on water, taken from underwater, Ardennes, La Hoegne, Belgium.

Theo Bosboom / Oak and Beech tree leaves in autumn colours floating on water of mountain stream, La Hoegne / High Fenn, Ardennes, Belgium

Theo Bosboom / A pile of autumn Beech leaves caught behind a rock in a mountain stream La Helle, Ardennes, Belgium.

Theo Bosboom / Yellow coloured Birch leaf (Betula) floating on the bubbles and foam of a stream, De Veluwe (Leuvenumse bos), Netherlands.

Theo Bosboom / One of the many small waterfalls of a mountain stream La Hoegne, Belgium.

Theo Bosboom / Split level view of autumn leaves underwater and tree reflections on the water surface, Levenumse beek, the Netherlands, November.

Theo Bosboom / Autumn leaves in a mountain stream (La Hoegne) in the Belgian Ardennes, Belgium.

Jack Dykinga / Indian paintbrush (Castilleja sp.) flowers amid boulders in a stream, in narrow canyon with conifers in background Grand Staircase-Escalante National Monument, Utah, USA.

Jack Dykinga / Narrows with canyon wall reflections in mud patterned shore, Vermilion Cliffs National Monument, Paria Canyon Wilderness, Arizona, USA.

John Waters / Small group of Rainbow trout (Oncorhynchus mykiss) swimming in the River Kennet, Berkshire, England, UK, March.

John Waters / Small shoal of Brown trout (Salmo trutta) swimming and feeding in the River Kennet, Berkshire, England, UK, March.

John Waters / Shoal of Minnows (Phoxinus phoxinus) swimming and feeding in the River Wye, Wales, UK, July.

SCOTLAND: The Big Picture / Atlantic salmon (Salmo salar) leaping up a small waterfall in order to reach breeding grounds further upstream, Cairngorms National Park, Scotland, UK, October.

Alex Hyde / Fishing spider (Trechalea) waiting to catch a Killifish (Cyprinodontiformes) in a rainforest stream at night, Central Caribbean foothills, Costa Rica.

Juan Carlos Munoz / Water cascading down Toberia falls, Andoin, Sierra Entzia Natural Park, Alava, Basque Country, Spain, April.

Dong Lei / Blue poppy (Meconopsis betonicifolia), Mount Namjagbarwa, Yarlung Zangbo Grand Canyon National Park, Tibet, China.

Mark MacEwen / Japanese firefly (Luciola cruciata) light trails at night above stream in rural Japan. June.

Juan Carlos Munoz / Tourists looking down onto underground stream, from illuminated pathway, Skocjan Caves, Green Karst, Slovenia, October 2014.

Ole Jorgen Liodden / Chatham stream on the main Chatham island, New Zealand, March 2014.

Ernie Janes / Sea lavender (Limonium vulgare) growing in saltmarsh, with Blakeney Village in the background, Norfolk, England, UK, July.

Kirkendall-Spring / Hiker crossing Newton Creek, Elk Meadows Trail, Mount Hood Wilderness. Oregon, USA, July 2014. Model released.

Kirkendall-Spring / Hikers on the trail to Three Fingered Jack, Mount Jefferson Wilderness, Duschutes National Forest. Oregon, USA, July 2014. Model released.

Floris van Breugel / Autumnal landscape with snow, Arrigetch Peaks region of Brooks Range, Gates of the Arctic National Park, Alaska, USA, August 2014.

Floris van Breugel / Ice cave melting in Mendenhall Glacier, Juneau, Alaska, USA, August 2014.

Floris van Breugel / Black and white photograph of Ice crystals up to 12 inches long along a small creek in a remote valley, Brooks Range, Gates of the Arctic National Park, Alaska, August 2014.

Hougaard Malan / Waterfall and autumn foliage with view to Mount Fitz Roy. El Chalten, Patagonia, Argentina. April 2013.

Peter Cairns / Calcified trees at Tangled Creek in winter, Yellowstone National Park, Wyoming, USA, February 2013.

Charlie Summers / Two juvenile Brown Bear siblings (Ursus arctos) look for food on the banks of the Anan Creek lagoon, Alaska, July.

Charlie Summers / Black Bear (Ursus americanus) hunting for spawning Salmon during low tide, Neets Creek estuary, Alaska, July.

Eric Medard / Grey heron (Ardea cinerea) in small stream at night, taken with infra-red remote camera trap, France. October.

Eric Medard / Grey heron (Ardea cinerea) at night, taken with infra-red, Mayenne, Pays de la Loire, France, September.

Theo Bosboom / Beech trees (Fagus sylvatica) in autumn, seen from under bubbling brook, the Netherlands, November. Runner up in Creative Visions category of the Wildlife Photographer of the Year 2013 competition

Theo Bosboom / La Hoegne mountain stream in autumn, under water, near Hockai, Belgian Ardennes, November

Theo Bosboom / La Hoegne mountain stream in autumn, near Hockai, Belgian Ardennes, November 2007

Inaki Relanzon,Inaki Relanzon / Bujaruelo Waterfall, Ordesa National Park, Huesca, Pyrenees, Spain, May 2013.

Yukihiro Fukuda,Yukihiro Fukuda / Japanese fireflies (Luciola cruciata) in flight at night, Japan endemic species, Hino-River, Nichinan-chou, Tottori, Japan, July

Yukihiro Fukuda / Japanese fireflies (Luciola cruciata) in flight at night, Japan endemic species, Hino-River, Nichinan-chou, Tottori, Japan, July

Igor Shpilenok,Igor Shpilenok / Red Fox (Vulpes vulpes) jumping across stream. Kronotsky Zapovednik Nature Reserve, Kamchatka Peninsula, Russian Far East, March.

Sven Zacek / Vahandu River in spate after snow melt. Southern Estonia, February 2013.

Ross Hoddinott / 2020VISION / River Plym flowing fast through Dewerstone Wood, Shaugh Prior, Dartmoor National Park, Devon, England, UK, October 2011. Did you know? The name Plym comes from the Old English term for plum tree.

George Sanker / Ellis River high in White Mountain National Forest. New Hampshire, October 2012.

Richard Steel / 2020VISION / Dipper (Cinclus cinclus) standing in stream, Clwyd, Wales, UK, February.

Niall Benvie / Waterfalls in woodland. Craigengillan Estate, Dalmellington, Ayrshire, October.

Linda Pitkin / 2020VISION / Water-crowfoot (Ranunculus fluitans subsp. penicillatus) flowering underwater, Cumbria, England, UK, September. Did you know? The latin name for this genus 'Ranunculus' comes from the Latin for 'Litte...

Linda Pitkin / 2020VISION / Split-level view of the River Leith, showing Water-crowfoot (Ranunculus fluitans subsp. penicillatus) growing underwater, Cumbria, England, UK, September. Did you know? Cumbria is one of the least den...

Linda Pitkin / 2020VISION / Fisheries assistant Stephanie Kershaw and volunteer John Dumont from the Eden Rivers Trust searching for White clawed crayfish (Austropotamobius pallipes) as part of a capture and release conservation...

Linda Pitkin / 2020VISION / White clawed crayfish (Austropotamobius pallipes) on river bed, viewed underwater, River Leith, Cumbria, England, UK, September 2012.

Linda Pitkin / 2020VISION / White clawed crayfish (Austropotamobius pallipes) underwater on riverbed, showing defensive posture, River Leith, Cumbria, England, UK, September 2012. Did you know? White clawed crayfish can live fo...

Linda Pitkin / 2020VISION / White clawed crayfish (Austropotamobius pallipes) underwater on riverbed, River Leith, Cumbria, England, UK, September 2012.

Linda Pitkin / 2020VISION / Brown trout (Salmo trutta) fry on river bed, Cumbria, England, UK, September.

Linda Pitkin / 2020VISION / Fisheries assistant Stephanie Kershaw and volunteer John Dumont at the Eden Rivers Trust electrofishing for juvenile Atlantic salmon (Salmo salar) and Brown trout (Salmo trutta) as part of a capture a...

Ross Hoddinott / 2020VISION / Tarr Steps, medieval clapper bridge crossing the River Barle, Exmoor National Park, Somerset, UK. May 2012

Ross Hoddinott / 2020VISION / River Exe, near Winsford, showing river correctly fenced to stop cattle from polluting the river, or eroding the river banks. Healthy example of river habitat. Exmoor National Park, Somerset, UK. May...

Ross Hoddinott / 2020VISION / School children carrying equipment to release salmon fry in the River Haddeo and to do invertebrate kick samples with Westcountry Rivers Trust (WRT) warden. Bury, Exmoor National Park, Somerset, UK. M...

Ross Hoddinott / 2020VISION / School child releases salmon fry in the River Haddeo, with Westcountry Rivers Trust (WRT) warden. Bury, Exmoor National Park, Somerset, UK. May 2012. Editorial use only

Ross Hoddinott / 2020VISION / Golitha Falls, River Fowey flowing through wooded valley with moss covered trees, Nr St Cleer, Cornwall, UK, May 2012

Mark Carwardine / Looking down on Sumatran rhino (Dicerorhinus sumatrensis) walking through stream. Captive-Sumatran Rhino Sanctuary, within Way Kambas National Park, Lampung Province, southern Sumatra, Indonesia

Oriol Alamany / Nigel Creek with conifer forest at dusk, Banff National Park, Rocky Mountains, Alberta, Canada

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) dominant male silverback 'Makumba' aged 32 years sitting by a river in forest interior, Bai Hokou, Dzanga Sangha Special Dense Forest Reserve, Central...

Anup Shah / Western lowland gorilla (Gorilla gorilla gorilla) juvenile female 'Bokata' aged 6 years approaching a river, Bai Hokou, Dzanga Sangha Special Dense Forest Reserve, Central African Republic. December 2...

Graham Eaton / A split level image of a small mountain stream. Cwm Idwal, Snowdonia, Wales, September 2011.

Yukihiro Fukuda / Japanese giant salamander (Andrias japonicus) eating the eggs of another salamander, Japan, August

Yukihiro Fukuda / Japanese giant salamander (Andrias japonicus) moving upstream to spawn, Japan, August

Yukihiro Fukuda / Male Japanese giant salamander (Andrias japonicus) in river, Japan, August

Yukihiro Fukuda / Male Japanese giant salamander (Andrias japonicus) protecting his eggs inside his nest, Japan, October

Yukihiro Fukuda / Male Japanese giant salamander (Andrias japonicus) protecting his eggs inside his nest, Japan, September

Yukihiro Fukuda / Japanese giant salamander (Andrias japonicus) eggs, Japan, September

Yukihiro Fukuda / Japanese giant salamander (Andrias japonicus) at the entrance to its nest, raising its head to the surface, Japan, August

Yukihiro Fukuda / Japanese giant salamander (Andrias japonicus) in river, Japan, March

Yukihiro Fukuda / Japanese giant salamander (Andrias japonicus) reaching up to the surface to breathe, Japan, August

Yukihiro Fukuda / Japanese giant salamander hunting at night in a river, Japan, May