We call them lakes in England, lochs in Scotland, llyns in Wales and loughs in Ireland, but a feature all these waterbodies share is their natural origin. This puts clear water, as it were, between them and those waterbodies with decidedly anthropogenic beginnings, such as reservoirs. But when does a lake, llyn, loch or lough become a pond, and vice versa?
Well, according to limnologists, who study freshwater habitats for a living, the strict definition should not be based on the size of the waterbody, but on its depth. Ponds, for example, are shallow enough to allow rooted plants to conceivably grow right across their surface. This ‘photic zone’ is where the sun’s rays are able to penetrate right to the bottom. By contrast, their deeper cousins will also incorporate an ‘aphotic zone’, which extends downwards sufficiently far to prevent sunlight reaching the bed.
Lakes, lochs and so on additionally tend to have distinct layers of warmer and colder water, particularly in the summer months, while pond temperatures tend to be more consistent throughout. Finally, if the water body is only ever capable of producing small wavelets, on even the windiest day, then it should definitively be placed into the ‘pond’ category.
Continue reading your story on the app
Continue reading your story in the magazine
Theme park could go ahead despite site's protected status
Swanscombe peninsula is designated as an SSSI but campaigners fear it is not enough to save the wildlife haven from proposed development.
MIKE DILGER'S - WILDLIFE WATCHING
In his series of great places to watch wildlife in the UK, the star of BBC One’s The One Show this month heads to our pebble-strewn shores to spot the species that thrive on shingle beaches.
TRUTH OR FICTION? It's perfectly safe to airlift a rhinoceros
Flying rhinos upside down looks ungainly but is it harmful, too? New research set out to find the answer.
Norway's star wolf moved for safety
Norway’s most famous wolf has been captured and moved south with a female companion to protect him from licensed killing.
It may be the nation’s favourite mammal, but the hedgehog is rapidly vanishing from towns and countryside across the UK. Why have things gone so badly wrong for British hedgehogs? And, more importantly, what’s being done to help them?
DISTURBANCE IN THE DEEP
With land resources rapidly depleting, eyes are turning to the seabed as a whole new source of metals. But at what cost to marine wildlife?
MEET THE SCIENTIST - Lauriane Suyin Chalmin-Pui
Well-being fellow, Royal Horticultural Society and postdoctoral researcher, University of Sheffield
Cranes becoming more common
Record numbers of common cranes bred in the UK last year, with 64 pairs producing 23 chicks.
My Way Of Thinking - Mark Carwardine
The conservationist discusses Jair Bolsonaro’s actions concerning the Amazon rainforest and invites your thoughts on the subject.
Gorillas In The Midst Of A Pandemic
Close encounters with tourists may be exposing great apes to COVID-19.