LISTEN: Scientist captures the bizarre underwater sounds of pondlife

PhD student Jack Greenhalgh listening to the sounds of underwater wildlife in a restored pond at Swanton Morley Farms

PhD student Jack Greenhalgh listening to the sounds of underwater wildlife in a restored pond at Swanton Morley Farms - Credit: Chris Hill

The mysterious underwater soundscape of Norfolk's ponds is being recorded to bring a new sonic perspective to conservation efforts.

An acoustic ecologist is submerging a microphone in farmland ponds across the Wensum valley to hear how successful restoration efforts have been.

Once dark, barren and silent, they are now humming with life - both above and below the surface.

From the ticking of underwater plants respiring, to the loud rhythmic pulses made by water boatmen, the sounds tell a story of aquatic wildlife thriving.

The study is being carried out by Jack Greenhalgh, a PhD student from the University of Bristol, who became intrigued by the subject after meeting Norfolk ponds enthusiast Prof Carl Sayer while studying at University College London.

He said: "Ponds are absolutely packed full of life, and all this life, all the beetles and bugs and even the plants make sounds underwater and it is a really quite an incredible thing to listen to.

"It is like an underwater jungle, or a disco. It is amazing.

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"The loudest thing in a pond is a water boatman, and actually we now know the water boatman can produce a sound louder than any other animal in the animal kingdom when scaled to its tiny body length.

"It makes this incredibly loud noise by rubbing its penis against its leg. That is something that is almost omnipresent. It is laying down the bassline of a pond soundscape.

"The other thing is the aquatic plants. You can hear as they respire in the sun as they photosynthesise, all the oxygen bubbles come streaming out of the leaves underwater and they make a ticking sound, or sometimes a whining sound, and you can hear that too.

Wensum Farmers group advisor Lizzie Emmett surveying wildlife in a restored pond at Swanton Morley Farms

Wensum Farmers group advisor Lizzie Emmett surveying wildlife in a restored pond at Swanton Morley Farms - Credit: Chris Hill

"All of these ponds are restored on farmland and we are coming to them one year after restoration.

"It is amazing to see all the plant life and insect life, and when you listen to the sound you can hear the amazing diversity that has come back in just that short time."

In all, more than 20 restored ponds are being studied within the Wensum Farmers group, which has 27 members farming 10,000 hectares of land across the river valley.

While Mr Greenhalgh is recording the sounds, there are also more traditional surveys being carried out of all the aquatic creatures and plants to give a full picture of all the pond's species and how they relate to each other.

They include newts, invertebrates, countless damselflies and four-spotted chaser, darter and emperor dragonflies.

A baby newt found in a restored pond at Swanton Morley Farms

A baby newt found in a restored pond at Swanton Morley Farms - Credit: Chris Hill

Lizzie Emmett, Wensum Farmers group advisor, said: "The main reason we have to restore these ponds is that they get very overgrown, dark and clogged up with nutrition, and the aquatic species don't thrive when there is no sunlight and no oxygen.

"We are trying to open up the light, and dig out to get more water in, because the more mature trees are sucking the water out.

"By taking that silt away, that high-nutrition sludge, we are then exposing this very species-diverse seed bank where all these native species are waiting to pop through, given the opportunity.

"The reason I wanted to get in touch with Jack is I wanted to do something a bit different for my farmers. We always go back to the ponds and see all the vegetation but it is sometimes hard to work out what is going on underneath.

"I heard about this acoustic data and I thought it would give us a whole new meaning."

Conservationists at a restored farmland pond in Swanton Morley

Pictured from left at a restored pond at Swanton Morley Farms are landowner James Keith, Wensum Farmers group advisor Lizzie Emmett, PhD student Jack Greenhalgh and farm manager Simon Brock - Credit: Chris Hill

One of the restored ponds is at Swanton Morley Farms, near Dereham, managed by Simon Brock.

He said: "We've got loads of these marlpit type ponds - they are everywhere, most fields will have one.

"Some of them are dry, some will have water in them, but this one was a classic. It was completely overgrown and they go black, there is no real life in them, and it tends to dry out into a muddy black landscape because the trees suck all the water out.

"With Lizzie's help, we have really transformed it. All the pondlife in there now is extraordinary."

Wensum Farmers group advisor Lizzie Emmett and farm manager Simon Brock surveying wildlife in a restored pond

Wensum Farmers group advisor Lizzie Emmett and farm manager Simon Brock surveying wildlife in a restored pond at Swanton Morley Farms - Credit: Chris Hill

A restored pond at Swanton Morley Farms

A restored pond at Swanton Morley Farms - Credit: Chris Hill

A dragonfly in a restored pond at Swanton Morley Farms

A dragonfly in a restored pond at Swanton Morley Farms - Credit: Chris Hill

Wensum Farmers group advisor Lizzie Emmett surveying wildlife in a restored pond at Swanton Morley Farms

Wensum Farmers group advisor Lizzie Emmett surveying wildlife in a restored pond at Swanton Morley Farms - Credit: Chris Hill

PhD student Jack Greenhalgh listening to the sounds of underwater wildlife in a restored pond at Swanton Morley Farms

PhD student Jack Greenhalgh listening to the sounds of underwater wildlife in a restored pond at Swanton Morley Farms - Credit: Chris Hill