David Aldridge on the BioBullet for Zebra Mussels

10:36 Tuesday 6th September
Mid-Morning Show
BBC Radio Cambridgeshire

ANDY HARPER: An invasive species is wreaking havoc along Cambridgeshire’s waterways. But it could soon be on the way out. The zebra mussel costs Anglian Water hundreds of thousands of pounds in repairs by clogging pipes. But now a Cambridgeshire company has developed a pellet known as a toxic malteser to deal with it. Dr David Aldridge is from BioBullets. David, good morning to you.
DAVID ALDRIDGE: Good morning Andy.
ANDY HARPER: So what are the problems caused by these things? And presumably it’s not just the zebra mussel.
DAVID ALDRIDGE: Zebra mussels are a member of a whole swathe of non-native organisms spreading through Britain’s fresh waters. We have zebra mussels in East Anglia. We have signal crayfish that people may have heard of. We’ve just recently received the arrival of the killer shrimp in Grafham Water. There’s lots of non-native organisms around. The zebra mussel is a particular nuisance, because it comes from the Black Sea and Caspian Sea area. And it’s a little bit like the marine mussels that you eat, in that it produces a beard. This is threads which they use to attach to solid surfaces. And this means they can attach not only to pipes, but they can also attach to each other. So they form very thick crusts in pipelines, and this obviously has big implications for the movement of raw water from rivers to reservoirs, and also from storage reservoirs onto water treatment works.
ANDY HARPER: So prior to the toxic malteser coming along, how were they dealt with in the past?
DAVID ALDRIDGE: The most widespread and licensed technique around the world for dealing with zebra mussels is to use chlorine. The problem with chlorine is that the zebra mussels are very clever, and they can taste the chlorine in the water and close their shells. And they can stay closed for up to three or four weeks. So you have to continuously expose them to chlorine or other treatment agents to finally get them to open and take in the toxin. What we do with the BioBullet is that we take a product which is toxic to the mussels, but we cover it in a tasty coating. This is where the malteser analogy comes in. And we cover it in a tasty coating which is just the right size and shape for the mussels to filter from the water. And so they swallow this miniature poison pill without realising they’ve taken in a toxic product. And they die straight away. And the beauty with this is that we engineer the coating materials so that it dissolves and degrades, and the entire product degrades within hours of going in the water. So anything which passes out into the open environment dissolves to totally harmless concentrations. So we have this big added bonus that there’s no impact on the wider biodiversity living in rivers and streams that might receive the outflow water.
ANDY HARPER: So what attracted you to the study of mussels? Is it the water? Is that where your interest lies?
DAVID ALDRIDGE: Well I also work at Cambridge University, where I head up what’s called the Aquatic Ecology Group, in the Zoology Department. And I’ve been working for many years on freshwater mussels, particularly with a focus on conserving freshwater mussels. So a lot of my work is going around the world and using native biodiversity such as mussels to clean up polluted systems, and help monitor change. And the idea for the zebra mussel really was a result of an industrial need for a solution, and I got my head together with a colleague who’s a chemical engineer, and knows something about making tiny particles. And so it was a combination of two different scientific disciplines, coming together to meet an industrial need.
ANDY HARPER: And how has it been welcomed, your invention?
DAVID ALDRIDGE: It’s been welcomed incredibly well. We’ve been working for the last couple of years with Anglian Water and Thames Water, following a big grant from the Government, something called the Technology Strategy Board, which has allowed us to produce products at a commercial scale now, which have been extremely successful in testing. We’ve tested in two UK waterworks now very effectively. And yes, the water industry is certainly behind us. And two of our products have now received approval from the Drinking Water Inspectorate, which means that it’s totally safe for use in the UK drinking waters. It’s important to say that we only put this in the raw water side of the pipelines. So this is before all the water is treated and processed, ready for dispersal to households. But yes, it’s been accepted and adopted very widely. And trials in the United States suggests independently that there’s no impact on native wildlife. We’ve just finished some work in Spain in irrigation systems. And we’re also working on some other invasive pests as well, which filter feed. So we have some very broad patents on this invention, which means that we can try and control pests around the world, in different environments.
ANDY HARPER: Well David, it’s been great talking to you. Congratulations. And hopefully we’ll talk to you again when you come up with yet more problem solvings. Thank you.
DAVID ALDRIDGE: Bye bye.
ANDY HARPER: That’s Dr David Aldridge, who is a Cambridge University zoologist, who helped to develop the malteser, the BioBullet. Fascinating stuff.

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