For months, ITV News has been investigating the problem of river pollution - and the Wye, which runs from its source in mid-Wales through Herefordshire and Gloucestershire, is among the worst.
A special investigation from ITV News journalists in the Central, Wales and West Country regions examines what is going wrong - and what needs to be done.
In part two of our series, ITV Wales Rural Affairs Correspondent Hannah Thomas examines allegations that poultry farming could be playing a big part.
With music, chanting, and - most strikingly - a coffin, the message from anti-pollution campaigners could not be any clearer: “Stop polluting our rivers.”
High levels of dangerous pollutants have been found at almost all stages of the River Wye, from near its source in the mountains of mid-Wales, through Herefordshire, and into Gloucestershire, before washing out into the sea at the Severn Estuary.
Angela Jones has seen it first hand, and helped lead the protests in Cardiff. A dedicated wild swimmer, she says she’s seen plant, fish and bird life diminish in recent years, as pollutant levels increase.
Water companies dumping sewage into the waterways is one culprit but there is also the huge increase in the number of poultry farms adding to the problem throughout the Wye catchment area.
“The Wye has been part of my life for decades. It’s my office. It’s my playground,” Angela says.
“We have allowed it to die in front of our eyes, through pollution, through poultry farming.
“So I decided to get a coffin and tow it along the Wye, and then bring it to the Senedd. And then I’ll be going up to London with the coffin, because if change doesn’t come, we are going to lose our gorgeous, beautiful river.”
There are an estimated four million chickens being reared in mid-Wales, and, it’s thought, another 16 million in Herefordshire.
Meanwhile, between 2010 and 2017 alone, there was a six-fold increase in the number of large egg and chicken producers in Gloucestershire and Somerset.
Chicken faeces is notorious for being high in phosphates, and in some cases is actually used as fertiliser as the chemical aids for plant growth.
But while that may be of benefit on land, if it washes into the rivers it becomes a nutrient source for algae, and large algal blooms - such as those seen along the Wye in recent years - choking off other plant life and robbing fish of both food and places to lay eggs.
That, in turn, affects wild bird life.
Campaign group River Action has been calling for major egg producers to play a part in solving the problem.
“We want them to behave responsibly, and what we’re saying to them is ‘you are part of the problem, therefore you need to be part of the solution',” said chief executive Charles Watson.
“We’re not here telling you not to eat eggs, eggs are delicious, they’re an incredibly important and affordable source of protein.
“But the fact is that chicken poo has four times the content of phosphate than any other kind of animal manure. Four times more than cows, four times more than sheep or pigs.
“The land cannot take any more phosphate, and there is only one place it is going to end up, and that’s in the river.”
Avara Foods has now made a step towards heeding that call, telling a meeting of the Wye Nutrient Management Board that it was developing new ways of disposing of its manure to ensure it was not spread on land.
It stopped shy of admitting responsibility, but said: “While not a direct contributor to River Wye pollution, we recognise that the use of our chicken litter on land in the Wye catchment does have an impact.”
Farmer Sharon Hammond rears 40,000 hens at her farm in Powys for Avara - and she says she isn’t happy about being blamed for the problems on the Wye.
“As an industry, we are very very heavily regulated, so even before we can consider applying for planning permission to build poultry sheds, we have to seek a permit to do so from Natural Resources Wales in our case,” she said.
“That permit has over 30 conditions to it that we have to comply with in terms of our emissions, and that then is all regulated after we get our permit and we get our planning permission and we put our sheds up. Everything is recorded, and reported and inspected.”
Stella Owen, from the National Farmer’s Union in Wales, agrees.
“NFU Cymru has always said you have to deal with the scientific evidence. Now, if there is evidence coming forward, then farmers will work with anybody to help things get better,” she said.
“But until there is that evidence, and until there is solid evidence, NRW said they could not attribute it to poultry farms. So it’s very very difficult for poultry farmers to be taking the rap all the time.”
Whatever the reasons behind the demise of the wildlife in the Wye, campaigners believe that time is running out to rescue the river.
A river they want to revive, and crown the nation’s favourite, once again.