Ducks have been ditching bread for a cleaner diet after members of the public were asked to ban the breadcrumbs.
Figures from the Canal & River Trust, who care for 2,000 miles of waterway in England and Wales, show a 20 per cent fall in feeding ducks bread.
Although the number of people feeding ducks a healthier dinner - of seeds, fruit and vegetables - has doubled, people are still throwing 3.5 million loaves into canals, rivers, ponds and lakes every year.
Bread is bad for ducks for multiple reasons.
It has been proven to cause overpopulation, as birds flock to the food.
The bread that is uneaten then spreads disease and attracts pests.
In addition the excessive droppings can reduce water quality and clog channels.
Peter Birch, national environment manager for the Canal & River Trust, said: “We’re really pleased with the public response to our campaign so far and the way people are changing their duck feeding habits.
“However there’s still work to be done and still too much bread is being dumped in the waterways. We need more people to get the word out and encourage everyone to feed the ducks sensibly.
“It only takes a few simple changes such as swapping bread for healthy food that is closer to a duck’s natural diet - like oats, corn or peas.
“If everyone avoids going to the same duck-feeding hotspots and exercises portion control that would also make a big difference.”
The recent public poll for the Canal & River Trust found people in the south-west have changed their habits the most, with a 23 per cent drop in the number of people feeding ducks bread.
The north-east was a close second with a 22 per cent fall.