Imagine an inner city where most people eat what they can grow, and raise, on their own doorstep. A place where community gardens teem with bees, vegetables, chickens, and... fish.

That's the utopian vision of New Yorker Christopher Toole.

A pioneer in the latest urban farming craze - freshwater tilapia - he is leading a movement in the dilapidated South Bronx called "aquaponics".

Aquaponics encourages people to grow fish in their high-rise bathrooms, in large rubbish bins or tanks. The next step is to raise the fish on a bigger scale in the city's many community gardens, where their waste can be used to fertilise plants.

It is a bold vision, but hundreds of New Yorkers are joining in, and Mr Toole is optimistic that aquaponics will become a staple in America's organic urban food culture.