Green islands released in Bristol Harbour

The 17-metre long island is made from recycled plastic water pipes

Two large floating platforms covered in 500 native plants have been launched in a city harbour to help improve the water quality.

The two islands, which measure approximately 17m in length, were created at Bristol's Festival of Nature and are the first of a number of platforms due to be floated in the water this year.

It is part of a £500,000 project to regenerate the Capricorn Quay area of Bristol Harbour.

Savita Willmott, CEO of the Natural History Consortium that runs the festival, said the ecosystems were made in response to the "challenges around our waterways".

The islands are made from former drinking water pipes, stainless steel connections and coconut fibre

"They are there to help make the water cleaner and better for wildlife and for people in the harbour," she added.

Ellen Hebdon, operations manager for Biomatrix Water Solutions that designed the platforms, said: "We're giving nature back a structure to be able to do what it does best, so that is bring back habitat above and below the water."

She said above the water the floating islands create a habitat for the likes of pollinators, birds, bats and invertebrates.

"Below the water you've got a whole wilderness of microorganisms which bring back the underwater biofilms."

The beds were prepared at Bristol's Festival of Nature

Biofilms help to recycle organic matter and contribute to water quality, as well as supplying food for aquatic life.

Ms Hebdon said the platforms also "bring back that green space to an intense urban environment".

It is hoped the platforms will help improve water quality in Bristol Harbour

Ms Hebdon said over time the platforms would cleanse the water as the plants obtain nutrients from other unwanted plants, such as algae, leading them to die out.

The floating platforms have been planted with species including Ragged Robin, Carex Juncus, Water Forget-Me-Not and Irises.

Ms Hebdon said they would be treated like usual gardens, requiring weeding and clearing of litter.

The islands were made from recycled materials and were fully recyclable, she added.

The plants would bring "wellbeing" back to the water, said Ellen Hebdon