Giant light sculptures inspired by the appearance of small marine organisms now light up the Marina Bay waterfront.

Called Ocean Pavilion, the installation features creations made from 25,000 recycled bottles and energy-efficient LED lighting, and is inspired by algae and radiolarians, which have glass-like exoskeletons.

The installation was the focal point of the official opening of the fifth edition of i Light Marina Bay 2017 yesterday.

The showcase, organised by the Urban Redevelopment Authority (URA), features 20 pieces of work by artists from nine countries. It will run till March 26.

This year's overall theme is "Light and Nature", with three hubs focusing on related concepts: The Fantastical World of eco.me focuses on sustainability-themed activities; Art-Zoo on imaginative play; and GastroBeats on food and music.

URA said the installations "highlight the importance of sustainability and reinforce Marina Bay's position as a sustainable precinct".

Mr Jason Chen, festival director and director of place management at URA, added: "The festival has grown beyond a showcase of sustainable light art installations. It is also a platform for active involvement of the community and partners to drive the sustainability cause in various ways.

"It is encouraging to see more partners getting involved in the festival and supporting its cause, making it a festival for the community and by the community."

About 80 building owners and organisations will be switching off non-essential lighting and turning up air-conditioning temperatures throughout the festival period to offset the power consumption of the light art installations at the festival.

Admission to the Marina Bay waterfront is free, although charges apply for some attractions.

The light installations are on from 7.30pm to 11pm, ending an hour later on Fridays and Saturdays.