More than 20,000 pieces of discarded plastic - from water bottles and drinking straws to cling film and plastic bags - have found their way into a gallery at the Singapore Art Museum.

Painstakingly collected, cleaned and artfully composed in a room by artist-illustrator Tan Zi Xi, the immersive installation is meant to evoke in the audience a sense of being submerged in a sea of swirling trash.

The work, titled Plastic Ocean, is part of Imaginarium, the museum's annual contemporary art show for children. This is the sixth edition and it is put together by the museum's curators - Ms Tan Siuli, Ms Andrea Fam and Mr John Tung.

This year, the exhibition's theme draws inspiration from the ocean and sea. Works on display include an enclosed, temperature-controlled installation of coral-like structures made by chef Janice Wong using more than 1,300kg of isomalt sugar and confectionery.

There is also a colourful underwater seascape crocheted from yarn by Indonesian artist Mulyana.

The work by Polish-born artist Karina Smigla-Bobinski on the other hand, veers towards the monochrome. A large, illuminated, gas-filled sphere with short charcoal rods that protrude from the surface floats freely throughout the darkened room and visitors can interact with it.

The sphere may bring to mind a bioluminescent aquatic creature that swims in the depths of the ocean as well as spark thoughts about the consequences of man's interaction with the sea.

The potentially destructive relationship between man and the ocean is explored in Tan's installation. It draws inspiration from the Great Pacific garbage patch in the North Pacific Ocean where litter such as plastic items pools.

Her work aims to get the audience to consider recycling and reducing waste, but already, the process of making the work has changed lives.

The 31-year-old artist had called on friends and family earlier this year to help her create a stockpile of "resource", as she calls the trash used for the installation.

As they got into the habit of keeping recyclable plastics, some of them became conscious of the amount of waste they were generating and took steps to reduce it.

For example, a couple she knows, who used to drink bottled water at home because they could not get used to the taste of tap water here, installed a water-filter system in their house.

The artist has also made it a habit to take along a glass jar when she goes to coffee shops to buy takeaway coffee.

For Papermoon Puppet Theatre, a contemporary art group from Indonesia that uses puppetry as its medium, stories about the people who live where land and sea meet take centre stage.

Its work for the exhibition, Suara Muara (The Sounds Of The Estuary), was inspired by the history of Lasem, a once famous port town in Java, Indonesia, where hundreds of boats were deliberately sunk in the sea by its residents to prevent enemy forces from using the boats for attacks during World War II.

The group's work often deals with sombre socio-political issues and its puppets have an aesthetic that is "not cute and fluffy", says its director, Ms Maria Tri Sulistyani, 34. "Most of our works are not aimed at children, but kids can enjoy it," she says.

Her husband and the theatre's artistic director, Mr Iwan Effendi, 36, says its work in Imaginarium "is made for children, but there are many layers that the adults can experience and both adults and children can talk about together".

Curator Mr Tung, 26, says while Imaginarium is a children's art show, it "doesn't lack complexity or depth".

Ms Fam, 28, who echoes the sentiment, says: "The works may be more tactile, colourful and light-hearted to appeal to children, but they also introduce big ideas about recycling or forgotten histories, which we try to unpack through the presentation of the works."