Lynda Duncan, a "school teacher by day and maker by night" has used bull kelp or rimurapa to create a hanging sea forest among the branches of a large pohutukawa tree on the slopes of Piki mai/Church Hill in Nelson.
She collected the bull kelp from Ward, near Kaikōura after a storm and used balloons to inflate the seaweed before laying it out to dry and lining it with beeswax.
Duncan said the "big dark chocolate-coloured drum shapes" are lit up with changing shapes to give the sense there is something alive inside.
Scattered among the kelp are a number of mermaid's purses' - the egg cases of skates and sharks.
"The skate and shark lay their egg cases in amongst the big kelp because it blends in and they just hang out in there wriggling around until they are ready to be born."
To recreate the cases, Duncan covered four of her family members in plaster and said she loved the challenge of making artwork for Te Ramaroa.
"Not only do you want to make something that's beautiful and you want people to engage with, but then you have to make it interact in the dark and I love that."
Te Ramaroa project manager Sophie Kelly said this year's festival, which was previously known as Light Nelson, had expanded with more than 30 installations scattered throughout the city, in laneways, projected onto buildings and in Queens Gardens which is where it first began in 2013.
She said the balance between community participation and work from established artists was part of what made the event so special.
Kelly said the expanded footprint of this year's festival offered people a chance to explore places they mightn't otherwise.
"Piki mai offers so many beautiful historic trees, little hidden spaces, all sorts of kind of things, places that people wouldn't ordinarily see in the day and a chance to see it by night."
She said the region could be quiet during the winter months, but people found light so alluring that they embraced the opportunity to wrap up warm and get out in the dark.
"It's a really great way to see Nelson in a different light."