These are Bali’s coral reef stars.
The hexagon-shaped steel structures have live coral fragments attached - designed to encourage new growth in damaged areas.
Location: Bali, Indonesia
And this is conservationist Pariama Hutasoit giving the reef stars a clean.
She, and her non-profit Nusa Dua Reef Foundation, have installed almost 6,000 of them in an effort to protect Bali’s reefs from climate change and human impact.
Courtesy: Nusa Dua Reef Foundation
"The conditions of coral reefs globally have worsened due to various factors, including destructive fishing, sedimentation due to mass development on coastal areas, and climate change, which clearly has a huge impact (on the reefs)."
The Indonesian archipelago harbors more than 75% of the world's coral species, many of which are facing erosion and bleaching every year.
Only just over half of Bali's coral reefs are considered to be in "good" condition, with 30% in "poor" condition, and the remaining 15% in "very poor" condition.
Source: Bali's Marine and Fisheries Department
A lack of education is also to blame for the demise of Balis’ reefs, says local fisherman I Nyoman Sadnya.
"I will be frank and not cover up the truth. Our parents' generation didn't have jobs and the area here used to be arid, and sometimes it was difficult to even find food. So because of that, my parents resorted to coral mining to mine for building materials, because they didn't know better. We were not educated about this issue back then, so now it's regrettable to see this (the current condition of the coral reefs)."
According to Hutasoit, the Nusa Dua Reef Foundation is working on community outreach programmes to educate local residents about the importance of area’s reefs.
And she said there are still more reef stars to come.
"Currently, I don't have a target for Nusa Dua except for planting new and replacing the dying coral. But we have a target for northern Bali, and we are aiming to install about 5,000 reef stars over the next five years. We do have any other goals in mind, but if possible, we want to expand our conservation work for the restoration of coral reefs outside of Bali."