GALLE, Sri Lanka – Buses are the most common mode of public transport in Sri Lanka. But after thousands of trips and millions of commuter rides, the buses are decommissioned and sent to junkyards, where they decay and corrode under the elements.

Now the Sri Lankan government is giving them a second life by sinking them in the ocean to serve as fish-breeding sites.

The Sri Lankan Department of Fisheries and Aquatic Resources (DFAR), working with other government agencies, has so far sunk dozens of buses at three sites. It sank the first 20 buses off Trincomalee on the island's northeastern coast in November last year. The buses were ferried on a navy ship to a spot about 5 kilometers offshore. The DFAR selected Galle in southern Sri Lanka as the second site, where it dumped 25 buses, and dumped another 24 buses in the third site in Jaffna, in the island's north.

"The results are encouraging as the buses we dumped at the first site have already attracted a lot of fish," Susantha Kahawatta, director-general of the DFAR, told Mongabay. Sri Lanka has a narrow continental shelf, so apart from a few coral reefs, there are very few sites around the island that facilitate fish breeding. "But knowing that structures like sunken ships become artificial coral reefs over time, becoming fish breeding sites, we wanted to try out providing more such places around Sri Lanka," Kahawatta said.

The structure of a bus body is ideal for fish to congregate in and around, he added. The DFAR says it expects fast-growing corals to start sprouting on these structures soon.

The department obtained the buses for a small price from the Sri Lanka Transport Board, which stores hundreds of decommissioned buses in its depots. "If we are to build a structure of this caliber, it would cost us more," Kahawatta said.

Along with buses, the DFAR has also sunk a number of decommissioned fishing boats, and is also trying to get more substantial structures such as train cars for the project. On land, these broken-down structures are an eyesore. They also collect rainwater, becoming mosquito-breeding sites, contributing to the spread of diseases like malaria and dengue fever. Sinking them therefore has benefits beyond those for marine life, Kahawatta said.

Terney Pradeep Kumara, general manager of the Marine Environment Protection Authority, said his agency had checked the buses and other structures to ensure they were free of pollutants before being sunk. Kumara, who is also a marine biologist and former head of the Marine Sciences & Technology Department at the University of Ruhuna, said it's important to monitor the sites to assess the program's success.

Marine ecologist Arjan Rajasuriya welcomed the program's intent, but said it would be more robust if it used metal structures purposely built for life at sea, like ships or barges, as they would last longer. He also warned against sinking fiberglass boat hulls, as they could later break up into microplastics.

In another initiative, the Sri Lanka navy has set up underwater "art galleries" at a number of sites in Trincomalee, Galle and in Nilwella in southern Sri Lanka. These sites mainly consist of cement statues depicting historical characters. The navy expects the sites to be tourist attractions while also supporting fish breeding and marine biodiversity.

This story is from the Solutions Journalism Network, a nonprofit organization dedicated to rigorous reporting about responses to social problems.