GALLE, Sri Lanka – Buses are the most common mode of public transport in Sri Lanka. But after thousands of trips, facilitating millions of commuter trips over their lifetimes, buses are taken out of service and sent to landfills, where they decompose and corrode under the elements.

Today, however, the Sri Lankan government is giving them a second life by sinking them into the ocean to serve as fish breeding grounds.

Sri Lankan Ministry of Fisheries and Aquatic Resources (DFAR), together with other government agencies, has so far sunk dozens of buses at three sites. He sank the first 20 buses Trincomalee on the northeast coast of the island in November of last year. The buses were transported on a Navy vessel to a location about 5 kilometers (3 miles) offshore. The selected DFAR Gall in southern Sri Lanka as a second site, where it dropped 25 buses, and emptied another 24 buses at the third site in Jaffna, in the north of the island.

“The results are encouraging because the buses that we dropped on the first site have already attracted a lot of fish”, Susantha Kahawatta, director general of DFAR, told Mongabay. Sri Lanka has a narrow continental shelf, so other than a few coral reefs, there are very few sites around the island that facilitate fish breeding. “But knowing that structures such as sunken ships become artificial coral reefs over time, becoming fish breeding grounds, we wanted to try and provide more such places around Sri Lanka,” Kahawatta said.

Fish breeding sites

The structure of a bus body is ideal for the fish to worsen in and around, he added, noting that after some time on the seabed, the tit begins to accumulate algae. , barnacles and mollusks. DFAR says it expects fast-growing corals to start sprouting on these structures soon as well.

The ministry obtained the buses for a symbolic price of the Sri Lanka Transport Authority (SLTB), which stores hundreds of decommissioned buses in its depots. “If we were to build a structure of this caliber, it would cost us more,” Kahawatta said.

In addition to buses, DFAR has also sunk a number of disused fishing boats and is also trying to secure more substantial structures such as train cars for the project. On earth, these dilapidated structures are an eyesore and take up space that could be used for other purposes. They also collect rainwater, becoming mosquito breeding sites, contributing to the spread of diseases like malaria and dengue. Sinking them therefore has benefits beyond ecological benefits, Kahawatta said.

Site selection

The National Agency for Research and Development of Aquatic Resources (NARA) selected sites for this project, looking for areas with a water depth of 10 to 15 meters (33 to 49 feet). He also took into account the wave patterns in the particular area, said Prasada Punyadeva, Head of the Fisheries Technology Division of NARA. Having the right depth is important, he added, as the site needs to have enough sunlight to support the growth of marine life.

Terney Pradeep Kumara, Director General of the Marine Environment Protection Authority (MEPA), said his agency checked buses and other structures to make sure they were free of pollutants before they were sunk. Kumara, who is also a marine biologist and former head of the marine science and technology department of the Ruhuna University, said it is important to monitor sites regularly and systematically to assess the success of the program.

Marine ecologist Arjan Rajasuriya praised the intention of the program, but said it would be more robust if it used metal structures specifically designed for life at sea, such as ships or barges, as they would last longer. He noted that there had been a previous case where buses were thrown into the ocean for fish farming. In this case, the buses had been damaged during communal riots in 1983, and the NARA had sunk them. Bambalapitiya in Colombo, on the west coast of the island. When Rajasuriya dived at the site the following year, he found only the chassis of the remaining buses sticking out of the sand. He also warned against sinking fiberglass boat hulls, as they could later shatter into microplastics.

Accumulated wrecks

Sri Lanka sits on an important maritime trade route in the Indian Ocean and, over time, has accumulated numerous wrecks of large and medium-sized ships in its waters. These include the world’s first purpose-built aircraft carrier, the HMS Hermes, which was sunk by Japanese warplanes in 1942. In 2018, the Sri Lankan Navy lifted the wreckage of another British ship, the SS Sagaing, also sunk by the Japanese in 1942, and moved it from the port of Trincomalee to another location.

The new site has since been regularly monitored by the Navy to see how corals and other marine life thrived there. Similar monitoring should also be applied to check the progress of sunken buses, said Rasika Muthucumarana of Maritime archeology unit (MAU) of the Central Cultural Fund (CCF).

In another initiative, the Sri Lankan Navy has created underwater “art galleries” at several sites in Trincomalee, Galle and Nilwella in southern Sri Lanka. These sites are mostly made up of cement statues depicting different historical figures and are also labeled as underwater museums by the Navy. He expects the sites to be tourist attractions while supporting fish farming and marine biodiversity.

Sri Lanka’s oceans have no shortage of natural habitats for fish reproduction, but many of these habitats have been lost due to destructive fishing practices such as blast fishing. This makes protecting these habitats and stopping harmful illegal fishing methods extremely important, Rajasuriya said. “It is important to tackle the problem of overfishing in the long term to revive the fish stocks in Sri Lanka,” Rajasuriya said.

Over time, sunken ships transform into artificial reefs housing marine life, like this one, known as the Battery Barge, off Colombo on the west coast of Sri Lanka. Banner image courtesy of Rasika Muthucumarana.