A National University of Singapore (NUS) sailing trip has come under scrutiny after photos of students posing with giant clam shells they had found drew flak online.
Last month, 12 NUS students and alumni sailed to Indonesia's Riau Islands on a schooner for a week with Associate Professor Martin Henz, who teaches at NUS' School of Computing and Faculty of Engineering.
The group of students from different faculties returned to Singapore with some shells, including those of the giant clam, as keepsake.
But a photo of them with the shells in a Straits Times article on Monday sparked a debate.
Environmental groups and researchers pointed out that the giant clam is a protected species under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (Cites), and that proper permits are needed before any animal parts can be imported across borders, even if they are shells of dead clams.
Mr David Tan, 27, a researcher in the Evolutionary Biology Laboratory at NUS, said it was "alarming" to see that the group had brought the giant clam shells back. "One of the stated objectives of the programme was to encourage a love for nature... but this ran entirely counter to it."
Giant clams play an important role in the building of coral reefs. When they die, their shells are deposited on the reefs, which then attract marine life to live there and enhance overall biodiversity.
Ms Ria Tan, who runs the Wildsingapore.com nature website, said on the site's blog that better outdoor ethics training is needed for such trips.
Prof Henz, an avid sailor who has taken NUS students sailing in the region since 2013, said the trip was "a unique out-of-classroom learning experience".
He added: "The voyage team had picked up a few dead shells that were washed ashore, and the team was not aware of the international guidelines on collection of shells which would be applicable even if they are dead shells. This has been a learning experience for all involved, and we will be more mindful of our actions in the future to neither leave anything behind nor remove anything from nature."
Professor Peter Ng, head of the Lee Kong Chian Natural History Museum, said he is working with the group to hand the shells over to the relevant authorities.