Why you should not throw coins into ‘wishing ponds’ – S.E.A. Aquarium, Dolphin Island blog

On 6 March 2017, a 25-year-old female green sea turtle in Thailand, nicknamed Omsin (Thai for piggy bank), underwent a 4-hour operation to remove a 5kg mass of 915 coins from its stomach. These coins were loose change visitors tossed into its enclosure for good luck, which she mistook for food.

Omsin weighed about 59kg, which means the coins made up about 10% of her body weight. Her ventral (underside) shell eventually cracked under the immense weight of the coins, leading to a life-threatening infection.

Omsin was brought to Chulalongkorn University’s veterinary facility, where five veterinary surgeons painstakingly removed the coins, many of which were badly corroded. Leading the surgery was Dr Nantarika Chansue, head of the university’s veterinary medical aquatic animal research center. Two years ago, Dr Chansue was part of S.E.A. Aquarium’s Save the Irrawaddy Dolphin Project, where she assisted our veterinary team in conducting a population assessment of Irrawaddy dolphins in Songkhla Lake, the largest natural lake in Thailand.

The surgery went well. Omsin was swimming and eating normally despite high levels of nickel in her blood due to ingesting coins over a prolonged period of time. Just when recovery seemed promising as the veterinary team worked on her nickel levels, things took a turn for the worse.

On 19 March, two weeks post surgery, Omsin was found to be breathing too slowly. The veterinarians discovered that it had a serious intestinal infection, and they performed an emergency surgery the next day to repair her damaged intestines. Unfortunately, due to her physical weakness and multiple complications, including toxicity in her blood stream, Omsin succumbed to the infection. She slipped into a coma after surgery and passed away on 21 March.

It was concluded that her intestinal damage was likely due to the coins inhibiting protein intake. Nickel toxicity 200 times the safe dose for the species also appeared to have damaged her immune system.

Sea turtles are known to ingest debris and foreign objects that resemble prey. A study of sea turtles off the coast of Australia found they frequently ingested clear plastic because it resembles jellyfish.

In an interview with Bangkok Post, Dr Chansue said, “I want the case of [Omsin] to be an example for people in general who may wrongly believe that throwing coins into ponds where there are live animals brings good fortune. It only hurts the animals.”