Sea Life Park’s oldest male bottlenose dolphin died Thursday, according to park officials.

Kamoana was 54 years old and died of a sudden, age- related decline in health.

“As one of the oldest dolphins under human care in the U.S., Kamoana was a beloved member of our ohana for many decades,” said Valerie King, general manager of Sea Life Park. “He lived a long and enriching life and was our ‘grandpa’ of the ohana.”

The average life span of a male common bottlenose dolphin is 40-45 years, according to the National Oceanic and Atmospheric Administration.

A veterinary team will conduct a full postmortem examination, park officials said.