Nick Mavar Jr., a deckhand for the F/V Northwestern who was featured on the series "Deadliest Catch" over the course of 15 years, has died.

He was 59 years old.

Mavar died Thursday in Naknek, Alaska, following a medical emergency, Bristol Bay Borough Police Chief Jeff Elbie told USA TODAY Friday. The longtime fisherman, whose legal name was Nickola Mavar Jr., was pronounced dead after he was transported to a medical facility, according to Elbie.

USA TODAY has reached out to representatives for the F/V Northwestern and Discovery for comment.

TMZ was first to report the news.

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In a statement to USA TODAY on Friday, F/V Northwestern Captain Sig Hansen shared, "I have known Nick Mavar for my entire fishing career, he has worked on our family boat for 25 plus years. He was more than a crew member, he was a very good friend and a right hand man."

He continued, "The passing of Nick Mavar spread through the fishing community like wild fire. This is no surprise because of how well known and respected he was by the fishing fleet."

Mavar appeared on 16 seasons of "Deadliest Catch," which started airing on Discovery Channel in 2005. Fifteen years after making his debut in Season 2, Mavar's final appearance on the Emmy-nominated show was in Season 17, which aired in 2021.

"Deadliest Catch," now in its 20th season, follows crab fisherman off the coast of Alaska as they continuously defy death during expeditions in the Bering Sea.

In December 2022, Mavar sued his employer F/V Northwestern, LLC, alleging he was "seriously and permanently injured" when he suffered a ruptured appendix while on board the ship "following a time period of repeated reports of pain and discomfort."

Mavar claimed his employer was negligent in failing to obtain timely medical care that would have prevented the rupture. A "cancerous tumor" was later found to be growing inside his appendix, he claimed. A trial date is scheduled for April 2025, according to King County Superior Court records.

Several months after Mavar's filing, the F/V Northwestern sued "Deadliest Catch's" production company for failing to provide appropriate medical care while requiring the vessel's adherence to COVID-19 protocols.

The production company, in a June 2023 filing, asked the court to dismiss the case and denied "any and all liability, and denies that it acted negligently or contributed to any injury Mavar may have suffered that is or becomes the subject of this action."

The case is ongoing, though the judge ruled to suspend proceedings pending the resolution Mavar's case in Washington.