Dubbed the “accordion-playing merman,” Gary Sredzienski, known for his “surf rock” fare, will undertake a sizable swim in January to raise money for the New Hampshire SPCA.

Sredzienski, who has completed similar wintery events in the past, will brave bone-chilling temperatures once more for a dunk on Saturday, Jan. 21, from Adams Point in Durham to Newick’s Restaurant in Dover.

“The waters that he will encounter on this four-mile swim will be the coldest he has faced at temperatures of 34 degrees or less,” event organizers said in a written statement. “Since the salt waters mix with the fresh waters of the Piscataqua river in this area, it allows the waters to be that much colder.”

But Sredzienski said his motivation is the SPCA’s mission. “I had a great dog that used to swim with me all the time,” Sredzienski said.

“He was my best friend and companion. If I can do this to help other animals find a home, I’m happy to do it.”

Sredzienski is known in music circles for his work with his band the Serfs. He has released several CDs, and his compositions and music have been featured in feature films and television sound tracks including Paramount’s “Bad News Bears” and “The A Team,” Eddie Murphy’s “Meet Dave,” CBS’s series “Love Monkey,” ABC’s “Dirty Sexy Money” and “Brothers and Sisters,” CW Network’s “Everybody Hates Chris,” and The Food Channel and NBC’s “The Philanthropist.” He also hosts a weekly 1950s-style radio show, “Polka Party,” on WUNH-FM. I Sredzienski said he swims two to three miles about five times a week all year round in the estuaries of Maine and New Hampshire. In 2008 he raised more than $17,000 for the Krempels Brain Injury Foundation for a swim six miles from Portsmouth to the Isle of Shoals, and in 2011, he made swims in support of lighthouse preservation projects on the Seacoast, he said. For details on his latest planned plunge, log onto nhspca.org or call Sheila Ryan at 772-2921, ext. 106.