The middle forward from Rabaul in Papua New Guinea has played the past three seasons for the PNG Hunters in the Hostplus Cup.
The 24-year old has also represented Papua New Guinea at the Commonwealth Championships Under 23s Nines competition in 2018.
Seagulls Coach Adam Brideson says he is excited about what Kapinias can offer the club this season.
“Epel is an experienced middle forward at Hostplus Cup level,” Brideson said.
“He is a strong athlete with good skills and will add a lot to our forward pack.