"I'm very excited to join the Bombers, it's been a stressful period of time but cannot wait to get started," Duursma said.
"My best football is ahead of me, and I can't wait to be pulling on the red and black, and running out in front of all the amazing Bomber fans."
The deal went down to the wire on the final day of the 2023 Continental Tyres AFL Trade Period, with Zerk-Thatcher, pick No.73 and two future fourth-round picks headed to the Power in exchange for the 23-year-old Duursma.
"We identified a need for tall defenders in our backline and we are excited to bring Brandon to the club because he fills that need,” said Port list manager Jason Cripps said of Zerk-Thatcher.
"He is athletic for his size and has developed a consistency to his game over the last 12 months."