Shea has held the leadership role since March 2020, when she agreed to become the interim chair.
She was permanently appointed in April, becoming the first Māori board chair for the DHB.
She said it had been a "real privilege" to serve the Bay of Plenty community and acknowledged the "dedication and commitment" of the DHB board, the team, and Iwi Runanga partners.
"It's been a challenging time with natural disasters and Covid-19. While we've made some gains, such as thinking differently about how the system can pivot to meet challenges, there is still more work to do," she said.
"I'm particularly proud of our relationships with our Māori Health Runanga and the work we are doing together to uphold our Te Tiriti o Waitangi inspired relationship."
Edlin has an extensive governance resume as a fellow and a chartered director of the Institute of Directors.
She has been chair and served on a number of boards and trusts over the past 19 years including Netball Waikato.
Edlin said she was "committed" to working with the management team, iwi and board members to "provide constructive input" as the DHB prepares for a new future.
She said the DHB continued to respond to a number of "unique and long-term challenges" including the aftermath of the Edgecumbe floods, White Island eruption and the pandemic.
"Financial sustainability and the planned transformation of the health system is requiring us to work even more jointly with the Ministry of Health and consultants, to ensure our people throughout the Bay of Plenty will continue to receive the appropriate health services they require."
She wished Shea "all the very best" in her new roles.
"Her extensive skills, experience and strong leadership will ensure these new organisations navigate carefully and clearly through the many challenges a health system like ours faces."
Bay of Plenty Māori Runanga chairperson Linda Steel also thanked Sharon and welcomed Edlin.
"Her ability to be able to navigate a way forward through empathy and kotahitanga while maintaining the high standards she sets for herself both from a Tikangā Māori and general world view is outstanding."
"The Rūnanga would also like to congratulate Bev Edlin on her appointment. Bev has added another level of governance experience to DHB since she joined the Board, and she is a strong advocate for equity and diversity.
"Te Rūnanga Hauora Māori o Te Moana a Toi look forward to working with her to ensure our whānau will flourish into the future."
"Waiho I te toipoto, kaua I te toiroa."