He bears no ill feelings for the loss, he said. "It's the choice of the people. Arapeta has the enthusiasm, he's ambitious and he had plenty of energy ... he'll be great for Maoridom and for the community."
Mr Eru, a highly-respected Te Arawa kaumatua, said he would continue to help in decision-making in the region through his many roles on numerous trust boards.
He supported a strong working partnership with iwi and territorial local authorities to bring results.
"Maori own many of the resources in the region but we need a partnership otherwise it gets lopsided.
"Everyone has responsibility to take ownership of issues, such as lakes water quality."
In the same year he was made a Member of the New Zealand Order of Merit (MNZM) for his services to Maori in the Queen's Birthday honours list.
Mr Tahana said he was "initially pleased with the [election] result and was looking forward to the journey".
"I intend to get the lie of the land and get to know how the machine works."
He was supportive of policy which would assist Maori development and aspirations.
Mr Tahana, who was educated at Auckland University, is the Maori Trustee central region portfolio manager working with the Maori owners and trustees of more than 100 land trusts in the Bay of Plenty.
He has 12 years' experience in business, local government, community and Maori development.