Prime minister Henry Puna met with Maru as she took up her appointment.
"We have always looked to engage our people at the highest level and to encourage our women to lead whenever the opportunity avails itself,” said Puna.
Maru, while in her role at Pacific Islands Forum Fisheries Agency (FFA), said: “We have the ability to shape our fisheries in a way that suits our long-term needs, feeding and providing for our Pacific Islands.
“We need to invest in our people, and management of these resources - to give back, as we take out - if we really want to move ahead.
“We need to speak up more and stop shying away from things that matter but which might be uncomfortable to raise.”
Maru leaves her position at the regional body; Pacific Islands Forum Fisheries Agency (FFA) to take up her role as Secretary of MMR.
She began her career as a Fisheries Officer at MMR and later was appointed Fisheries Management Adviser at FFA in the Solomon Islands.
From 2009 to 2011 she was Vice Chair of the Western and Central Pacific Fisheries Commission.
In 2017 she led the creation and implementation of a Port State Measure to combat illegal fishing through port inspections.
Maru hails from the village of Arorangi and her mother from Tahiti.