Further protected areas are planned in Kaikoura, known for its whale-watching industry, and in Otago, home to New Zealand sea lions, yellow-eyed penguins and the northern royal albatross.
Consultation has also begun with Auckland Council on plans for its marine environment, which could lead to further protected areas around the city's coastline.
Historically, most of the Department of Conservation's focus has been on protecting land.
But because 70 per cent of this country's native species were found in the ocean, Dr Smith said he was placing more emphasis on offshore projects.
"The marine environment is the new frontier for conservation and it's an area I do want to make more progress this year," he said.
The National-led Government has a goal of having 10 per cent of New Zealand's waters covered by marine reserves.
The addition of the new reserves would mean that 9.56 per cent of its territorial waters - the area out to 12 miles from the coast - was protected.
This figure was considered misleading by some.
Green Party oceans spokesman Gareth Hughes said that if the entire Exclusive Economic Zone was taken into account, just 0.41 per cent of New Zealand waters was a no-take zone.
In comparison, a third of New Zealand's land was protected by DoC.
Mr Hughes has tabled a bill that would establish a reserve in the Kermadec Islands.
Dr Smith said greater research was required on the economic losses and conservation gains of the proposal, which would be the the world's largest no-fishing zone.