A paper analysing the impact of the protection measures by Prof Slooten and Associate Professor Steve Dawson was presented to the International Whaling Commission (IWC) scientific committee in Chile recently.
More than 200 scientists from around the world attended the meeting, with the committee expressing its appreciation for the large investment by government agencies in the development and implementation of the measures.
However, it was noted "that additional measures are likely to be required to ensure recovery of the species".
The measures, announced by Fisheries Minister Jim Anderton last month, include regional bans on set netting, trawling and drift netting in some coastal waters, as well as increased monitoring.
The population of Hector's dolphins, which are among the rarest dolphins in the world, is less than 8000, down from 30,000 in 1970.
Without protection the population was projected to decline to just over 5000 by 2050.
Prof Slooten said the measures were a huge step in the right direction, given numbers were "plummeting", and now it was possible they could "almost hold their own".
It meant dolphins on the east coast of the South Island, including off Otago, were protected, while those on the west coast of the South Island, which were only protected for 3 months of the year, were likely to decline in number.
The North Island's west coast was likely to hold its own, although protection measures did not go as far south as hoped, she said.
"Overall, there will be a slight decline of 600 dolphins by 2050. It'll hold the population at its current level rather than recover."
The measures did not yet meet national or international guidelines for marine mammal protection, Prof Slooten said.
In coming years, there would need to be more work done to plug some of the gaps around Banks Peninsula, Taranaki and around Cook Strait, she said.
Full protection from bycatch in gillnets and trawl fisheries would help the population almost double by 2050.
While at the commission, the University of Otago researchers also entered into a partnership with the University of Chile, in Santiago, to help survey numbers of Chilean dolphins.
"They are where we were 20 years ago. They do not know how many there are, or if the population has gone up or down."
The Otago researchers would pass on the "blueprint" developed through years of work with Hector's dolphins so a conservation plan could be developed if needed, she said.
