A new estimate of Māui dolphin numbers is encouraging for the future of the species, say Primary Industries Minister Nathan Guy and Conservation Minister Maggie Barry.

The preliminary results of a comprehensive scientific survey carried out over the last two summers has estimated the population of the critically endangered dolphin at approximately 63 adults, with 95 per cent confidence there are between 57 and 75.

This represents an increase from a 2010-11 survey which estimated the number of adults at 55, with 95 per cent confidence there were between 48 and 69.

'These results are encouraging but there is no dispute the Māui population remains at a very low level and the Government remains committed to ensuring their long-term survival,” says Maggie.

'While it is impossible to count every dolphin in the sea and this figure can only ever be an estimate, the survey was carried out according to rigorous scientific standards.

'What it does show is that Māui numbers over the past five years have stabilised, which can only be good news.”

DOC, MPI and researchers from Auckland and Oregon State Universities carried out the survey using a boat-based 'mark-recapture” technique – taking genetic samples from encountered dolphins over two summers, then comparing results to count how many unique dolphins were spotted.

'This survey is as close to definitive as it is possible to be and a great improvement on desktop-based predictive modelling figures which have been widely publicised in the last few years,” says Maggie.

It follows a recent survey which found the population of Hector's dolphin is about 15,000, more than double the previous estimate of 7000.

The full report from the abundance survey will be published next month and used to inform the review of the Hector's and Māui Dolphin Threat Management Plan scheduled for 2018.

The TMP has been in place since 2008 and identifies human-induced threats to both dolphin species and strategies to mitigate them.

Primary Industries Minister Nathan Guy says the new figures are an encouraging sign the restrictions on fishing are having an effect.

'More than 1700 square kilometres off the west coast of the North Island have been closed to trawl net fishing since 2003, and over 6200 square kilometres closed to set netting,” says Nathan.

'Since July 2012 there has been mandatory observer coverage on all commercial set net vessels operating offshore out to seven nautical miles in the Taranaki region. Since March 2014, there has also been increasing observer coverage on the trawl fleet north of Taranaki.”