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Fishing Industry Spin on Maui Dolphin

A series of full page advertisements in the Dominion Post by Seafood NZ is suggestive of an industry throwing its weight and money behind a ‘lip service’ campaign to reassure the public of a sustainable industry. Science Advisor for Our Seas Our Future, Veronica Rotman, provides some feedback to these Seafood NZ advertisements..

A series of full page advertisements in the Dominion Post by Seafood NZ is suggestive of an industry throwing its weight and money behind a ‘lip service’ campaign to reassure the public of a sustainable industry. Science Advisor for Our Seas Our Future, Veronica Rotman, responds to these Seafood NZ advertisements…

Claims that “most (dolphins) feed around river mouths in the protected area”, and the existing sanctuary is the “heart of the Māui habitat” are vague and misleading. Māui dolphin habitat is largely inaccessible, along rough coastline where boat surveys are near impossible for most of the year, and research is limited to summer months. This means there isn’t enough information to fully support Seafood NZ’s self-serving claims.

It is known that Māui come inshore during these summer months, however acoustic surveys suggest that they travel offshore during the winter months. This is likely outside the current protection area, therefore both better protection measures and improved understanding of Māui dolphin movements  are required to prevent them from joining the list of New Zealand’s extinct species. In order to gain an accurate understanding of where they live, potential habitat should be surveyed year round to reveal any changes in movements over time. Modelling of Māui prey should also be prioritised as the dolphin range may be changing with food sources and environmental conditions.  

We challenge Seafood NZ to support research efforts to improve understanding of Māui dolphin distribution (their movements) via new technologies such as drones, artificial intelligence, thermal imaging and acoustic monitoring. This information must be continually updated to develop informed spatial management decisions and implement effective policy. 

One advertisement states that the “Last confirmed death of a Māui dolphin by commercial fishing happened 17 years ago”. Bycatch data sourced from “Dragonfly Data Science” indicated zero observed bycatch associated with set net or trawl commercial fisheries between 2003 and 2017. Again, Seafood NZ is misleading the public. Set net commercial fisheries on the West coast of the North Island had an average observer coverage of <1%, while trawls were between 4% – 55.5% during this time period (Abraham & Thompson, 2011; Dragonfly, 2018). It is proposed that set nets attribute 84% of the fisheries risk to Māui dolphins, however trawls had far greater coverage of observers (DOC, 2019).  Seafood NZ would be more accurate to say that the last confirmed death willingly recorded by the commercial fishing industry happened 17 years ago.

The Department Of Conservation’s Māui dolphin incident database conversely displays the death of a Māui dolphin in 2012 with cause of death on the 02/01/2012, clearly stating “known bycatch in commercial setnet” (DOC). This is well within the previous 17 year time period and was reported by a commercial fisherman. However, because the dolphin was not brought ashore, a necroscopy was not performed, and on their Facebook page Seafood NZ claim that the dolphin ‘was not identified as a Māui’.  Very fishy indeed.

The incident database states that it relies on reports from fishing vessels, as well as public sightings of dead dolphins, and is bias towards areas with high visitor numbers. In many cases, dolphin carcasses in this database have been found decomposed beyond the possibility of a necroscopy, and cause of death has not been determined (DOC). 

The 2012 Māui Dolphin Threat Management Plan states that bycatch is likely under-reported. The Ministry for Primary Industries (2017) suggest that the incidental capture information available on the DOC database is not representative of the scale or magnitude of fisheries capture. This is likely due to under-reporting, carcasses not washing ashore, or lack of evidence of that fishing gear was the cause of death. International Whaling Commission representative, Elisabeth Slooten, suggested that not all dolphins caught in set-nets show symptoms of capture. Trawl deaths are even more difficult to distinguish as there are often no definitive signs of cause of death. The recent 2019 Threat Management Plan Risk Assessment estimates that commercial fishing currently accounts for one Māui dolphin death every 9 years. Although fishermen are compelled by law to report any entanglements, there is no existing incentive to do so (MFish & DOC, 2007; Slooten, 2007). 

Trawl commercial fisheries are known to kill Hector’s dolphins, however there have been no records of Māui dolphins caught as bycatch (MFish & DOC, 2007). Other cetacean species such as Common dolphins have been reported as bycatch in trawls operating off the west coast of the North Island, indicating that the ongoing threat of bycatch of Māui dolphins is significant (Manning & Grantz, 2017). In order to evaluate the full extent of bycatch risk and mortality rate of Māui dolphins, observer coverage must be greatly improved.

The New Zealand Marine Mammals Act (1978) clearly states that bycatch mortality must be managed to ensure that threatened species should achieve non-threatened status as soon as practicable, not exceeding a period of 20 years. This is not possible with existing protection measures (Manning & Grantz, 2017). 

Although a small portion of Māui dolphin range is protected, there is still considerable overlap between Māui dolphin habitat and commercial set net and trawl fisheries. Considering their conservation status as ‘Nationally critical’ and depleted population of ~63 individuals, any bycatch is unsustainable and completely unacceptable. 

Recommendations provided by the International Whaling Commission (IWC) encouraged full protection from set net and trawl commercial fishing for both Māui and Hector’s dolphins in the entirety of their range out to the 100 metre depth contour. A prominent dolphin researcher, Elisabeth Slooten suggests that creating small specific areas of protection does not solve the problem but merely shifts it to another area that is still an integral part of the species habitat. Large-scale issues requires a large-scale solution – providing protection out to the 100 metre depth contour throughout the species range will provide the best chance of population recovery (Slooten et al. 2013).

Until definitive information on dolphin distribution has been acquired, OSOF urges extended protection measures from human-caused threats such as set net and trawls in the species range. We recognise that bycatch is the most immediate and manageable threat to these dolphins. We also acknowledge the need for urgent research into non-fisheries related threats to give these dolphins the best chance of survival.

If Seafood NZ cannot “countenance the obliteration of small fishing companies”, then efforts should be made to support their transition to sustainable dolphin-safe fishing methods in the region, such as hook and line techniques and fish-traps. A recent report by Fisheries New Zealand estimated a financial loss of between $20.9 million and $143.5 million over five years depending on area of fishery closed. The assessment completely excludes potential catch gained using sustainable alternative methods and Market Economics’  associate director Rodney Yeoman suggested figures to be 10 times overestimated, urging the figures to be reviewed (Newsroom). Does anyone smell a red herring?

Maui dolphins provide ecosystem value, and also cultural and economic value, being the smallest and rarest marine dolphin in the world. It is important that actions put in place now reflect these values of Aotearoa, and not those of the fishing industry.

OSOF Founder, Noel Jhinku says “For Māui and Hector’s, cameras on boats, implementing a much greater observer coverage, industry investment in transitioning to dolphin-friendly fishing methods, more basic research to better understand populations, and incorporating the use of cutting-edge monitoring technology is needed to prevent extinction.”


Our Seas Our Future:

Sustainable Seafood Now:

Abraham, E. R., & Thompson, F. N. (2011b). Summary of the capture of seabirds, marine mammals, and turtles in New Zealand commercial fisheries, 1998–99 to 2008–09. New Zealand Aquatic Environment and Biodiversity Report No. 80. 170 pages. Download from Ministry for Primary Industries.

DOC & MFish (2007) Department of Conservation, and the Ministry of Agriculture & Fisheries. Hector’s dolphin threat management discussion document, April 2007. Available at 

DOC (2019) Consultation on proposals for an updated Threat Management Plan, June 2019. Available at

DOC. 1 August 2011 – 31 July 2012. Retrieved from

Dragonfly Data Science: Data. Retrieved from

Manning, L., & Grantz, K. (2017). Endangered Species Act status review report for Hector’s dolphin (Cephalorhynchus hectori). Retrieved from

Ministry for Primary Industries (2017). Aquatic Environment and Biodiversity Annual Review 2017. Compiled by the Fisheries Science Team, Ministry for Primary Industries, Wellington, New Zealand. 724 p. 

Newsroom (2019, July 9). Cost of saving dolphins ‘overstated’ by 10 times. Retrieved from

Slooten, E. (2007). Conservation management in the face of uncertainty: effectiveness of four options for managing Hector’s dolphin bycatch. Endangered Species Research, 3, 169-179. doi: 10.3354/esr003169

Slooten, E. (2014). Effectiveness for partial protection for Māui’s dolphin. International Whaling Commission. 

Slooten, E. (2013) Effectiveness of area-based management in reducing bycatch of the New Zealand dolphin. Endangered Species Research, 20(2), 121-130. doi: 10.3354/esr00483

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