Māui’s dolphin: going, going, gone?

Opinion: Clean, green New Zealand? Not when we may cause extinction of the world's smallest dolphin, writes Veronica Rotman.

Two Māui Dolphins - the smallest dolphins in the world, native to New Zealand and endangered by commercial fishing practices. (Photo: ©Department of Conservation, New Zealand)
Māui Dolphins, the smallest dolphins in the world, native to New Zealand and endangered by commercial fishing practices. (Photo ©Department of Conservation, New Zealand)

Clean, green New Zealand. With a dirty little secret. We are on track to becoming the first country in the world to cause the extinction of a marine dolphin. The smallest in the world - the Māui Dolphin.

I don't know about you, but I struggle to see how New Zealand marketing and PR could recover.

The hobbit of the ocean is native to New Zealand waters, ours to enjoy, ours to protect. Split into two subspecies, the Hectors roam the south, while the elusive Māui Dolphin take refuge on the west coast of the North Island.

Although both are considered endangered, the Māui population is critical. With less than 10 per cent of the original 2000 dolphins, the remaining 55 are teetering on the brink of extinction.

The decline has been at the hands of the commercial fishing industry where trawl, set net and driftnet methods have been detrimental to the survival these dolphins. Through bycatch and reduced food availability, commercial fishing accounts for the majority of Māui mortalities. There is an average of approximately five fishing related deaths per year – a number the current population simply cannot afford.

Another major threat to these dolphins comes from a puzzling source – cat faeces. Killer cat poop? Exactly.

Cats and other mammals are hosts for the parasite Toxoplasma gondii. But it is exclusively in cats that T. Gondii can sexually reproduce. Once an army has been assembled, the parasites are ‘excavated’ and contaminate fresh water runoff before making their way out to sea. As organic matter fuels life in the ocean, the parasite bioaccumulates up the food chain until it infects our small endemic dolphin – causing death, still births, behavioural changes and reduced reproductive ability.

With both our native birds and dolphins threatened by their presence, it begs the controversial question, New Zealand cat free by 2050?

Boating and tourism, oil exploration, pollution, predation and disease also contribute to the mortalities.

Does New Zealand want its clean-green reputation tarnished, as the first country in the world to cause the extinction of a marine dolphin as a result of human activity? 

So what do we know about Māui dolphins:

  • They are almost the rarest marine mammal in the world, second only to the Mexican Vaquita porpoise of which only 30 individuals remain. The species share twin fates with commercial fishing, particularly set net bycatch, driving their decline.
  • Māui are the smallest dolphins in the world – the size of your average 10-year-old child – and easily identified by their unique rounded dorsal fin which is similar in shape to one of Micky Mouse's ears.
  • Having such large brains, Māui’s dolphin exhibits complex social behaviour. Pods of two to eight are generally comprised of all male, or all females and calves.
  • Like humans, the young are playful, blowing bubbles and enjoying ‘toys’ like seaweed.
  • Unfortunately they seldom live past 22 years, and with a late sexual maturity of seven to nine years and pregnancy occurring once every two to four years, they reproduce very slowly.
  • Their population range is small, just like them and they live only in shallow coastal waters up to 100m in depth. This makes them surprisingly easy to protect.

But if protection was that simple it would have been done. The main barrier comes down to money, or lack of it. With fishing vessels expected to travel further out, past the 100m depth contour, costs will be higher and incentives required.

With promises of electronic monitoring on boats, it's time for the government and Fisheries Minister Stuart Nash to cough up. Observer coverage is limited to a feeble single figure percentage of boats, and bycatch continues to go unreported. Why? Because it's bad for business. No one wants a side of Māui Dolphin with their fish and chips.

An attractive option is for the government to support local industries transition into dolphin safe fishing methods. Harmful techniques such as set net and trawl would be replaced with longline fishing, which poses no direct threat to the dolphins.

Business Economic Research Ltd reported that it would cost as little as $26 million dollars to make the shift to Maui-friendly fishing methods – the same figure proposed by the government to change our New Zealand flag design.

This is a small price to pay for the survival of a species.

Alternatively, a section of coastline out to the 100m depth contour from Raglan Harbour in the south, to Kaipara harbour in the North could be protected as an interim measure. This area exhibits the highest risk for Maui’s dolphin populations through the overlap of high dolphin density and fishing effort.

Year after year, the International Whaling Commission calls on the New Zealand government to put their money where their mouth is and provide further protection. And year after year, propositions are rejected.

The reality is that the Māui population will continue to decline steadily unless urgent action is taken. Current protection measures are feeble, with less than half of their tiny habitat free from set net and trawl.

In a small victory for our dolphins earlier this year, Prime Minister Jacinda Ardern announced her ban on oil exploration, protecting the Maui habitat and the entirety of New Zealand.

So fortunately all is not grim and our small country has a large number of individuals fighting tirelessly for their survival. This is true of the scientists who dedicate their life's work to produce the valuable research behind the implementation of marine protected areas. They are at the forefront of the battle against the fishing industries, using science and public education to turn the tide for these aquatic hobbits.

And scientists are not the only ones who can help our flippered friends!

You can get involved in the conservation of these incredible animals by educating yourself and others on their plight. There are many online petitions as well as local protests to attend, but nothing beats the good old handwritten letter. Address it to the Prime Minister, Minister of Conservation, and your local MP, urging them to implement full protection. Also, donations to scientists will make funds available for the continued research of our dolphins down-under!

When you are talking about the extinction of a species, we cannot solve a crisis without treating it like a crisis. A large-scale issue requires a large-scale solution and full habitat protection provides the best chance of population recovery.

There is still time, but not much. Does New Zealand want its clean-green reputation tarnished, as the first country in the world to cause the extinction of a marine dolphin as a result of human activity?

Veronica Rotman is studying for an MSc in Marine Science at the University of Auckland. This article reflects the opinion of the author and not the views of the University of Auckland.

Used with permission from Newsroom, Māui’s dolphin: going, going, gone?, published on 31 December 2018.