Freedive world champion William Trubridge has penned a letter to the fishing industry, calling for more action to protect New Zealand's endangered dolphin species.
In the letter, the 36-year-old double world record holder said fishing in the country had come in for criticism, from within New Zealand and overseas, over Hector's and Maui's dolphin deaths in their fishing nets.
The number of Hector's dolphins is understood to range between around 12,000 and 19,000 and is divided into two sub-species; the Maui's dolphin, whose population was recently estimated at just 63 adults, and the South Island Hector's dolphin.
Trubridge acknowledged new steps taken by major fishing companies Sanford and Moana Fishing to reduce dolphin deaths, and that the industry had agreed the Maui's dolphin situation was critical.
But he was concerned that the dolphins remained without full protection, that bycatch was continuing at a rate greater than what was reported, and that fishing would "eventually render the species extinct".
"In short, there is a conflict between dolphin conservation and the use of gillnets and trawling."
Trubridge advocated for New Zealand to follow Mexico's step of bringing in legislative changes to protect its endangered Vaquita porpoise and make the transition from gillnets and trawling to more selective, sustainable fishing methods.
"Fish traps and hook and line methods are all dolphin-safe, and these options will be better not only for sea mammals, seabirds, and other endangered species, but also for fish stocks and therefore for fishermen.
"One of the greatest qualities of New Zealand, and the reason we're known over the world for punching above our weight, is that we are a united nation.
"It's why we excel in team sports like rugby and sailing. If only we could unite on this issue also then we could make the changes that will uphold our other great reputation: as the clean, green haven of the Pacific."
In response to the letter, Tim Pankhurst, chief executive of industry body Seafood New Zealand, argued the commercial fishing industry was "doing exactly what he urges, that is working to minimise its impact on the ocean environment".
Dolphin protections had been extended at the industry's initiative, Pankhurst said, and while there was no dispute Maui's dolphins were critically endangered, there were "a number of factors at play, including disease".
"The latest estimates by MPI scientists show a slight increase in Maui's numbers, rather than a decrease, and set netting and trawling is being increasingly prohibited in a large part of their coastal habitat," he said.
"We do appear to common aims, that is a healthy and sustainable fishery that provides sought after seafood, employment and export income, whilst conserving our wildlife."
Pankhurst also challenged figures cited in Trubridge's letter, noting self-imposed restrictions by Sanford and Moana affected more than 50 fishers, not five.
"And the 'recent revelations of an MPI observer being hushed having witnessed a Maui capture' are a fiction. There is no evidence to support such an allegation."
Ministry for Primary Industries acting director for fisheries management David Scranney said more than 1700 and 6200 square kilometres of water off the west coast had been respectively closed to trawl net fishing and set netting since 2003, and more than $2 million had been budgeted for research.
Scientific information would aid a full review of a threat management plan for the dolphins, due to be completed next year, that would assess those measures already in place, risk of fishing-related threats and whether extra measures were needed.
It would also an analysis of the recent voluntary measures announced by Sanford and Moana, Scranney said.
"MPI is surprised by Mr Trubridge's assertion that an MPI observer was 'hushed up' after seeing a Maui dolphin caught in a net.
"If Mr Trubridge has any evidence, or specific information to back up his assertion then we encourage him to supply it to us or the police."
Both government departments the MPI (Ministry of Primary Industries) and DoC (Department of Conservation) have reported a decline in Maui's dolphins from 1800 in the 1970s to fewer than 100 dolphins today.
Likewise, Hector's dolphin populations are below 30 per cent of their original numbers.
All studies attribute this decline predominantly to recreational and commercial gill net fishing and trawling in the dolphins' territory (MPI and DoC estimate fishing is responsible for 95.5 per cent of the Maui's dolphin decline).
Currently the dolphins are protected from trawling in five per cent and from gill netting in 19 per cent of their scientifically-determined territory.
The latter was increased by MPI and DoC from 16 per cent to 19 per cent in 2013, and is the only recent change to these figures.
As a result, the number of dolphins caught per year has been reduced from five per year to three to four per year.
The recent revelation of an MPI observer being hushed after seeing a Maui's dolphin caught in the nets confirms that these dolphin deaths are continuing to happen.
Even if there was only one dolphin death every five years then it would still be an untenable pressure to the population, as demonstrated by peer-reviewed population studies, which show the population can support one human-induced mortality per 10 to 23 years.
It is clear that the observed catch is not the only case.
According to the DoC Incident Database, between 2000-2006 less than one per cent of dolphin bycatch is reported by fishermen or independent observers.
So the dolphins aren't fully protected, bycatch is definitely continuing, at a rate greater than what is reported, and fishing will eventually render the species extinct.
In short, there is a conflict between dolphin conservation and the use of gillnets and trawling.
A fisherman wants to put food on the table (for his family and for society in general).
A minority call the dolphins "idiots" for getting trapped in their nets, and, as described in a particularly alarming account from one commercial fishermen, plan on shooting the dolphins when they see them in order to wipe the population out sooner, so they can reclaim the 19 per cent of the dolphin territory they're prohibited from.
Each side can argue there are fanatics on the other.
But that doesn't mean there is no solution.
We should ignore these sorts of emotive comments, and consider how we might compare the value of a species with the use of fishing methods that endanger it.
In his book What's so good about biodiversity: A call for better reasoning about nature's value, Donald Maier explains why it is difficult to put specific value on biodiversity.
He finds holes in the common arguments for biodiversity's worth, showing them to be internally contradictory or logically indefensible.
While it is difficult to define, he concludes that humanity does put value on the "natural fit" of humans in nature, which includes the abundant variety of life forms we share the planet with.
Of course this morality is guilty of being anthropocentric, which is why no one cares for the extinction of a species of bacteria, but then how can (human-created) morality not be?
For a person to claim that biodiversity has zero value, they are suggesting it would be okay to live in a world populated only by humans: no pets, flora or fauna.
Since such a world would be dead and uninhabitable the claim is redundant.
Whether we like or are in love with the dolphins or not, we must all place value on nature in general, which infers some specific value for dolphins (as a building block of biodiversity).
How does this compare to the value that a fisherman places on their business and source of income?
My opinion is that we don't need to make that comparison.
Business must by nature be adaptable.
Fashions change, and designers must adjust to them.
Medical knowledge grows, and doctors work to stay up-to-date.
Markets fluctuate, and investors must ride the waves.
Natural resources, including fish stocks and dolphin numbers, vary or diminish, and those whose livelihood depend upon them adjust their practices.
Imagine if there was more business revenue in taking tourists to swim with Maui's dolphins than in removing fish from their territory.
The dolphins would have had full protection long ago, and some of those who are now fishing would instead be employed in dolphin tourism.
This can't happen now, as the numbers are too few, but the hypothetical situation suggests that it is purely financial concerns driving the decisions being made.
If there is a scenario where employment of the fishermen can continue while the dolphin species are awarded full protection, then we don't even need to make the tricky value judgement between employment and the survival of a species.
The good news is that there is such a scenario.
Two years ago, Mexico, a country with less than half the average family income to NZ, made the required legislative changes to protect the Vaquita porpoise (that has numbers similar to Maui's), and dedicated over NZ$50 million for a trial period of two years to help out-of-work fishermen into new roles and compensate them for the upheaval.
If Mexico can do it then NZ can as well, but this change can only come from government, and it needs to be demanded by a unified voice of fishermen and conservationists.
There might even be more fishing jobs if we make the transition from gillnets and trawling to more selective, sustainable fishing methods.
Fish traps and hook and line methods are all dolphin-safe, and these options will be better not only for sea mammals, seabirds, and other endangered species, but also for fish stocks and therefore for fishermen.
I know most fishermen love the sea and its inhabitants.
There are also a few who have already moved on to other employment after seeing dolphins entangled in their nets.
If we all step up and say we want change that gives Maui's a fighting chance, but that a few local fishermen should not be singled out to pay the price by themselves, then with pressure from both sides of the table the government will have to act.
One of the greatest qualities of New Zealand, and the reason we're known over the world for punching above our weight, is that we are a united nation.
It's why we excel in team sports like rugby and sailing.
If only we could unite on this issue also then we could make the changes that will uphold our other great reputation: as the clean, green haven of the Pacific.
I invite any fishermen who read this and wish for positive change to contact me directly through my website.