When Liz Slooten and Steve Dawson graduated from university in New Zealand in 1982, they became interested in the country’s diminutive endemic dolphins, about which only six scientific papers had been written. A summation of all that was known about them was all of four pages long.

The New Zealand coastal dolphins, which have relatives in Chile, Argentina and South Africa, are the world’s smallest. They are friendly to people, fight rarely and have sex often. One sub-species, which hadn’t bred with the others for 16,000 years, according to a mitochondrial DNA analysis, is called the Maui’s dolphin,

When Slooten and Dawson decided to make the dolphins the centerpiece of their doctoral theses, they had no idea that 30 years later, fishermen’s nets would have reduced the Mauis to some 60 individuals, from 2,000 or so in the 1970s, making it the world’s rarest dolphin. The others, which are slightly smaller, are called Hector’s dolphins, and fishing nets have brought them down from 50,000 to 10,000, according to one estimate (New Zealand also has 11 species of non-endemic oceanic dolphins).

Slooten, tall and energetic, and Dawson, whose blue eyes are as piercing as his wit, never married, complete each other’s sentences and seem to do everything together. They made the dolphins the centerpiece of their doctorates at the University of Canterbury and later of their research as professors at Otago University in Dunedin, the southernmost university in the world. Together, they have published over 90 scientific peer-reviewed papers on the dolphins, more than anyone else.

In 1984, they set out in a four-meter inflatable dinghy for a six-month survey of 8,300 km of coastline to determine the dolphins’ distribution. In the late 1990s, they repeated the survey with a 15-meter sailing catamaran equipped with a crow’s nest. Each specialized in a different aspect of the dolphin: Liz on the dolphins’ behavior and breeding; Steve on the sounds they make and how they use them to communicate. He also photographs them and has compiled a data base of more than 400 dolphins recognizable by dents in their signature round dorsal fins or scars and markings on the upper bodies.

When they started their doctoral research, they noticed dead dolphins were washing up on beaches with clear gill-net markings. So as part of his research, Dawson interviewed fishermen every month about their dolphin interactions, and asked them bring their bodies for dissection. “We thought that over the four years of our Ph.D.s, we’d dissect maybe 10,” he said. “Instead, we got swamped, they brought us 61.” A paper he published in 1990 was the first to describe the extent of the carnage, with some fishermen reporting killing up to 44 a season.

It soon became clear that the dolphin populations diminished faster in the more heavily fished areas. Because they rarely travel for more than 50 km, the casualties are not replaced by members of another group. By 2004, a continuous population of Hectors around the South Island had become fragmented into 10 small groups, some with fewer than 40 individuals.

That’s why one sunny November afternoon, Slooten, Dawson and I found ourselves crisscrossing Akaroa Harbour on their fast dinghy, looking for dolphins to photograph. We saw 10 in several groups. The long and narrow bay, hemmed in by spectacular cliffs that keep out wind and swells, is an ideal place to view the 100 or so dolphins who call it home.

That’s no accident: In 1988, Slooten and Dawson’s research – and more than 6,000 letters from conservation groups and members of the public – persuaded the Labour government to create the first dolphin sanctuary around the South Island’s Banks Peninsula, into which Akaroa Harbour penetrates. It banned commercial gill nets, which rise like invisible curtains from the bottom and are believed to be the main cause of dolphin drownings, and restricted recreational nets.

Over the next three decades, as the numbers of dolphins elsewhere in New Zealand plunged, scientists, environmentalists and, from 2012, the International Whaling commission, urged successive governments to ban trawl and gill nets from all the areas where the Maui dolphins live and allow only fish traps and hook-and-line fisheries, which do not harm cetaceans.

But the result has been a case study of the influence of money and political ideology over conservation.

Every time a Labour government was elected, it would enact some protection, primarily reining in the gillnetters, who are more numerous, less profitable and tend to be owned by individuals. The trawlers, which are mostly owned by relatively large corporations, had the clout to fend off most trawl restrictions. In 2008, Shaun Driscoll, at the time the Fisheries Ministry’s head of investigations, complained in an unpublished report obtained by the Ecologist of an “overbearing and over-powerful fishing industry.”

Every time a National Party government came in, it asserted that protection was working well and saw little need for more restrictions. The fact that the president of the National Party, Peter Goodfellow, also happens to be a main shareholder, board member and former chairman of Sanford Ltd., the country’s biggest seafood company, is often cited as evidence of the close links between the industry and its government regulators.

In the Maui habitat, Sanford uses only trawlers and owns 60 percent of the quota for snapper, the most valuable fish. It has pledged to stop allowing fishermen to sell net-caught snapper from the Maui habitat at the auction houses it owns from April. It has also promised to stop its own ships from trawling in the Maui range by 2022 if it can’t find a way of avoiding dolphin deaths. Scientists say the measure won’t stop the decline of the dolphin population.

The biggest improvement to the dolphins’ prospects came in 2003, at the tail end of five years of Labour rule, when all nets were banned in 5 percent of the Maui’s habitat and gillnets were banned in an additional 14 percent. In 2008, at the end of the last Labour government, similar measures were put in place to protect the South Island’s Hectors. “That made the difference between rapid decline and slow decline,” Slooten explained.

A government-funded study published in 2012 found that the number of Maui dolphins was falling at a rate of 2.8% a year. A more recent study by the same authors put it at 1.5% to 2%. “We do not say that the population has stabilized,” noted lead author Scott Baker of Oregon State University. “The estimated rate of decline has decreased.”

That hasn’t prevented the government, citing the paper, as saying that “Māui numbers over the past five years have stabilized,” in the words of Conservation Minister Maggie Barry.

Opinion polls have shown that 60% of New Zealanders would be more likely to vote for a government that would restrict fishing nets and protect the dolphins and that 63% would be willing to pay more for fish to protect dolphins. NABU, a German charity, has called for an international boycott of New Zealand seafood until the government reverses the dolphins’ decline by banning all nets in its habitat. “Buy New Zealand fish, get dead Maui’s dolphins free,” goes NABU’s slogan.

New Zealand snapper caught in the Maui and Hector habitats is exported to several countries, including the US and the UK, but consumers have no way of knowing exactly where and how they were caught. “If British consumers want to be sure they’re not contributing to the extinction of this rare dolphin, they should avoid New Zealand seafood,” said Barry Torkington, a New Zealand fisheries expert.

The next parliamentary election is in September, after nine years of National Party rule. So far, both Labour and the Greens have backed the recommendation of the International Whaling Commission, the IUCN and dozens of other organizations to ban all nets in the Maui’s 600-km coastal range. The National Party’s position is that existing restrictions are working and there is no need to extend them.

This Author

Christopher Pala is a reporter based in Washington DC

This article was reported in partnership with The Investigative Fund at The Nation Institute in New York.