For tourists on the Hauraki Gulf whale and dolphin-watching cruises, an added thrill often comes after a whale encounter, when one of the crew heads for the back of the boat, grabs a fine mesh net and scoops up a load of whale poo.
"You have to be in the right place at the right time but, when we can, we collect a sample for research purposes," says Andy Light, senior master on the Dolphin Explorer.
"It goes down well with our guests when we explain that their presence on the boats helps fund research that is helping to protect whales and dolphins."
Light hastens to add there's no smell associated with the filmy layer of excrement that the gulf's resident population of Bryde's whales and other visiting whales leave on the surface. "It's just planktonic matter." In fact, the project is known as "From plankton to poo".
Such is the persuasive power of Dr Rochelle Constantine, of the University of Auckland's school of biological sciences.
Constantine is a force of nature acting on behalf of the highly vulnerable cetaceans - marine mammals including dolphins and whales - in our coastal waters. Her research interests include maui's dolphins, Bryde's whales, bottlenose dolphins and oceanic humpback whales. These species inspire awe and admiration among many of us - but most are threatened with extinction in our waters, due to human activity.
The past fortnight has proved a high tide for Constantine's efforts to save them. After a six-year campaign, the shipping industry this week agreed to reduce speeds in the Hauraki Gulf, and take other measures to improve the chances of Bryde's whales surviving ship strikes. The "transit protocol" devised with Ports of Auckland will cost shipping companies time and money - matters Constantine confesses she finds less important than survival of a whale. The port company and the Auckland Council are chipping in with funding for further research; DoC is involved; iwi for whom cetaceans are a taonga are supportive.
Last week, her efforts were recognised at the Hauraki Gulf Forum's annual seminar, where she was one of three inaugural recipients of the Holdaway Awards, named in honour of the architect of the Hauraki Gulf Marine Park, the late Jim Holdaway.
Days earlier, Conservation Minister Nick Smith tore up a new management plan for the critically endangered Maui's dolphin, launching fresh consultation on a revised plan that takes into account new research in which Constantine had a hand.
The behavioural ecologist is one of a community of scientists working collaboratively at New Zealand universities - despite fierce competition for scarce research funds - and overseas to better understand the cetaceans and develop science-based responses to what threatens them. All are driven by passion: Constantine stands out for her ability to engage - to articulate the science and its purpose, to advocate pragmatic solutions and to take people with her.
Put in front of an audience (she is a repeat guest at the forum seminars), it's soon apparent why she succeeds.
"They are annoying animals when you're trying to tag them," she says of the Bryde's whales.
"They do short dives, less than 10m mostly. They spend the day foraging, with a lot of side-lunge feeding [she imitates the movement]. At night they are nearer the surface, either slowly skim-feeding or resting. It's pretty much unheard of - a whale that sleeps at night."
The Bryde's whale is a type of baleen whale, growing to about 14m and 20 tonnes. Though not threatened internationally, the New Zealand population is listed as critically endangered - estimated at 200 at best. Normally a wide-ranging species, it favours the Hauraki Gulf for its abundant supply of plankton, krill and small fish. At any one time, about 50 are living in the gulf - one of only three resident populations worldwide. Trouble is, home is also a shipping lane.
It's estimated that at least two a year, on average, are killed by ship-strike in the gulf. "Their natural mortality is around 4 per cent [about eight a year], so losing at least two on top of that is quite significant.
"They are a real treasure. They are in other places but that doesn't make it okay that we lose them in New Zealand."
The protocol asks ships to post whale lookouts in daylight hours, to slow down in areas where the whales gather, stick to recommended routes, steer 1km clear of sighted whales and report sightings so other ships are alerted to alter course. The protocol is voluntary but indications are that shipping lines and ship masters will co-operate. As Constantine says, "No one wants to kill whales."
Similar agreements have been forged for much busier shipping lanes, such as the North American eastern seaboard. But getting the schedule-driven industry here to agree was a tortuous journey, involving the forum, the port company, the Environmental Defence Society and iwi. Science was needed.
Obtaining data from suction-tag devices, boat-based surveys and photo identification, Constantine and her team of postgraduate students and contacts considerably improved knowledge of the little-studied species. The suction tags developed by New Zealand scientist Dr Mark Johnson provided data about movements and dive patterns and hours of acoustic recordings.
They revealed that the whales, while usually below the surface and not easily seen, spend 90 per cent of their time at depths of less than 12m. Unfortunately, that's the draft of the big ships coming and going from Auckland. Just as disturbing is their tendency to go even closer to the surface at night - and sleep.
"This is a feature of whales that are not migrating long distances to feed, which is what most baleens do.
"It appears they are feeding during the day and resting at night, which is really neat."
Permission to perform full necropsies on washed-up carcases, with DoC and iwi blessing, helped to underscore the contribution of ship strikes. "The whales often look okay on the outside but then you find fractures and contusions on the inside."
But overseas research has found that the chances of a whale surviving a collision rise considerably as speeds drop. At 15 knots, there's a 75 per cent chance that the strike will be fatal. But if the ship is travelling at 9 knots, the fatality rate drops to 25 per cent. "It sounds like a small speed difference but it has a big consequence for the whales."
Necropsies have also provided tissue samples for DNA analysis.
The new protocol isn't watertight - the whales are often hard to spot and there will be times when coastal ships on short runs can't go slow.
Constantine acknowledges there is a cost for the industry. "But as a conservation scientist I look at it in a different way: what's the value of a dead whale?
"If we don't find a solution that minimises the risk to the whales, we will continue with this rate of mortality."
Over on the west coast, the plight of the Maui's dolphin is even more desperate. The diminutive dolphin, which plays in the surf, is thought to be almost totally confined to a 120km stretch of the Auckland and Waikato coast, though their traditional habitat extends south of Wanganui. DoC-funded surveys in 2010 and 2011 involving Auckland and Oregon State University researchers, while heightening alarm over the population's decline, also raised glimmers of hope. The dolphins move much further than previously thought, while confirmed sightings of two female Hector's dolphins - strays from the South Island west coast - raise the possibility of enhancing the low genetic diversity of the remaining population. Nick Smith is now proposing to extend the current ban on set nets further south, threatening what's left of the New Plymouth fishing industry. Constantine is aware of the stakes but, again, lack of conservation funding has contributed to the plight of the Maui's dolphin.
"The Maui's have lived in that space for many more years than we've been here; they are part of that ecosystem. They have an inherent right to exist and we are likely to lose them, which will put us on the same environmental footing as China, which lost the Yangtse River dolphin. We have to try."
Her interest in behavioural ecology developed as a post-graduate student in the 1990s, researching the impacts of tourism boats on bottlenose dolphins in the Bay of Islands. There were about 200 in the bay back then, now there are about 50. She believes tour boat activity in the 1990s, and its unregulated nature, prompted the dolphins to steer clear of the bay. She plans further research to see how many of them are now in the gulf.
Her humpback whale research has taken her to Antarctica and Australia, while last year she visited the Kermadecs, one of three scientists invited on a Pew Foundation expedition. She plans to return to Raoul Island next year to tag and track the movements of humpbacks and collect samples for genetic analysis.
Though humpback populations are recovering around the world, the oceanic humpbacks that pass through New Zealand on their northern migration are struggling, perhaps due to the distances they cover to reach their Antarctic feeding grounds. "I love it that New Zealand is part of their migratory journey."
There's more work in store for the Bryde's whales. A year-long aerial survey, funded by the port company, Auckland Council and the whale watch operators' levy, has just begun, aiming to better understand where and how numerous the whales are. Better information on their distribution and habits could lead to changes in established shipping routes in and out of the gulf. Already, ships are being urged to steer clear of the channel between Little Barrier and Great Barrier islands.
She is chasing further funding for research into what cues the whales use to find their often invisible prey, which again affects their distribution.
That's where the poo comes in. Using gene-sequencing techniques, post-doctoral researcher Emma Carroll is analysing samples from the Explore NZ vessels and the university's own research boat to assess the relative importance of each food source.
"It helps us to understand the drivers behind why they are here year-round and how they use the space," says Constantine. "Emma's work has opened our eyes to the variety of species they are eating - it's very glamorous."
Constantine's commitment to these creatures wasn't planned, she says. Though she grew up by the beach (in Papamoa, before it became an extension of Mt Maunganui) and loved animals, she never set her sights on cetaceans. "It's still not my lifelong dream. Of all the animals you could study, these must be the hardest."
She spends about 40 per cent of her time on research including grant applications and field work; the rest lecturing and other university work (she directs a graduate school on coastal and marine sciences run jointly with Niwa).
It's lucky, she says, that her husband is a scientist (at Plant and Food) - they accept there are times when each will be consumed by their work. They juggle their work with time with their daughter, who has just started school.
"For me the idea that people don't always think about their job is unusual. It has its benefits and disadvantages."
She acknowledges she is demanding of her students. "I think if you set expectations they will reach them and we do get excellent results in our lab.
"I just wish it wasn't so hard getting funds. Funding for conservation research in New Zealand is appallingly low.
"I find that unfortunate because generally people don't visit New Zealand for the nightlife, they visit for the natural environment and the conservation estate.
"We take it for granted and I don't think that's all right - it won't always be there. That's what our Maui's dolphin and Bryde's whale work is about - making sure these animals are still there."