A deeper understanding
The sea might seem a distant, even hostile, place. But our coasts and oceans – and the creatures in them – not only grant us wealth, sustenance and pleasure, they keep our planet functioning, finds Aimee Whitcroft.
Eighty per cent of New Zealand’s biodiversity is in the sea. Our Exclusive Economic Zone (EEZ) – the world's fifth largest – is home to an estimated 17,134 known species, and, on average, another seven are added to the list every week. There are still 4315 more waiting undescribed, anonymous, in various collections. The Department of Conservation thinks there could be a total of 65,000 species off our shores, and it may be another 100 years before we get to know them all.
About 60 per cent of our marine creatures are found nowhere else on Earth. New Zealand is recognised as one of the top 25 global hotspots of biodiversity, and we’ve signed a raft of international treaties – and enacted tomes of legislation – that oblige us to look after it.
The EEZ also features, according to GNS Science, “a number of geological structures capable of holding giant oil and gas fields,” and industry is eyeing iron sand and methane deposits. The challenge for policymakers and managers, then, is to strike the right balance between prosperity and perpetuity.
Decisions can only be as good as the science they rest on. We need to know what’s at stake; what the risks – and the consequences – are. Which is where NIWA comes in.
Plumbing the depths
First, you have to know what’s down there; what part it plays in a healthy ecosystem, and how much disturbance – if any – it can tolerate.
NIWA Principal Scientist Dr Malcolm Clark and his colleagues have been looking at benthic communities across a range of deepwater habitats, such as seamounts and vents, and gauging their vulnerability to human impacts such as trawling or mining.
It’s hard work – such communities can live hundreds of metres beneath an often tempestuous surface. Clark necessarily works remotely, towing video and photographic arrays above the sea floor, and sampling deepwater bottom sediment, where tiny creatures perform as much as 90 per cent of biological production.
“We look at species diversity, and various measures of it, then we try to relate it to environmental factors we’re measuring at the same time – things like depth, substrate type, dissolved oxygen and salinity – so we’re getting an idea of what’s driving the species composition we’re seeing. With repeat surveys, we can see over time what’s happening naturally, and what’s likely being caused by human impact.”
By comparing, for instance, fished areas with unfished, Clark can measure impacts on species biodiversity or habitat integrity. This kind of deepwater expertise caught the attention of conservation NGO WWF-NZ in 2007, when they commissioned an ambitious catalogue of New Zealand’s marine biodiversity – a project called Treasures of the Sea, A Summary of Biodiversity in the New Zealand Marine Ecoregion.
“We felt there was a real need for a comprehensive compendium,” says WWF-NZ Marine Programme Manager Rebecca Bird. Information was scattered across dozens of sources, “but there wasn’t a one-stop shop you could go to. Treasures of the Sea represented the latest information in one package.”
Apart from informing WWF-NZ’s own advocacy work, says Bird, Treasures was also produced for decision-makers, educators, researchers and students.
The work aimed to fill some of the holes in our understanding of New Zealand’s marine biodiversity, and to mesh into a worldwide WWF assessment, Global 200, which set out a network of 238 ecoregions based on a hierarchy of biogeographic assessments. The ultimate aim was to identify representative habitat types – terrestrial, freshwater and marine.
Criteria such as species richness, endemism, taxonomic uniqueness, unusual ecological or evolutionary phenomena and relative rarity were then used to estimate ‘urgency of action’ or conservation priority.
“It was an idea NIWA really supported,” says Bird, “and we felt we could trust the integrity of the information, too, because it was coming through an independent, reputable organisation.”
Not all NIWA’s work happens at depth: in the coastal zone, the job is at least a little simpler. Researchers like Principal Scientist Dr Judi Hewitt use a combination of traditional methods, such as point sampling – installing cameras or taking core samples – and the more innovative. “Since 1994, we’ve been looking for methods to nest that sort of data within the more remotely-obtained types of assessments, and have been using sidescan and multibeam sonar, aerial and underwater photographs and long video transects.” But, as yet, she says, there’s no affordable technology that can handle both the intertidal and subtidal areas, which studies often move between.
When Greater Wellington Regional Council (GW) wanted to get a better handle on the area’s biodiversity last year, they got NIWA to take a look. Surveying found seven sites of special significance, from the shallow Porirua Harbour, down to methane seeps in 1100m of water on Opouawe Bank.
The project, a requirement of Wellington’s Regional Policy Statement (RPS), demanded “the best available information,” says GW Senior Policy Advisor Jo Beaglehole. “We thought that NIWA would be an obvious first port of call.”
NIWA’s report went into a mix of other information on estuaries, bird habitats and other sites identified by the RPS or the Department of Conservation.
Beaglehole will now add a schedule to the regional plan, listing sites of significant indigenous biodiversity in the coastal marine area. “I’m also drafting policies and rules that will apply to those sites, that will try to afford protection under the RMA over and above the management of biodiversity across the region.”
She says that, while it’s not always easy to articulate the need to protect ecosystems, “I think it’s fairly accepted now that loss of biodiversity is a bad thing.”
A thousand billion support staff
Increasingly, in fact, marine management asks not what we can do for ecosystems, but what ecosystems can do for us. Marine organisms provide us with food, refresh our air (half the oxygen you breathe has been purified by marine plankton), recycle energy and nutrients, regulate our climate, sustain the marine leisure and tourism industries and offer our souls a touchstone – all for free.
Collectively, this economic aid is called ecosystem goods and services, or EGS. It can include leisure activities, tourism, food (such as fisheries), energy and nutrient cycling, temperature regulation, carbon dioxide absorption, cultural values and more.
Much is made of the putative value of oil and gas reserves, but a 1999 study estimated that New Zealand’s marine ecosystems annually perform $184 billion worth of labour – more than twice our national GDP that year. Globally, the economic value of ecosystem services has been reckoned at US$33 trillion every year. The figure sparked a debate: one commentator considered it “a serious underestimate of infinity.”
Whatever the number, local government increasingly recognises that contribution. Says Waikato Regional Council’s (WRC’s) Peter Singleton, Programme Manager Coasts and Marine: “A healthy, functioning ecosystem – and the environment it produces – is an economic asset, because people are coming to the beaches, to the harbours, to benefit from that asset.”
But the very fact that their services come for free, he says, can put ecosystems at risk: “A lot of the aspects of the environment that we take for granted, like clean water, production of fish and shellfish – are under threat in a way, precisely because we’re taking them for granted.
He says we need “to reverse our thinking from seeing biodiversity as a nice-to-have, to seeing it as essential in underpinning our economy and our lifestyle.”
For more than 20 years, WRC has relied on NIWA’s marine expertise; more recently to help assess consent applications for mangrove management, building the first ever detailed map (in terms of its habitats and geography) of the Hauraki Gulf, and mapping habitats within estuaries. “To date, the coastal area for us has been very much an unknown frontier,” says Singleton. “NIWA has … proved to be an incredibly valuable, if not indispensable, resource for us as a regional council. It’s helped us go into that frontier and understand what resources we have there – how important they are, how scarce or common they are – and that helps us manage them,” he says.
Taking a picture of health
Watching the creatures of a rocky shore defy pounding breakers, you’d assume ecosystems are tough and resilient. And they can be, but they’re also complex, depending on intricate, often nebulous, relationships and flows. Ecosystems are a team effort, and some players, it turns out, can be game breakers. Harm them, and you can compromise the entire assemblage. Push them past some cryptic tipping point, and the whole system might collapse, promptly withdrawing all that volunteer labour that keeps our own systems going: for example, the Atlantic cod fishery collapsed in the early 1990s, some 19,000 jobs were promptly axed, and another 20,000 lost or scaled back in the subsequent fallout.
In our own Hauraki Gulf, overzealous dredging since the 1920s destroyed the once-vast mussel beds of the Firth of Thames and inner Gulf. The grounds used to yield up to 500 tonnes of mussels a year – some 15 million mussels were landed in 1961 alone, but the very next year, the ecosystem collapsed. Apart from the squandered revenue, the Gulf lost an important water purifier and habitat for other organisms. The mussel beds have not recovered, even though dredging stopped nearly 50 years ago. A NIWA study suggests that, despite problems with juvenile recruitment and survival, restoration may yet be possible.
“Because the ocean is big,” says Dr Simon Thrush, “and ecosystems are complex, there’s a tendency to take notice only after major loss of biodiversity, and the ecosystem services that provides. But at that point, it’s very difficult to go back.”
But before you can spot a damaged ecosystem, you must first know what a healthy one looks – and functions – like.
Under contract to Auckland Council, Thrush, a NIWA Principal Scientist, and his team have devised a way to gauge an ecosystem’s integrity. They’ve been looking at functional groups – various species which perform a given task in similar ways. “The degree of overlap gives you an idea of the redundancy within that function. Redundancy means that if one species is particularly stressed by some environmental phenomenon or human activity, then there are other species that are able to step in and, to some degree or other, perform that function.”
As systems become more degraded, he says, they take on a more homogeneous nature. Small, rapidly-growing and reproducing species start to dominate. “A terrestrial example is a change from forest to grassland,” says Thrush. “The degree of habitat diversity in a forest is way bigger than in a grassland."
We need to make smart decisions, then, on behalf of those communities – the countless billions of unpaid workers out there which sustain our very existence. The economic and environmental rationales are clear, but it’s not just a business case, says Thrush: “If we don’t have places that people can reference themselves to,” he says, “and remember that, when they were a kid, they could walk into the water and have fish around their feet, or find rock pools filled with life, then I think we lose a lot as a society, by not having that sense of place. I think that’s pretty deep in the Kiwi psyche.”
Sidebar: The sky's the limit
If anyone can perceive order in Nature's apparent chaos of profusion, it's Dr Dennis Gordon. Last year, the NIWA Principal Scientist completed an edit of the monumental New Zealand Inventory of Biodiversity, a three-volume, 1758-page catalogue of nothing less than every known New Zealand animal, plant, fungus and micro organism, both living and extinct. That adds up to more than 56,200 living species and 14,700 fossil species.
But his labours aren't over. "New Zealand is still very much in the discovery phase," he says. "For macroinvertebrates – and I'm not even talking about protozoa or bacteria – our rate of discovery is about seven new species a fortnight. We can't keep up with the rate of discovery." By which he means taxonomists are struggling to identify, name and describe all those novel creatures that NIWA research vessel Tangaroa and others bring back.
"Add bacteria to that, and well ... we don't even have the faintest idea. The sky's the limit. There's over a century of work here waiting on the shelves to be done," says Gordon, "let alone the stuff at Te Papa."
Not only is much of it new to science, it's exclusive to New Zealand – probably, offers Gordon, down to New Zealand's long geographic isolation. That confers a duty: "We're one of the world's top 25 biodiversity hotspots, so we don't just owe it to ourselves: we have a global responsibility to conserve what's unique.
"If you look at the language concerning life these days," he muses, "it's that of the market: it's called a resource. It's almost a philosophical shift. But I feel that many people who simply love life and love Nature would say; 'we share this planet – we're organisms too'."
Sidebar: Renaming nori
The abiding ambition of taxonomy might well be to abolish anonymity. It tells us where creatures fit on the vast family tree of life. It identifies organisms according to shared common characteristics, gives them a name, then assorts them in a hierarchy. As Dr Wendy Nelson, NIWA's Taxonomy and Systematics Science Leader, explains, it also reveals the differences, similarities and evolutionary links between all life on Earth.
"The names are actually a whole lot of hypotheses and theories," she says. "People sometimes get testy about why taxonomists change names, but we're always trying to get a better understanding of these relationships, so if we discover new ones, or get fresh insights into how they relate to one another, the names change to reflect that."
Take sushi, as many of us do each lunchtime. We know it comes wrapped in a handy roll of 'seaweed' sheet called nori, but what exactly is it? Nelson recently took part in award-winning international research that began with just that question. It's a prime example of how research into marine taxonomy can pay huge dividends.
Nori is processed from particular types of red algae. Nelson and her team realised that the scientific names of the specific species in question didn't accurately reflect their evolution, or the way they really related to each other. So the project completely reorganised the taxonomy for the whole group of organisms.
So what? Well, 600 square kilometres of Japanese coastal waters produce 350,000 tonnes of nori a year, worth more than a billion US dollars. Being able to identify those with the best characteristics, in terms of consistency and nutrition, is gold. Industry leaders have already picked up this new research, and use it to guide their work.
As Nelson points out: "People were trying to breed algae that were actually of such different types that they were doomed to failure. Taxonomic research may seem esoteric, but it has really profound implications."