Water & Atmosphere February 2011 Scrutiny on the Bounty The risks and riches of seabed mining Seagrass Serengetis Our vanishing fish nurseries Pernicious particles What's in the air you breathe? Looking for CLEWS An eye on the sky for Samoa 1080 tests clear Water safe after pest control Water & Atmosphere Water & Atmosphere February 2011 Issue 2 February 2011 Scrutiny on the Bounty The risks and riches of seabed Cover mining Since 2007, the Tui oil field has yielded nearly 30 million barrels of crude. Now, energy companies are searching the depths for other minerals and gases to drive New Zealand's energy future. Seagrass Serengetis (New Zealand Oil & Gas) Our vanishing fish nurseries Pernicious particles What's in the air you breathe? Looking for CLEWS An eye on the sky for Samoa 1080 tests clear Water safe after pest control Water & Atmosphere is published by the National Institute of Water & Atmospheric Research (NIWA). It is available online at www.niwa.co.nz/pubs/wa Enquiries to: 4 The Editor Water & Atmosphere Editorial NIWA When values collide – NIWA’s Chief Executive, Private Bag 14901 John Morgan, emphasises that science and Kilbirnie Wellington 6241 business must go hand-in-hand New Zealand email: [email protected] ©National Institute of Water & Atmospheric Research Ltd 2011 ISSN 1172-1041 5 Water & Atmosphere team: Solutions Advisory Board: Eradicating a freshwater invader Geoff Baird, Dr Bryce Cooper, Dr Barb Hayden, Dr Rob Murdoch Managing Editor: Michele Hollis Editor: Dave Hansford 6 Subeditor: Harriet Palmer In brief Designer: Mark Tucker From the ozone hole to the depths of the Production Assistant: Frances Nolan Kaikoura canyon, mapping and stream restoration tools to sea-level rise, and the Canterbury earthquake 34 34 Q&A Undersea earthquakes – the lowdown Water & Atmosphere is produced using vegetable-based inks on paper made from FSC certifed mixed-source fibres under the ISO 14001 environmental management system. 2 Water & Atmosphere February 2011 www.niwa.co.nz 10 Ocean's treasure Jim Robinson talks to the specialists, and asks: what's the role of science in delivering the answers? 20 22 It’s a wonderful Where will the young fish play? world Our seagrass meadows are vanishing, taking vital fish nurseries with them They may be small and ugly, but they are vital – sea cucumbers and lamprey 24 The air we breathe: who's most at risk? Does your urban lifestyle threaten your health? New approaches to urban air quality research 28 The Snares: seabird citadel Islands in the Southern Ocean are home to some spectacular, but threatened, species 30 32 Early warning for Water safe after Samoa 1080 drop Vulnerable Pacific Islands such as Fiona Proffitt finds reassuring evidence Samoa are investing in better climate about the impacts of 1080 on water information to help them adapt to climate change www.niwa.co.nz Water & Atmosphere February 2011 3 Editorial When values collide Billions of dollars in mineral wealth may lie untapped leaders to provide the evidence base they need; we must beneath our seabed. But how do we explore it without clearly communicate what we know, and what we don’t know. harming the priceless biodiversity living there? The Land and Water Forum exemplifies that approach. In In this edition of Water & Atmosphere, our cover story looks September, the Forum released its report, A Fresh Start for at seabed mining. It’s an issue of national importance, and Fresh Water – the result of more than a year of dialogue highlights the role of good science in a world of competing between primary industry, electricity generation, tourism, environmental and economic interests environmental and recreational interest groups, and iwi. Seabed mining, like so many resource controversies, is NIWA’s Chief Scientist Freshwater, Dr Clive Howard- debated by many voices with many values, but is based on Williams, and his team spent many hours behind the scenes patchy information, relying on decades-old assessments. with Forum members, helping them understand what drives the amount and quality of freshwater around New Zealand. Many more discoveries await, new technologies must be We were proud that NIWA scientists were able to provide a tested, and questions answered about the ecological impacts solid evidence base upon which Forum members, with their of mining. widely different perspectives, could debate the issues. Filling in those blanks is the vital role of science. I’m particularly pleased to see the Forum’s statement that I’ve worked in science organisations for well over two “freshwater science and knowledge (including Mātauranga decades, and I’ve yet to meet a leader who does not sincerely Māori) is an essential part of governance”. believe in robust, evidence-based policy and business Long-term investment in science works. Our story about decisions. the near-eradication of the appalling water weed, hydrilla But then the real world kicks in. Our teams face tight (see Solutions, opposite), is one example. Scientists and deadlines and limited funds, and sometimes we struggle government agencies doggedly plugged away against hydrilla even to access the existing knowledge, let alone commission for more than 30 years, scoring incremental wins that added new research. up to success. Last November, Science and Innovation Minister Wayne There’s much more great science and great reading in Mapp released a Statement of Core Purpose for each of New this issue of Water & Atmosphere, from air quality to Zealand’s eight Crown Research Institutes. Those statements earthquakes, from majestic subantarctic birds to an spell out why the government owns CRIs, and what it expects astonishingly ugly creature which can liquefy its body to from them. In NIWA’s case, it formally recognises our role “to escape predators. We look at how Samoa is adapting to enhance the economic value and sustainable management climate change, and we highlight the disappearance of of New Zealand’s aquatic resources and environments, seagrass meadows – vital fish habitat vanishing faster than to provide understanding of climate and the atmosphere tropical forests. We hope you find this issue of Water & and increase resilience to weather and climate hazards to Atmosphere enlightening and absorbing. improve the safety and wellbeing of New Zealanders.” In other words, CRIs are expected to deliver real benefit to New Zealand in return for the public’s investment in science. John Morgan That implies working closely with government and business Chief Executive 4 Water & Atmosphere February 2011 www.niwa.co.nz Solutions Eradicating a freshwater invader One of the world’s worst freshwater weeds was threatening lakes in Hawke’s Bay. Now, it is almost gone. Here’s a case where long-term science investment, plus inter-agency cooperation, paid big dividends for New Zealand. Hydrilla blankets the bed of Lake Opouahi, near Wairoa, before the When Indian star vine was introduced into the United States release of grass carp. The plant's dense, branching habit blocks out in the 1950s as an aquarium plant, it took only a decade to most other species. (Rohan Wells) become a major aquatic weed in Florida, choking 150 000 hectares of lakes and waterways. Control efforts to protect cashew nut) that can lie dormant in the sediment for over 10 irrigation and flood-control schemes have cost more than years. Every single plant sprouting from these tubers must US$225 million to date. be removed to break the cycle and prevent new tubers being produced. The best option for removing the new shoots was In the 1960s, the same plant – now known as hydrilla – was grass carp, a plant-eating fish (not to be confused with koi discovered in an isolated lake in Hawke’s Bay. Alarmed by the carp, a pest fish now infesting the lower Waikato River). American experience, MAF (then the Ministry of Agriculture and Fisheries) sought a control programme. A project was In 1988, a field trial using 400 grass carp began in privately started by the Aquatic Plants Section at MAF’s Ruakura owned Lake Eland in Hawke’s Bay. Each year, researchers Agricultural Research Station, the scientists who eventually dredged and sieved sediment to count hydrilla tubers, and became NIWA’s freshwater plants team. meticulously searched for shoots. They found tubers and shoots for a further 12 years after the main weed beds had The scientists began with ‘competition experiments’, growing been removed, but now the lake has been hydrilla-free for hydrilla in secure contained facilities with all the other eight years. submerged weeds known in New Zealand. As predicted, hydrilla was by far the most invasive species, forming thick The experimental science behind the tools and a mats in surface waters and confirming its reputation as the management plan developed by NIWA gave confidence that ‘world’s worst submerged waterweed’. the ‘world’s worst’ could be eradicated from New Zealand; MAF Biosecurity NZ then took responsibility for hydrilla The New Zealand strain of hydrilla was not only highly management. invasive, but also incredibly difficult to control. The only herbicide registered for aquatic use in New Zealand failed In 2008, endothall was used to reduce the biomass of hydrilla to even check its growth. Fluridone, the herbicide of choice in strategic high-use areas, before more than 2700 grass in the US, was no better. The NIWA team screened available carp were released into the three remaining infested lakes. and potential products, first in small-scale containment trials Only 15 months later, hydrilla has been significantly reduced, and then in field trials. Finally, they identified endothall as a and the risk of spread to new water bodies is negligible. The safe and effective herbicide. It could remove up to 95 percent aquatic weed is 99 percent gone from New Zealand.