Dr Daniel Collins is a hydrologist at NIWA. He formed the Waiology blog to bring together commentary on New Zealand's freshwater systems. The blog features commentary from numerous contributors.

What makes wetlands wet lands? - Waiology

Feb 04, 2013

By Daniel Collins The simple answer is, of course, water. But that says little about the natural history of wetlands, or what physical conditions are necessary to maintain, restore or even engineer them. For that, we need to take a closer look at wetland hydrology. Wetlands are tracts of land that are water-logged at least seasonally. They may be spongy bogs, mountain tarns, verdant swamps, or many other types. They remain wet because the inputs of water from rain, rivers or groundwater compensate any losses. The various types can be distinguished based on their hydrology. In their book on wetland restoration, Bev Clarkson and Monica Peters (2010) quantify this continuum with the “gumboot test”. Short “red bands” are usually okay for keeping you dry in bogs, taller gumboots are needed for fens, thigh waders for swamps, and waist waders … Read More

Happy World Wetlands Day! - Waiology

Feb 02, 2013

By Daniel Collins Halfway through Waiology’s series for World Wetlands Day we’ve already learned a lot about New Zealand wetlands and efforts to study and restore them. But today being the day, how about you actually visit one? I’ll be at Christchurch’s Travis Wetland. And then come back for more articles in the coming week. In the meantime, here is a buoyant cartoon from Ramsar. Dr Daniel Collins is a hydrologist and water resources scientist at NIWA. Read More

Why measure carbon budgets in NZ peat wetlands? - Waiology

Jan 31, 2013

By Dave Campbell In 1769 Captain James Cook’s Endeavour anchored at the mouth of the Waihou River near the present-day town of Thames. Cook’s naturalist, Joseph Banks, was impressed by the evident resources within the vast swamp forest that covered the lower Hauraki Plains: …The Noble timber, of which there is such an abundance, would furnish plenty of materials either for building defences, houses or Vessels. …Swamps which might doubtless Easily be drained, and sufficiently evinced the richness of their soils by the great size of the plants that grew upon them, and more particularly of the timber trees which were the streightest (sic), cleanest, and I may say the largest I have ever seen… Aerial view of the south eastern portion of Kopuatai bog, Mt Te Aroha in the distance. In the foreground is Empodisma robustum rush-land, … Read More

World Wetlands Day at Lake Serpentine, site for proposed National Wetlands Centre - Waiology

Jan 30, 2013

By Shonagh Lindsay The Rotopiko/Serpentine complex, a headwater of the Waikato River at Ohaupo south of Hamilton, is steadily being developed by the National Wetland Trust as the site of New Zealand’s National Wetland Centre, a showcase for wetland education, training and research. To celebrate World Wetlands Day, the Trust will launch work on the National Wetland Centre on Sunday 3rd February. A blessing by local iwi and brief addresses will be followed by a range of family fun activities that reflect the vision to create a ‘masterpiece’ at this beautiful site. Collecting insect samples.The Trust has so far received significant funding to develop a predator-free wildlife sanctuary and restore vegetation in the peat lake/swamp forest complex. Getting the local community involved is integral and last year the lake area became a hive of forensic activity … Read More

The state of Canterbury’s coastal wetland vegetation - Waiology

Jan 29, 2013

By Philip Grove Canterbury has a wide variety of wetland types in a range of landscapes from the mountains and high country through to the foothills, plains and the coast. The biological productivity of coastal wetlands and their ecological importance in the life cycles of many native fish and birds is well recognised. A national database of inland freshwater wetlands has been developed recently, but it does not cover saltmarsh or brackish wetland habitats, and is of limited accuracy in areas where freshwater wetlands adjoin or grade into brackish coastal lagoons and estuaries. A small coastal wetland at Raupo Bay, Banks Peninsula, that is intermittently open to the sea also supports saltmarsh vegetation – three-square (Schoenoplectus pungens), sea rush (Junkus kraussii) and saltmarsh ribbonwood (Plagianthus divaricatus).To complement the freshwater wetland database for Canterbury, Regional Council staff surveyed and … Read More

From “swamps” to “wetlands”: The transformation of wetlands as both conceptual and physical landscapes - Waiology

Jan 28, 2013

By Catherine Knight The boardwalk through the wetland at Papaitonga, south of Levin, Horowhenua (photo: C. Knight). Through time, not only has our environment been transformed, but also the way we perceive it and the words we use to describe it. No example illustrates this better than the “swamp” to “wetland” transformation. When European settlement of New Zealand began in earnest about 150 years ago, about 670, 000 hectares of freshwater wetlands existed. By the 20th century, this had been reduced to 100,000 hectares. Wetlands were seen as swamps – or, as Charles Hursthouse put it in 1857: “Damp and dripping forests, exhaling pestilent vapours from rank and rotten vegetation…” Not only were swamps “unproductive”, they were also undesirable to the European aesthetic – “messy” and without order. In order to transform these swamps into productive and useful land, … Read More

The use of dicyandiamide (DCD) to control nitrogen pollution in NZ - Waiology

Jan 25, 2013

By Bob Wilcock For the last 20 years New Zealand has been undergoing a rapid expansion in dairy farming, driven by commodity prices. New Zealand’s dairy exports, although small on a global scale of production, comprise 30-40% of internationally traded dairy products and are a major component of our gross domestic product (roughly 3%). Dairy farming is an intensive form of agriculture and its expansion into areas that were previously used for sheep and beef farming, combined with increased stocking rates in established dairy farming regions, has resulted in much greater leaching of nitrate to groundwater, and to surface waters receiving inputs of groundwater. About 40% of the nitrogen in our rivers originates from pasture. Increased nitrate concentrations adversely affect nitrogen-sensitive lakes, such as Taupo, by promoting phytoplankton growth, and cause periphyton blooms in some rivers. In addition, recent research … Read More

Discovering the unique fauna of alpine streams - Waiology

Jan 22, 2013

By Richard Storey Each summer many of us don a backpack and head into the mountains to immerse ourselves in spectacular scenery relatively untouched by human activities. Undoubtedly the tracks we follow will take us across dozens of clear, tumbling streams where we might refill our water bottles or splash cool water on our faces. But how often do we think about what lives in these streams? We might think that being close to popular walks, the animal communities inhabiting these streams are well known to science. But despite over 150 years of freshwater research in New Zealand, little is actually known about the stream invertebrates (insects, crustaceans, worms, etc.) living at high altitudes, or how the animal community differs from one alpine stream to another. This is largely because most freshwater research focuses on areas where human activities could … Read More

2012 in review - Waiology

Dec 21, 2012

By Daniel Collins Another year has come and gone, and with it more science of New Zealand water’s shared near and far. As I look back, with this handy Wordle below, it’s no surprise that “water” got mentioned a lot. Other common words in this year’s posts include “groundwater”, “Canterbury”, “flow”, “rainfall”, “recharge” and “snow”. All very important topics. One of this year’s successes was the crowd-sourcing project we initiated to collect snow depth data on June 6. Waiology had more visitors that day than on any other. This says something about extreme events and public participation in science and should provide food for thought as we build bridges between the hydrological community and NZ at large. Based on visits and social media mentions, the post on the water footprint of milk was also very … Read More