By Catherine 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, they first had to be drained. Throughout the 19th century, settlers had drained smaller areas of swampland for their own farms and homes. But in the early 20th century, the government set about massive scale drainage works throughout the country, starting with Hauraki Plains, and Rangitaiki Swamp in the Bay of Plenty, to convert these areas into farmland and settlements.
In 1889, William Pember Reeves gave this poignant description of swamp environments and their desiccation:
Small streams ran out of the swamp… and disappeared in the shingle of the beach. When not disturbed with draining work, their water was sweet and clear. The swamps had been covered with tall flax, toetoe, rushes and small bushes, green and beautiful in the sunlight, but as drains did their work, the peat sank, cracked and dried, the surface was systematically burnt and became stretches of black, hideous ashes and mud, poached up by the hoofs of cattle.
Today, New Zealand has the unenviable record of an 85 to 90 per cent reduction in wetlands since European settlement. As Geoff Park states in Environmental Histories of New Zealand, one of the most dramatic declines anywhere in the world. But with that dramatic decline has come a heightening in awareness of the ecological importance of wetlands. No longer dismissed as useless “swamps”, wetlands are recognised as having numerous functions vital to both environmental and human wellbeing. Acting rather like a giant sponge, they control water flow and quality. Plants slow the flow of surface water from the land, absorbing excess water during flood events. During dry periods, stored water is slowly released from wetlands, maintaining flows. Bacteria in the damp soils of wetlands absorb and break down 90 per cent of the nitrogen contained in farm run-off (such as in fertilisers and animal waste). Plants also trap waterborne sediment, preventing silt entering streams and harbours. They are highly productive ecosystems, providing habitat and a rich food source for fish, birds and other animals. They absorb large amounts of water and nutrients from outside sources and contain micro-organisms (fungi and bacteria) that efficiently decompose and recycle nutrients.
In the Manawatu, which is the focus of my current research, much of the flood plains of the lower Manawatu River were once a network of wetlands of some nature: swamps, lagoons created by the cut-off meanders of the river, and once the river reached the Tasman Sea, an extensive estuary. These wetlands were greatly valued (and contested) by Maori in the region, who treated them as a highly valued resource, particularly as eel fisheries. However, to the European, they were seen as a barrier to the productive use of land, as well as an unwelcome encumbrance to movement across the land. Drainage boards were established almost immediately to create and maintain drains across the swampiest of land, thereby allowing the “march of progress” to proceed, in the form of the ever-expanding pastoral landscape. One of the largest wetlands to be drained was Taonui Swamp, in the basin between Oroua and Manawatu Rivers. Others that were initially valued as flax-producing swamps, but later drained when the boom was over, were the Makerua and Moutoa Swamps.
Palmerston North itself was established on an area that included five lagoons, all highly valued by Maori, whose settlements were sited close by. All but one of these is now drained. Even the lagoon that remains is in a form vastly transformed from its indigenous state, and few Palmerstonians are aware of its illustrious pre-European history.
Sadly, no amount of effort will restore the likes of the Awapuni Lagoon, once located on the western boundary of the city, which can now only be remembered by historical photographs (see above). But, like many other regions of New Zealand, wetlands are undergoing a revival in the Manawatu, both in terms of the value attributed to them, and the effort invested in restoring them.
One such example is the Manawatu Estuary. In 2005, after prolonged representations by the self-appointed guardians of the estuary, the Manawatu Estuary Trust, the Manawatu Estuary was designated as New Zealand’s sixth Wetland of International Importance, under the RAMSAR convention, an inter-government treaty on the conservation of wetlands. It is now recognised that the estuary has one of the most diverse ranges of birds to be seen at any one place in New Zealand, a total of 93 species have been identified at the estuary. It is a significant area of salt marsh and mudflat and an important feeding ground for many birds, including the migratory eastern bar-tailed godwit, which flies non-stop for 11, 000 kms from Siberia to escape the harsh northern winter. The estuary is also a permanent home to 13 species of birds, six species of fish and four plants species, all of which are threatened. It regularly supports about one per cent of the world population of wrybills.
Another wetland that has been the focus of local restoration efforts is Ashhurst wetland (pictured). And while an investigation of the site’s environmental history reveals that this is not a “restoration” in the strict sense, the restoration project has nevertheless produced an ecosystem of significant natural value and a landscape of aesthetic value, from which many derive considerable pleasure. Hopefully, restoration projects of the future will also reveal the important ecological, aesthetic, recreational and cultural values of places once dismissed as “unproductive wastelands”.
Dr Catherine Knight is an environmental history researcher, and an honorary research associate at Massey University. She is currently working on a book exploring the environmental history of the Manawatu region, from prehistory to today.
This article adapted from a post originally published on envirohistory NZon 6 December 2009.