Archive: Waiology June 2014

By Judi Hewitt Estuaries are the transition between fresh water and the open coast, sheltered water that is neither fully saline nor fresh. The New Zealand coastline contains 441 estuaries, whose environmental characteristics are recorded in the Estuarine Classification database. Estuaries support a wide range of human activities and values and are an integral part of the cultural identity … Read More

By Neil Deans New Zealand is blessed with an abundance and multitude of freshwaters which provide the habitat for an equally diverse array of species, including both native and introduced fish and wildlife. Some of these have intrinsic value; others are also valued because they provide food or recreational pursuit, or are indicators of a healthy environment. (Credit: … Read More

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By David Rowe The presence and abundance of fish in our rivers depends on many factors, water quality being one. Water temperature, the amount of oxygen dissolved in the water, acidity (pH), ammonia concentration, and suspended sediment level can all influence the suitability of water for fish. When changes in land-use occur in river catchments, or pollutants enter waterways, … Read More

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By Gary Bedford When it comes to recreational use of freshwater, are we swimming in mixed messages? Fairfax reported that ‘More than 60 per cent of monitored rivers in New Zealand are unsafe for swimming according to Environment Ministry figures’. Dr Mike Joy from Massey University reportedly stated that 95% of New Zealand’s lowland rivers fail … Read More

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By Jonathan Moores and Jenni Gadd In keeping with urban areas throughout the world, New Zealand’s cities were established next to streams, rivers, lakes and harbours. As well as water supply, these waterways provided for transport, trade and recreation. Paradoxically, however, there is substantial evidence that urban development is harming these very same waterbodies. Parts of Auckland’s harbours, for … Read More

By Rob Davies-Colley The quality of water in rivers and downstream lakes and estuaries strongly affects how we can use it and what value we place on it. And to define water quality, it is imperative to make long-term, national measurements. Much information on the water quality of New Zealand rivers at national scale has come from monitoring at … Read More

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By Clive Howard-Williams Society is increasingly concerned over water quality. The means by which this is maintained and enhanced while growing an economy is a major challenge for governments in many places. Here I introduce some underlying concepts around water quality that Waiology followers will need to appreciate when they look at the forthcoming series of blogs. What is … Read More

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By Daniel Collins The state of our waters is a hot button topic. Water quality has become an election issue from Southland to Northland, from towns to nation, and it is often in the news. Swimming water quality and implications of the proposed Ruataniwha water storage and irrigation scheme in Hawke’s Bay are cases in point. Sediment plume from … Read More

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By Julia Bradshaw George Wood canned whitebait at Hokitika from 1893 until at least the 1920s. (Photo: Hokitika Museum, #4578)Unlike the rest of New Zealand, on the West Coast the season for catching whitebait starts on 1 September and the build-up has been noticeable during the last week. Distinctive huts have appeared along the sides of rivers, motor-homes … Read More

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By Jane Goodman A bucketful of Giant kokopu (Photo: Emily Funnell).New Zealand’s whitebait fishery consists of the young of five migratory galaxiid species – inanga (Galaxias maculatus), koaro (Galaxias brevipinnis), banded kokopu (Galaxias fasciatus), giant kokopu (Galaxias argenteus) and shortjaw kokopu (Galaxias postvectis). Smelt (Retropinna retropinna) are also present in catches from some rivers along with the young … Read More

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