title: Distribution of mine waste along the Waihou River flood plains

authors: Ahmed, Tofeeq

abstract: Solid waste production, in the form of mine tailings, is the result of mining of natural mineral resources. The Ohinemuri River tributary of the Waihou River was designated as an official sludge channel during the period of mining operations in the catchment as an official sludge channel during the mining period for mining operations in the catchment in 1895. The 1910 Commission recommended it be revoked and only “slimes” be discharged under a range of restrictions. Essentially processing technology had changed by 1910 and it was no longer necessary to discharge most of the waste. However, the designation remained in place as an official sludge channel during the mining period for mining operations in the catchment. Mine waste included metals such as: copper (Cu), Zinc (Zn), Manganese (Mn), Lead (Pb) and Arsenic (As). Regular flooding of the Ohinemuri and Waihou Rivers resulted in the rivers overtopping their banks and dispersing mine waste into the floodplain areas. The result was dispersion of metal contaminants in the Waihou River catchment area. The effects of this regular flooding had an adverse effect on stocks. The flooding destroyed the crops, the slimes and sludge from flood damaged grass paddocks. The cyanide sludge destroyed the fish stock in the lower Ohinemuri River and upper Waihou River. This continued until stop-banks were installed to reduce the occurrence of overbank flooding, mostly long after any mining disposal had ceased. It was assumed that the heavy metals were migrating downstream. However, recent studies show no strong evidence of downstream migration of contaminated sediments in the Waihou River to the Firth of Thames. This research will investigate the heavy metal concentration along the Waihou River floodplain by mapping metal concentrations from mine waste.
Field sampling has found that the mine waste has not travelled far beyond Paeroa and is concentrated on the flood plains. Some sample sites have levels of contaminants that exceed the thresholds for chronic toxicity. These results are consistent with research limited to the immediate vicinity of the river channel.
Key words: Waihou River, Ohinemuri River, mine tailings, heavy metals, contaminated sediments.

text: Distribution of mine waste along the Waihou River flood plains Solid waste production, in the form of mine tailings, is the result of mining of natural mineral resources. The Ohinemuri River tributary of the Waihou River was designated as an official sludge channel during the period of mining operations in the catchment as an official sludge channel during the mining period for mining operations in the catchment in 1895. The 1910 Commission recommended it be revoked and only “slimes” be discharged under a range of restrictions. Essentially processing technology had changed by 1910 and it was no longer necessary to discharge most of the waste. However, the designation remained in place as an official sludge channel during the mining period for mining operations in the catchment. Mine waste included metals such as: copper (Cu), Zinc (Zn), Manganese (Mn), Lead (Pb) and Arsenic (As). Regular flooding of the Ohinemuri and Waihou Rivers resulted in the rivers overtopping their banks and dispersing mine waste into the floodplain areas. The result was dispersion of metal contaminants in the Waihou River catchment area. The effects of this regular flooding had an adverse effect on stocks. The flooding destroyed the crops, the slimes and sludge from flood damaged grass paddocks. The cyanide sludge destroyed the fish stock in the lower Ohinemuri River and upper Waihou River. This continued until stop-banks were installed to reduce the occurrence of overbank flooding, mostly long after any mining disposal had ceased. It was assumed that the heavy metals were migrating downstream. However, recent studies show no strong evidence of downstream migration of contaminated sediments in the Waihou River to the Firth of Thames. This research will investigate the heavy metal concentration along the Waihou River floodplain by mapping metal concentrations from mine waste.
Field sampling has found that the mine waste has not travelled far beyond Paeroa and is concentrated on the flood plains. Some sample sites have levels of contaminants that exceed the thresholds for chronic toxicity. These results are consistent with research limited to the immediate vicinity of the river channel.
Key words: Waihou River, Ohinemuri River, mine tailings, heavy metals, contaminated sediments.

year: 2019

title: Historicising Gerd Koch's Ethnographic Films on Tuvalu

authors: Goldsmith, Michael

subjects: Gerd Koch

abstract: Gerd Koch is probably best known for his studies of Tuvalu in the early 1960s, when it was still part of the Gilbert and Ellice Islands Colony. In the process of recording aspects of material and expressive culture on Niutao, one of the northernmost islands, he shot a series of black-and-white silent films. Fifteen of these films were archived at IWF Wissen und Medien in G ttingen, Germany, formerly the Institut f r den Wissenschaftlichen Film, as part of an encyclopaedic project reflecting mid-20th-century scientific and philosophical assumptions. What do these films tell us about Tuvalu and the histories of anthropology and ethnographic film-making in the Pacific? This paper proposes some answers by focusing on two films featuring styles of combat that are both called 'failima' yet are clearly different from each other.

text: Historicising Gerd Koch's Ethnographic Films on Tuvalu Gerd Koch is probably best known for his studies of Tuvalu in the early 1960s, when it was still part of the Gilbert and Ellice Islands Colony. In the process of recording aspects of material and expressive culture on Niutao, one of the northernmost islands, he shot a series of black-and-white silent films. Fifteen of these films were archived at IWF Wissen und Medien in G ttingen, Germany, formerly the Institut f r den Wissenschaftlichen Film, as part of an encyclopaedic project reflecting mid-20th-century scientific and philosophical assumptions. What do these films tell us about Tuvalu and the histories of anthropology and ethnographic film-making in the Pacific? This paper proposes some answers by focusing on two films featuring styles of combat that are both called 'failima' yet are clearly different from each other.

year: 2010

title: Recognising the negative impacts of aquatic weed management: Okawa Bay, Lake Rotoiti case study

authors: Scholes, Paul

abstract: The Te Arawa Rotorua Lakes Programme continues to implement measures to maintain and restore lake water quality in line with trophic level indices (TLI’s) for respective lakes. In Lakes Rotorua and Rotoiti this has also meant not only reducing nutrients to and in the lakes but also managing periodic cyano-bacterial (blue-green) algal blooms.
Restoration measures in the Rotorua and Rotoiti catchments have included land use management efforts to arrest nutrient inputs; diversion of Lake Rotorua waters from entering Rotoiti; sewage reticulation of lakeside communities; and treatment of inflows
with aluminium sulphate (alum). While restoration efforts have produced water quality gains in both lakes, in recent years, cyano-bacterial blooms have occurred in the shallow embayment of Lake Rotoiti, known as Okawa Bay.
These water quality gains have not come without a cost. Submerged aquatic weeds such as Hornwort are an increasing problem in the Rotorua Te Arawa Lakes and significant resources are needed to manage infestations primarily for aesthetic and recreational
amenity. Control of exotic aquatic weed is mostly with application of herbicide. Herbicide treatment leaves a decomposing biomass in the waterbody, potentially increasing the nutrient status.
We examine the impact aquatic weed decomposition has had on Okawa Bay’s nutrient status and the cyano-bacterial blooms over recent summers, and Bay of Plenty Regional Council’s response to reduce localised bloom development.

text: Recognising the negative impacts of aquatic weed management: Okawa Bay, Lake Rotoiti case study The Te Arawa Rotorua Lakes Programme continues to implement measures to maintain and restore lake water quality in line with trophic level indices (TLI’s) for respective lakes. In Lakes Rotorua and Rotoiti this has also meant not only reducing nutrients to and in the lakes but also managing periodic cyano-bacterial (blue-green) algal blooms.
Restoration measures in the Rotorua and Rotoiti catchments have included land use management efforts to arrest nutrient inputs; diversion of Lake Rotorua waters from entering Rotoiti; sewage reticulation of lakeside communities; and treatment of inflows
with aluminium sulphate (alum). While restoration efforts have produced water quality gains in both lakes, in recent years, cyano-bacterial blooms have occurred in the shallow embayment of Lake Rotoiti, known as Okawa Bay.
These water quality gains have not come without a cost. Submerged aquatic weeds such as Hornwort are an increasing problem in the Rotorua Te Arawa Lakes and significant resources are needed to manage infestations primarily for aesthetic and recreational
amenity. Control of exotic aquatic weed is mostly with application of herbicide. Herbicide treatment leaves a decomposing biomass in the waterbody, potentially increasing the nutrient status.
We examine the impact aquatic weed decomposition has had on Okawa Bay’s nutrient status and the cyano-bacterial blooms over recent summers, and Bay of Plenty Regional Council’s response to reduce localised bloom development.

year: 2015