title: Multiple stressor effects on marine infauna: responses of estuarine taxa and functional traits to sedimentation, nutrient and metal loading

authors: Ellis, Joanne I.

subjects: Science & Technology

abstract: Sedimentation, nutrients and metal loading to coastal environments are increasing, associated with urbanization and global warming, hence there is a growing need to predict ecological responses to such change. Using a regression technique we predicted how maximum abundance of 20 macrobenthic taxa and 22 functional traits separately and interactively responded to these key stressors. The abundance of most taxa declined in response to sedimentation and metal loading while a unimodal response was often associated with nutrient loading. Optimum abundances for both taxa and traits occurred at relatively low stressor levels, highlighting the vulnerability of estuaries to increasing stressor loads. Individual taxa were more susceptible to stress than traits, suggesting that functional traits may be less sensitive for detecting changes in ecosystem health. Multiplicative effects were more common than additive interactions. The observed sensitivity of most taxa to increasing sedimentation and metal loading and the documented interaction effects between multiple stressors have important implications for understanding and managing the ecological consequences of eutrophication, sedimentation and contaminants on coastal ecosystems.

text: Multiple stressor effects on marine infauna: responses of estuarine taxa and functional traits to sedimentation, nutrient and metal loading Sedimentation, nutrients and metal loading to coastal environments are increasing, associated with urbanization and global warming, hence there is a growing need to predict ecological responses to such change. Using a regression technique we predicted how maximum abundance of 20 macrobenthic taxa and 22 functional traits separately and interactively responded to these key stressors. The abundance of most taxa declined in response to sedimentation and metal loading while a unimodal response was often associated with nutrient loading. Optimum abundances for both taxa and traits occurred at relatively low stressor levels, highlighting the vulnerability of estuaries to increasing stressor loads. Individual taxa were more susceptible to stress than traits, suggesting that functional traits may be less sensitive for detecting changes in ecosystem health. Multiplicative effects were more common than additive interactions. The observed sensitivity of most taxa to increasing sedimentation and metal loading and the documented interaction effects between multiple stressors have important implications for understanding and managing the ecological consequences of eutrophication, sedimentation and contaminants on coastal ecosystems.

year: 2017

title: Purification of Tannery Effluent by electrolytic corrosion of aluminium

authors: Mathieson, Grant Alexander

subjects: Tannery Effluent

abstract: Tannery Effluent is noxious because tanning process chemicals are preservatives, including chromium, and the pH is high. Electrolytic processing is feasible because the high salt content gives a high electrical conductivity. While research on the subject dates back to early in the 20th Century, commercialization has not occurred, perhaps due to excessive power consumption. Other researchers have produced promising results with rendering plant effluent (Tetrault 2003). During 2005 a specialised proprietary prototype with a novel anode design was trialed extensively at a Tannery site in New Zealand and produced good results during continuous inline operation despite wide variation in the inflow. Greater than 90% removal of chromium from solution with similar reductions in turbidity were achieved at lower operating cost, residual aluminum and total aluminum addition than by dosing with usual commercial aluminum based flocculants. Results from the field trials are shown and discussed.

text: Purification of Tannery Effluent by electrolytic corrosion of aluminium Tannery Effluent is noxious because tanning process chemicals are preservatives, including chromium, and the pH is high. Electrolytic processing is feasible because the high salt content gives a high electrical conductivity. While research on the subject dates back to early in the 20th Century, commercialization has not occurred, perhaps due to excessive power consumption. Other researchers have produced promising results with rendering plant effluent (Tetrault 2003). During 2005 a specialised proprietary prototype with a novel anode design was trialed extensively at a Tannery site in New Zealand and produced good results during continuous inline operation despite wide variation in the inflow. Greater than 90% removal of chromium from solution with similar reductions in turbidity were achieved at lower operating cost, residual aluminum and total aluminum addition than by dosing with usual commercial aluminum based flocculants. Results from the field trials are shown and discussed.

year: 2006

title: Maori children and death: Views from parents

authors: Jacob, Juanita

subjects: Maori

abstract: Research about Maori children's experiences and perceptions of death and tangi (Maori death rituals) is sparse. What is available tends to be generalised and stems from Western paradigms of knowledge. In this study we explore Maori children's experiences of death and tangi through the eyes of Maori parents. Through semi-structured interviews with 17 Maori parents, five areas were explored: a) the childhood experiences of parents and how they learned about death and an afterlife; b) what their adult beliefs about these matters are; c) how they have communicated the death concept to their children; and d) whether their children are likely to do the same in the future. From this study we learn that death was not hidden from children, that parents talked with their children in very open and age relevant ways, and considered their children's participation in tangi an important way to grieve and ensure continuity with kinship networks and support. This study suggests that the challenge now is to ensure that these practices continue to persist between parents and their children, and future generations.

text: Maori children and death: Views from parents Research about Maori children's experiences and perceptions of death and tangi (Maori death rituals) is sparse. What is available tends to be generalised and stems from Western paradigms of knowledge. In this study we explore Maori children's experiences of death and tangi through the eyes of Maori parents. Through semi-structured interviews with 17 Maori parents, five areas were explored: a) the childhood experiences of parents and how they learned about death and an afterlife; b) what their adult beliefs about these matters are; c) how they have communicated the death concept to their children; and d) whether their children are likely to do the same in the future. From this study we learn that death was not hidden from children, that parents talked with their children in very open and age relevant ways, and considered their children's participation in tangi an important way to grieve and ensure continuity with kinship networks and support. This study suggests that the challenge now is to ensure that these practices continue to persist between parents and their children, and future generations.

year: 2011-12