title: Evaluating the properties, fate and individual-to-ecosystem level impacts of contrasting microplastics in freshwaters

authors: McKie, Brendan G.

subjects: Environmental Sciences

abstract: Microplastic particles (MPs) are fragments, fibres and other shapes derived from plastic polymers in the size range of 1–5 000 μm. Concern about the environmental impacts of MPs and their implications for human wellbeing has never been higher. Unfortunately, growth in the empirical understanding of the dynamics and impacts of MPs lags behind. This hinders the capacity of scientists, managers and policymakers to address public concerns about the true level of risk posed by MPs, and to develop effective management, policy and governance strategies for eliminating or reducing those risks. Research on the behaviour and impacts of MPs in freshwater ecosystems is especially deficient, despite their vulnerability to inputs of plastic waste (e.g. via storm water and other terrestrial runoff), and their capacity to act as key transport pathways through the landscape. This represents a substantial black box in our understanding of the dynamics of MPs from inland to the ocean. In seven research activities (5 mesocosm experiments, 1 field study and 1 literature review) we addressed two broad research questions :a) Initial fate and environmental interactions of MP particles in streams, including biofilm formation and sorption of chemical stressors b) Ecological impacts of MPs on resource consumption, growth and survival of organisms, and on key ecosystem processes. Among our key results addressing the initial fate and biofilm formation of MP particles, we found that (i) biofilm formation generally made denser particles more buoyant and caused more buoyant particles to sink faster, (ii) biofilms on polystyrene MPs supported more cyanobacteria than other polymers, and (iii) aquatic macrophytes increase MP retention by up to 94 %. Among our key results addressing the ecological impacts of MPs, we found that almost all MP shapes and polymers studied had one or more effects on stream microbial organisms and associated ecosystem processes (e.g. microbial respiration, detritus breakdown), and/or on the life history of a model macroinvertebrate detritivore. We also provide evidence that effects of MPs on microbial organisms can propagate up food-chains to affect consumer growth and fat storage. Some MP impacts were similar to those of naturally occurring organic and inorganic particles, whilst others represented a risk over and above that associated with natural particles. The number of MP impacts detected in our experiments provides sufficient basis for “moving beyond the precautionary principle” when motivating a need for monitoring and management – there is now sufficient evidence that MPs alter key aspects of the functioning of stream benthic food webs to motivate a need for action. Based on our results, we further provide a series of recommendations for monitoring, policy and management targeting MPs, and for future research.

text: Evaluating the properties, fate and individual-to-ecosystem level impacts of contrasting microplastics in freshwaters Microplastic particles (MPs) are fragments, fibres and other shapes derived from plastic polymers in the size range of 1–5 000 μm. Concern about the environmental impacts of MPs and their implications for human wellbeing has never been higher. Unfortunately, growth in the empirical understanding of the dynamics and impacts of MPs lags behind. This hinders the capacity of scientists, managers and policymakers to address public concerns about the true level of risk posed by MPs, and to develop effective management, policy and governance strategies for eliminating or reducing those risks. Research on the behaviour and impacts of MPs in freshwater ecosystems is especially deficient, despite their vulnerability to inputs of plastic waste (e.g. via storm water and other terrestrial runoff), and their capacity to act as key transport pathways through the landscape. This represents a substantial black box in our understanding of the dynamics of MPs from inland to the ocean. In seven research activities (5 mesocosm experiments, 1 field study and 1 literature review) we addressed two broad research questions :a) Initial fate and environmental interactions of MP particles in streams, including biofilm formation and sorption of chemical stressors b) Ecological impacts of MPs on resource consumption, growth and survival of organisms, and on key ecosystem processes. Among our key results addressing the initial fate and biofilm formation of MP particles, we found that (i) biofilm formation generally made denser particles more buoyant and caused more buoyant particles to sink faster, (ii) biofilms on polystyrene MPs supported more cyanobacteria than other polymers, and (iii) aquatic macrophytes increase MP retention by up to 94 %. Among our key results addressing the ecological impacts of MPs, we found that almost all MP shapes and polymers studied had one or more effects on stream microbial organisms and associated ecosystem processes (e.g. microbial respiration, detritus breakdown), and/or on the life history of a model macroinvertebrate detritivore. We also provide evidence that effects of MPs on microbial organisms can propagate up food-chains to affect consumer growth and fat storage. Some MP impacts were similar to those of naturally occurring organic and inorganic particles, whilst others represented a risk over and above that associated with natural particles. The number of MP impacts detected in our experiments provides sufficient basis for “moving beyond the precautionary principle” when motivating a need for monitoring and management – there is now sufficient evidence that MPs alter key aspects of the functioning of stream benthic food webs to motivate a need for action. Based on our results, we further provide a series of recommendations for monitoring, policy and management targeting MPs, and for future research.

year: 2023-06

title: Liberation and spread of stoats (Mustela erminea) and weasels (M. nivalis) in New Zealand, 1883-1920

authors: King, Carolyn M.

subjects: Science & Technology

abstract: This paper reviews the timing and spread of weasels and stoats across the South and North Islands of New Zealand during the late nineteenth century, entirely from historical records. The flavour of the debates and the assumptions that led to the commissioning of private and government shipments of these animals are best appreciated from the original documents. I describe the sites of the early deliberate releases in Otago, Canterbury, Marlborough, and Wairarapa, and list contemporary observations of the subsequent dispersal of the released animals to named locations in Southland, Westland, Wellington, Hawke’s Bay, Auckland and Northland. Originally, weasels were landed in far greater numbers than stoats (2622 weasels and 963 stoats listed in shipment records) and, while at first they were very abundant, they are now much less abundant than stoats. Two non-exclusive hypotheses could explain this historic change: (1) depletion of supplies of their preferred small prey including birds, mice, roosting bats, lizards, frogs and invertebrates, and (2) competition with stoats. Contemporary historic written observations on the first impacts of the arrivals of weasels and stoats on the native fauna offer graphic illustrations of what has been lost, but usually failed to consider the previous impacts of the abundant rats (Rattus exulans since the late 13th century, and R. norvegicus since 1770s–90s), and cannot now be distinguished from the activities of R. rattus arriving in the 1860s–90s.

text: Liberation and spread of stoats (Mustela erminea) and weasels (M. nivalis) in New Zealand, 1883-1920 This paper reviews the timing and spread of weasels and stoats across the South and North Islands of New Zealand during the late nineteenth century, entirely from historical records. The flavour of the debates and the assumptions that led to the commissioning of private and government shipments of these animals are best appreciated from the original documents. I describe the sites of the early deliberate releases in Otago, Canterbury, Marlborough, and Wairarapa, and list contemporary observations of the subsequent dispersal of the released animals to named locations in Southland, Westland, Wellington, Hawke’s Bay, Auckland and Northland. Originally, weasels were landed in far greater numbers than stoats (2622 weasels and 963 stoats listed in shipment records) and, while at first they were very abundant, they are now much less abundant than stoats. Two non-exclusive hypotheses could explain this historic change: (1) depletion of supplies of their preferred small prey including birds, mice, roosting bats, lizards, frogs and invertebrates, and (2) competition with stoats. Contemporary historic written observations on the first impacts of the arrivals of weasels and stoats on the native fauna offer graphic illustrations of what has been lost, but usually failed to consider the previous impacts of the abundant rats (Rattus exulans since the late 13th century, and R. norvegicus since 1770s–90s), and cannot now be distinguished from the activities of R. rattus arriving in the 1860s–90s.

year: 2017

title: Enacting Kaitiakitanga Challenges and Complexities in the Governance and Ownership of Rongoā Research Information.

authors: Boulton, Amohia

subjects: Indigenous

abstract: This article explores the tensions one research team has faced in securing appropriate governance or stewardship (which we refer to as kaitiakitanga) of research data. Whilst ethical and regulatory frameworks exist which provide a minimum standard for researchers to meet when working with Māori, what our experience has highlighted is there is currently a “governance” gap in terms of who should hold stewardship of research data collected from Māori individuals or collectives. In the case of a project undertaken in the traditional healing space, the organisation best placed to fulfil this governance role receives no funding or support to take on such a responsibility; consequently by default, this role is being borne by the research team until such time as capacity can be built and adequate resourcing secured. In addition, we have realised that the tensions played out in this research project have implications for the broader issue of how we protect traditional knowledge in a modern intellectual property law context, and once again how we adequately support those, often community-based organisations, who work at the interface between Indigenous knowledge and the Western world.

text: Enacting Kaitiakitanga Challenges and Complexities in the Governance and Ownership of Rongoā Research Information. This article explores the tensions one research team has faced in securing appropriate governance or stewardship (which we refer to as kaitiakitanga) of research data. Whilst ethical and regulatory frameworks exist which provide a minimum standard for researchers to meet when working with Māori, what our experience has highlighted is there is currently a “governance” gap in terms of who should hold stewardship of research data collected from Māori individuals or collectives. In the case of a project undertaken in the traditional healing space, the organisation best placed to fulfil this governance role receives no funding or support to take on such a responsibility; consequently by default, this role is being borne by the research team until such time as capacity can be built and adequate resourcing secured. In addition, we have realised that the tensions played out in this research project have implications for the broader issue of how we protect traditional knowledge in a modern intellectual property law context, and once again how we adequately support those, often community-based organisations, who work at the interface between Indigenous knowledge and the Western world.

year: 2014