John M. Quinn

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The impact of clay discharges on benthic invertebrates was investigated by comparison of communities upstream and downstream of alluvial gold mining on 6 streams on the West Coast of the South Island, New Zealand. Mean turbidity was increased by 7–154 NTU above background (mean 1.3–8.2 NTU) by the mine discharges during the 2 months before sampling.(More)
Five streams in catchments with pastoral dairy farming as the dominant land useweremonitored for periods of 7–16 years to detect changes in response to adoption of best management practices (BMPs). Stream water quality was degraded at the start with respect to N, P, suspended solids (SS) and E. coli concentrations, and was typical of catchments with(More)
We have used vector measurements of the electron drift velocity made by the Electron Drift Instrument (EDI) on Cluster between February 2001 and March 2006 to derive statistical maps of the high-latitude plasma convection. The EDI measurements, obtained at geocentric distances between ∼4 and ∼20RE over both hemispheres, are mapped into the polar ionosphere,(More)
Few studies have comprehensively measured the effect on water quality of catchment rehabilitation measures in comparison with baseline conditions. Here we have analyzed water clarity and nutrient concentrations and loads for a 13-year period in a headwater catchment within the western Waikato region, New Zealand. For the first 6 years, the entire catchment(More)
Tobacco use is the leading cause of preventable death in the United States. It has been shown to lead to preventable injury in not only those who use tobacco products directly, but also in those who are exposed to tobacco indirectly such as by passive smoking (Barendregt, Bonneux, & Maas, 1997). Many who use tobacco products indicate that they cannot stop(More)
New Zealand is unique in that half of its national greenhouse gas (GHG) inventory derives from agriculture--predominantly as methane (CH4) and nitrous oxide (N2O), in a 2:1 ratio. The remaining GHG emissions predominantly comprise carbon dioxide (CO2) deriving from energy and industry sources. Proposed strategies to mitigate emissions of CH4 and N2O from(More)
To understand the timescales and magnitude of responses that can be expected following catchment and riparian rehabilitation, we forecast changes to selected stream ecosystem attributes following tree planting in a pastoral catchment. All planting scenarios were predicted to lead to decreases in daily maximum water temperature after 15-20 years to levels(More)
A method was developed to score the ecological condition of first- to third-order stream reaches in the Auckland region of New Zealand based on the performance of their key ecological functions. Such a method is required by consultants and resource managers to quantify the reduction in ecological condition of a modified stream reach relative to its(More)
We present the ®rst triangulation measurements of electric ®elds with the electron drift instrument (EDI) on Equator-S. We show results from ®ve highdata-rate passes of the satellite through the nearmidnight equatorial region, at geocentric distances of approximately 5±6 RE, during geomagnetically quiet conditions. In a co-rotating frame of reference, the(More)
We present the ®rst electron time-of̄ight measurements obtained with the Electron Drift Instrument (EDI) on Equator-S. These measurements are made possible by amplitude-modulation and coding of the emitted electron beams and correlation with the signal from the returning electrons. The purpose of the time-of̄ight measurements is twofold. First, they provide(More)