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Boyer, Australia

van den Heuvel M.R.,University of Prince Edward Island | Slade A.H.,Scion Research | Landman M.J.,Norske Skog
Water Quality Research Journal of Canada | Year: 2010

The effluent of the Tasman pulp and paper mill (Kawerau, New Zealand) has been intensively studied for its effects on the health of fishes between 1998 and present. This review summarizes peer-reviewed scientific literature on the reproductive effects of the Tasman Mill effluent on fishes. In the 1990s there was an emerging body of literature from around the world showing that exposure to pulp and paper effluent could cause subtle reproductive alterations in exposed fishes. Locally, the Tarawera River had proved to be a difficult environment to conduct field studies. To overcome some of the difficulties with studying fish populations in the Tarawera River, initial studies on the reproductive health of fishes were focused on mesocosm and laboratory bioassays. During the later part of this period of study, wild fish population sampling was conducted in river to assess the cumulative impact of multiple discharges. The initial mesocosm studies were conducted with rainbow trout exposures over an entire reproductive development cycle. The Tasman Mill effluent was initially observed to cause reductions in gonad size in females corresponding with lower circulating sex steroid hormones and reduced egg and larval sizes. This result was not observed again in the two subsequent long-term exposures conducted after 2001. Laboratory studies initially found the effluent to have a masculinizing effect on female mosquitofish (Gambusia affinis). This mosquito fish masculinization response disappeared after 2001 and was also not seen in effluent-exposed wild populations. Upstream and downstream populations of the native common bully (Gobiomorphus cotidianus) showed different reproductive timing, and investigation revealed that genetic differences were a potential reason for these differences. Subsequent investigation compared the Tarawera River bully to genetically similar Rangitiki River bully and found no evidence of reproductive alterations. The entire body of published data was assessed with regards to changes at the mill and chemical profiles of the effluent. It was evident that continuing effort on the part of the mill has resulted in gradual improvement in effluent quality over the duration of the studies. However, the disappearance of reproductive effects as assessed by multiple bioassays corresponds to one major change: screen room closure in the pulp mill. This change would have resulted in wood extractives being shunted from the treatment system to the recovery boiler, resulting in a net reduction in compounds derived from wood. © 2010, CAWQ. Source

Dennis M.A.,Scion Research | Landman M.,Norske Skog | Wood S.A.,Cawthron Institute | Hamilton D.,University of Waikato
Water Science and Technology | Year: 2011

Flow cytometry has potential as a rapid assessment technique to evaluate phytoplankton biomass and species composition. It facilitates for multi-parameter analysis of individual cells on the basis of light scattering effects induced from cellular constituents, as well as auto-fluorescence. Fluorescence emission characteristics may be especially useful in classifying cyanobacteria as they contain phycoerythrin which emits light predominantly in the 550-600 nm waveband, chlorophyll-a (650-700 nm emission) and allophycocyanin (660 nm emission). The objective of our study was to assess the utility of flow cytometry for the rapid identification and sorting of freshwater algae and cyanobacteria species. Using a selection of laboratory-cultured freshwater algae and cyanobacteria species, this study demonstrated unique light scatter and fluorescent characteristics for each species examined, allowing for rapid species identification and sorting of mixed populations of laboratory cultures and samples from two lakes in the Rotorua region (New Zealand). Analysis of lake water samples collected over seven months demonstrated changes in abundance and community composition of phytoplankton in the two lakes and demonstrates that flow cytometry may be a useful technique for examining seasonal changes in phytoplankton composition. © IWA Publishing 2011. Source

Pinkard E.,CSIRO | Battaglia M.,CSIRO | Bruce J.,CSIRO | Matthews S.,CSIRO | And 11 more authors.
Forestry | Year: 2015

Forest managers around the world face the problem of coping with current climatic variability as well as developing strategies for future climate change adaptation. Using Australia as an example, we describe past forest management responses to climatic variability and discuss these in the context of future adaptation strategies to deal with increasingly variable and more extreme climatic events. We propose that while climatic changes remain within the bounds of those experienced historically for a particular species across its commercial distribution, the past 'will' provide an indication of management that will work in the future. If climatic conditions at particular forest locations move outside that range, more extreme measures may be required for which there is less or no historical precedent. We link this concept to previous research that is applicable to any species at any location in the world. This has analysed suitable conditions for particular species under current conditions, as well as analysing where and when climate change is likely to place particular species and forest locations outside the range of conditions known to be suitable for current climate. Responding to more extreme climatic changes will require policy and infrastructure support and greater planning at regional and national levels that will inform and re-direct adaptation strategies in the future. This analysis provides insights into adaptation strategies that may be effective in the future, revolving around incremental (e.g. small changes in current management) and more transformational (e.g. altered species choice) management changes. It points to areas where knowledge is limiting and where existing trials and research may be exploited to advance our understanding of plantation management in more variable climates. It discusses the role of adaptive management in improving the decision-making capacity of the forest industry in the face of uncertainties associated with changing climate. © 2014 © Institute of Chartered Foresters, 2014. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com. Source

Lee R.,University of Tasmania | Stack K.,University of Tasmania | Richardson D.,Norske Skog | Lewis T.,University of Tasmania | Garnier G.,Monash University
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2012

The effect of pH, temperature and shear on the coagulation dynamics of a wood resin suspension destabilized by salt additions was investigated. Stability of wood resin colloids was measured as a function of time using a photometric dispersion analyser (PDA) upon the step addition of salt solutions. Colloidal stability upon salt addition was found to be a function of pH (directly related to colloidal wood resin charge). This follows the predictions from the Derjaguin, Landau, Verwey and Overbeek (DLVO) theory. In general temperature also affected colloidal stability according to expectations. However, the effects were found to be strongly related to salt type. The effect of shear on the stability of a colloidal suspension was more important than expected. At low shear, the critical coagulation concentration of colloidal wood resins scaled with salt valency to the -6 power. Deviations from the Shultz-Hardy rule become important as shear was increased and a critical coagulation concentration (CCC) proportional to the counter ion charge to the power of 7 (CCC∝z -7) relationship was measured at the highest shear. We suggest a relationship of the form: CCC∝(Ωz) -6τ or CCC∝[z -6τ+Ω] where Ω=f(G) and τ=g(G). An additional term would be required for the systems under orthokinetic conditions usually found in industry. © 2011 Elsevier B.V. Source

Lee R.,University of Tasmania | Stack K.,University of Tasmania | Richardson D.,Norske Skog | Lewis T.,University of Tasmania | Garnier G.,Monash University
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2012

The dynamic coagulation of colloidal pitch was quantified under orthokinetic conditions. The effects of single salt, multiple salt and cation valency on the stability of the colloidal pitch were investigated as a function of salt concentration. Critical coagulation concentrations (CCCs) were determined for a range of individual cations. The CCC in the presence of a number of divalent or trivalent cations was investigated to gain an understanding of the effect of multiple salts normally found in industrial systems.Electrostatic destabilisation of wood resin colloids by a single salt is strongly influenced by salt valency (z) and mostly independent of the individual cation (at constant z). Addition of a second cation to solution resulted in a decrease in the CCC for both calcium and aluminium ions in the presence of sodium ions. The decrease in the CCC for the wood resin colloids was non-linear and showed restabilisation of the colloids above the CCC, unlike the effects observed for a single salt. Comparison of the experimental CCC results with the DVLO theory indicates that a higher Hamaker constant than reported for the interaction of abietic acid with talc in water (used here as a model interaction) is needed. This suggests that the aggregation process of the wood resin colloids involves a stronger interaction than abietic acid with talc. Experimental CCC values for divalent and trivalent ions were also lower than those predicted theoretically. To obtain agreement between theory and experimental results, reduced Stern potentials and higher Hamaker constants were required, suggesting specific ion adsorption of the multivalent cations is occurring to reduce surface charge of the colloid. © 2012 Elsevier B.V. Source

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