Restoration of Lake Hakanoa: Results of model simulations

This report was requested by Waikato District Council. It covers the lake water quality of, and possible restoration scenarios for, Lake Hakanoa a riverine lake situated in Huntly. The lake is used as a recreational resource by the community. In the past it has been reported to have had very poor water quality and is known to be eutrophic. It is currently in an algal-dominated, devegetated state and has low water clarity. The shallowness of this lake makes it potentially susceptible to resuspension of sediments through wind action. A community group, Friends of Hakanoa, has been responsible for the formation of a path around the perimeter of the lake, retiring about 3.6% of the catchment from pastoral farming and creating a riparian margin. Results from more recent reports and this report indicate a trend of improving water quality which may be related to recent restoration actions such as re-establishment of a riparian margin

Parameterisation of sediment geochemistry for simulating water quality responses to long-term catchment and climate changes in polymictic, eutrophic Lake Rotorua, New Zealand

Numerical models of aquatic ecosystems that couple physics and biogeochemistry are valuable tools in aquatic ecosystem research. These models provide opportunities to test theories and to inform environmental management. In this study, we used the dynamic, process-based hydrodynamic-ecological model DYRESM-CAEDYM to simulate key ecosystem processes of Lake Rotorua, New Zealand, for six 8-year periods between 1920 and 2100 in order to evaluate the potential effects of future changes in land use and climate. Longterm variations in external boundary conditions (e.g. inflows) to the lake ecosystem are incorporated by varying the relevant input files in the DYRESMCAEDYM model. However, quantification of internal lake processes, specifically those at the sediment-water interface, presents a major challenge for long-term simulations. The sediment model within CAEDYM is ‘static’, with assumed constant sediment composition and a relatively simplistic process representation for nutrient and oxygen fluxes between sediment and water. Specifically, the model regulates sediment phosphate and ammonium release according to concentrations of oxidising species (i.e. oxygen and nitrate), and temperature in the overlying water layer. Sediment oxygen demand is controlled by dissolved oxygen concentrations and temperature in the water layer overlying the sediments. We used a ‘trial and error’ approach to estimate parameters for calibrating and validating the model, and regression modelling to infer the parameters beyond the calibration/validation simulation period (2001–2009). We observed a significant relationship in historic monitoring data between the external nitrogen load to the lake and its hypolimnetic oxygen demand as well as the bottom-sediment nitrogen concentrations. This relationship was used to hindcast and forecast model parameters for sediment nutrient release and oxygen demand in the six model simulation periods. The inclusion of a dynamic response of sediment nutrient release and oxygen demand parameters to changes in external nutrient loads enabled a more conceptually concise simulation of water quality for the simulations. This model is currently being used by regional environmental management authorities for developing an Action Plan for the restoration of Lake Rotorua

International Festival del cartel de la Habana 4x3 Poster Project

4×3 is an exhibition, a memory-bank, and a game. Conceived and organised by Xavier Meade and John Mandelberg, this project draws on the personal archives of four artist/designers who have been active in creating and collecting politically inspired posters during the past four decades: Chris McBride (Auckland), John Mandelberg (Hamilton), John Phillips (London) and Xavier Meade (Raglan). Our personal archives became both the subject, and content, of the game and the exhibition

4x3 International Poster Project

4x3 is an international curated poster project by collaborators John Mandelberg, Chris McBride, Xavier Meade, John Phillips. The project features 48 posters from the collections of the 4 contributors and includes works designed by a range of international artists and designers including Chris McBride, Xavier Meade and John Phillips. Includes the publication 4x3 published by Ramp Press includes colour reproductions of the 48 poster designs and text by John Mandelberg, Chris McBride, Xavier Meade, John Phillips and Flor de Lis Lopez Hernandez. 4x3 is published in english and spanish

Ramp Exhibition 4x3 Poster Project

4×3 is an exhibition, a memory-bank, and a game. Conceived and organised by Xavier Meade and John Mandelberg, this project draws on the personal poster archives of four artist/designers who have been active in creating and collecting politically inspired posters during the past four decades: Chris McBride (Auckland), John Mandelberg (Hamilton), John Phillips (LondonPrintStudio) and Xavier Meade (Raglan). With an initial set of three posters being put forward from their personal archives – the collaboration heats up when each artist responds to these initial works by proposing another poster that they feel in some way comments upon, or reflects the choices made by the others. This dialogue was completed when the final 48 posters were collated. 4×3, is the outcome of an enjoyable, intercontinental, time-travelling escapade, which was described by the artists’ as feeling at times as close to a game of poker, as it did an act of collaborative curation. Join the artists in the gallery at 4pm, prior to the opening preview, for a discussion about this projec

4x3 poster project

4x3 is an exhibition, a memory bank, and a game. Conceived and organised by Xavier Meade and John Mandelberg, this project draws on the personal archives of four artist/designers who have been active in creating and collecting politically inspired posters during the past four decades: Chris McBride (Auckland), John Mandelberg (Hamilton), John Phillips (London) and Xavier Meade (Raglan). Our personal archives became both the subject, and content, of the game and the exhibition, first launched at Ramp Gallery, Hamilton, 2014. The exhibition consists of 48 posters of different dimensions and techniques as indicated in the poster/catalogue including a description of the project by John Phillip

Light attenuation characteristics of glacially-fed lakes

Transparency is a fundamental characteristic of aquatic ecosystems and is highly responsive to changes in climate and land use. The transparency of glacially-fed lakes may be a particularly sensitive sentinel characteristic of these changes. However, little is known about the relative contributions of glacial flour versus other factors affecting light attenuation in these lakes. We sampled 18 glacially-fed lakes in Chile, New Zealand, and the U.S. and Canadian Rocky Mountains to characterize how dissolved absorption, algal biomass (approximated by chlorophyll a), water, and glacial flour contributed to attenuation of ultraviolet radiation (UVR) and photosynthetically active radiation (PAR, 400–700 nm). Variation in attenuation across lakes was related to turbidity, which we used as a proxy for the concentration of glacial flour. Turbidity-specific diffuse attenuation coefficients increased with decreasing wavelength and distance from glaciers. Regional differences in turbidity-specific diffuse attenuation coefficients were observed in short UVR wavelengths (305 and 320 nm) but not at longer UVR wavelengths (380 nm) or PAR. Dissolved absorption coefficients, which are closely correlated with diffuse attenuation coefficients in most non-glacially-fed lakes, represented only about one quarter of diffuse attenuation coefficients in study lakes here, whereas glacial flour contributed about two thirds across UVR and PAR. Understanding the optical characteristics of substances that regulate light attenuation in glacially-fed lakes will help elucidate the signals that these systems provide of broader environmental changes and forecast the effects of climate change on these aquatic ecosystems

Hydration Efficiency of a Protein Beverage Consumed in a Bolus vs. Metered Pattern during Recovery

International Journal of Exercise Science 13(2): 1476-1486, 2020. This study compared hydration efficiency of a carbohydrate-protein (CHO-PRO) beverage consumed in a bolus (BOL) vs. a metered (MET) drinking pattern during recovery from exercise induced hypohydration. Participants (n = 10) lost 2 - 2.5% of body mass from sweating during a morning exercise session. Participants were then assigned to either consume a carbohydrate/electrolyte/protein beverage in a bolus (BOL) or metered incremental consumption (MET) (counterbalanced) pattern post exercise. Total rehydration beverage administered during recovery equaled 125% of fluid lost during exercise. BOL was administered within the first hour of recovery, MET was administered 25% during the first 30 min, then 12.5% every 30 min for the next 4 hours. Mean (±SD) intake was 2475 ± 324 mL (MET) and 2525 ± 293 mL (BOL) (p = 0.22). Mean urine production was significantly greater for BOL (1167 ml ± 293 ml) than MET (730 ml ± 324 ml) (p = 0.003). Hydration efficiency (fluid ingested vs. fluid retained as percent) was significantly greater for MET (69.1 ± 15.4) than BOL (53.7 ± 9.7) (p = 0.004). Results indicate that, across a ~ 6-hour recovery, a metered drinking pattern improves fluid retention and therefore, hydration efficiency when a carbohydrate-protein beverage is consumed. More research is needed in paradigms characterized by unlimited fluid availability

A Review of Undergraduate Education Student Responses to the Online Component of Blended Learning: A Cautionary Tale

Calls for enhancing the digital interface for teaching and learning within tertiary institutions have played out in one School of Education, with variable results. Online learning tasks were added in 2018 to regular classes to provide more flexibility for student engagement. A team of lecturers developed a questionnaire for students to be completed after the first semester pilot. Data and findings indicated that one-third of students identified online learning as an enhancement to their learning. A second survey was conducted one year later to assess changes made and analyse the longer-term impacts. During the COVID-19 lockdown, fully online pedagogy was required; anecdotal observation indicated an improvement in satisfaction and engagement, but perhaps only because online was the only way possible to complete assessments. The conclusion contains recommendations and a cautionary tale, when introducing online learning across existing courses

Review of best management practices for aquatic vegetation control in stormwater ponds, wetlands, and lakes

Auckland Council (AC) is responsible for the development and operation of a stormwater network across the region to avert risks to citizens and the environment. Within this stormwater network, aquatic vegetation (including plants, unicellular and filamentous algae) can have both a positive and negative role in stormwater management and water quality treatment. The situations where management is needed to control aquatic vegetation are not always clear, and an inability to identify effective, feasible and economical control options may constrain management initiatives. AC (Infrastructure and Technical Services, Stormwater) commissioned this technical report to provide information for decision- making on aquatic vegetation management with in stormwater systems that are likely to experience vegetation-related issues. Information was collated from a comprehensive literature review, augmented by knowledge held by the authors. This review identified a wide range of management practices that could be potentially employed. It also demonstrated complexities and uncertainties relating to these options that makes the identification of a best management practice difficult. Hence, the focus of this report was to enable users to screen for potential options, and use reference material provided on each option to confirm the best practice to employ for each situation. The report identifies factors to define whether there is an aquatic vegetation problem (Section 3.0), and emphasises the need for agreed management goals for control (e.g. reduction, mitigation, containment, eradication). Resources to screen which management option(s) to employ are provided (Section 4.0), relating to the target aquatic vegetation, likely applicability of options to the system being managed, indicative cost, and ease of implementation. Initial screening allows users to shortlist potential control options for further reference (Section 5.0). Thirty-five control options are described (Section 5.0) in sufficient detail to consider applicability to individual sites and species. These options are grouped under categories of biological, chemical or physical control. Biological control options involve the use of organisms to predate, infect or control vegetation growth (e.g. classical biological control) or manipulate conditions to control algal growth (e.g. pest fish removal, microbial products). Chemical control options involve the use of pesticides and chemicals (e.g. glyphosate, diquat), or the use of flocculants and nutrient inactivation products that are used to reduce nutrient loading, thereby decreasing algal growth. Physical control options involve removing vegetation or algal biomass (e.g. mechanical or manual harvesting), or setting up barriers to their growth (e.g. shading, bottom lining, sediment capping). Preventative management options are usually the most cost effective, and these are also briefly described (Section 6.0). For example, the use of hygiene or quarantine protocols can reduce weed introductions or spread. Catchment- based practices to reduce sediment and nutrient sources to stormwater are likely to assist in the avoidance of algal and possibly aquatic plant problems. Nutrient removal may be a co-benefit where harvesting of submerged weed biomass is undertaken in stormwater systems. It should also be considered that removal of substantial amounts of submerged vegetation may result in a sudden and difficult-to-reverse s witch to a turbid, phytoplankton dominated state. Another possible solution is the conversion of systems that experience aquatic vegetation issues, to systems that are less likely to experience issues. The focus of this report is on systems that receive significant stormwater inputs, i.e. constructed bodies, including ponds, amenity lakes, wetlands, and highly-modified receiving bodies. However, some information will have application to other natural water bodies