title: Ecotoxicological Review of Alum Applications to the Rotorua Lakes: Supplementary Report

authors: Tempero, Grant Wayne

abstract: This report is intended to supplement the original 2015 report “Ecotoxicological Review of Alum Applications to the Rotorua Lakes” published as Environmental Institute Report Number 52 by the University of Waikato. A number of relevant studies published since 2015 regarding toxicological effects of aluminium (Al) are reviewed, and aspects specific to Lake Rotorua which were identified during the Plan Change 10 science review conducted by Professor Warwick Vincent for the Bay of Plenty Regional Council in 2018 including;
1) Are the aluminium concentrations used in toxicological testing relevant to the low concentration of aluminium measured in the water of Lake Rotorua?
2) Given Lake Rotorua has a low buffering capacity, are pH shifts driven by algal bloom photosynthesis likely to result in toxic aluminium complexes?
3) What is the potential for long-term chronic toxicological effects, particularly on downstream receiving ecosystems?
4) What is the effect of natural geothermal sources of aluminium in Sulphur Bay?

Since 2015, significant advances have been made in determining toxic thresholds for Al, particularly chronic effects. The United States Environmental Protection Agency (USEPA) has recently published as series of studies (i.e., Cardwell et al. 2018, DeForest et al. 2018, Gensemer et al. 2018, Wang et al. 2018) covering acute and chronic toxicological testing on eight aquatic species under a wide range of environmental conditions and total aluminium concentrations, including those common to Lake Rotorua (i.e., water hardness 14 mg L⁻¹ (as CaCO₃); dissolved organic matter 2 mg L⁻¹, pH 6.8; total Al ~0.020 mg L⁻¹. This work resulted in the publication of a multiple linear regression (MLR) model developed to predict chronic Al toxicity under varying conditions of dissolved organic matter (DOM), pH and water hardness (. The model predicts the likely total aluminium concentrations hazardous to 5% (HC5) of species or genera for a range of pH’s. The HC5 value is a statistically derived value from sensitivity data of multiple species to a single toxicant, and is similar to the Predicted No-Effect Concentration (PNEC) reported for single species toxicological tests. The mean total Al concentration in Lake Rotorua (0.020 mg L⁻¹) was found to be well below the calculated threshold for chronic toxicity effects based on the modelled HC5 estimates (from 0.045 mg L1 at pH 6.5 to 0.644 mg L⁻¹ at pH 8, under typical DOM and hardness conditions). Therefore, chronic toxicological effects from Al exposure are unlikely to occur under typical pH conditions in Lake Rotorua. However, caution should be used in applying these values as the data is not based on New Zealand species.
In poorly buffered eutrophic systems such as Lake Rotorua, diel pH cycling of up to 3 pH units (i.e., pH 6.5 - 9.5) is common. When pH >8, Al(OH)₃ converts to the more toxic Al(OH)₄⁻ species, resulting in a lowering of the toxic threshold concentration at pH levels >8. Compared to acidic conditions there is relatively little research examining toxic effects of Al under alkaline conditions. Most research indicates that toxicity increases above pH 8, with acute effects becoming more prevalent above pH 9. However, given the low total Al concentrations in Lake Rotorua and comparatively short exposure times to high pH during algal blooms, acute Al toxicological effects resulting from phytoplankton driven diel shifts in pH are unlikely. However, it is recommended that chronic effects of combined total aluminium and shortduration alkaline pH shifts be further investigated to determine the potential osmoregulatory impacts on key species for Lake Rotorua.

 
Currently, there is no requirement for monitoring of potential downstream impacts in the Kaituna River or Ōngātoro/Maketu Estuary from alum dosing to Lake Rotorua. A total Al concentration of 0.08 mg L⁻¹ measured at the half-way point of the Kaituna River in May 2008 (following dosing to the Utuhina Stream but prior to Puarenga Stream dosing) has been reported, well below predicted HC5 toxicity threshold. Notably, tributaries to the Lower Kaituna River appear to make greater contributions to total Al loading of the Kaituna River, with inflow concentrations ranging from 0.14 - 0.52 mg L⁻¹, presumably associated with increased suspended sediment levels. The ultimate discharge point of Lake Rotorua is the Ōngātoro/Maketu Estuary. Golding et al. (2015) proposed a guideline value of 0.024 mg total Al L⁻¹ for 95% species protection, based on chronic effect values from 11 species covering six taxonomic groups. This value is well above the mean total Al concentration for Lake Rotorua, therefore direct impacts of alum dosing on organisms in the downstream receiving environment are unlikely, however toxicological impacts may be occurring due to the contributing high total Al in some tributaries of the Kaituna River.
Concentrations of total aluminium in the Sulphur Bay area of Lake Rotorua are naturally high (>1 mg L⁻¹) due to geothermal fluid infiltration. This has produced an area of naturally low aquatic biodiversity due to the low pH (~3) and prevalence of highly toxic Al³⁺. However, these effects are negated at the mouth of bay where the geothermally influenced waters mix with water from the main lake body. At this point normal lake diversity can be observed. No adverse effects have been observed from alum dosing of the Puarenga Stream. 
The cautious use of continuous low level alum dosing remains the preferred option for reducing phosphorus loading to Lake Rotorua. However, the low buffering capacity, soft water and low dissolved organic matter preclude bulk or widespread application of alum for phosphorus management. Under the present alum dosing regimen, impacts on downstream biota are unlikely due to low water column aluminium concentration. However, further evaluation of potential toxic effects during phytoplankton driven diel pH cycling is recommended.

text: Ecotoxicological Review of Alum Applications to the Rotorua Lakes: Supplementary Report This report is intended to supplement the original 2015 report “Ecotoxicological Review of Alum Applications to the Rotorua Lakes” published as Environmental Institute Report Number 52 by the University of Waikato. A number of relevant studies published since 2015 regarding toxicological effects of aluminium (Al) are reviewed, and aspects specific to Lake Rotorua which were identified during the Plan Change 10 science review conducted by Professor Warwick Vincent for the Bay of Plenty Regional Council in 2018 including;
1) Are the aluminium concentrations used in toxicological testing relevant to the low concentration of aluminium measured in the water of Lake Rotorua?
2) Given Lake Rotorua has a low buffering capacity, are pH shifts driven by algal bloom photosynthesis likely to result in toxic aluminium complexes?
3) What is the potential for long-term chronic toxicological effects, particularly on downstream receiving ecosystems?
4) What is the effect of natural geothermal sources of aluminium in Sulphur Bay?

Since 2015, significant advances have been made in determining toxic thresholds for Al, particularly chronic effects. The United States Environmental Protection Agency (USEPA) has recently published as series of studies (i.e., Cardwell et al. 2018, DeForest et al. 2018, Gensemer et al. 2018, Wang et al. 2018) covering acute and chronic toxicological testing on eight aquatic species under a wide range of environmental conditions and total aluminium concentrations, including those common to Lake Rotorua (i.e., water hardness 14 mg L⁻¹ (as CaCO₃); dissolved organic matter 2 mg L⁻¹, pH 6.8; total Al ~0.020 mg L⁻¹. This work resulted in the publication of a multiple linear regression (MLR) model developed to predict chronic Al toxicity under varying conditions of dissolved organic matter (DOM), pH and water hardness (. The model predicts the likely total aluminium concentrations hazardous to 5% (HC5) of species or genera for a range of pH’s. The HC5 value is a statistically derived value from sensitivity data of multiple species to a single toxicant, and is similar to the Predicted No-Effect Concentration (PNEC) reported for single species toxicological tests. The mean total Al concentration in Lake Rotorua (0.020 mg L⁻¹) was found to be well below the calculated threshold for chronic toxicity effects based on the modelled HC5 estimates (from 0.045 mg L1 at pH 6.5 to 0.644 mg L⁻¹ at pH 8, under typical DOM and hardness conditions). Therefore, chronic toxicological effects from Al exposure are unlikely to occur under typical pH conditions in Lake Rotorua. However, caution should be used in applying these values as the data is not based on New Zealand species.
In poorly buffered eutrophic systems such as Lake Rotorua, diel pH cycling of up to 3 pH units (i.e., pH 6.5 - 9.5) is common. When pH >8, Al(OH)₃ converts to the more toxic Al(OH)₄⁻ species, resulting in a lowering of the toxic threshold concentration at pH levels >8. Compared to acidic conditions there is relatively little research examining toxic effects of Al under alkaline conditions. Most research indicates that toxicity increases above pH 8, with acute effects becoming more prevalent above pH 9. However, given the low total Al concentrations in Lake Rotorua and comparatively short exposure times to high pH during algal blooms, acute Al toxicological effects resulting from phytoplankton driven diel shifts in pH are unlikely. However, it is recommended that chronic effects of combined total aluminium and shortduration alkaline pH shifts be further investigated to determine the potential osmoregulatory impacts on key species for Lake Rotorua.

 
Currently, there is no requirement for monitoring of potential downstream impacts in the Kaituna River or Ōngātoro/Maketu Estuary from alum dosing to Lake Rotorua. A total Al concentration of 0.08 mg L⁻¹ measured at the half-way point of the Kaituna River in May 2008 (following dosing to the Utuhina Stream but prior to Puarenga Stream dosing) has been reported, well below predicted HC5 toxicity threshold. Notably, tributaries to the Lower Kaituna River appear to make greater contributions to total Al loading of the Kaituna River, with inflow concentrations ranging from 0.14 - 0.52 mg L⁻¹, presumably associated with increased suspended sediment levels. The ultimate discharge point of Lake Rotorua is the Ōngātoro/Maketu Estuary. Golding et al. (2015) proposed a guideline value of 0.024 mg total Al L⁻¹ for 95% species protection, based on chronic effect values from 11 species covering six taxonomic groups. This value is well above the mean total Al concentration for Lake Rotorua, therefore direct impacts of alum dosing on organisms in the downstream receiving environment are unlikely, however toxicological impacts may be occurring due to the contributing high total Al in some tributaries of the Kaituna River.
Concentrations of total aluminium in the Sulphur Bay area of Lake Rotorua are naturally high (>1 mg L⁻¹) due to geothermal fluid infiltration. This has produced an area of naturally low aquatic biodiversity due to the low pH (~3) and prevalence of highly toxic Al³⁺. However, these effects are negated at the mouth of bay where the geothermally influenced waters mix with water from the main lake body. At this point normal lake diversity can be observed. No adverse effects have been observed from alum dosing of the Puarenga Stream. 
The cautious use of continuous low level alum dosing remains the preferred option for reducing phosphorus loading to Lake Rotorua. However, the low buffering capacity, soft water and low dissolved organic matter preclude bulk or widespread application of alum for phosphorus management. Under the present alum dosing regimen, impacts on downstream biota are unlikely due to low water column aluminium concentration. However, further evaluation of potential toxic effects during phytoplankton driven diel pH cycling is recommended.

year: 2018

title: Necessary non-apodicity: Hermeneutic priority and textual authority in Christian-Muslim dialogue

authors: Pratt, Douglas

subjects: Christian

abstract: This article seeks to explore something of the significance of the notion of necessary non-apodicity as a leitmotif for the reading of sacred text in the context of Christian-Muslim dialogical engagement. Far from being a contentious challenge to received traditions of the status and reception of our respective scriptures, it contends that the notion of an inherent requirement to apply hermeneutic tools and approaches to sacred text is a mark of the mode of divine revelation as such. The absolute word of God was and is spoken into and through multifarious concrete contexts; the apprehension of the divine message throughout changing contexts and differing situations is thus intended to invite interpretive engagement necessarily. Or, put otherwise, the hermeneutical task that necessarily applies to the reading of scripture suggests that the sacred text of divine revelation is marked by necessary non-apodicity. In exploring this idea further, the article addresses some general issues of Christian and Muslim perspectives on sacred text then turns to an examination of the 2007 letter, 'A Common Word', from Muslims to Christians that seeks a renewed emphasis on dialogue.

text: Necessary non-apodicity: Hermeneutic priority and textual authority in Christian-Muslim dialogue This article seeks to explore something of the significance of the notion of necessary non-apodicity as a leitmotif for the reading of sacred text in the context of Christian-Muslim dialogical engagement. Far from being a contentious challenge to received traditions of the status and reception of our respective scriptures, it contends that the notion of an inherent requirement to apply hermeneutic tools and approaches to sacred text is a mark of the mode of divine revelation as such. The absolute word of God was and is spoken into and through multifarious concrete contexts; the apprehension of the divine message throughout changing contexts and differing situations is thus intended to invite interpretive engagement necessarily. Or, put otherwise, the hermeneutical task that necessarily applies to the reading of scripture suggests that the sacred text of divine revelation is marked by necessary non-apodicity. In exploring this idea further, the article addresses some general issues of Christian and Muslim perspectives on sacred text then turns to an examination of the 2007 letter, 'A Common Word', from Muslims to Christians that seeks a renewed emphasis on dialogue.

year: 2009

title: Ati Ue: Te Aitanga a Tuoro

authors: James, Steven (Tipene) Robert

subjects: Ngati Whakaue

abstract: This thesis is based on the manuscripts of my tupuna Tuoro Akapita Pango that are held in a treasured whānau box. The manuscripts contain history and kōrero of Te Arawa written by multiple generations of the whānau Pango. Within this thesis I explore the value of inter-generational knowledge through considering what lies within these whānau manuscripts and taking the opportunity to discover more history about Ngāti Whakaue through a whānau lens. Researching these manuscripts enables reconnection of the past and the present; the reconnection between forgotten knowledge and whānau. 
Specifically, this thesis proposes a Ngāti Whakaue approach to engaging historical materials and research. It centres the voices of the people, such as the many family members involved within the process, as well as the box of writings and the many gems that hide within. Also, it asks what the manuscripts mean for the current descendants involved in the research. 
The research has been a means of reconnecting with the past to give relevance and context to the present. The objective is demonstrating the value of iwi-specific research methods so that whānau feel encouraged to embark on their own journey.

text: Ati Ue: Te Aitanga a Tuoro This thesis is based on the manuscripts of my tupuna Tuoro Akapita Pango that are held in a treasured whānau box. The manuscripts contain history and kōrero of Te Arawa written by multiple generations of the whānau Pango. Within this thesis I explore the value of inter-generational knowledge through considering what lies within these whānau manuscripts and taking the opportunity to discover more history about Ngāti Whakaue through a whānau lens. Researching these manuscripts enables reconnection of the past and the present; the reconnection between forgotten knowledge and whānau. 
Specifically, this thesis proposes a Ngāti Whakaue approach to engaging historical materials and research. It centres the voices of the people, such as the many family members involved within the process, as well as the box of writings and the many gems that hide within. Also, it asks what the manuscripts mean for the current descendants involved in the research. 
The research has been a means of reconnecting with the past to give relevance and context to the present. The objective is demonstrating the value of iwi-specific research methods so that whānau feel encouraged to embark on their own journey.

year: 2021