title: Variability in the trophic level index in Lake Rotoehu from 1990 to 2021

authors: Woelmer, Whitney

abstract: Setting an appropriate Trophic Level Index (TLI) target for lakes in the Rotorua Te Arawa region is critical for informing short- and long-term management decisions. Due to high variability in the observed TLI of Lake Rotoehu, coupled with contrasting understanding of historical water quality in the lake, the Bay of Plenty Regional Council requested a robust analysis of the drivers of the TLI over time to help inform the suitability of the current TLI target. To undertake this, we first quantified the uncertainty around the TLI in the 1990s, when the current TLI target was set based on the “best” observed water quality within the long-term monitoring program, to understand how a lower sampling frequency from 1990-2000 (~every 2-3 months) impacted TLI estimates. We found that while sampling fewer times in the year in the 1990s increased uncertainty around TLI estimates by 0.2-0.3 TLI units, a marked shift in water quality from a TLI of 3.6 in 1992 to 4.5 in 1993 remained evident.
To understand if the main drivers affecting the TLI were different during the 1990s as opposed to later decades, we calculated the Pearson correlation coefficient between the TLI and several driver variables separately for each decade. Drivers in this analysis included meteorological variables, lake water level, and in-lake water quality not in the TLI calculation (e.g., bottom water nutrients, water temperature, stratification metrics), and the amount of aluminium sulphate dosed to the lake. While several variables were consistently important across all decades (e.g., bottom water nutrients, bottom water temperature, and mean monthly air temperature), average monthly water level and minimum windspeeds were only important in the 1990s, indicating that these variables had been related to major shifts in water quality seen during that time.
Lastly, to better understand the relative importance of multiple drivers of the TLI and whether this importance changes over time, we conducted a moving window analysis. We fit autoregressive models, meaning the models included the previous month’s TLI estimate, as well as a single driver variable over a moving window of ~8 years, where each window moved forward one month at a time. We found that air temperature, bottom water temperature, and bottom water dissolved reactive phosphorus (DRP) were most often the top predictors of the TLI. However, the relative importance of average monthly water level increased sharply to the most important driver during a time period which also corresponded to very high water levels. Additionally, examination of model parameters over the simulation period demonstrated that the strength and magnitude of the relationship between the TLI and individual drivers changed over time, indicating that that relationships are not fixed through time.
Overall, this work highlights the importance of re-evaluating the underlying relationships between the TLI and drivers over time, emphasising the dynamic nature of Lake Rotoehu. We demonstrate a clear shift in water quality between 1992 and 1993, likely driven by low water levels and windspeeds, which may have induced a pattern of increased external loading that still exists. Importantly, many of the variables which emerged as important for the TLI (water level, windspeed) will continue to vary with changing climate and are outside of the control of management. In light of this, while the current TLI target (3.9) may be feasible for Lake Rotoehu given historical observations and possible reference conditions, achieving this target consistently may be very difficult going forward due to catchment and climate pressures which have put Lake Rotoehu outside of an undisturbed reference state. This work can be built upon through future analyses which continue quantifying the changing relationships between the TLI and drivers over time, increasing the use of high-frequency buoy data to better inform water quality dynamics at shorter time scales, and testing our understanding of the drivers of water quality through predictions. The overall aim for future research would therefore be to establish water quality targets that not only align with community aspirations but are also technically feasible, especially in light of global change.

text: Variability in the trophic level index in Lake Rotoehu from 1990 to 2021 Setting an appropriate Trophic Level Index (TLI) target for lakes in the Rotorua Te Arawa region is critical for informing short- and long-term management decisions. Due to high variability in the observed TLI of Lake Rotoehu, coupled with contrasting understanding of historical water quality in the lake, the Bay of Plenty Regional Council requested a robust analysis of the drivers of the TLI over time to help inform the suitability of the current TLI target. To undertake this, we first quantified the uncertainty around the TLI in the 1990s, when the current TLI target was set based on the “best” observed water quality within the long-term monitoring program, to understand how a lower sampling frequency from 1990-2000 (~every 2-3 months) impacted TLI estimates. We found that while sampling fewer times in the year in the 1990s increased uncertainty around TLI estimates by 0.2-0.3 TLI units, a marked shift in water quality from a TLI of 3.6 in 1992 to 4.5 in 1993 remained evident.
To understand if the main drivers affecting the TLI were different during the 1990s as opposed to later decades, we calculated the Pearson correlation coefficient between the TLI and several driver variables separately for each decade. Drivers in this analysis included meteorological variables, lake water level, and in-lake water quality not in the TLI calculation (e.g., bottom water nutrients, water temperature, stratification metrics), and the amount of aluminium sulphate dosed to the lake. While several variables were consistently important across all decades (e.g., bottom water nutrients, bottom water temperature, and mean monthly air temperature), average monthly water level and minimum windspeeds were only important in the 1990s, indicating that these variables had been related to major shifts in water quality seen during that time.
Lastly, to better understand the relative importance of multiple drivers of the TLI and whether this importance changes over time, we conducted a moving window analysis. We fit autoregressive models, meaning the models included the previous month’s TLI estimate, as well as a single driver variable over a moving window of ~8 years, where each window moved forward one month at a time. We found that air temperature, bottom water temperature, and bottom water dissolved reactive phosphorus (DRP) were most often the top predictors of the TLI. However, the relative importance of average monthly water level increased sharply to the most important driver during a time period which also corresponded to very high water levels. Additionally, examination of model parameters over the simulation period demonstrated that the strength and magnitude of the relationship between the TLI and individual drivers changed over time, indicating that that relationships are not fixed through time.
Overall, this work highlights the importance of re-evaluating the underlying relationships between the TLI and drivers over time, emphasising the dynamic nature of Lake Rotoehu. We demonstrate a clear shift in water quality between 1992 and 1993, likely driven by low water levels and windspeeds, which may have induced a pattern of increased external loading that still exists. Importantly, many of the variables which emerged as important for the TLI (water level, windspeed) will continue to vary with changing climate and are outside of the control of management. In light of this, while the current TLI target (3.9) may be feasible for Lake Rotoehu given historical observations and possible reference conditions, achieving this target consistently may be very difficult going forward due to catchment and climate pressures which have put Lake Rotoehu outside of an undisturbed reference state. This work can be built upon through future analyses which continue quantifying the changing relationships between the TLI and drivers over time, increasing the use of high-frequency buoy data to better inform water quality dynamics at shorter time scales, and testing our understanding of the drivers of water quality through predictions. The overall aim for future research would therefore be to establish water quality targets that not only align with community aspirations but are also technically feasible, especially in light of global change.

year: 2025

title: Comparative importance of training stimuli in avian aversion training for the domestic dog (Canis familiaris)

authors: Hobbs, Alisha Aroha

abstract: Dogs are the most significant threat to adult kiwi (Apteryx spp.), and kiwi aversion training (KAT) has been developed to reduce the likelihood of dogs harming and killing kiwi. In KAT, dogs are presented with a range of kiwi-related stimuli, which attempt to emulate live kiwi. The kiwi stimuli used can vary between trainers and may affect the overall efficacy of KAT. Thus, there is a need to assess the innate ‘interest’ of dogs in relation to kiwi stimuli to evaluate the potential relevance of different kiwi stimuli for KAT.
In this study, I assessed three groups of dogs with differing experience with kiwi: kiwi conservation dogs, KAT dogs, and kiwi naïve pet dogs. I presented dogs with four kiwi-related stimuli: a kiwi carcass, a taxidermy kiwi, kiwi feathers, kiwi scats, and a blank stimulus using a single-choice preference assessment. Within each trial, dogs were presented with a single kiwi or blank stimulus and were allowed two minutes with the stimulus. The amount of time the dogs spent within the experimental area as well as the behaviour of dogs were videoed throughout the experiment. I used the amount of time the dogs spent investigating a stimulus, as well as their latency to approach the stimulus, as measures of ‘interest’ from the dogs to each stimulus.
I found that, on average, dogs in all three groups spent more time investigating the kiwi carcass and taxidermy kiwi stimuli. However, the KAT dogs showed the lowest mean duration of investigating each stimulus, while the kiwi conservation dog group had the highest duration. For dogs in the naïve and kiwi conservation dog groups, there was a significant difference in the amount of time they spent investigating each stimulus, with the dogs spending significantly longer investigating the kiwi carcass and taxidermy kiwi in comparison to the scats, feathers and blank stimulus. There was no significant difference in the time the dogs spent investigating the different stimuli in the KAT dog group. Despite the decreased duration of investigation behaviour, dogs within the KAT dog group did not show fear-related behaviour in response to the kiwi stimuli presented. When the duration of time that the dogs spent investigating the different kiwi stimuli was compared across all three groups, no significant difference was found. This indicates that dogs across groups spent similar amounts of time investigating each stimulus.
The lack of obvious learned avoidance behaviours towards kiwi stimuli by KAT dogs in this study suggest that dogs did not show a generalised avoidance toward kiwi stimuli that were not used in their initial KAT. Dogs may still show avoidance toward the stimuli used in their initial training but learned avoidance may not generalise to other kiwi stimuli even if these stimuli are the same type. This poses an issue as each trainer uses different stimuli during KAT, and if dogs are not learning to avoid all kiwi stimuli, dogs may not adequately learn to avoid live kiwi. The kiwi carcass and taxidermy kiwi were of the greatest ‘interest’ to dogs across groups and so these may be useful stimuli for use in KAT, more so that kiwi scats and feathers. From this study, it seems that visual cues provoke an initial ‘interest’ in the dogs to investigate a stimulus. I suggested to use several conspicuous items such as taxidermy kiwi models during KAT to ensure generalisation across different stimuli and increase the efficacy of KAT.

text: Comparative importance of training stimuli in avian aversion training for the domestic dog (Canis familiaris) Dogs are the most significant threat to adult kiwi (Apteryx spp.), and kiwi aversion training (KAT) has been developed to reduce the likelihood of dogs harming and killing kiwi. In KAT, dogs are presented with a range of kiwi-related stimuli, which attempt to emulate live kiwi. The kiwi stimuli used can vary between trainers and may affect the overall efficacy of KAT. Thus, there is a need to assess the innate ‘interest’ of dogs in relation to kiwi stimuli to evaluate the potential relevance of different kiwi stimuli for KAT.
In this study, I assessed three groups of dogs with differing experience with kiwi: kiwi conservation dogs, KAT dogs, and kiwi naïve pet dogs. I presented dogs with four kiwi-related stimuli: a kiwi carcass, a taxidermy kiwi, kiwi feathers, kiwi scats, and a blank stimulus using a single-choice preference assessment. Within each trial, dogs were presented with a single kiwi or blank stimulus and were allowed two minutes with the stimulus. The amount of time the dogs spent within the experimental area as well as the behaviour of dogs were videoed throughout the experiment. I used the amount of time the dogs spent investigating a stimulus, as well as their latency to approach the stimulus, as measures of ‘interest’ from the dogs to each stimulus.
I found that, on average, dogs in all three groups spent more time investigating the kiwi carcass and taxidermy kiwi stimuli. However, the KAT dogs showed the lowest mean duration of investigating each stimulus, while the kiwi conservation dog group had the highest duration. For dogs in the naïve and kiwi conservation dog groups, there was a significant difference in the amount of time they spent investigating each stimulus, with the dogs spending significantly longer investigating the kiwi carcass and taxidermy kiwi in comparison to the scats, feathers and blank stimulus. There was no significant difference in the time the dogs spent investigating the different stimuli in the KAT dog group. Despite the decreased duration of investigation behaviour, dogs within the KAT dog group did not show fear-related behaviour in response to the kiwi stimuli presented. When the duration of time that the dogs spent investigating the different kiwi stimuli was compared across all three groups, no significant difference was found. This indicates that dogs across groups spent similar amounts of time investigating each stimulus.
The lack of obvious learned avoidance behaviours towards kiwi stimuli by KAT dogs in this study suggest that dogs did not show a generalised avoidance toward kiwi stimuli that were not used in their initial KAT. Dogs may still show avoidance toward the stimuli used in their initial training but learned avoidance may not generalise to other kiwi stimuli even if these stimuli are the same type. This poses an issue as each trainer uses different stimuli during KAT, and if dogs are not learning to avoid all kiwi stimuli, dogs may not adequately learn to avoid live kiwi. The kiwi carcass and taxidermy kiwi were of the greatest ‘interest’ to dogs across groups and so these may be useful stimuli for use in KAT, more so that kiwi scats and feathers. From this study, it seems that visual cues provoke an initial ‘interest’ in the dogs to investigate a stimulus. I suggested to use several conspicuous items such as taxidermy kiwi models during KAT to ensure generalisation across different stimuli and increase the efficacy of KAT.

year: 2018

title: Whānau Stories: Creating meaningful engagement and wellbeing for the indigenous culture of Aotearoa New Zealand

authors: Cruse, Diana Caroline Annavale

subjects: Engagement

abstract: This research sees my interests coalesce into a particular focus on how collaborative partnerships with parents/caregivers can provide whānau Māori with opportunities to strengthen wellbeing in their own lives. It is located in Aotearoa New Zealand and within the context of Te Whāriki (Ministry of Education, 1996), Aotearoa New Zealand’s early childhood curriculum.  The Ministry of Education has a target that 98% of all children in Aotearoa New Zealand under 5 will attend an early childhood education setting (Ministry of Education, 2016), with Māori children having lower participation rates than the national participation rate (Ministry of Education, 2013).  The premise for this thesis is that meaningful whānau engagement in early learning contexts within Aotearoa New Zealand can empower whānau Māori, and honour the promises made in Te Tiriti o Waitangi of partnership, participation, and protection.
Therefore, this thesis sets out to examine what constitutes meaningful engagement for whānau Māori in an early childhood setting in Aotearoa New Zealand, and how meaningful engagement can assist whānau to enjoy an increase of wellbeing.
To explore this issue, I conducted research within an early childhood setting in Aotearoa New Zealand, using methodologies of Kaupapa Māori Research and Narrative Inquiry.  I listened to the narratives of whānau Māori indicating how meaningful engagement was created for them, and investigated if links were generated between engagement and wellbeing for their whānau. These links were identified in the literature as significant levers for educational success.
This research discovered three stages of engagement for the whānau Māori who participated in this study: establishing engagement, developing engagement and solidifying engagement.  Once created, meaningful engagement can lead to flourishing, indicating that there is relationship between meaningful engagement and whānau wellbeing.

text: Whānau Stories: Creating meaningful engagement and wellbeing for the indigenous culture of Aotearoa New Zealand This research sees my interests coalesce into a particular focus on how collaborative partnerships with parents/caregivers can provide whānau Māori with opportunities to strengthen wellbeing in their own lives. It is located in Aotearoa New Zealand and within the context of Te Whāriki (Ministry of Education, 1996), Aotearoa New Zealand’s early childhood curriculum.  The Ministry of Education has a target that 98% of all children in Aotearoa New Zealand under 5 will attend an early childhood education setting (Ministry of Education, 2016), with Māori children having lower participation rates than the national participation rate (Ministry of Education, 2013).  The premise for this thesis is that meaningful whānau engagement in early learning contexts within Aotearoa New Zealand can empower whānau Māori, and honour the promises made in Te Tiriti o Waitangi of partnership, participation, and protection.
Therefore, this thesis sets out to examine what constitutes meaningful engagement for whānau Māori in an early childhood setting in Aotearoa New Zealand, and how meaningful engagement can assist whānau to enjoy an increase of wellbeing.
To explore this issue, I conducted research within an early childhood setting in Aotearoa New Zealand, using methodologies of Kaupapa Māori Research and Narrative Inquiry.  I listened to the narratives of whānau Māori indicating how meaningful engagement was created for them, and investigated if links were generated between engagement and wellbeing for their whānau. These links were identified in the literature as significant levers for educational success.
This research discovered three stages of engagement for the whānau Māori who participated in this study: establishing engagement, developing engagement and solidifying engagement.  Once created, meaningful engagement can lead to flourishing, indicating that there is relationship between meaningful engagement and whānau wellbeing.

year: 2017