title: Assessment of trophic state change and lake health in selected lakes of the Auckland region based on zooplankton assemblages: 2012-2019

authors: Duggan, Ian C.

abstract: This report provides an assessment of eight natural lakes in the Auckland region, from zooplankton samples collected between 2012 and late 2019 at a frequency of six to eight samples per year. From these samples, the lakes have been assessed to establish their trophic state, the proportion of nonnative zooplankton species, and the proportion of crustacean zooplankton relative to rotifers. 

Inferred trophic states of the lakes based on zooplankton composition has been generally ranked in a similar manner over time; of the lakes sampled over the entire period, Lake Tomarata typically had the best inferred water quality (generally as mesotrophic, though late in the study it sat near the eutrophic boundary). The median Trophic Level Index (TLI) based on zooplankton for this lake was 3.5 between 2015 and 2019. Lake Whatihua, only sampled from late-2017, was also assessed to contain species typical of mesotrophic conditions (median TLI = 3.4). For the remaining lakes, median TLI values based on zooplankton composition between 2015 and 2019 were; Rototoa 3.5 (mesotrophic), Wainamu 4.0, Pupuke 4.3 (both eutrophic) and Kuwakatai 5.2 (supertrophic; sampling ceased in August 2017). Lakes Kereta and Spectacle were not assessed during the 2015- 2019 time period. 

Lake Pupuke rapidly declined in water quality in 2019, to have hypertrophic assessments at the end of the study; this is consistent with reported high chlorophyll a concentrations at this time. Lake Tomarata was assessed to have declining water quality based on zooplankton composition, in common with traditional TLI assessments. However, this lake was assessed to have higher water quality overall, and to diverge in assessments by 1.2 TLI units; this may in part be due to elevated TN concentrations in this lake, not reflected in concentrations of TP or chlorophyll a, which may unduly affect traditional TLI assessments for this lake. The other long-term lakes, Waimanu, Pupuke and Rototoa, all has assessments within 0.5 TLI units when comparing the traditional and rotifer inferred TLI systems. 

The proportion of non-native species and the proportion of crustacean zooplankton relative to rotifers both showed promise as monitoring tools for the Auckland lakes. Two non-native species were recorded in the lakes, with various levels of dominance. Daphnia galeata was recorded in all of the monitored lakes, while Skistopiaptomus pallidus was recorded in Lake Kereta only. For the proportions of non-native species, Lake Tomarata was least affected, with samples comprising 4.9% non-native species on average. Data from 2012 and 2013 indicated that the overall relative abundances of the calanoid copepod Skistodiaptomus pallidus in Lake Kereta were far lower than they were in the year’s immediately following invasion in late 2008. No new non-native species were recognised in the monitored lakes during this survey, although an unusual occurrence of the copepod Boeckella propinqua was recorded in Lake Whatihua; this species has otherwise been found from natural lakes only in the central North Island, although has been recorded previously in Auckland dams. 

On average, larger crustaceans dominated over the smaller rotifers in all of the Auckland lakes monitored. Lake Rototoa was the least crustacean dominated (53%), followed by lakes Tomarata (58%), Kereta (68%), Spectacle (78%), Whatihua (79%), Wainamu (81%), Pupuke (88%), and Kuwakatai (95%) was the most crustacean dominated. Lake Wainamu appears to have reduced proportions of crustaceans between 2018 and 2019 relative to the 2012 to 2017 period, which may indicate this lake is undergoing a change in its trophic ecology; control of pest fish ceased in this lake in 2015, including of European perch (Perca fluviatilis), which may be reducing the importance of larger, more visible crustaceans.

text: Assessment of trophic state change and lake health in selected lakes of the Auckland region based on zooplankton assemblages: 2012-2019 This report provides an assessment of eight natural lakes in the Auckland region, from zooplankton samples collected between 2012 and late 2019 at a frequency of six to eight samples per year. From these samples, the lakes have been assessed to establish their trophic state, the proportion of nonnative zooplankton species, and the proportion of crustacean zooplankton relative to rotifers. 

Inferred trophic states of the lakes based on zooplankton composition has been generally ranked in a similar manner over time; of the lakes sampled over the entire period, Lake Tomarata typically had the best inferred water quality (generally as mesotrophic, though late in the study it sat near the eutrophic boundary). The median Trophic Level Index (TLI) based on zooplankton for this lake was 3.5 between 2015 and 2019. Lake Whatihua, only sampled from late-2017, was also assessed to contain species typical of mesotrophic conditions (median TLI = 3.4). For the remaining lakes, median TLI values based on zooplankton composition between 2015 and 2019 were; Rototoa 3.5 (mesotrophic), Wainamu 4.0, Pupuke 4.3 (both eutrophic) and Kuwakatai 5.2 (supertrophic; sampling ceased in August 2017). Lakes Kereta and Spectacle were not assessed during the 2015- 2019 time period. 

Lake Pupuke rapidly declined in water quality in 2019, to have hypertrophic assessments at the end of the study; this is consistent with reported high chlorophyll a concentrations at this time. Lake Tomarata was assessed to have declining water quality based on zooplankton composition, in common with traditional TLI assessments. However, this lake was assessed to have higher water quality overall, and to diverge in assessments by 1.2 TLI units; this may in part be due to elevated TN concentrations in this lake, not reflected in concentrations of TP or chlorophyll a, which may unduly affect traditional TLI assessments for this lake. The other long-term lakes, Waimanu, Pupuke and Rototoa, all has assessments within 0.5 TLI units when comparing the traditional and rotifer inferred TLI systems. 

The proportion of non-native species and the proportion of crustacean zooplankton relative to rotifers both showed promise as monitoring tools for the Auckland lakes. Two non-native species were recorded in the lakes, with various levels of dominance. Daphnia galeata was recorded in all of the monitored lakes, while Skistopiaptomus pallidus was recorded in Lake Kereta only. For the proportions of non-native species, Lake Tomarata was least affected, with samples comprising 4.9% non-native species on average. Data from 2012 and 2013 indicated that the overall relative abundances of the calanoid copepod Skistodiaptomus pallidus in Lake Kereta were far lower than they were in the year’s immediately following invasion in late 2008. No new non-native species were recognised in the monitored lakes during this survey, although an unusual occurrence of the copepod Boeckella propinqua was recorded in Lake Whatihua; this species has otherwise been found from natural lakes only in the central North Island, although has been recorded previously in Auckland dams. 

On average, larger crustaceans dominated over the smaller rotifers in all of the Auckland lakes monitored. Lake Rototoa was the least crustacean dominated (53%), followed by lakes Tomarata (58%), Kereta (68%), Spectacle (78%), Whatihua (79%), Wainamu (81%), Pupuke (88%), and Kuwakatai (95%) was the most crustacean dominated. Lake Wainamu appears to have reduced proportions of crustaceans between 2018 and 2019 relative to the 2012 to 2017 period, which may indicate this lake is undergoing a change in its trophic ecology; control of pest fish ceased in this lake in 2015, including of European perch (Perca fluviatilis), which may be reducing the importance of larger, more visible crustaceans.

year: 2021

title: Naive Bayes for regression

authors: Frank, Eibe

subjects: computer science

abstract: Despite its simplicity, the naïve Bayes learning scheme performs well on most classification tasks, and is often significantly more accurate than more sophisticated methods. Although the probability estimates that it produces can be inaccurate, it often assigns maximum probability to the correct class. This suggests that its good performance might be restricted to situations where the output is categorical. It is therefore interesting to see how it performs in domains where the predicted value is numeric, because in this case, predictions are more sensitive to inaccurate probability estimates. 
This paper shows how to apply the naïve Bayes methodology to numeric prediction (i.e. regression) tasks, and compares it to linear regression, instance-based learning, and a method that produces “model trees” - decision trees with linear regression functions at the leaves. Although we exhibit an artificial dataset for which naïve Bayes is the method of choice, on real-world datasets it is almost uniformly worse than model trees. The comparison with linear regression depends on the error measure: for one measure naïve Bayes performs similarly, for another it is worse. Compared to instance-based learning, it performs similarly with respect to both measures. These results indicate that the simplistic statistical assumption that naïve Bayes makes is indeed more restrictive for regression than for classification.

text: Naive Bayes for regression Despite its simplicity, the naïve Bayes learning scheme performs well on most classification tasks, and is often significantly more accurate than more sophisticated methods. Although the probability estimates that it produces can be inaccurate, it often assigns maximum probability to the correct class. This suggests that its good performance might be restricted to situations where the output is categorical. It is therefore interesting to see how it performs in domains where the predicted value is numeric, because in this case, predictions are more sensitive to inaccurate probability estimates. 
This paper shows how to apply the naïve Bayes methodology to numeric prediction (i.e. regression) tasks, and compares it to linear regression, instance-based learning, and a method that produces “model trees” - decision trees with linear regression functions at the leaves. Although we exhibit an artificial dataset for which naïve Bayes is the method of choice, on real-world datasets it is almost uniformly worse than model trees. The comparison with linear regression depends on the error measure: for one measure naïve Bayes performs similarly, for another it is worse. Compared to instance-based learning, it performs similarly with respect to both measures. These results indicate that the simplistic statistical assumption that naïve Bayes makes is indeed more restrictive for regression than for classification.

year: 1998-10

title: Aotearoa's heart language: An investigation of compulsory te reo Māori language learning for non-Māori teaching students in Aotearoa New Zealand

authors: Moon, Watene Malcolm Ernest

subjects: Te reo Māori

abstract: Te Reo Māori is becoming more prominent on our airwaves, in government agencies and within schools. Within a wider education system that increasingly seeks to give effect to Te Tiriti o Waitangi, teachers in New Zealand are being asked to become more competent in their development and use of Te Reo Māori, despite over 70% of teachers identifying as New Zealand European. The Teaching Council of Aotearoa New Zealand passed a requirement in 2021 specifying that new teachers should demonstrate Te Reo Māori competency at between level 3 and 4 of the Māori language curriculum by the time they graduate from their initial teacher education. Learning any second language as an adult can be challenging, and so the Teaching Council’s requirement is a big ask, particularly for non-Māori teaching students who may have had little to no exposure to the Māori language prior to enrolling into the teaching programme.

This thesis reports on a qualitative study that investigated the experiences of four non-Māori pre-service teaching students in relation to the requirement that they learn Te Reo Māori as a part of their teaching degree programme. Semi-structured interviews were used to gather data, incorporating culturally responsive approaches during data collection and thematic analysis was undertaken to identify findings. The backdrop for this study was an interpretivist paradigm that recognises the socially constructed nature of each individual’s reality. This research paradigm was appropriate for this research study as I sought to interpret and understand the experiences of each participant with the Teaching Council’s Te Reo Māori requirement. An interpretivist research design also aligns with a qualitative approach to data collection which made this paradigm a good fit for the research project.

The findings suggest that the new Teaching Council requirement is leading to language progress, although there have been challenges for the participants. All four participants have increased their knowledge, understanding and confidence to engage with Te Reo Māori. There was also a noticeable shift in cultural competence amongst all four participants. A very positive outcome when considering that all of the participants came into the teaching programme with little to no experience with Māori language and culture. However, learning Te Reo Māori has at times been confronting for these participants, primarily when historical issues associated with colonisation and the repression of the Māori language have surfaced. Technical aspects of second language acquisition have also caused challenges such as in relation to correct pronunciation and participants’ opportunities to use Te Reo Māori.
 
An over-riding theme from this research has been that although the Teaching Council’s language learning mandate presents an ambitious challenge for pre-service teachers, the four participants in this study have all experienced what can be characterised as a transformative learning process in relation to their Te Reo Māori journey thus far. That is, each participant had learning moments where they were able to critically reflect on their worldview and prior knowledge of Māori language and culture. Through this transformative process not only did the participants gain a deeper understanding of a Māori worldview, but they were able to transition this understanding into their developing teacher practice to the benefit of themselves and their students. While the participants for this study were purposively selected, the positive outcomes evident in their language learning journey suggest that there is potential for this new Teaching Council mandate to be achievable. The findings suggest that this new mandate might be a powerful lever towards a cultural shift for our English-medium teachers and within their classrooms as Te Reo Māori becomes more prominent. This study is also significant because of the scarcity of research on this new policy, and on non-Māori who are required to learn Te Reo Māori as part of their teaching degree. There could be wider significance for this research in the public sphere with attitudes potentially shifting more favourably towards Te Reo Māori and a bicultural country, centred on a Te Tiriti o Waitangi partnership. The findings of this study will be of use to future and current non-Māori teaching students to help navigate this new mandate. Teacher educators could benefit from the implications for culturally responsive teaching and learning. This study may inform researchers in the field of linguistics and education who might wish to build on the results of this research project to inform further studies. Finally, policy makers may be interested to learn about the benefits and challenges that have emerged from this new Teaching Council mandate. Lastly, this research presents an exciting opportunity to showcase this new Teaching Council mandate, and what one participant in the present study described as the ‘heart language’ of New Zealand, with the potential for Te Reo Māori to flourish beyond language classrooms and Māori-medium education and into our mainstream education system, where it belongs.

text: Aotearoa's heart language: An investigation of compulsory te reo Māori language learning for non-Māori teaching students in Aotearoa New Zealand Te Reo Māori is becoming more prominent on our airwaves, in government agencies and within schools. Within a wider education system that increasingly seeks to give effect to Te Tiriti o Waitangi, teachers in New Zealand are being asked to become more competent in their development and use of Te Reo Māori, despite over 70% of teachers identifying as New Zealand European. The Teaching Council of Aotearoa New Zealand passed a requirement in 2021 specifying that new teachers should demonstrate Te Reo Māori competency at between level 3 and 4 of the Māori language curriculum by the time they graduate from their initial teacher education. Learning any second language as an adult can be challenging, and so the Teaching Council’s requirement is a big ask, particularly for non-Māori teaching students who may have had little to no exposure to the Māori language prior to enrolling into the teaching programme.

This thesis reports on a qualitative study that investigated the experiences of four non-Māori pre-service teaching students in relation to the requirement that they learn Te Reo Māori as a part of their teaching degree programme. Semi-structured interviews were used to gather data, incorporating culturally responsive approaches during data collection and thematic analysis was undertaken to identify findings. The backdrop for this study was an interpretivist paradigm that recognises the socially constructed nature of each individual’s reality. This research paradigm was appropriate for this research study as I sought to interpret and understand the experiences of each participant with the Teaching Council’s Te Reo Māori requirement. An interpretivist research design also aligns with a qualitative approach to data collection which made this paradigm a good fit for the research project.

The findings suggest that the new Teaching Council requirement is leading to language progress, although there have been challenges for the participants. All four participants have increased their knowledge, understanding and confidence to engage with Te Reo Māori. There was also a noticeable shift in cultural competence amongst all four participants. A very positive outcome when considering that all of the participants came into the teaching programme with little to no experience with Māori language and culture. However, learning Te Reo Māori has at times been confronting for these participants, primarily when historical issues associated with colonisation and the repression of the Māori language have surfaced. Technical aspects of second language acquisition have also caused challenges such as in relation to correct pronunciation and participants’ opportunities to use Te Reo Māori.
 
An over-riding theme from this research has been that although the Teaching Council’s language learning mandate presents an ambitious challenge for pre-service teachers, the four participants in this study have all experienced what can be characterised as a transformative learning process in relation to their Te Reo Māori journey thus far. That is, each participant had learning moments where they were able to critically reflect on their worldview and prior knowledge of Māori language and culture. Through this transformative process not only did the participants gain a deeper understanding of a Māori worldview, but they were able to transition this understanding into their developing teacher practice to the benefit of themselves and their students. While the participants for this study were purposively selected, the positive outcomes evident in their language learning journey suggest that there is potential for this new Teaching Council mandate to be achievable. The findings suggest that this new mandate might be a powerful lever towards a cultural shift for our English-medium teachers and within their classrooms as Te Reo Māori becomes more prominent. This study is also significant because of the scarcity of research on this new policy, and on non-Māori who are required to learn Te Reo Māori as part of their teaching degree. There could be wider significance for this research in the public sphere with attitudes potentially shifting more favourably towards Te Reo Māori and a bicultural country, centred on a Te Tiriti o Waitangi partnership. The findings of this study will be of use to future and current non-Māori teaching students to help navigate this new mandate. Teacher educators could benefit from the implications for culturally responsive teaching and learning. This study may inform researchers in the field of linguistics and education who might wish to build on the results of this research project to inform further studies. Finally, policy makers may be interested to learn about the benefits and challenges that have emerged from this new Teaching Council mandate. Lastly, this research presents an exciting opportunity to showcase this new Teaching Council mandate, and what one participant in the present study described as the ‘heart language’ of New Zealand, with the potential for Te Reo Māori to flourish beyond language classrooms and Māori-medium education and into our mainstream education system, where it belongs.

year: 2023