title: Anthropogenic phosphorus loads to Lake Rotorua

authors: Tempero, Grant Wayne

abstract: Past wastewater disposal practices and ongoing catchment land-use intensification have resulted in the eutrophication of Lake Rotorua. These changes have been associated with elevated nutrient loads to the lake from point and diffuse sources. Phosphorus and nitrogen are important macronutrients limiting phytoplankton growth. Bioassay studies in Lake Rotorua have shown temporal and spatial variability of phytoplankton growth limitation by either or both of these nutrients, hence the importance of controlling both phosphorus and nitrogen loads to the lake. This report was commissioned by the Bay of Plenty Regional Council to quantify sources of anthropogenic (i.e., associated with human activity) phosphorus in the catchment, so that these sources can be managed with the aim of reducing phytoplankton biomass in Lake Rotorua. This will form part of an integrated framework of catchment management which also aims to reduce the nitrogen load to the lake.
Determination of anthropogenic and natural (baseline) sources of phosphorus is essential for managing lake eutrophication. Natural concentrations (indicative of baseline or reference levels) of dissolved reactive phosphorus (DRP) and total phosphorus (TP) can be modelled from observed concentrations in undisturbed catchments. This model can then be used to estimate anthropogenic phosphorus in other catchments as the difference between natural and observed concentrations.
Mean annual discharge (MAD) was estimated individually for nine major stream sub-catchments of Lake Rotorua, and a combined MAD was estimated for other minor and ungauged stream sub-catchments. Natural stream phosphorus concentrations were derived from published values based on the River Environment Classification (REC) land classes within the lake catchment. Natural groundwater phosphorus concentrations were derived from published relationships between groundwater age and phosphorus concentrations in the Rotorua sub-catchments. Total phosphorus and DRP loads were calculated for each inflow for the period 2007-2014 (‘contemporary loads’) using the daily discharge estimates and time series of estimated daily mean concentrations of each nutrient species (TP, DRP) for each inflow. Daily loads were then summed to calculate annual loads. Natural loads for each inflow were subtracted from contemporary loads to estimate anthropogenic loads. Anthropogenic phosphorus loads to Lake Rotorua were estimated to be 22% (expressed as a catchment areal rate of 0.12 kg DRP ha-1 y-1) of the total DRP load and 48% (0.47 kg P ha-1 y-1) of the TP load. Relative to other New Zealand catchments, anthropogenic phosphorus was a relatively low proportion of the total load, given that the Rotorua catchment is highly developed. This can be attributed to the large volume of groundwater discharge to the lake, which is DRP-enriched due to gradual dissolution of phosphorus in the rhyolitic pumice bedrock. In sub-catchments where groundwater discharge to the lake was volumetrically dominant, e.g., Hamurana (89.3%) and Awahou (79.6%), the natural contribution to DRP loads was high, despite extensive agricultural land-use. By contrast, sub-catchments dominated by surface water discharges, e.g., Ngongotaha (34% groundwater) and Waiteti (14.5% groundwater), had comparatively high anthropogenic TP loads and elevated concentrations of particulate phosphorus. The minor and ungauged catchments, representing drains, small streams, overland flow, groundwater discharge to the bed of the lake, discharge below gauged stream sites and a residual term, were estimated to contribute the largest percentage (33%) of anthropogenic particulate phosphorus loads to Lake Rotorua despite being groundwater dominated.

text: Anthropogenic phosphorus loads to Lake Rotorua Past wastewater disposal practices and ongoing catchment land-use intensification have resulted in the eutrophication of Lake Rotorua. These changes have been associated with elevated nutrient loads to the lake from point and diffuse sources. Phosphorus and nitrogen are important macronutrients limiting phytoplankton growth. Bioassay studies in Lake Rotorua have shown temporal and spatial variability of phytoplankton growth limitation by either or both of these nutrients, hence the importance of controlling both phosphorus and nitrogen loads to the lake. This report was commissioned by the Bay of Plenty Regional Council to quantify sources of anthropogenic (i.e., associated with human activity) phosphorus in the catchment, so that these sources can be managed with the aim of reducing phytoplankton biomass in Lake Rotorua. This will form part of an integrated framework of catchment management which also aims to reduce the nitrogen load to the lake.
Determination of anthropogenic and natural (baseline) sources of phosphorus is essential for managing lake eutrophication. Natural concentrations (indicative of baseline or reference levels) of dissolved reactive phosphorus (DRP) and total phosphorus (TP) can be modelled from observed concentrations in undisturbed catchments. This model can then be used to estimate anthropogenic phosphorus in other catchments as the difference between natural and observed concentrations.
Mean annual discharge (MAD) was estimated individually for nine major stream sub-catchments of Lake Rotorua, and a combined MAD was estimated for other minor and ungauged stream sub-catchments. Natural stream phosphorus concentrations were derived from published values based on the River Environment Classification (REC) land classes within the lake catchment. Natural groundwater phosphorus concentrations were derived from published relationships between groundwater age and phosphorus concentrations in the Rotorua sub-catchments. Total phosphorus and DRP loads were calculated for each inflow for the period 2007-2014 (‘contemporary loads’) using the daily discharge estimates and time series of estimated daily mean concentrations of each nutrient species (TP, DRP) for each inflow. Daily loads were then summed to calculate annual loads. Natural loads for each inflow were subtracted from contemporary loads to estimate anthropogenic loads. Anthropogenic phosphorus loads to Lake Rotorua were estimated to be 22% (expressed as a catchment areal rate of 0.12 kg DRP ha-1 y-1) of the total DRP load and 48% (0.47 kg P ha-1 y-1) of the TP load. Relative to other New Zealand catchments, anthropogenic phosphorus was a relatively low proportion of the total load, given that the Rotorua catchment is highly developed. This can be attributed to the large volume of groundwater discharge to the lake, which is DRP-enriched due to gradual dissolution of phosphorus in the rhyolitic pumice bedrock. In sub-catchments where groundwater discharge to the lake was volumetrically dominant, e.g., Hamurana (89.3%) and Awahou (79.6%), the natural contribution to DRP loads was high, despite extensive agricultural land-use. By contrast, sub-catchments dominated by surface water discharges, e.g., Ngongotaha (34% groundwater) and Waiteti (14.5% groundwater), had comparatively high anthropogenic TP loads and elevated concentrations of particulate phosphorus. The minor and ungauged catchments, representing drains, small streams, overland flow, groundwater discharge to the bed of the lake, discharge below gauged stream sites and a residual term, were estimated to contribute the largest percentage (33%) of anthropogenic particulate phosphorus loads to Lake Rotorua despite being groundwater dominated.

year: 2015

title: Reading Comprehension Instruction of Effective Grades 5 and 6 Saint Lucian Teachers

authors: Sargusingh-Terrance, Lisa Merlene

subjects: Reading Comprehension Instriction

abstract: This study set out primarily to investigate the nature of reading comprehension instruction in Saint Lucia, and to examine the explanations of teachers with regard to the factors that they perceive contribute to Grade 6 students' failure in the main idea comprehension test in the national Common Entrance Examination in Saint Lucia.  Four effective Grades 5 and 6 teachers (two per grade) from two Saint Lucian primary schools participated in a total of four individual semi-structured interviews and were observed in their regularly scheduled reading comprehension lessons.  A total of 27 lessons were observed and audio tape-recorded to examine the nature of reading comprehension instruction in the classrooms.  From this cohort of lessons, a sample of 16 lessons was randomly selected and transcribed to determine the presence of direct instruction in comprehension strategies, and the quality of instruction that took place. This quality was measured and described in terms of the elements of the Direct Instruction Model (Pearson  Dole, 1987), the nature of questioning, and time allotted to instruction. This data was also used to make comparisons between Grades 5 and 6 classes.  The results show that the four teachers perceived that there are four areas of blame for students' poor performance in reading comprehension: the teacher's inability to instruct, the students' poor decoding and comprehension abilities, the inadequacy of the main idea test, and the teaching materials available for teaching comprehension.  However, the main factor perceived by teachers as contributing to the students' poor performance is teachers' inability to instruct.  Nonetheless, the observation of the Grades 5 and 6 effective teachers' reading comprehension lessons showed that these teachers were indeed teaching a number of comprehension strategies.  They relied predominantly on the question answering strategy in all their lessons which was mainly taught in combination with other strategies.  However, it was the teaching of summarization through the main idea that was the dominant strategy more explicitly taught in 7 of the 16 lessons observed, appearing more frequently in the Grade 6 classes.  An assessment of the quality of the reading comprehension instruction revealed that 11 of1 6 lessons, included all the four elements of direct instruction, and were rated as 'excellent' in quality.  None of the lessons had fewer than two elements identified on the model.  An assessment of the types of questions asked also showed that questioning was used both for the purpose of assessment and as an instructional strategy.  The timing of the lessons support the quality of instruction, as 90% of the total time observed was allotted to instruction.  The greater portion of that time went to guided practice (38%) and independent practice (33%) of reading comprehension strategies.  This study shows that explicit comprehension instruction of strategies is evident in the reading comprehension classes of the 4 effective Saint Lucian Grades 5 and 6 teachers.  It is therefore recommended that educational officials ensure that similar practices are maintained in other Saint Lucian classes, that the reading comprehension instruction practices of a wider cross section of Saint Lucian teachers be examined, and that future research looks into other probable causes of students' failure on the main idea comprehension test.

text: Reading Comprehension Instruction of Effective Grades 5 and 6 Saint Lucian Teachers This study set out primarily to investigate the nature of reading comprehension instruction in Saint Lucia, and to examine the explanations of teachers with regard to the factors that they perceive contribute to Grade 6 students' failure in the main idea comprehension test in the national Common Entrance Examination in Saint Lucia.  Four effective Grades 5 and 6 teachers (two per grade) from two Saint Lucian primary schools participated in a total of four individual semi-structured interviews and were observed in their regularly scheduled reading comprehension lessons.  A total of 27 lessons were observed and audio tape-recorded to examine the nature of reading comprehension instruction in the classrooms.  From this cohort of lessons, a sample of 16 lessons was randomly selected and transcribed to determine the presence of direct instruction in comprehension strategies, and the quality of instruction that took place. This quality was measured and described in terms of the elements of the Direct Instruction Model (Pearson  Dole, 1987), the nature of questioning, and time allotted to instruction. This data was also used to make comparisons between Grades 5 and 6 classes.  The results show that the four teachers perceived that there are four areas of blame for students' poor performance in reading comprehension: the teacher's inability to instruct, the students' poor decoding and comprehension abilities, the inadequacy of the main idea test, and the teaching materials available for teaching comprehension.  However, the main factor perceived by teachers as contributing to the students' poor performance is teachers' inability to instruct.  Nonetheless, the observation of the Grades 5 and 6 effective teachers' reading comprehension lessons showed that these teachers were indeed teaching a number of comprehension strategies.  They relied predominantly on the question answering strategy in all their lessons which was mainly taught in combination with other strategies.  However, it was the teaching of summarization through the main idea that was the dominant strategy more explicitly taught in 7 of the 16 lessons observed, appearing more frequently in the Grade 6 classes.  An assessment of the quality of the reading comprehension instruction revealed that 11 of1 6 lessons, included all the four elements of direct instruction, and were rated as 'excellent' in quality.  None of the lessons had fewer than two elements identified on the model.  An assessment of the types of questions asked also showed that questioning was used both for the purpose of assessment and as an instructional strategy.  The timing of the lessons support the quality of instruction, as 90% of the total time observed was allotted to instruction.  The greater portion of that time went to guided practice (38%) and independent practice (33%) of reading comprehension strategies.  This study shows that explicit comprehension instruction of strategies is evident in the reading comprehension classes of the 4 effective Saint Lucian Grades 5 and 6 teachers.  It is therefore recommended that educational officials ensure that similar practices are maintained in other Saint Lucian classes, that the reading comprehension instruction practices of a wider cross section of Saint Lucian teachers be examined, and that future research looks into other probable causes of students' failure on the main idea comprehension test.

year: 2008

title: Introducing the Draft Learning Progression Framework for Maori in the New Zealand Curriculum

authors: Crombie, Winifred

subjects: Māori education

abstract: This paper introduces the draft Learning Progression Framework for Māori in mainstream schools which we prepared in the first half of 2003 for the New Zealand Ministry of Education. Readers are invited to contact the authors if they wish to make any suggestions in relation to the final content of the document.

text: Introducing the Draft Learning Progression Framework for Maori in the New Zealand Curriculum This paper introduces the draft Learning Progression Framework for Māori in mainstream schools which we prepared in the first half of 2003 for the New Zealand Ministry of Education. Readers are invited to contact the authors if they wish to make any suggestions in relation to the final content of the document.

year: 2003-09