title: Partitioning the influence of anthropogenic and oceanic nutrient fluxes in the coastal ocean, and the question of cultural eutrophication

authors: Lee, Randall

abstract: A multi-disciplinary study was implemented in the mid 1990’s in order to address concerns about apparent increases in the frequency and magnitude of marine phytoplankton blooms along the eastern Australian coast off New South Wales. This coastal region is frequently impacted by the western boundary flow of the East Australian Current (EAC), and anthropogenic discharges from major estuaries, and sewage outfalls within the Newcastle-Sydney-Wollongong conurbation. These coastal waters are typically nitrogen limited with respect to idealised Redfield ratios for optimal phytoplankton growth, indicating plankton sensitivity to nitrogen loading. Three deepwater outfalls servicing the city of Sydney represented the principal (~80%), continuous, anthropogenic source of nutrients to NSW coastal waters, predominantly in the form of ammonia nitrogen. The discharged effluent typically dilutes to 1:1000 to form plumes that remain trapped (~90%) by thermal stratification (≥1°C), and are dispersed by the prevailing alongshore currents. Of the eleven coastal catchments in this study region, the large Hunter and Hawkesbury catchments account for ~80% of the total catchment area and account for the majority of catchment nutrient loads discharged into the ocean. These discharges only produced significant increases to coastal waters (mainly as silica) when major flooding breached strong salinity gradients in the lower estuary. Episodic slope water intrusions were identified as the principal source of nitrogen in the form of nitrate to coastal waters. These shelf encroachments occurred seasonally associated with strong thermal dynamics observed during spring and summer. An understanding of mechanisms of slope water intrusion emerged from the deployment extensive mooring arrays, modelling exercises and responsive sampling transects triggered by synoptic monitoring of telemetered moorings and satellite imagery. Slope water intrusions operated over (alongshore) length scales of hundreds of kilometres and over time scales of a few days to a few weeks. Intrusions were related to coherent alongshore wind induced upwellings and EAC shelf encroachments, and localised baroclinic instabilities on the shoreward edge of EAC formed by perturbations in shelf topography. Phytoplankton blooms were correlated to these slope water intrusions irrespective of proximity to other major anthropogenic nutrient sources. However, the high frequency of occurrence of both the chain-forming diatom Thalassiosira spp. and the ‘red tide’ heterotrophic dinoflagellate Noctiluca scintillans during the study period was unprecedented in these waters. Long-term monitoring data indicated these anomalous conditions were associated with the strong El Niño episode of 1997/98, where warmer conditions prevailed. Corresponding studies along the New Zealand east-coast indicated a similarly unusual phytoplankton responses to El Niño episodes.

text: Partitioning the influence of anthropogenic and oceanic nutrient fluxes in the coastal ocean, and the question of cultural eutrophication A multi-disciplinary study was implemented in the mid 1990’s in order to address concerns about apparent increases in the frequency and magnitude of marine phytoplankton blooms along the eastern Australian coast off New South Wales. This coastal region is frequently impacted by the western boundary flow of the East Australian Current (EAC), and anthropogenic discharges from major estuaries, and sewage outfalls within the Newcastle-Sydney-Wollongong conurbation. These coastal waters are typically nitrogen limited with respect to idealised Redfield ratios for optimal phytoplankton growth, indicating plankton sensitivity to nitrogen loading. Three deepwater outfalls servicing the city of Sydney represented the principal (~80%), continuous, anthropogenic source of nutrients to NSW coastal waters, predominantly in the form of ammonia nitrogen. The discharged effluent typically dilutes to 1:1000 to form plumes that remain trapped (~90%) by thermal stratification (≥1°C), and are dispersed by the prevailing alongshore currents. Of the eleven coastal catchments in this study region, the large Hunter and Hawkesbury catchments account for ~80% of the total catchment area and account for the majority of catchment nutrient loads discharged into the ocean. These discharges only produced significant increases to coastal waters (mainly as silica) when major flooding breached strong salinity gradients in the lower estuary. Episodic slope water intrusions were identified as the principal source of nitrogen in the form of nitrate to coastal waters. These shelf encroachments occurred seasonally associated with strong thermal dynamics observed during spring and summer. An understanding of mechanisms of slope water intrusion emerged from the deployment extensive mooring arrays, modelling exercises and responsive sampling transects triggered by synoptic monitoring of telemetered moorings and satellite imagery. Slope water intrusions operated over (alongshore) length scales of hundreds of kilometres and over time scales of a few days to a few weeks. Intrusions were related to coherent alongshore wind induced upwellings and EAC shelf encroachments, and localised baroclinic instabilities on the shoreward edge of EAC formed by perturbations in shelf topography. Phytoplankton blooms were correlated to these slope water intrusions irrespective of proximity to other major anthropogenic nutrient sources. However, the high frequency of occurrence of both the chain-forming diatom Thalassiosira spp. and the ‘red tide’ heterotrophic dinoflagellate Noctiluca scintillans during the study period was unprecedented in these waters. Long-term monitoring data indicated these anomalous conditions were associated with the strong El Niño episode of 1997/98, where warmer conditions prevailed. Corresponding studies along the New Zealand east-coast indicated a similarly unusual phytoplankton responses to El Niño episodes.

year: 2002

title: Dairy calves' preference for rearing substrate

authors: Worth, Gemma

subjects: Dairy calves

abstract: Rearing substrate is an important component of the pre-weaning environment of dairy calves. Traditional substrate types, such as sawdust, are becoming difficult and/or expensive for farmers to obtain in New Zealand. Therefore, there is a need to evaluate alternative rearing substrates for dairy calves that that are economically viable for farmers, readily available and provide an acceptable level of animal welfare. The preference of dairy calves for four different rearing substrates and the effects on behaviour and physiology were evaluated. At 1 wk of age, 24 calves were housed in groups of four, in pens which were evenly divided into four rearing substrates: sawdust, rubber, sand and stones. During the first 3 d calves were given free access to all four substrates. Calves were then restricted to each substrate type for 48 h. In order to rank preference, calves were subsequently exposed to two surfaces simultaneously for 48 h until calves experienced all six treatment combinations. Finally, calves were given free access to all four substrates simultaneously for 48 h. Lying behaviour and location in the pen was recorded for 24 h at the end of each experimental period using handycams and accelerometers. Preference was determined based on lying times on each substrate. The insulating properties of each substrate were assessed using iButtons®. 
During the initial free choice period, the proportion of time spent standing (p < .001) and lying (p < .001) was influenced by substrate. Calves spent a higher proportion of time on sawdust (88%) than all other substrates (rubber: 6%, sand: 4% and stones: 3%). 
When restricted to each substrate, calves spent more (p <.05) time running on sawdust, rubber and sand compared to calves on stones. There were no effects (p > .05) of rearing substrate on the frequency of jumps, buck/kicks, head to object and mount/frontal pushing. Calves spent more (p < .05) time lying on sawdust and rubber in comparison to sand and stones. There were no effects (p > .05) of rearing substrate on the number and duration of lying bouts. We detected no effect (p > .05) of rearing substrate on concentrations of cortisol, lactate, glucose, or white blood cell, neutrophil and lymphocyte count or the neutrophil:lymphocyte ratio. The insulating properties were greatest for sawdust and lowest for sand.
During the pairwise choice period, calves had a strong preference for one substrate over another, spending on average, 89% of their time on the preferred surface. Calves preference ranking was for sawdust, rubber, sand then stones as determined by the proportion of time spent on each surface. At the end of the study, when given free access to all rearing substrates again, calves spent a higher proportion of time on sawdust (85%) than all other substrates (rubber: 5%, sand: 7% and stones: 3%). 
In conclusion, dairy calves showed a clear preference for sawdust over rubber, sand and stones. This preference remained consistent over the course of the study. The calves’ preference for sawdust may be associated with the physical and thermal properties in comparison to the alternative substrates. However, factors such as cost to the farmer, availability and practicality of alternative substrates need to be considered along with animal preferences before any recommendations can be made.

text: Dairy calves' preference for rearing substrate Rearing substrate is an important component of the pre-weaning environment of dairy calves. Traditional substrate types, such as sawdust, are becoming difficult and/or expensive for farmers to obtain in New Zealand. Therefore, there is a need to evaluate alternative rearing substrates for dairy calves that that are economically viable for farmers, readily available and provide an acceptable level of animal welfare. The preference of dairy calves for four different rearing substrates and the effects on behaviour and physiology were evaluated. At 1 wk of age, 24 calves were housed in groups of four, in pens which were evenly divided into four rearing substrates: sawdust, rubber, sand and stones. During the first 3 d calves were given free access to all four substrates. Calves were then restricted to each substrate type for 48 h. In order to rank preference, calves were subsequently exposed to two surfaces simultaneously for 48 h until calves experienced all six treatment combinations. Finally, calves were given free access to all four substrates simultaneously for 48 h. Lying behaviour and location in the pen was recorded for 24 h at the end of each experimental period using handycams and accelerometers. Preference was determined based on lying times on each substrate. The insulating properties of each substrate were assessed using iButtons®. 
During the initial free choice period, the proportion of time spent standing (p < .001) and lying (p < .001) was influenced by substrate. Calves spent a higher proportion of time on sawdust (88%) than all other substrates (rubber: 6%, sand: 4% and stones: 3%). 
When restricted to each substrate, calves spent more (p <.05) time running on sawdust, rubber and sand compared to calves on stones. There were no effects (p > .05) of rearing substrate on the frequency of jumps, buck/kicks, head to object and mount/frontal pushing. Calves spent more (p < .05) time lying on sawdust and rubber in comparison to sand and stones. There were no effects (p > .05) of rearing substrate on the number and duration of lying bouts. We detected no effect (p > .05) of rearing substrate on concentrations of cortisol, lactate, glucose, or white blood cell, neutrophil and lymphocyte count or the neutrophil:lymphocyte ratio. The insulating properties were greatest for sawdust and lowest for sand.
During the pairwise choice period, calves had a strong preference for one substrate over another, spending on average, 89% of their time on the preferred surface. Calves preference ranking was for sawdust, rubber, sand then stones as determined by the proportion of time spent on each surface. At the end of the study, when given free access to all rearing substrates again, calves spent a higher proportion of time on sawdust (85%) than all other substrates (rubber: 5%, sand: 7% and stones: 3%). 
In conclusion, dairy calves showed a clear preference for sawdust over rubber, sand and stones. This preference remained consistent over the course of the study. The calves’ preference for sawdust may be associated with the physical and thermal properties in comparison to the alternative substrates. However, factors such as cost to the farmer, availability and practicality of alternative substrates need to be considered along with animal preferences before any recommendations can be made.

year: 2014

title: Understanding the potential exposure of coastal marae and urupā in Aotearoa New Zealand to sea level rise

authors: Bailey-Winiata, Akuhata Patrick Stephen

subjects: Marae

abstract: In Aotearoa New Zealand, Māori are Indigenous and have inhabited these islands for the past 700 years. They have an intricate physical and spiritual connection to places and the environment. This is reflected in the Māori creation story, where Ranginui (sky father) and Papatūānuku (Earth mother) are the ancestral parents of Māori. Between these two gods is the marae, the Māori meeting house. Marae are where the domestic life of Māori traditionally ran its course, with marae being an overarching term to illustrate multiple buildings which each have a specific role to play within the community. Often, marae have an associated urupā (burial ground). Historically, marae and their associated urupā are positioned along the low-lying coast, providing easy access to kaimoana (sea food), transport and trade. However, coastal marae and urupā are at an increasing threat of inundation and erosion from sea level rise, and will also be impacted by other effects of climate change such as drought and other changes to weather patterns such as storms.
Many coastal marae and urupā are already experiencing the impacts of coastal flooding and erosion, however, little is known about the exposure of coastal marae and urupā to sea level rise nationally. Therefore, the main aim of this thesis is to explore the potential exposure of coastal marae nationally, with a particular focus on the Bay of Plenty coastal marae including coastal urupā. This aim was achieved by addressing three objectives. The first of which was to investigate the potential national exposure of coastal marae to a 100 year annual recurrence interval extreme sea level event, with the addition of sea level rise. Second, I conducted a nationally-focused assessment of the local coastal geomorphology surrounding coastal marae to determine the potential response of the coast to sea level rise. I also undertook a case study on the BOP which included a more detailed assessment of the geomorphology around the coastal marae and urupā in this region. Third, findings from these two objectives are brought together to consider the next steps to determine how to move forward with planning to manage coastal marae and urupā with sea level rise.
A spatial mapping approach using Arc GIS and existing datasets was used to address these aims, combining the Coastlines and Islands polygon, marae and urupā locational data and the Aotearoa New Zealand coastal hydrosystem classification system proposed by Hume in 2016. This showed that 191 marae around Aotearoa New Zealand are within 1 km of the coast and in the Bay of Plenty 41 urupā are within 1 km. I then used the bathtub modelling approach to get a national first-pass assessment of the potential exposure of these marae and urupā to a 100 year extreme sea level event at current mean sea level, with 10 cm increments of sea level rise up to 3 m. Six coastal marae were potentially exposed to a 100 year extreme sea level event at current mean sea level, with 41 coastal marae are potentially exposed to a 100 year extreme sea level event with a 3 m rise in mean sea level. The most common type of coastal geomorphology nationally and in the Bay of Plenty was shallow drowned valleys, with 72 coastal marae in this category. The response of these systems to sea level rise manifests as changes in the tidal regime and sediment transport dynamics which will affect inundation and erosion of low-lying areas, where many coastal marae and urupā are positioned.
Thus, it is clear that marae and urupā are nationally at risk to sea level rise, and their responses will be highly variable with geomorphology. But what are the next steps? There are many legislative documents such as the coastal climate change and hazards report by the Ministry for the Environment which suggests that the Dynamic Adaptive Policy Pathways strategy to address the uncertainty surrounding climate change, recommended as a method for future planning. Another is the pending reform of the Resource Management Act which will introduce a climate change adaptation act where support for managed retreat will be made available. However, any management strategies for marae, hapū and iwi will need to be cognisant of the tapū and māna that these places hold, and there will be no one size fits all approach.

text: Understanding the potential exposure of coastal marae and urupā in Aotearoa New Zealand to sea level rise In Aotearoa New Zealand, Māori are Indigenous and have inhabited these islands for the past 700 years. They have an intricate physical and spiritual connection to places and the environment. This is reflected in the Māori creation story, where Ranginui (sky father) and Papatūānuku (Earth mother) are the ancestral parents of Māori. Between these two gods is the marae, the Māori meeting house. Marae are where the domestic life of Māori traditionally ran its course, with marae being an overarching term to illustrate multiple buildings which each have a specific role to play within the community. Often, marae have an associated urupā (burial ground). Historically, marae and their associated urupā are positioned along the low-lying coast, providing easy access to kaimoana (sea food), transport and trade. However, coastal marae and urupā are at an increasing threat of inundation and erosion from sea level rise, and will also be impacted by other effects of climate change such as drought and other changes to weather patterns such as storms.
Many coastal marae and urupā are already experiencing the impacts of coastal flooding and erosion, however, little is known about the exposure of coastal marae and urupā to sea level rise nationally. Therefore, the main aim of this thesis is to explore the potential exposure of coastal marae nationally, with a particular focus on the Bay of Plenty coastal marae including coastal urupā. This aim was achieved by addressing three objectives. The first of which was to investigate the potential national exposure of coastal marae to a 100 year annual recurrence interval extreme sea level event, with the addition of sea level rise. Second, I conducted a nationally-focused assessment of the local coastal geomorphology surrounding coastal marae to determine the potential response of the coast to sea level rise. I also undertook a case study on the BOP which included a more detailed assessment of the geomorphology around the coastal marae and urupā in this region. Third, findings from these two objectives are brought together to consider the next steps to determine how to move forward with planning to manage coastal marae and urupā with sea level rise.
A spatial mapping approach using Arc GIS and existing datasets was used to address these aims, combining the Coastlines and Islands polygon, marae and urupā locational data and the Aotearoa New Zealand coastal hydrosystem classification system proposed by Hume in 2016. This showed that 191 marae around Aotearoa New Zealand are within 1 km of the coast and in the Bay of Plenty 41 urupā are within 1 km. I then used the bathtub modelling approach to get a national first-pass assessment of the potential exposure of these marae and urupā to a 100 year extreme sea level event at current mean sea level, with 10 cm increments of sea level rise up to 3 m. Six coastal marae were potentially exposed to a 100 year extreme sea level event at current mean sea level, with 41 coastal marae are potentially exposed to a 100 year extreme sea level event with a 3 m rise in mean sea level. The most common type of coastal geomorphology nationally and in the Bay of Plenty was shallow drowned valleys, with 72 coastal marae in this category. The response of these systems to sea level rise manifests as changes in the tidal regime and sediment transport dynamics which will affect inundation and erosion of low-lying areas, where many coastal marae and urupā are positioned.
Thus, it is clear that marae and urupā are nationally at risk to sea level rise, and their responses will be highly variable with geomorphology. But what are the next steps? There are many legislative documents such as the coastal climate change and hazards report by the Ministry for the Environment which suggests that the Dynamic Adaptive Policy Pathways strategy to address the uncertainty surrounding climate change, recommended as a method for future planning. Another is the pending reform of the Resource Management Act which will introduce a climate change adaptation act where support for managed retreat will be made available. However, any management strategies for marae, hapū and iwi will need to be cognisant of the tapū and māna that these places hold, and there will be no one size fits all approach.

year: 2021