title: Water column turbidity not sediment nutrient enrichment moderates microphytobenthic primary production

authors: Mangan, Stephanie

subjects: Science & Technology

abstract: Soft sediment intertidal habitats are under intense anthropogenic pressure resulting from increased land derived sediment and nutrient delivery. Long term, this can cause high water column turbidity and nutrient enrichment of sediment porewaters, which has cascading effects on coastal ecosystem functionality. However, how these stressors may interact and influence benthic productivity over alternating periods of submergence and emergence is largely unknown. This study investigates the effects of sediment nutrient enrichment (at three levels for 20 months) on benthic primary production at six sites in four New Zealand estuaries that spanned a gradient in water column turbidity. While nutrient enrichment had no detectable effect on microphytobenthic primary production, water column turbidity had a significant influence, explaining up to 40% of variability during tidal submergence, followed by temperature and sediment characteristics. In addition, negative net primary production (NPP) estimates and therefore net heterotrophy for the most turbid estuaries during tidal submergence resulted in an increased reliance on production during emerged periods, where NPP was positive across all sites. This study highlights the prominent role of water column turbidity over nutrient enrichment in moderating microphytobenthic production, and the increasing importance of emerged periods to maintain the health and functioning of coastal habitats.

text: Water column turbidity not sediment nutrient enrichment moderates microphytobenthic primary production Soft sediment intertidal habitats are under intense anthropogenic pressure resulting from increased land derived sediment and nutrient delivery. Long term, this can cause high water column turbidity and nutrient enrichment of sediment porewaters, which has cascading effects on coastal ecosystem functionality. However, how these stressors may interact and influence benthic productivity over alternating periods of submergence and emergence is largely unknown. This study investigates the effects of sediment nutrient enrichment (at three levels for 20 months) on benthic primary production at six sites in four New Zealand estuaries that spanned a gradient in water column turbidity. While nutrient enrichment had no detectable effect on microphytobenthic primary production, water column turbidity had a significant influence, explaining up to 40% of variability during tidal submergence, followed by temperature and sediment characteristics. In addition, negative net primary production (NPP) estimates and therefore net heterotrophy for the most turbid estuaries during tidal submergence resulted in an increased reliance on production during emerged periods, where NPP was positive across all sites. This study highlights the prominent role of water column turbidity over nutrient enrichment in moderating microphytobenthic production, and the increasing importance of emerged periods to maintain the health and functioning of coastal habitats.

year: 2020

title: Rock art and frontier conflict in Southeast Asia: Insights from direct radiocarbon ages for the large human figures of Gua Sireh, Sarawak

authors: Huntley, J

abstract: Gua Sireh, located in western Sarawak (Malaysian Borneo), is known for its rock art. The cave houses hundreds of charcoal drawings depicting people, often with headdresses, knives and other accoutrements. Here, we present direct radiocarbon dates and pigment characterizations from charcoal drawings of two large (>75 cm), unique Gua Sireh human figures (anthropomorphs). To our knowledge, these are the first chronometric ages generated for Malaysian rock art, providing insights into the social contexts of art production, as well as the opportunities and challenges of dating rock art associated with the Malay/Austronesian diasporas in Southeast Asia more generally. Previous archaeological excavations revealed that people occupied Gua Sireh from around 20,000 years ago to as recently as AD 1900. The site is within Bidayuh territory, and these local Indigenous peoples recall the cave's use as a refuge during territorial violence in the early 1800s. The age of the drawings, dated between 280 and 120 cal BP (AD 1670 to 1830), corresponds with a period of increasing conflict when the Malay elites controlling the region exacted heavy tolls on the local hill tribes. We discuss rock art production at Gua Sireh in this context of frontier conflict and Bidayuh resistance.

text: Rock art and frontier conflict in Southeast Asia: Insights from direct radiocarbon ages for the large human figures of Gua Sireh, Sarawak Gua Sireh, located in western Sarawak (Malaysian Borneo), is known for its rock art. The cave houses hundreds of charcoal drawings depicting people, often with headdresses, knives and other accoutrements. Here, we present direct radiocarbon dates and pigment characterizations from charcoal drawings of two large (>75 cm), unique Gua Sireh human figures (anthropomorphs). To our knowledge, these are the first chronometric ages generated for Malaysian rock art, providing insights into the social contexts of art production, as well as the opportunities and challenges of dating rock art associated with the Malay/Austronesian diasporas in Southeast Asia more generally. Previous archaeological excavations revealed that people occupied Gua Sireh from around 20,000 years ago to as recently as AD 1900. The site is within Bidayuh territory, and these local Indigenous peoples recall the cave's use as a refuge during territorial violence in the early 1800s. The age of the drawings, dated between 280 and 120 cal BP (AD 1670 to 1830), corresponds with a period of increasing conflict when the Malay elites controlling the region exacted heavy tolls on the local hill tribes. We discuss rock art production at Gua Sireh in this context of frontier conflict and Bidayuh resistance.

year: 2023

title: Social deprivation in New Zealand

authors: Harcourt, Brian James

subjects: Deprivation

abstract: The purpose of the thesis was to better understand the phenomenon of social deprivation, world-wide and in particular in New Zealand. Social deprivation has been defined in many ways with multiple surrogates used to ‘measure’ its prevalence. The aim of this research was to provide examples of the lived experiences of social deprivation.

Social constructivist and interpretive lenses were used to portray the voices of those living in deprivation, as well as those people tasked to assist them. A narrative case study approach was employed with participants from Whānau Ora. This social and health initiative offered a holistic approach to assistance in contrast to the usual State agencies operating in a silo fashion, with separate agencies providing for different aspects of social deprivation such as housing, employment, mental health and other services. The approach of Whānau Ora is to support clients’ needs holistically and encourage people to develop their own plans for self- improvement. Navigators help people develop their plans and assist in their interactions with the various State agencies whose services they require. This approach allowed a better understanding of ways to overcome people’s feelings of powerlessness and desperation.

The findings from the study lead to suggestions for the application of evidence-based, complementary, integrated assistance programmes rather than having segregated public service agencies acting independently. The recommendations are simple yet require profound changes in public service operations when attempting to ameliorate or prevent social deprivation among citizens.

text: Social deprivation in New Zealand The purpose of the thesis was to better understand the phenomenon of social deprivation, world-wide and in particular in New Zealand. Social deprivation has been defined in many ways with multiple surrogates used to ‘measure’ its prevalence. The aim of this research was to provide examples of the lived experiences of social deprivation.

Social constructivist and interpretive lenses were used to portray the voices of those living in deprivation, as well as those people tasked to assist them. A narrative case study approach was employed with participants from Whānau Ora. This social and health initiative offered a holistic approach to assistance in contrast to the usual State agencies operating in a silo fashion, with separate agencies providing for different aspects of social deprivation such as housing, employment, mental health and other services. The approach of Whānau Ora is to support clients’ needs holistically and encourage people to develop their own plans for self- improvement. Navigators help people develop their plans and assist in their interactions with the various State agencies whose services they require. This approach allowed a better understanding of ways to overcome people’s feelings of powerlessness and desperation.

The findings from the study lead to suggestions for the application of evidence-based, complementary, integrated assistance programmes rather than having segregated public service agencies acting independently. The recommendations are simple yet require profound changes in public service operations when attempting to ameliorate or prevent social deprivation among citizens.

year: 2019