title: Human impact on the McMurdo Dry Valley soils of Antarctica: Extending the limits of DNA detection

authors: Wakerley, Georgia L.J.

subjects: Antarctica

abstract: Antarctica is commonly regarded as the most pristine place on Earth and is safeguarded by the Antarctic Treaty System (ATS). The ATS designates the continent as a “natural reserve, devoted to peace and science” and sets out environmental principles regulating human activities. The obligations under the ATS include providing environmental impact assessments and leaving the environment minimally impacted after all operations. The associated human footprint inevitably increases as human activity increases in intensity and diversity on the continent. The human footprint is not clearly defined, and most investigation has focused on visible disturbances of physical (e.g., soil disturbance) and chemical (e.g., hydrocarbon spills) nature. The unseen human footprint remains to be investigated and quantified, which includes released genetic materials and human-associated microorganisms. Given the extremely low biomass in most of terrestrial Antarctica, these materials' presence can be a reliable indicator of human presence and activities.
As part of New Zealand’s effort to carry out an evidence-based risk assessment of the McMurdo Dry Valley ecosystem (DryVER project), this research quantified human impact, in the form of DNA released from humans and human-associated microbiota, across spatial and temporal scales. This project was part of the MBIE grant entitled “Evidence-based Risk Assessment of the McMurdo Dry Valley Ecosystem”. Areas of human activity, including seasonal field camps and facilities zones, were selected as sampling sites in the McMurdo Dry Valleys (MDVs), from which soil samples were collected. Human-specific genetic and microbial markers were used with digital PCR to quantify human presence at the lowest possible detection limit across spatial scales. A marker targeting a human MT-CYB gene region was the best marker for detecting and predicting human trace up to 1 km from a highly occupied site. Human impact derived from mtDNA was accumulative with occupancy and greatest closest to a campsite. A marker targeting 16S rRNA of Bacteroides dorei, a human-associated gut bacterium, was used to detect faecal trace. The faecal signal was generally localised to the toilet area of a camp and was too low to predict the distance of detectable signal, regardless of the intensity of occupancy. A DNA longevity experiment was established in situ in Miers Valley to investigate DNA persistence in a cold desert across temporal scales. The results from this experiment demonstrated that intracellular and extracellular DNA remained detectable with endpoint PCR for at least two years. DNA persistence was not significantly affected by soil sterility or UV exposure but did accumulate damage over time.
The direct outcome of this research will be a review of the environmental management systems in place, namely the McMurdo Dry Valleys Antarctic Specially Managed Area (ASMA) Management Plan. Better management will safeguard the unique MDV ecosystems by using the best practice to minimise anthropogenic impact and strengthen New Zealand’s stewardship over the Ross Dependency as one of the original 12 signatories to the Antarctic Treaty.

text: Human impact on the McMurdo Dry Valley soils of Antarctica: Extending the limits of DNA detection Antarctica is commonly regarded as the most pristine place on Earth and is safeguarded by the Antarctic Treaty System (ATS). The ATS designates the continent as a “natural reserve, devoted to peace and science” and sets out environmental principles regulating human activities. The obligations under the ATS include providing environmental impact assessments and leaving the environment minimally impacted after all operations. The associated human footprint inevitably increases as human activity increases in intensity and diversity on the continent. The human footprint is not clearly defined, and most investigation has focused on visible disturbances of physical (e.g., soil disturbance) and chemical (e.g., hydrocarbon spills) nature. The unseen human footprint remains to be investigated and quantified, which includes released genetic materials and human-associated microorganisms. Given the extremely low biomass in most of terrestrial Antarctica, these materials' presence can be a reliable indicator of human presence and activities.
As part of New Zealand’s effort to carry out an evidence-based risk assessment of the McMurdo Dry Valley ecosystem (DryVER project), this research quantified human impact, in the form of DNA released from humans and human-associated microbiota, across spatial and temporal scales. This project was part of the MBIE grant entitled “Evidence-based Risk Assessment of the McMurdo Dry Valley Ecosystem”. Areas of human activity, including seasonal field camps and facilities zones, were selected as sampling sites in the McMurdo Dry Valleys (MDVs), from which soil samples were collected. Human-specific genetic and microbial markers were used with digital PCR to quantify human presence at the lowest possible detection limit across spatial scales. A marker targeting a human MT-CYB gene region was the best marker for detecting and predicting human trace up to 1 km from a highly occupied site. Human impact derived from mtDNA was accumulative with occupancy and greatest closest to a campsite. A marker targeting 16S rRNA of Bacteroides dorei, a human-associated gut bacterium, was used to detect faecal trace. The faecal signal was generally localised to the toilet area of a camp and was too low to predict the distance of detectable signal, regardless of the intensity of occupancy. A DNA longevity experiment was established in situ in Miers Valley to investigate DNA persistence in a cold desert across temporal scales. The results from this experiment demonstrated that intracellular and extracellular DNA remained detectable with endpoint PCR for at least two years. DNA persistence was not significantly affected by soil sterility or UV exposure but did accumulate damage over time.
The direct outcome of this research will be a review of the environmental management systems in place, namely the McMurdo Dry Valleys Antarctic Specially Managed Area (ASMA) Management Plan. Better management will safeguard the unique MDV ecosystems by using the best practice to minimise anthropogenic impact and strengthen New Zealand’s stewardship over the Ross Dependency as one of the original 12 signatories to the Antarctic Treaty.

year: 2024-05-21

title: Work-family conflict and stress

authors: Brough, Paula

subjects: family

abstract: Over the past twenty years, increasing attention has been paid by researchers and organizations to the interface between people’s work and their family lives. In 1977, Rosabeth Kanter argued that the notion that work and life off the job are separate worlds is a ‘myth’. Since then there has been a growing volume to research on the interaction between job or work demands are experiences and family life. The burgeoning literature on this topic can be attributed to a variety of reasons, including changing family structures, with a significant increase in the number of dual-earner families and single-parent families; changing family orientations, with many couples now delaying the onset of children and also reducing the overall number of children; increasing participation of women in the workforce to the point where in many Western countries, in particular, employed women now out-number their male colleagues; and finally, a greater desire to achieve some kind of ‘balance’ between work and family responsibilities, to enhance both individual and family well-being.

text: Work-family conflict and stress Over the past twenty years, increasing attention has been paid by researchers and organizations to the interface between people’s work and their family lives. In 1977, Rosabeth Kanter argued that the notion that work and life off the job are separate worlds is a ‘myth’. Since then there has been a growing volume to research on the interaction between job or work demands are experiences and family life. The burgeoning literature on this topic can be attributed to a variety of reasons, including changing family structures, with a significant increase in the number of dual-earner families and single-parent families; changing family orientations, with many couples now delaying the onset of children and also reducing the overall number of children; increasing participation of women in the workforce to the point where in many Western countries, in particular, employed women now out-number their male colleagues; and finally, a greater desire to achieve some kind of ‘balance’ between work and family responsibilities, to enhance both individual and family well-being.

year: 2005

title: Merea Wikiriwhi and George Thomas Wilkinson

authors: Hart, Philip

abstract: Merea Wikiriwhi was one of the few women to invest in Te Aroha mining. Her life has been traced in as much detail as can be found because so little has survived about the lives of Maori women. As George Thomas Wilkinson’s surviving diaries reveal his importance in her life, his story was included as well, concentrating on his personal life rather than his official career. 
Merea was a member of several Ohinemuri hapu, with links through whakapapa to some of their more senior rangatira. Mostly living at or near Waitoki, between Paeroa and Te Aroha, she lived a frugal life, not wasting the income she received from land sales. These sales first required her to insist on her rights both in the land court and in a convoluted legal battle over a will signed in her favour by a distant relative. Over time, she would sell most of her land, but never became entirely landless. She invested in only one mining claim, but in the 1930s joined others to claim that the government was not paying them goldfields revenue for land they had sold.
George Thomas Wilkinson entered her life in 1880, when he was the ‘native agent’ in Hauraki. Despite having fought against Maori and nearly being killed, his surviving diaries reveal that he lived in the manner of a Pakeha Maori with three Maori women (simultaneously for a time), having children both by Merea and the woman he would eventually marry. Wilkinson had close friendships with many Maori and Pakeha Maori, and his genuine regard for them is reflected not only in his attempting, in his official capacity, to be fair to their interests – even as he assisted the government to separate them from their land – but in particular by his affection for a young girl, Wairingiringi, who shared his house in Thames. Although he and Merea would part, he tried to ensure that her children, like all his children, would do well in a Pakeha world.

text: Merea Wikiriwhi and George Thomas Wilkinson Merea Wikiriwhi was one of the few women to invest in Te Aroha mining. Her life has been traced in as much detail as can be found because so little has survived about the lives of Maori women. As George Thomas Wilkinson’s surviving diaries reveal his importance in her life, his story was included as well, concentrating on his personal life rather than his official career. 
Merea was a member of several Ohinemuri hapu, with links through whakapapa to some of their more senior rangatira. Mostly living at or near Waitoki, between Paeroa and Te Aroha, she lived a frugal life, not wasting the income she received from land sales. These sales first required her to insist on her rights both in the land court and in a convoluted legal battle over a will signed in her favour by a distant relative. Over time, she would sell most of her land, but never became entirely landless. She invested in only one mining claim, but in the 1930s joined others to claim that the government was not paying them goldfields revenue for land they had sold.
George Thomas Wilkinson entered her life in 1880, when he was the ‘native agent’ in Hauraki. Despite having fought against Maori and nearly being killed, his surviving diaries reveal that he lived in the manner of a Pakeha Maori with three Maori women (simultaneously for a time), having children both by Merea and the woman he would eventually marry. Wilkinson had close friendships with many Maori and Pakeha Maori, and his genuine regard for them is reflected not only in his attempting, in his official capacity, to be fair to their interests – even as he assisted the government to separate them from their land – but in particular by his affection for a young girl, Wairingiringi, who shared his house in Thames. Although he and Merea would part, he tried to ensure that her children, like all his children, would do well in a Pakeha world.

year: 2016