title: The effects of climate change on the benthic community in a temperate fjord

authors: Shellem, Claire T.

abstract: Climate change exerts a profound impact on marine ecosystems, with coastal environments uniquely affected by both oceanic and terrestrial influences. In coastal areas, oceanic drivers, such as rising temperatures and altered circulation patterns, combine with terrestrial inputs like changes in freshwater inflow to create unique environmental conditions. Beyond the gradual warming of ocean temperatures, the increasing occurrence of extreme temperature anomalies poses considerable threats to ecosystem stability, necessitating detailed investigations into their underlying mechanisms and ecological consequences. This thesis focuses on how climate change manifests in Doubtful Sound, a temperate fjord characterized by rocky subtidal benthic communities.
First, using an 18-year high resolution dataset, I investigate the spatiotemporal trends in temperature and salinity throughout Doubtful Sound. I analyse the fjord’s temperature dynamics spatially, spanning from 0.5 m to 19 m and from the inner fjord to outer fjord. Linked with climate change, I identify increasing mean temperatures and increases in temperature anomalies. Furthermore, I report the occurrence of two marine heatwaves in Doubtful Sound. Lastly, I note a deepening of the low salinity layer, a key physical feature that drives the structure and stability of benthic communities in this fjord.
Coupled with these oceanographic analyses, I explore spatial and temporal drivers of the benthic communities in Doubtful Sound. I document higher diversity and variability in the outer sites as compared to the inner sites. Additionally outer fjord communities show significant shifts in benthic community composition through time, while the inner fjord communities remain largely constant. Though a range of factors influence the abundance of benthic organisms including biotic interactions, salinity levels and physical disturbance, thermal profiles provide insights into the potential sensitivity of taxa to warming oceans. By linking benthic abundance with temperature trends, I identify potential thermal thresholds for several key taxa. In the shallow waters for example, barnacles and mussels peak in abundance at 15.5-16 °C and sharply decline in higher temperatures. Conversely, encrusting sponges increase dramatically in response to warming temperatures. Lastly, I investigate the role of the 2018 Tasman Sea marine heatwave in structuring the benthic community in Doubtful Sound. Minimal impacts on the benthic community after the heatwave were recorded, although notable increases in green algae and encrusting sponge were observed at two sites.
The final chapter of this thesis investigates how environmental changes associated with climate change, specifically increased temperature and decreased salinity, influence the fitness of Coscinasterias muricata, a keystone predator in Fiordland’s subtidal ecosystems. I designed a laboratory experiment to identify the effects of temperature, salinity, and the interaction between the two on the fitness of C. muricata. Righting trials, a well-established proxy for fitness, were carried out to investigate the effects of altered physical conditions. Interestingly, only salinity had a significant effect on C. muricata fitness, highlighting the potential of low salinity events to affect benthic communities in estuarine environments.
Overall, this thesis underscores the multifaceted impacts of climate change on fjord ecosystems, emphasizing the importance of physical anomalies beyond increases in mean temperature. These findings highlight how increasing anomalies and shifts in temperature and salinity regimes can profoundly influence the structure and dynamics of benthic communities. By integrating long term environmental data with experimental insights, this work advances our understanding of the complex interactions between climatic drivers and ecological responses, providing critical perspectives on the vulnerability and resilience of temperate fjord ecosystems under changing physical conditions.

text: The effects of climate change on the benthic community in a temperate fjord Climate change exerts a profound impact on marine ecosystems, with coastal environments uniquely affected by both oceanic and terrestrial influences. In coastal areas, oceanic drivers, such as rising temperatures and altered circulation patterns, combine with terrestrial inputs like changes in freshwater inflow to create unique environmental conditions. Beyond the gradual warming of ocean temperatures, the increasing occurrence of extreme temperature anomalies poses considerable threats to ecosystem stability, necessitating detailed investigations into their underlying mechanisms and ecological consequences. This thesis focuses on how climate change manifests in Doubtful Sound, a temperate fjord characterized by rocky subtidal benthic communities.
First, using an 18-year high resolution dataset, I investigate the spatiotemporal trends in temperature and salinity throughout Doubtful Sound. I analyse the fjord’s temperature dynamics spatially, spanning from 0.5 m to 19 m and from the inner fjord to outer fjord. Linked with climate change, I identify increasing mean temperatures and increases in temperature anomalies. Furthermore, I report the occurrence of two marine heatwaves in Doubtful Sound. Lastly, I note a deepening of the low salinity layer, a key physical feature that drives the structure and stability of benthic communities in this fjord.
Coupled with these oceanographic analyses, I explore spatial and temporal drivers of the benthic communities in Doubtful Sound. I document higher diversity and variability in the outer sites as compared to the inner sites. Additionally outer fjord communities show significant shifts in benthic community composition through time, while the inner fjord communities remain largely constant. Though a range of factors influence the abundance of benthic organisms including biotic interactions, salinity levels and physical disturbance, thermal profiles provide insights into the potential sensitivity of taxa to warming oceans. By linking benthic abundance with temperature trends, I identify potential thermal thresholds for several key taxa. In the shallow waters for example, barnacles and mussels peak in abundance at 15.5-16 °C and sharply decline in higher temperatures. Conversely, encrusting sponges increase dramatically in response to warming temperatures. Lastly, I investigate the role of the 2018 Tasman Sea marine heatwave in structuring the benthic community in Doubtful Sound. Minimal impacts on the benthic community after the heatwave were recorded, although notable increases in green algae and encrusting sponge were observed at two sites.
The final chapter of this thesis investigates how environmental changes associated with climate change, specifically increased temperature and decreased salinity, influence the fitness of Coscinasterias muricata, a keystone predator in Fiordland’s subtidal ecosystems. I designed a laboratory experiment to identify the effects of temperature, salinity, and the interaction between the two on the fitness of C. muricata. Righting trials, a well-established proxy for fitness, were carried out to investigate the effects of altered physical conditions. Interestingly, only salinity had a significant effect on C. muricata fitness, highlighting the potential of low salinity events to affect benthic communities in estuarine environments.
Overall, this thesis underscores the multifaceted impacts of climate change on fjord ecosystems, emphasizing the importance of physical anomalies beyond increases in mean temperature. These findings highlight how increasing anomalies and shifts in temperature and salinity regimes can profoundly influence the structure and dynamics of benthic communities. By integrating long term environmental data with experimental insights, this work advances our understanding of the complex interactions between climatic drivers and ecological responses, providing critical perspectives on the vulnerability and resilience of temperate fjord ecosystems under changing physical conditions.

year: 2025

title: Challenges in accessing fieldwork in rural Himalayas: an emerging researcher’s experiences

authors: Rana, Karna

subjects: case study

abstract: This article is the reflection of an emerging researcher who has experienced different nudges from the beginning of accessing the research field to the final stage of collating data in rural Nepal. My experiences and reflections may provide provocations to researchers to consider before they undertake field research. Areas that researchers should be aware of before entering the field include strategies of approaching the resources, socio-cultural and language diversities, topography and travel complication. The article offers those considering field research in remote areas, such as rural Nepal, an opportunity for rethinking a case study research approach, choosing appropriate methodological tools, sampling strategies and accessing resources.

text: Challenges in accessing fieldwork in rural Himalayas: an emerging researcher’s experiences This article is the reflection of an emerging researcher who has experienced different nudges from the beginning of accessing the research field to the final stage of collating data in rural Nepal. My experiences and reflections may provide provocations to researchers to consider before they undertake field research. Areas that researchers should be aware of before entering the field include strategies of approaching the resources, socio-cultural and language diversities, topography and travel complication. The article offers those considering field research in remote areas, such as rural Nepal, an opportunity for rethinking a case study research approach, choosing appropriate methodological tools, sampling strategies and accessing resources.

year: 2019

title: Creating whanaungatanga: Kaupapa Maori support in the Psychology Department at the University of Waikato

authors: Masters-Awatere, Bridgette

subjects: Maori students

abstract: Attendance at university has been recognized by some as a competitive environment that does not cater for the co-operative philosophy followed by many Maori.  Within the Psychology Department at the University of Waikato there have been efforts since the Departments early days to place emphasis on the Maori cultural experience, but there were few Maori students and no Maori staff back then.  Now, in 2004, the Department has a team of Maori staff and courses with Maori content at both undergraduate and graduate levels.  Yet the environment that the students move in is still competitive. Grades are based on individual assessment through undergraduate level. At graduate level the emphasis on group dynamics comes to the fore.  The availability and accessibility of Maori staff at different levels in a Kaupapa Maori programme provides one of the strategies of support for maori students at Waikato.  This paper discusses the issues around managing, delivering and providing opportunities so that Maori students studying psychology feel supported for the duration of their time at Waikato University.

text: Creating whanaungatanga: Kaupapa Maori support in the Psychology Department at the University of Waikato Attendance at university has been recognized by some as a competitive environment that does not cater for the co-operative philosophy followed by many Maori.  Within the Psychology Department at the University of Waikato there have been efforts since the Departments early days to place emphasis on the Maori cultural experience, but there were few Maori students and no Maori staff back then.  Now, in 2004, the Department has a team of Maori staff and courses with Maori content at both undergraduate and graduate levels.  Yet the environment that the students move in is still competitive. Grades are based on individual assessment through undergraduate level. At graduate level the emphasis on group dynamics comes to the fore.  The availability and accessibility of Maori staff at different levels in a Kaupapa Maori programme provides one of the strategies of support for maori students at Waikato.  This paper discusses the issues around managing, delivering and providing opportunities so that Maori students studying psychology feel supported for the duration of their time at Waikato University.

year: 2004-12