title: Comparative tolerances of non-indigenous bridled goby and native exquisite goby to salintiy, temperature and sediment

authors: Theobald, Kylie

subjects: non-indigenous

abstract: The Australian bridled goby (Arenigobius bifrenatus) has been in New Zealand since 1996, and has subsequently spread to thirteen estuaries and the coastal Otara Lake. The native exquisite goby (Favonigobius exquisitus) may be displaced or threatened by the bridled goby as they share estuarine habitat. The ecophysiological tolerances and sediment preferences for both goby species were examined to determine the potential for niche overlap and habitat selection. 

The results of acute salinity and temperature tolerance tests supported the hypotheses that bridled gobies are more tolerant than exquisite gobies to extremes of salinity and temperature. The incipient ten day LT50 values were 6.7 C and 11.8 C for bridled and exquisite gobies, respectively, however, both tolerated temperatures up to 35 C. Both species showed some mortality at low salinities, but mortality did not exceed 50% for either species at the lowest salinity tested (2.2 ppt) after 96 h. Bridled gobies displayed a strong preference for fine sediment (less than 63 um), whereas exquisite gobies were less selective, accepting a broad range of sediment grain sizes (63-250 um).

Bridled gobies have successfully established and dispersed in New Zealand, and their ecophysiological adaptations that allowed them to survive harsh conditions in ballast water, their presumed introduction vector, will likely aid their future spread throughout New Zealand. Their increasing abundance is likely to see them encounter and possibly encroach on the habitat of exquisite gobies. Bridled gobies may displace the smaller exquisite gobies from optimal habitats, as exquisite gobies are unlikely to survive competition from and predation by bridled gobies. However, exquisite gobies should be able to relocate to adjacent habitat with coarse sediment that is unsuitable for burrow construction by bridled gobies. Additionally, acclimatisation to local environmental conditions may extend the tolerance limits determined in this thesis, and may allow bridled gobies to spread to upstream zones in estuaries and occupy freshwater.

New Zealand presently has eight recognised gobiid species of which one is endemic, two are native, two are not recorded in mainland waters and three are proposed as non-indigenous. Additionally, several tropical and subtropical gobies exist in the aquarium trade. Similar ecophysiological tests of tolerance and preference may determine the possibility that these species could establish in the wild following accidental release.

text: Comparative tolerances of non-indigenous bridled goby and native exquisite goby to salintiy, temperature and sediment The Australian bridled goby (Arenigobius bifrenatus) has been in New Zealand since 1996, and has subsequently spread to thirteen estuaries and the coastal Otara Lake. The native exquisite goby (Favonigobius exquisitus) may be displaced or threatened by the bridled goby as they share estuarine habitat. The ecophysiological tolerances and sediment preferences for both goby species were examined to determine the potential for niche overlap and habitat selection. 

The results of acute salinity and temperature tolerance tests supported the hypotheses that bridled gobies are more tolerant than exquisite gobies to extremes of salinity and temperature. The incipient ten day LT50 values were 6.7 C and 11.8 C for bridled and exquisite gobies, respectively, however, both tolerated temperatures up to 35 C. Both species showed some mortality at low salinities, but mortality did not exceed 50% for either species at the lowest salinity tested (2.2 ppt) after 96 h. Bridled gobies displayed a strong preference for fine sediment (less than 63 um), whereas exquisite gobies were less selective, accepting a broad range of sediment grain sizes (63-250 um).

Bridled gobies have successfully established and dispersed in New Zealand, and their ecophysiological adaptations that allowed them to survive harsh conditions in ballast water, their presumed introduction vector, will likely aid their future spread throughout New Zealand. Their increasing abundance is likely to see them encounter and possibly encroach on the habitat of exquisite gobies. Bridled gobies may displace the smaller exquisite gobies from optimal habitats, as exquisite gobies are unlikely to survive competition from and predation by bridled gobies. However, exquisite gobies should be able to relocate to adjacent habitat with coarse sediment that is unsuitable for burrow construction by bridled gobies. Additionally, acclimatisation to local environmental conditions may extend the tolerance limits determined in this thesis, and may allow bridled gobies to spread to upstream zones in estuaries and occupy freshwater.

New Zealand presently has eight recognised gobiid species of which one is endemic, two are native, two are not recorded in mainland waters and three are proposed as non-indigenous. Additionally, several tropical and subtropical gobies exist in the aquarium trade. Similar ecophysiological tests of tolerance and preference may determine the possibility that these species could establish in the wild following accidental release.

year: 2007

title: Meaningful Witnessing in the United States, India & New Zealand: The Possibility Space for Digital Video Within Human Rights, Protest Movements and Activist Practices

authors: Lenzner, Benjamin

subjects: digital video

abstract: This dissertation examines the emergence of digital video practices rooted in human rights, social justice issues and protest movements through a number of select case studies in the United States, India and New Zealand. This project analyzes and critiques the formation of digital video practices through the lens of Manuel DeLanda’s interpretation of assemblage theory. Examining interactions between crucial elements present in a possibility space that aid in the cultivation and assembling of budding forms of digital video, this study considers the implications in the relationships between both material and expressive qualities of these assemblings. The central argument of this thesis asserts that digital video practices centered on human rights, social justice and protest movements require adaptable linkages between supportive structures, creative capacities and digital video technologies in order to produce sustainable and creative digital video practices buttressed by documentary agendas that fuel their dynamic evolution.

My research seeks to engage with the complexities of agency and technology and examines their significance in different contexts by providing a constructive outlet for practitioners to share the process behind their methods in order to offer insight into their creative workflow. Digital video technologies are proliferating at a rapid pace, yet very few video practices have formed that suggest linkages to documentary traditions. One can bear witness, yet to traverse video documentation in order to create a rhetorical argument of meaningful witnessing is a complex process that requires more than easy access to mobile video tools connected to the Internet. The case studies analyzed in these three democratic nations support the argument threaded throughout the project; digital video practices have the potential to thrive, albeit in pockets where formal or informal support systems are present and through assemblages where digital video technologies are constantly being adapted and an investment in human capital is paramount to the privileging of digital video tools or online platforms. Case studies that focus on individual practices in New York City and New Zealand reinforce the difficulties practitioners face when attempting to cultivate video practices without supportive structures. Comparatively with other case studies in India and New York, individual practices with long-term organizational support navigate challenges and re-assemble their practices in order to remain sustainable and influential.

This study also engages with assemblage theory in the context of documentary history and contemporary digital video practices and reassesses the historic relationship between emerging photographic, film and video tools and the lens based practitioners that harness these apparatuses for documentary purposes. Like assemblings themselves, these creative associations are never smooth at their inception, but require adaptable solutions and adjustable reassemblings in order to maintain the potential for sustainable practices to develop and flourish. This dissertation argues that as digital video practices continue to evolve, they have the potential to redefine creative approaches to documentary media and the opportunity to confront historic traditions of the documentary form.

text: Meaningful Witnessing in the United States, India & New Zealand: The Possibility Space for Digital Video Within Human Rights, Protest Movements and Activist Practices This dissertation examines the emergence of digital video practices rooted in human rights, social justice issues and protest movements through a number of select case studies in the United States, India and New Zealand. This project analyzes and critiques the formation of digital video practices through the lens of Manuel DeLanda’s interpretation of assemblage theory. Examining interactions between crucial elements present in a possibility space that aid in the cultivation and assembling of budding forms of digital video, this study considers the implications in the relationships between both material and expressive qualities of these assemblings. The central argument of this thesis asserts that digital video practices centered on human rights, social justice and protest movements require adaptable linkages between supportive structures, creative capacities and digital video technologies in order to produce sustainable and creative digital video practices buttressed by documentary agendas that fuel their dynamic evolution.

My research seeks to engage with the complexities of agency and technology and examines their significance in different contexts by providing a constructive outlet for practitioners to share the process behind their methods in order to offer insight into their creative workflow. Digital video technologies are proliferating at a rapid pace, yet very few video practices have formed that suggest linkages to documentary traditions. One can bear witness, yet to traverse video documentation in order to create a rhetorical argument of meaningful witnessing is a complex process that requires more than easy access to mobile video tools connected to the Internet. The case studies analyzed in these three democratic nations support the argument threaded throughout the project; digital video practices have the potential to thrive, albeit in pockets where formal or informal support systems are present and through assemblages where digital video technologies are constantly being adapted and an investment in human capital is paramount to the privileging of digital video tools or online platforms. Case studies that focus on individual practices in New York City and New Zealand reinforce the difficulties practitioners face when attempting to cultivate video practices without supportive structures. Comparatively with other case studies in India and New York, individual practices with long-term organizational support navigate challenges and re-assemble their practices in order to remain sustainable and influential.

This study also engages with assemblage theory in the context of documentary history and contemporary digital video practices and reassesses the historic relationship between emerging photographic, film and video tools and the lens based practitioners that harness these apparatuses for documentary purposes. Like assemblings themselves, these creative associations are never smooth at their inception, but require adaptable solutions and adjustable reassemblings in order to maintain the potential for sustainable practices to develop and flourish. This dissertation argues that as digital video practices continue to evolve, they have the potential to redefine creative approaches to documentary media and the opportunity to confront historic traditions of the documentary form.

year: 2015

title: Consciousness-centered stewardship: An indigenous standpoint

authors: Spiller, Chellie

abstract: Dominion-driven stewardship, which stages human interventions with an anthropocentric lens, externalises problems. We present consciousness-centered stewardship, seen through the Māori ethic of kaitiakitanga, as the missing connective tissue that looks to fix ourselves. We advocate an approach that appreciates a collective self-intelligence in the world and being a steward with a “conscious mind” as part of a transformative way forward. Sustainable development from this perspective thus includes paying attention to personal growth.

text: Consciousness-centered stewardship: An indigenous standpoint Dominion-driven stewardship, which stages human interventions with an anthropocentric lens, externalises problems. We present consciousness-centered stewardship, seen through the Māori ethic of kaitiakitanga, as the missing connective tissue that looks to fix ourselves. We advocate an approach that appreciates a collective self-intelligence in the world and being a steward with a “conscious mind” as part of a transformative way forward. Sustainable development from this perspective thus includes paying attention to personal growth.

year: 2025