title: Gracilaria transtasmanica: a potential novel target species for the bioremediation of nutrient enriched estuaries

authors: Ross, Bethany Grace

subjects: Macroalgae

abstract: Estuaries are increasingly becoming eutrophic due to anthropogenically induced nutrient enrichment. Presently, 24% of global anthropogenically derived nutrients released into coastal catchments are delivered directly into coastal waters such as estuaries. Thirty five percent of New Zealand’s estuaries are susceptible to eutrophication and some are already severely degraded. In-situ macroalgal bioremediation – the cultivation of live macroalgae directly in nutrient-enriched waters for the primary purpose of nutrient assimilation – could help prevent and reduce estuarine eutrophication.

The indigenous red macroalga Gracilaria transtasmanica has been identified as a potential target species for bioremediation in New Zealand estuaries. Samples of G. transtasmanica were collected from estuaries in the Bay of Plenty region of New Zealand, and were isolated, formally identified and scaled up into stock cultures. Controlled experiments were then used to assess the bioremediation potential of this species in winter and summer conditions under ambient and extreme nutrient and sediment levels. Biomass productivity, photosynthetic health, and N removal were assessed to quantify performance. Biomass productivity and total N removed were 45 and 50% higher respectively in summer compared to winter. Biomass productivity ranged from 0.4 – 4.3 g DW m² in summer and 0.6 – 1.8 g DW m² in winter, and total N removed ranged from 6.0 – 30.7 mg N in summer and 6.1 – 9.1 mg N in winter. In contrast, standardised N removal rates were higher in winter (37.8 mg g DW biomass growth⁻¹ ± 0.6 S.E.) compared to summer (22.3 mg g DW biomass growth⁻¹ ± 1.2 S.E.), suggesting that the biomass was storing N and therefore that N uptake was independent of productivity under sub-optimal growing conditions. Productivity was significantly affected by sediment treatment, however this effect differed seasonally, with higher productivity in the high

sediment treatments in summer, and lower productivity in the high sediment treatments in winter. These results demonstrate that G. transtasmanica can assimilate nutrients under a range of environmental conditions that are representative of both local background and high levels of suspended sediment and nutrient concentrations, and therefore is a viable target species for the bioremediation of nutrient enriched estuaries.In addition to nutrient uptake and productivity, target species for in-situ estuarine bioremediation need to maintain productivity under a range of challenging abiotic conditions. In chapter three of this thesis, a series of independent experiments assessed the tolerance of G. transtasmanica to ambient and extreme levels of salinity, exposure, and light limitation that are likely to be experienced in an estuary. Photosynthetic functioning and growth were used to quantify the tolerance range of G. transtasmanica in each experiment. Specific Growth Rate (SGR) was significantly affected by salinity, exposure, and light limitation. Gracilaria transtasmanica was able to grow in salinities ranging from 5 to 35 ppt, but growth rates decreased with decreasing salinity. Exposure periods of up to 9 hours were tolerated, but growth rates were decreased as exposure period increased. Gracilaria transtasmanica was able to maintain growth with a loss of up to 75% of ambient light and was also able to tolerate short periods of no light. Measurements of optimal quantum yields showed photosynthetic function was unaffected by salinity, exposure, or light limitation. 

These results demonstrate the high tolerance and adaptability of G. transtasmanica to a broad range of challenging abiotic estuarine conditions. In combination, these findings demonstrate that Gracilaria transtasmanica is well suited to estuarine conditions. However, selection of habitats with optimal conditions for growth will maximise productivity. Moreover, as nutrient uptake appears to be independent of growth under challenging conditions, low productivity may not result in reduced bioremediation capability. These characteristics make G. transtasmanica an ideal species for in-situ bioremediation in New Zealand estuaries. Additionally, G. transtasmanica biomass is suitable for use in a range of bioproducts. Therefore, there is potential for a bioremediation based circular economy approach with the use of harvested G. transtasmanica biomass following bioremediation. In-situ trials are required to verifying the findings reported here and enable optimisation of both bioremediation efficiency and biomass productivity.

text: Gracilaria transtasmanica: a potential novel target species for the bioremediation of nutrient enriched estuaries Estuaries are increasingly becoming eutrophic due to anthropogenically induced nutrient enrichment. Presently, 24% of global anthropogenically derived nutrients released into coastal catchments are delivered directly into coastal waters such as estuaries. Thirty five percent of New Zealand’s estuaries are susceptible to eutrophication and some are already severely degraded. In-situ macroalgal bioremediation – the cultivation of live macroalgae directly in nutrient-enriched waters for the primary purpose of nutrient assimilation – could help prevent and reduce estuarine eutrophication.

The indigenous red macroalga Gracilaria transtasmanica has been identified as a potential target species for bioremediation in New Zealand estuaries. Samples of G. transtasmanica were collected from estuaries in the Bay of Plenty region of New Zealand, and were isolated, formally identified and scaled up into stock cultures. Controlled experiments were then used to assess the bioremediation potential of this species in winter and summer conditions under ambient and extreme nutrient and sediment levels. Biomass productivity, photosynthetic health, and N removal were assessed to quantify performance. Biomass productivity and total N removed were 45 and 50% higher respectively in summer compared to winter. Biomass productivity ranged from 0.4 – 4.3 g DW m² in summer and 0.6 – 1.8 g DW m² in winter, and total N removed ranged from 6.0 – 30.7 mg N in summer and 6.1 – 9.1 mg N in winter. In contrast, standardised N removal rates were higher in winter (37.8 mg g DW biomass growth⁻¹ ± 0.6 S.E.) compared to summer (22.3 mg g DW biomass growth⁻¹ ± 1.2 S.E.), suggesting that the biomass was storing N and therefore that N uptake was independent of productivity under sub-optimal growing conditions. Productivity was significantly affected by sediment treatment, however this effect differed seasonally, with higher productivity in the high

sediment treatments in summer, and lower productivity in the high sediment treatments in winter. These results demonstrate that G. transtasmanica can assimilate nutrients under a range of environmental conditions that are representative of both local background and high levels of suspended sediment and nutrient concentrations, and therefore is a viable target species for the bioremediation of nutrient enriched estuaries.In addition to nutrient uptake and productivity, target species for in-situ estuarine bioremediation need to maintain productivity under a range of challenging abiotic conditions. In chapter three of this thesis, a series of independent experiments assessed the tolerance of G. transtasmanica to ambient and extreme levels of salinity, exposure, and light limitation that are likely to be experienced in an estuary. Photosynthetic functioning and growth were used to quantify the tolerance range of G. transtasmanica in each experiment. Specific Growth Rate (SGR) was significantly affected by salinity, exposure, and light limitation. Gracilaria transtasmanica was able to grow in salinities ranging from 5 to 35 ppt, but growth rates decreased with decreasing salinity. Exposure periods of up to 9 hours were tolerated, but growth rates were decreased as exposure period increased. Gracilaria transtasmanica was able to maintain growth with a loss of up to 75% of ambient light and was also able to tolerate short periods of no light. Measurements of optimal quantum yields showed photosynthetic function was unaffected by salinity, exposure, or light limitation. 

These results demonstrate the high tolerance and adaptability of G. transtasmanica to a broad range of challenging abiotic estuarine conditions. In combination, these findings demonstrate that Gracilaria transtasmanica is well suited to estuarine conditions. However, selection of habitats with optimal conditions for growth will maximise productivity. Moreover, as nutrient uptake appears to be independent of growth under challenging conditions, low productivity may not result in reduced bioremediation capability. These characteristics make G. transtasmanica an ideal species for in-situ bioremediation in New Zealand estuaries. Additionally, G. transtasmanica biomass is suitable for use in a range of bioproducts. Therefore, there is potential for a bioremediation based circular economy approach with the use of harvested G. transtasmanica biomass following bioremediation. In-situ trials are required to verifying the findings reported here and enable optimisation of both bioremediation efficiency and biomass productivity.

year: 2022

title: Sterilisation and intellectually disabled people in New Zealand—still on the agenda?

authors: Hamilton, Carol

subjects: gender

abstract: Support through care and protection within a medical framework, rather than through the idea of independence within the least restrictive environment, continues to guide service provision for intellectually disabled people in the sexuality area. Past practices have included use of involuntary sterilisation. This article outlines the outcome of a search for information undertaken because of concerns that use of sterilisation-related procedures may remain embedded in contemporary approaches to sexuality support management. Verified instances of hysterectomy carried out between 1991 and 2001 were uncovered. Documents tabled at a Parliamentary Select Committee in 2003 expressing concerns about use in relation to young disabled girls were also found. Requests for sterilisation-related procedures exemplify how the right of all vulnerable citizens to full bodily integrity is currently adjudicated in New Zealand. It is suggested that further research is needed to pinpoint and address the underlying social customs through which requests for such procedures are negotiated and resolved.

text: Sterilisation and intellectually disabled people in New Zealand—still on the agenda? Support through care and protection within a medical framework, rather than through the idea of independence within the least restrictive environment, continues to guide service provision for intellectually disabled people in the sexuality area. Past practices have included use of involuntary sterilisation. This article outlines the outcome of a search for information undertaken because of concerns that use of sterilisation-related procedures may remain embedded in contemporary approaches to sexuality support management. Verified instances of hysterectomy carried out between 1991 and 2001 were uncovered. Documents tabled at a Parliamentary Select Committee in 2003 expressing concerns about use in relation to young disabled girls were also found. Requests for sterilisation-related procedures exemplify how the right of all vulnerable citizens to full bodily integrity is currently adjudicated in New Zealand. It is suggested that further research is needed to pinpoint and address the underlying social customs through which requests for such procedures are negotiated and resolved.

year: 2012

title: Using inclusive research with participants with learning (intellectual) disability to better inform adult literacy policies in Aotearoa New Zealand

authors: Newcombe, Nicolina

abstract: Western ideas about disability and literacy were developed in tandem during the Industrial Revolution and subsequently brought to Aotearoa New Zealand via colonisation. These ideas inform and reinforce educator attitudes, which are the leading factor impeding adults with learning [intellectual] disability from their educational pathways of choice. People without learning disability need to hear the voices of people with learning disability to counteract these attitudes and move towards transformational equality.

There is a paucity of information about the access to and accessibility of adult literacy education for people with learning disability in Aotearoa New Zealand. However, anecdotal evidence reports their exclusion, even from foundational adult learning. There was a gap in knowledge where collaborative research that conveys the experiences of adults with learning disability was needed to gain greater insight to these issues in our bicultural context. My original contribution to knowledge is to present the voices of adults with learning disability as they discuss and demonstrate their literacy practices, and to use their perspectives to make recommendations for adult literacy policies in Aotearoa New Zealand.

I undertook a thematic analysis of current adult literacy policies in Aotearoa New Zealand and found that they target “most” adult learners, while positioning disabled people as needing specialised, and by inference optional to provide, education and resources. These policies also prescribe a linear and progressive andragogy that may not meet the needs of all adults with learning disability, while measuring literacy skills in a way that does not foreground their strengths or value their purposes for engagement.

Then, I conducted Inclusive Participatory Action Research with five adults with learning disability to gather information about their literacy practices and perspectives. Participants in this research decided to call themselves the Passioners. We met for 10 research meetings, preceded by at least two home visits, and interspersed by reflective meetings with individual participants. All research information was presented in easy read and key information was distributed audiovisually.

The Passioners added value to this research by providing unique opportunities that are only available through doing inclusive research with them, prompting research improvements, innovation, and my efforts towards acculturation in their worlds. I evaluated my inclusive approach in this research to learn more about how people with learning disability do research as people with learning disability, and what dispositions, resources, and skills people without learning disability need to do research with them.

Using reflexive thematic analysis, I constructed six themes from our research meetings data: learning disability cultural literacies, Māori (Indigenous peoples of Aotearoa New Zealand) cultural literacies, Pākehā (New Zealanders of European descent) cultural literacies, encoding, decoding, and social media, which extends the narrow definition of literacy in our adult literacy policies. These findings, and those from my policy analysis, were used to inform policy recommendations. Policy recommendations in this research may support implementation of the United Nations Convention on the Rights of Persons with Disabilities, particularly access to lifelong learning on an equal basis with others.

text: Using inclusive research with participants with learning (intellectual) disability to better inform adult literacy policies in Aotearoa New Zealand Western ideas about disability and literacy were developed in tandem during the Industrial Revolution and subsequently brought to Aotearoa New Zealand via colonisation. These ideas inform and reinforce educator attitudes, which are the leading factor impeding adults with learning [intellectual] disability from their educational pathways of choice. People without learning disability need to hear the voices of people with learning disability to counteract these attitudes and move towards transformational equality.

There is a paucity of information about the access to and accessibility of adult literacy education for people with learning disability in Aotearoa New Zealand. However, anecdotal evidence reports their exclusion, even from foundational adult learning. There was a gap in knowledge where collaborative research that conveys the experiences of adults with learning disability was needed to gain greater insight to these issues in our bicultural context. My original contribution to knowledge is to present the voices of adults with learning disability as they discuss and demonstrate their literacy practices, and to use their perspectives to make recommendations for adult literacy policies in Aotearoa New Zealand.

I undertook a thematic analysis of current adult literacy policies in Aotearoa New Zealand and found that they target “most” adult learners, while positioning disabled people as needing specialised, and by inference optional to provide, education and resources. These policies also prescribe a linear and progressive andragogy that may not meet the needs of all adults with learning disability, while measuring literacy skills in a way that does not foreground their strengths or value their purposes for engagement.

Then, I conducted Inclusive Participatory Action Research with five adults with learning disability to gather information about their literacy practices and perspectives. Participants in this research decided to call themselves the Passioners. We met for 10 research meetings, preceded by at least two home visits, and interspersed by reflective meetings with individual participants. All research information was presented in easy read and key information was distributed audiovisually.

The Passioners added value to this research by providing unique opportunities that are only available through doing inclusive research with them, prompting research improvements, innovation, and my efforts towards acculturation in their worlds. I evaluated my inclusive approach in this research to learn more about how people with learning disability do research as people with learning disability, and what dispositions, resources, and skills people without learning disability need to do research with them.

Using reflexive thematic analysis, I constructed six themes from our research meetings data: learning disability cultural literacies, Māori (Indigenous peoples of Aotearoa New Zealand) cultural literacies, Pākehā (New Zealanders of European descent) cultural literacies, encoding, decoding, and social media, which extends the narrow definition of literacy in our adult literacy policies. These findings, and those from my policy analysis, were used to inform policy recommendations. Policy recommendations in this research may support implementation of the United Nations Convention on the Rights of Persons with Disabilities, particularly access to lifelong learning on an equal basis with others.

year: 2024-09