title: Ecology of common bully (Gobiomorphus cotidianus) in the Tarawera and Rangitaiki rivers: isolation by inland distance or anthropogenic discharge?

authors: Bleackley, Natalie Anne

subjects: diadromy

abstract: Previous research has identified distinct genetic, life-history and reproductive differences between populations of common bully (Gobiomorphus cotidianus) upstream and downstream of a pulp and paper mill outfall on the Tarawera River in the Bay of Plenty, New Zealand. This study investigated the distribution of common bully in the Tarawera River by examining fish collected from upstream (37 km inland) and downstream (20 km inland) locations and comparing them to fish from similar inland locations (40 km and 17 km inland, respectively) in the nearby Rangitaiki River. Reproductive divergence was observed between upstream and downstream sites of both rivers by differing annual trends in gonadosomatic index. Stable carbon and nitrogen isotopes confirmed residency at each sampling site and otolith microchemistry demonstrated different life-history strategies between upstream and downstream populations. Diadromous recruits dominated in both downstream river populations, with a general disappearance of diadromy upstream. A mixture of diadromous and non-diadromous fish were found in the upstream Rangitaiki River, whereas diadromous recruits were absent in the upstream Tarawera River. A reduction in oculoscapular canal structures also coincided with loss of diadromy in fish from both rivers. A behavioural study to determine whether pulp and paper mill effluent may deter fish migration within the Tarawera River demonstrated a strong avoidance of effluent, but only at concentrations (>25%) greater than those that naturally occur in the river (<15%). The results of this study suggest that combinations of influences coupled with inland distance are likely to be responsible for the isolation of common bully subpopulations within the Tarawera River.

text: Ecology of common bully (Gobiomorphus cotidianus) in the Tarawera and Rangitaiki rivers: isolation by inland distance or anthropogenic discharge? Previous research has identified distinct genetic, life-history and reproductive differences between populations of common bully (Gobiomorphus cotidianus) upstream and downstream of a pulp and paper mill outfall on the Tarawera River in the Bay of Plenty, New Zealand. This study investigated the distribution of common bully in the Tarawera River by examining fish collected from upstream (37 km inland) and downstream (20 km inland) locations and comparing them to fish from similar inland locations (40 km and 17 km inland, respectively) in the nearby Rangitaiki River. Reproductive divergence was observed between upstream and downstream sites of both rivers by differing annual trends in gonadosomatic index. Stable carbon and nitrogen isotopes confirmed residency at each sampling site and otolith microchemistry demonstrated different life-history strategies between upstream and downstream populations. Diadromous recruits dominated in both downstream river populations, with a general disappearance of diadromy upstream. A mixture of diadromous and non-diadromous fish were found in the upstream Rangitaiki River, whereas diadromous recruits were absent in the upstream Tarawera River. A reduction in oculoscapular canal structures also coincided with loss of diadromy in fish from both rivers. A behavioural study to determine whether pulp and paper mill effluent may deter fish migration within the Tarawera River demonstrated a strong avoidance of effluent, but only at concentrations (>25%) greater than those that naturally occur in the river (<15%). The results of this study suggest that combinations of influences coupled with inland distance are likely to be responsible for the isolation of common bully subpopulations within the Tarawera River.

year: 2009

title: Biophysical, environmental, and economic implications of removing imported supplementary feed from a pasture-based dairy farm system -An upper North Island case study

authors: McCahon, Kieran Shaun

subjects: milk production

abstract: The biological efficiency and profitability of pasture-based systems is optimised by matching pasture supply with the nutritional demands of the herd across the year. Despite the importance of grazed pasture to the profitability of pasture-based systems, the use of purchased (i.e., non-pasture) feeds (supplementary feeds) has increased considerably over the last two decades within the New Zealand (NZ) dairy industry. 
Supplementary feeds may be offered to maintain or increase dry matter intake (DMI) and milk production during periods when pasture supply is insufficient to meet herd demands (i.e., a pasture deficit). However, published results indicate that, despite greater milk production and gross farm revenue (GFR), imported supplementary feed is not associated with an increase in profitability. In addition, the intensification of grazing systems through concurrent increases in stocking rate (SR) have been associated with poorer environmental outcomes, such as reduced water quality and increased greenhouse gas (GHG) emissions. 
The primary objective of my Masters project was to investigate the biophysical, economic, and environmental effects of removing imported supplementary feed from a typical pasture-based system in the upper North Island of New Zealand. This was conducted over three years in Northland, New Zealand (35⁰56’39”S 173⁰50’34”E), using a quantitative case-study approach that compared three pasture-based dairy farming treatments differing in SR and the nature of feed supply. As a Control treatment, imported supplementary feed was offered as palm kernel expeller (PKE) during periods of pasture deficit (~ 550kg DM/cow/yr; ~ 10% of the cows’ diet; PKE treatment). This was compared with two alternative systems to remove the need for PKE: 1) reduced SR (Pasture treatment); or, 2) growing potentially high yielding forage crops on the dairy platform and maintaining SR (Cropping treatment). I used the nutrient budgeting software OVERSEER to model treatment effects on nitrogen (N) leaching, phosphorous (P) loss, and GHG emissions. In addition, I conducted a Monte Carlo analysis to investigate economic performance of all three treatments and how it varied over a range of key input prices.
On average, despite no significant difference in milk production, operating profit tended to be lower in the Cropping treatment relative to the PKE treatment. In addition, after accounting for variability in market prices, the Cropping treatment returned a lower operating profit at every probability level relative to the PKE treatment and was, therefore, an inferior system for a profit-focused decision maker.
Milk production and associated GFR were lower in the Pasture treatment compared with the PKE treatment; however, there was no effect of treatment on operating profit at average market prices. When accounting for potential market price variability, the PKE treatment returned a greater operating profit in 70% of scenarios. As a result, the PKE treatment would likely provide a preferable system for a profit-focused decision maker, with low to moderate risk aversion. However, the relative profitability of treatments was highly dependent on the marginal milk production response (MMPR) to supplementary feed. Consistently large MMPRs to supplementary feed were achieved in the current study: 30 to 50% greater than published farm systems experiments. A reduction in the MMPR to supplementary feed by 10% eroded the profit advantage of the PKE treatment. In addition, despite no treatment effect on N leaching, GHG emissions tended to be lower in the Pasture treatment relative to the PKE treatment. As a result, a decision maker, paying or receiving incentives to reduce environmental externalities would likely be indifferent between the PKE and Pasture treatments, even with the large MMPR to supplementary feed achieved in the current study. Depending on the potential response to supplementary feed, profitability may be maintained with the removal of imported supplementary feeds from a pasture-based system by decreasing SR.

text: Biophysical, environmental, and economic implications of removing imported supplementary feed from a pasture-based dairy farm system -An upper North Island case study The biological efficiency and profitability of pasture-based systems is optimised by matching pasture supply with the nutritional demands of the herd across the year. Despite the importance of grazed pasture to the profitability of pasture-based systems, the use of purchased (i.e., non-pasture) feeds (supplementary feeds) has increased considerably over the last two decades within the New Zealand (NZ) dairy industry. 
Supplementary feeds may be offered to maintain or increase dry matter intake (DMI) and milk production during periods when pasture supply is insufficient to meet herd demands (i.e., a pasture deficit). However, published results indicate that, despite greater milk production and gross farm revenue (GFR), imported supplementary feed is not associated with an increase in profitability. In addition, the intensification of grazing systems through concurrent increases in stocking rate (SR) have been associated with poorer environmental outcomes, such as reduced water quality and increased greenhouse gas (GHG) emissions. 
The primary objective of my Masters project was to investigate the biophysical, economic, and environmental effects of removing imported supplementary feed from a typical pasture-based system in the upper North Island of New Zealand. This was conducted over three years in Northland, New Zealand (35⁰56’39”S 173⁰50’34”E), using a quantitative case-study approach that compared three pasture-based dairy farming treatments differing in SR and the nature of feed supply. As a Control treatment, imported supplementary feed was offered as palm kernel expeller (PKE) during periods of pasture deficit (~ 550kg DM/cow/yr; ~ 10% of the cows’ diet; PKE treatment). This was compared with two alternative systems to remove the need for PKE: 1) reduced SR (Pasture treatment); or, 2) growing potentially high yielding forage crops on the dairy platform and maintaining SR (Cropping treatment). I used the nutrient budgeting software OVERSEER to model treatment effects on nitrogen (N) leaching, phosphorous (P) loss, and GHG emissions. In addition, I conducted a Monte Carlo analysis to investigate economic performance of all three treatments and how it varied over a range of key input prices.
On average, despite no significant difference in milk production, operating profit tended to be lower in the Cropping treatment relative to the PKE treatment. In addition, after accounting for variability in market prices, the Cropping treatment returned a lower operating profit at every probability level relative to the PKE treatment and was, therefore, an inferior system for a profit-focused decision maker.
Milk production and associated GFR were lower in the Pasture treatment compared with the PKE treatment; however, there was no effect of treatment on operating profit at average market prices. When accounting for potential market price variability, the PKE treatment returned a greater operating profit in 70% of scenarios. As a result, the PKE treatment would likely provide a preferable system for a profit-focused decision maker, with low to moderate risk aversion. However, the relative profitability of treatments was highly dependent on the marginal milk production response (MMPR) to supplementary feed. Consistently large MMPRs to supplementary feed were achieved in the current study: 30 to 50% greater than published farm systems experiments. A reduction in the MMPR to supplementary feed by 10% eroded the profit advantage of the PKE treatment. In addition, despite no treatment effect on N leaching, GHG emissions tended to be lower in the Pasture treatment relative to the PKE treatment. As a result, a decision maker, paying or receiving incentives to reduce environmental externalities would likely be indifferent between the PKE and Pasture treatments, even with the large MMPR to supplementary feed achieved in the current study. Depending on the potential response to supplementary feed, profitability may be maintained with the removal of imported supplementary feeds from a pasture-based system by decreasing SR.

year: 2019

title: Māori social identities in New Zealand and Hawai'i

authors: Nikora, Linda Waimarie

subjects: Maori

abstract: This research is comprised of two narrative interview studies of Māori in two different settings, New Zealand (n=20) and Hawai'i (n=30).  The data was gathered over the 1994-1996 period.  The two settings have some commonalities and differences.  In both settings Māori are required to make decisions about the continuity of their ethnic Māori identities and hereditary cultural identities of iwi, hapu and whanau, and the part that they wish these identities to play in their daily lives.  The focus of this research was about how Māori create meaning in their lives and maintain their social identities across and within those contexts they move through. 

The findings of this research suggest that Māori in New Zealand continue to value and gain meaning and satisfaction from their cultural collectivities and the social identities derived from them.  However, the results tend to suggest that there are changes in the ways that individuals conceptualise these identities and concomitantly, how they see of themselves.
For New Zealand participants, conceptions of hapu and iwi appear to be converging with an increasing focus on the physicality of marae, its environment and symbolism, and the social events and relationships negotiated in that space.  New Zealand participants saw some hapu and iwi maintenance activities as more legitimate than others.  More value was placed on returning to hapu and iwi homelands however irregular these returns were.  In contrast, conceptions of hapu and iwi held by participants in Hawai'i seemed less intense.  There were few opportunities to engage with other hapu or iwi members.  Being Māori had greater meaning and was understood, probed and valued by others in the culturally plural context of Hawai'i.  For New Zealand participants, being Māori was enacted in the context of being a discriminated, negatively constructed minority.  All were aware of the defining effect that the presence of a dominant majority could have and countered these effects by engaging in social justice and in-group solidarity activities.

The changing identity conceptions held by members of Māori social groups will have implications for a sense of community and social cohesion, for tribal asset management, service delivery and crown settlement processes.  If Māori are redefining and renegotiating their social identities to achieve greater meaning and satisfaction then these changes are important to respond to and recognise.

text: Māori social identities in New Zealand and Hawai'i This research is comprised of two narrative interview studies of Māori in two different settings, New Zealand (n=20) and Hawai'i (n=30).  The data was gathered over the 1994-1996 period.  The two settings have some commonalities and differences.  In both settings Māori are required to make decisions about the continuity of their ethnic Māori identities and hereditary cultural identities of iwi, hapu and whanau, and the part that they wish these identities to play in their daily lives.  The focus of this research was about how Māori create meaning in their lives and maintain their social identities across and within those contexts they move through. 

The findings of this research suggest that Māori in New Zealand continue to value and gain meaning and satisfaction from their cultural collectivities and the social identities derived from them.  However, the results tend to suggest that there are changes in the ways that individuals conceptualise these identities and concomitantly, how they see of themselves.
For New Zealand participants, conceptions of hapu and iwi appear to be converging with an increasing focus on the physicality of marae, its environment and symbolism, and the social events and relationships negotiated in that space.  New Zealand participants saw some hapu and iwi maintenance activities as more legitimate than others.  More value was placed on returning to hapu and iwi homelands however irregular these returns were.  In contrast, conceptions of hapu and iwi held by participants in Hawai'i seemed less intense.  There were few opportunities to engage with other hapu or iwi members.  Being Māori had greater meaning and was understood, probed and valued by others in the culturally plural context of Hawai'i.  For New Zealand participants, being Māori was enacted in the context of being a discriminated, negatively constructed minority.  All were aware of the defining effect that the presence of a dominant majority could have and countered these effects by engaging in social justice and in-group solidarity activities.

The changing identity conceptions held by members of Māori social groups will have implications for a sense of community and social cohesion, for tribal asset management, service delivery and crown settlement processes.  If Māori are redefining and renegotiating their social identities to achieve greater meaning and satisfaction then these changes are important to respond to and recognise.

year: 2007