title: Anticipating subnational depopulation: Policy responses and strategic interventions to regional decline

authors: McMillan, Rachael Christina

subjects: Depopulation

abstract: Population growth has already ended in a number of countries around the world. Significant demographic trends are transforming the global population, with record low fertility across the globe, increasing longevity and increasingly mobile populations. Depopulation is multifaceted and has major flow on effects for the allocation of resources, the provision of services and the viability of communities isolated from the economic powerhouses. 
This thesis studied the drivers of depopulation, the policy responses to population decline and the spectrum of interventions available to address population decline from a number of OECD countries. It also looked at whether population decline could be slowed or reversed through studying the demographic and distance challenges of peripheral towns in the Waikato Region in New Zealand. 
There is a strong relationship between depth and length of depopulation and the response to depopulation.  Responses to population decline vary from country to country based on historical, cultural, political, institutional arrangements, issues to be addressed and resource availability. 
The literature proposes that there are only three possible policy responses to population decline, non-intervention, countering and accepting.  It was found that successful ‘countering’ strategies were dependent on the location, economic and demographic context of each community and primarily slowed decline rather than reversing it.  None of the ‘accepting’ strategies that were identified were able to stop population decline.  It is easier to achieve improved quality of life than to slow population decline.  The research showed that in the context of zero or low national population growth peripheral towns are unlikely to gain population. Outmigration is even more significant in peripheral communities in nationally declining countries.
What became apparent through this research was that towns are like businesses – they need to keep reinventing themselves in the global marketplace to remain competitive.  However, some communities do not have the functional elements to succeed.  
It will be many years before New Zealand is depopulating at a national level, so there may still be opportunity to slow down population decline in peripheral locations.  The Waikato case study showed that this would be a challenging proposition for some Territorial Authorities on the periphery.  At the very least New Zealand can adapt to ageing population structure and increase the quality of life for those that inhabit small declining towns.  As more regional areas shift towards natural decline with low fertility rates and ageing populations and many enter permanent zero growth or decline, it is important that there are policies which are fit for purpose.

text: Anticipating subnational depopulation: Policy responses and strategic interventions to regional decline Population growth has already ended in a number of countries around the world. Significant demographic trends are transforming the global population, with record low fertility across the globe, increasing longevity and increasingly mobile populations. Depopulation is multifaceted and has major flow on effects for the allocation of resources, the provision of services and the viability of communities isolated from the economic powerhouses. 
This thesis studied the drivers of depopulation, the policy responses to population decline and the spectrum of interventions available to address population decline from a number of OECD countries. It also looked at whether population decline could be slowed or reversed through studying the demographic and distance challenges of peripheral towns in the Waikato Region in New Zealand. 
There is a strong relationship between depth and length of depopulation and the response to depopulation.  Responses to population decline vary from country to country based on historical, cultural, political, institutional arrangements, issues to be addressed and resource availability. 
The literature proposes that there are only three possible policy responses to population decline, non-intervention, countering and accepting.  It was found that successful ‘countering’ strategies were dependent on the location, economic and demographic context of each community and primarily slowed decline rather than reversing it.  None of the ‘accepting’ strategies that were identified were able to stop population decline.  It is easier to achieve improved quality of life than to slow population decline.  The research showed that in the context of zero or low national population growth peripheral towns are unlikely to gain population. Outmigration is even more significant in peripheral communities in nationally declining countries.
What became apparent through this research was that towns are like businesses – they need to keep reinventing themselves in the global marketplace to remain competitive.  However, some communities do not have the functional elements to succeed.  
It will be many years before New Zealand is depopulating at a national level, so there may still be opportunity to slow down population decline in peripheral locations.  The Waikato case study showed that this would be a challenging proposition for some Territorial Authorities on the periphery.  At the very least New Zealand can adapt to ageing population structure and increase the quality of life for those that inhabit small declining towns.  As more regional areas shift towards natural decline with low fertility rates and ageing populations and many enter permanent zero growth or decline, it is important that there are policies which are fit for purpose.

year: 2015

title: Computing L-Invariants for the Symmetric Square of an Elliptic Curve

authors: Delbourgo, Daniel

subjects: Science & Technology

abstract: Let E be an elliptic curve over Q, and p≠2 a prime of good ordinary reduction. The p-adic L-function for Sym²E always vanishes at s = 1, even though the complex L-function does not have a zero there. The L-invariant itself appears on the right-hand side of the formula
ddsLp(Sym²E,s)∣∣∣s=1=Lp(Sym²E)×(1−α⁻²ᵖ)(1−pα⁻²ᵖ)×L∞(Sym²E,1)(2πi)⁻¹Ω+EΩ-E
where X²−aᵖ(E)X+p=(X−αᵖ)(X−βᵖ) with αp∈Z×ᵖ. We first devise a method to calculate Lp(Sym²E) effectively, then show it is non-trivial for all elliptic curves E of conductor NE≤300 with 4|NE, and almost all ordinary primes p < 17. Hence, in these cases at least, the order of the zero in Lp(Sym²E,s) at s = 1 is exactly one.

text: Computing L-Invariants for the Symmetric Square of an Elliptic Curve Let E be an elliptic curve over Q, and p≠2 a prime of good ordinary reduction. The p-adic L-function for Sym²E always vanishes at s = 1, even though the complex L-function does not have a zero there. The L-invariant itself appears on the right-hand side of the formula
ddsLp(Sym²E,s)∣∣∣s=1=Lp(Sym²E)×(1−α⁻²ᵖ)(1−pα⁻²ᵖ)×L∞(Sym²E,1)(2πi)⁻¹Ω+EΩ-E
where X²−aᵖ(E)X+p=(X−αᵖ)(X−βᵖ) with αp∈Z×ᵖ. We first devise a method to calculate Lp(Sym²E) effectively, then show it is non-trivial for all elliptic curves E of conductor NE≤300 with 4|NE, and almost all ordinary primes p < 17. Hence, in these cases at least, the order of the zero in Lp(Sym²E,s) at s = 1 is exactly one.

year: 2019

title: Microplastics in the marine environment: Sediment contaminant and bioaccumulation rates in bivalves within the Bay of Plenty

authors: Lewis, Anita

subjects: Microplastic

abstract: Microplastic pollution is recognised as a significant anthropogenic issue in coastal ecosystems around the world. The accumulation of microplastics in coastal environments causes both direct and indirect effects on these already vulnerable ecosystems. Limited information was available of the scale of microplastic pollution across New Zealand, including the Bay of Plenty. To enable a greater understanding of microplastic accumulation in sediment and bioaccumulation in bivalves sampling  within the Bay of Plenty area was conducted.
The presence of  microplastic particles was investigated from sediment and shellfish samples collected across the Bay of Plenty, from Waihī Beach in the West, to Ōpōtiki in the East. Three species of shellfish were collected that differed in their functional feeding modes (filter feeder vs deposit feeder): tuangi (cockle: Austrovenus stuchburyi), hanikura (wedge shell: Macomona liliana), and tuatua (surf clam: Paphies subtriangulata). Microplastic particles from sediment and bivalves were separated from the sediment and shellfish samples in the laboratory and identified using visual light stereomicroscopy. Microplastic particles were identified and quantified into three categories: fragments, fibres, and films. 
Significant numbers of fibres, as well as some fragments and films were found to be present in the sediment throughout all sampling locations. The highest density of microplastic particles in sediment (up to 11,087.9 per m²) were observed at sites that were closed to municipal sewage outfalls and populated areas, and the lowest densities were observed at Matakana Island (63 particles per m²). Sites in Ōhiwa Harbour showed an average of 504.6 particles per m² at the high tide zone and 477.6 particles per m² at the intertidal zone in the sediment. Ohiwa Harbour showed similar levels of microplastic accumulation in sediment compared to Tauranga Harbour. However, higher levels of microplastic particles were found in the sediment at open coast sites.
All shellfish sampled had at least one microplastic particle found in their tissues. The highest number of microplastics in shellfish were found in the wedge shell (23 particles), with the least from the cockles (1). Statistical analysis reveal that the deep burrowing deposit feeder (Macomona liliana) demonstrated an elevated amount of microplastic particles ingested relative to the shallow burrowing suspension feeding cockle (Austrovenus stutchburyi). A notable amount of microplastic particles were also found at all sampling locations for the culturally important tuatua (Paphies subtriangulata). However, comparing all three bivalve species, the deposit feeding M. liliana, ingested higher amounts than both the A. stutchburyi and P. subtriangulata, which could be related to their different functional feeding modes in the marine environment. This research provides baseline information to assess the extent of microplastic pollution in sediments and the potential for bioaccumulation in bivalve species with differentiated feeding modes and functional roles in the marine environment. 
The problem with microplastics is a global emerging contaminant. Preventing the problem of plastic wastes in New Zealand will require change across all aspects of society, along with policy regulations to mitigate the issue of microplastic pollution.

text: Microplastics in the marine environment: Sediment contaminant and bioaccumulation rates in bivalves within the Bay of Plenty Microplastic pollution is recognised as a significant anthropogenic issue in coastal ecosystems around the world. The accumulation of microplastics in coastal environments causes both direct and indirect effects on these already vulnerable ecosystems. Limited information was available of the scale of microplastic pollution across New Zealand, including the Bay of Plenty. To enable a greater understanding of microplastic accumulation in sediment and bioaccumulation in bivalves sampling  within the Bay of Plenty area was conducted.
The presence of  microplastic particles was investigated from sediment and shellfish samples collected across the Bay of Plenty, from Waihī Beach in the West, to Ōpōtiki in the East. Three species of shellfish were collected that differed in their functional feeding modes (filter feeder vs deposit feeder): tuangi (cockle: Austrovenus stuchburyi), hanikura (wedge shell: Macomona liliana), and tuatua (surf clam: Paphies subtriangulata). Microplastic particles from sediment and bivalves were separated from the sediment and shellfish samples in the laboratory and identified using visual light stereomicroscopy. Microplastic particles were identified and quantified into three categories: fragments, fibres, and films. 
Significant numbers of fibres, as well as some fragments and films were found to be present in the sediment throughout all sampling locations. The highest density of microplastic particles in sediment (up to 11,087.9 per m²) were observed at sites that were closed to municipal sewage outfalls and populated areas, and the lowest densities were observed at Matakana Island (63 particles per m²). Sites in Ōhiwa Harbour showed an average of 504.6 particles per m² at the high tide zone and 477.6 particles per m² at the intertidal zone in the sediment. Ohiwa Harbour showed similar levels of microplastic accumulation in sediment compared to Tauranga Harbour. However, higher levels of microplastic particles were found in the sediment at open coast sites.
All shellfish sampled had at least one microplastic particle found in their tissues. The highest number of microplastics in shellfish were found in the wedge shell (23 particles), with the least from the cockles (1). Statistical analysis reveal that the deep burrowing deposit feeder (Macomona liliana) demonstrated an elevated amount of microplastic particles ingested relative to the shallow burrowing suspension feeding cockle (Austrovenus stutchburyi). A notable amount of microplastic particles were also found at all sampling locations for the culturally important tuatua (Paphies subtriangulata). However, comparing all three bivalve species, the deposit feeding M. liliana, ingested higher amounts than both the A. stutchburyi and P. subtriangulata, which could be related to their different functional feeding modes in the marine environment. This research provides baseline information to assess the extent of microplastic pollution in sediments and the potential for bioaccumulation in bivalve species with differentiated feeding modes and functional roles in the marine environment. 
The problem with microplastics is a global emerging contaminant. Preventing the problem of plastic wastes in New Zealand will require change across all aspects of society, along with policy regulations to mitigate the issue of microplastic pollution.

year: 2021