title: SHRIMP ion probe zircon geochronology and Sr and Nd isotope geochemistry for southern Longwood Range and Bluff Peninsula intrusive rocks of Southland, New Zealand

authors: Price, Richard C.

subjects: U-Pb geochronology

abstract: Permian–Jurassic ultramafic to felsic intrusive complexes at Bluff Peninsula and in the southern Longwood Range along the Southland coast represent a series of intraoceanic magmatic arcs with ages spanning a time interval of 110 m.y. New SHRIMP U-Pb zircon data for a quartz diorite from the Flat Hill complex, Bluff Peninsula, yield an age of 259 ± 4 Ma, consistent with other geochronological and paleontological evidence confirming a Late Permian age. The new data are consistent with an age of c. 260 Ma for the intrusive rocks of the Brook Street Terrane. SHRIMP U-Pb zircon ages for the southern Longwood Range confirm that intrusions become progressively younger from east to west across the complex. A gabbro at Oraka Point (eastern end of coastal section) has an age of 245 ± 4 Ma and shows virtually no evidence of zircon inheritance. The age is significantly different from that of the Brook Street Terrane intrusives. Zircon ages from the western parts of the section are younger and more varied (203–227 Ma), indicating more complex magmatic histories. A leucogabbro dike from Pahia Point gives the youngest emplacement age of 142 Ma, which is similar to published U-Pb zircon ages for the Anglem Complex and Paterson Group on Stewart Island.

text: SHRIMP ion probe zircon geochronology and Sr and Nd isotope geochemistry for southern Longwood Range and Bluff Peninsula intrusive rocks of Southland, New Zealand Permian–Jurassic ultramafic to felsic intrusive complexes at Bluff Peninsula and in the southern Longwood Range along the Southland coast represent a series of intraoceanic magmatic arcs with ages spanning a time interval of 110 m.y. New SHRIMP U-Pb zircon data for a quartz diorite from the Flat Hill complex, Bluff Peninsula, yield an age of 259 ± 4 Ma, consistent with other geochronological and paleontological evidence confirming a Late Permian age. The new data are consistent with an age of c. 260 Ma for the intrusive rocks of the Brook Street Terrane. SHRIMP U-Pb zircon ages for the southern Longwood Range confirm that intrusions become progressively younger from east to west across the complex. A gabbro at Oraka Point (eastern end of coastal section) has an age of 245 ± 4 Ma and shows virtually no evidence of zircon inheritance. The age is significantly different from that of the Brook Street Terrane intrusives. Zircon ages from the western parts of the section are younger and more varied (203–227 Ma), indicating more complex magmatic histories. A leucogabbro dike from Pahia Point gives the youngest emplacement age of 142 Ma, which is similar to published U-Pb zircon ages for the Anglem Complex and Paterson Group on Stewart Island.

year: 2006

title: Do benthic macrofauna functional groups or their key constituent species better predict variation in ecosystem functioning?

authors: Petersen, Grady

subjects: Marine science

abstract: Estuarine ecosystems are important zones for primary productivity and nutrient processing, have rich communities of plants and animals and support important fisheries and are fundamental to food webs. Intertidal habitats in estuaries are highly dynamic environments, subject to tidal variation and often have strong environmental gradients of salinity, turbidity and bed sediment grain size. These environmental factors contribute to the diversity of macrofaunal assemblages which vary over a range of spatial and temporal scales. This study was based in the Manukau Harbour, New Zealand, and aimed to investigate the spatial variation of nutrient processing within the harbour, and whether this variation is best explained by biotic or abiotic variables. Additionally, DistLM models were employed to find if either macrofauna functional groups or key species in these groups serve as better predictors of ecosystem function.
To provide empirical information to a project designing a whole-estuary nutrient mixing model, a team of ecologists deployed benthic incubation chambers (0.25 m2) to measure solute fluxes, and assessed the macrofauna community and sediment characteristics at 6 intertidal sandflat sites in the Manukau Harbour over a 4 day period in December 2016. Denitrification rates were measured at 2 sites to provide information on nitrogen removal from the harbour. This thesis deals specifically with how the macrofaunal communities and how they relate to and influence nutrient fluxes.
Macrofauna collected from the Manukau Harbour were assigned functional groups based on species specific traits. Multiple regression models were performed using functional groups and ecosystem variables as predictors, and dark chamber fluxes of O2, NH4+ and NOx- as response variables. Significantly correlated functional groups (p < 0.05) were substituted for their constituent species to determine whether functional groups or individual species served as better predictors of ecosystem functioning. 
The results indicated that while functional groups may provide redundancy in terms of multiple species carrying out similar functional roles, there are key species that dominate these roles. In addition to the macrofauna functional groups, several environmental variables (mud content, phaeophytin biomass and organic content) served as important predictors for changes in ecosystem functioning. 
This suggests that macrofauna functional groups form complex relationships with environmental variables which influence ecosystem functioning through benthic metabolism and excretion and macrofaunally-mediated such as bioturbation and irrigation of sediments. These biological processes alter the oxic-anoxic boundaries and facilitate the breakdown and remineralisation of deposited organic matter, fuelling primary productivity and nitrogen cycling.
At two sites where denitrification was measured, the total amount of nitrogen leaving the water column was similar (242.3 and 234.8 µmol N m-2 h-1), however the rates of denitrification of these sites was significantly (p = 0.0001) different, suggesting that permanent removal of nitrogen varies spatially across the harbour, which can have important connotations for ecosystem management.

text: Do benthic macrofauna functional groups or their key constituent species better predict variation in ecosystem functioning? Estuarine ecosystems are important zones for primary productivity and nutrient processing, have rich communities of plants and animals and support important fisheries and are fundamental to food webs. Intertidal habitats in estuaries are highly dynamic environments, subject to tidal variation and often have strong environmental gradients of salinity, turbidity and bed sediment grain size. These environmental factors contribute to the diversity of macrofaunal assemblages which vary over a range of spatial and temporal scales. This study was based in the Manukau Harbour, New Zealand, and aimed to investigate the spatial variation of nutrient processing within the harbour, and whether this variation is best explained by biotic or abiotic variables. Additionally, DistLM models were employed to find if either macrofauna functional groups or key species in these groups serve as better predictors of ecosystem function.
To provide empirical information to a project designing a whole-estuary nutrient mixing model, a team of ecologists deployed benthic incubation chambers (0.25 m2) to measure solute fluxes, and assessed the macrofauna community and sediment characteristics at 6 intertidal sandflat sites in the Manukau Harbour over a 4 day period in December 2016. Denitrification rates were measured at 2 sites to provide information on nitrogen removal from the harbour. This thesis deals specifically with how the macrofaunal communities and how they relate to and influence nutrient fluxes.
Macrofauna collected from the Manukau Harbour were assigned functional groups based on species specific traits. Multiple regression models were performed using functional groups and ecosystem variables as predictors, and dark chamber fluxes of O2, NH4+ and NOx- as response variables. Significantly correlated functional groups (p < 0.05) were substituted for their constituent species to determine whether functional groups or individual species served as better predictors of ecosystem functioning. 
The results indicated that while functional groups may provide redundancy in terms of multiple species carrying out similar functional roles, there are key species that dominate these roles. In addition to the macrofauna functional groups, several environmental variables (mud content, phaeophytin biomass and organic content) served as important predictors for changes in ecosystem functioning. 
This suggests that macrofauna functional groups form complex relationships with environmental variables which influence ecosystem functioning through benthic metabolism and excretion and macrofaunally-mediated such as bioturbation and irrigation of sediments. These biological processes alter the oxic-anoxic boundaries and facilitate the breakdown and remineralisation of deposited organic matter, fuelling primary productivity and nitrogen cycling.
At two sites where denitrification was measured, the total amount of nitrogen leaving the water column was similar (242.3 and 234.8 µmol N m-2 h-1), however the rates of denitrification of these sites was significantly (p = 0.0001) different, suggesting that permanent removal of nitrogen varies spatially across the harbour, which can have important connotations for ecosystem management.

year: 2018

title: Respecting and recognising Indigenous rights when challenged by commercial activities

authors: Toki, Valmaine

abstract: The United Nations Declaration on the Rights of Indigenous Peoples was hailed as a triumph among Indigenous peoples, signalling a long-awaited recognition of their fundamental human rights. Despite this, many violations of these basic rights continue, particularly in relation to extractive industries and business activities. In response, a business reference guide seeks to inform industries of their responsibilities. This article examines the tenuous relationship between Indigenous rights, state responsibilities and business expectations.

text: Respecting and recognising Indigenous rights when challenged by commercial activities The United Nations Declaration on the Rights of Indigenous Peoples was hailed as a triumph among Indigenous peoples, signalling a long-awaited recognition of their fundamental human rights. Despite this, many violations of these basic rights continue, particularly in relation to extractive industries and business activities. In response, a business reference guide seeks to inform industries of their responsibilities. This article examines the tenuous relationship between Indigenous rights, state responsibilities and business expectations.

year: 2018