title: The source, composition and typology of ‘Limestone’ Adzes from Eastern North Island, New Zealand

authors: Nelson, Campbell S.

subjects: adzes

abstract: Collections of stone adzes (toki) from the eastern North Island of New Zealand include a number of typologically early (Archaic) forms made from what has been previously described as ‘siliceous or silicified limestone’. Seventy five finished adzes and preforms of this material were recorded in the present study. Their geographic distribution is primarily restricted to southern Hawkes Bay – Wairarapa, and they apparently originated from a single manufacturing centre at Owahanga, on the northern Wairarapa coast. Chemical and mineralogical analyses (by X-ray fluorescence, portable XRF, vacuum gasometry and X-ray diffraction) of two artefacts from Owahanga show they contain about 20–30 per cent CaCO3 (as calcite), while samples of the presumed local source rock have a slightly higher carbonate content but comparable silica (quartz) and Rb concentrations. The rock type used in the manufacture of adzes was therefore not a true limestone but calcareous mudstone, compositionally distinct from siliceous limestones in southern Wairarapa and probably derived from the Whangai Formation. Possible reasons for the use of this stone material are discussed.

text: The source, composition and typology of ‘Limestone’ Adzes from Eastern North Island, New Zealand Collections of stone adzes (toki) from the eastern North Island of New Zealand include a number of typologically early (Archaic) forms made from what has been previously described as ‘siliceous or silicified limestone’. Seventy five finished adzes and preforms of this material were recorded in the present study. Their geographic distribution is primarily restricted to southern Hawkes Bay – Wairarapa, and they apparently originated from a single manufacturing centre at Owahanga, on the northern Wairarapa coast. Chemical and mineralogical analyses (by X-ray fluorescence, portable XRF, vacuum gasometry and X-ray diffraction) of two artefacts from Owahanga show they contain about 20–30 per cent CaCO3 (as calcite), while samples of the presumed local source rock have a slightly higher carbonate content but comparable silica (quartz) and Rb concentrations. The rock type used in the manufacture of adzes was therefore not a true limestone but calcareous mudstone, compositionally distinct from siliceous limestones in southern Wairarapa and probably derived from the Whangai Formation. Possible reasons for the use of this stone material are discussed.

year: 2016

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

title: Does direct grammar instruction improve students’ performance on grammar-based tests of English as a foreign language?

authors: Wu, Hsiao-li

subjects: language learning

abstract: This paper reports the results of an experiment designed to test the hypothesis that direct grammar instruction has a positive impact on the test performance of learners of English as a foreign language. At first sight, the results appear to indicate that direct grammar instruction had a negligible effect overall on test performance. However, a more detailed examination of the results suggests that there was a marked positive effect in the case of some students. Furthermore, the test itself proved useful as a diagnostic tool and as a measure of student progress. Perhaps most significant is the fact that a comparison of the results of a pilot study and the experimental study itself raises issues about the significance, or otherwise, of research on teaching and learning second and foreign languages that is based on single experiments. Teachers of languages (international, community and indigenous) need to be sure that experimentally-based research is both robust and of direct relevance to the particular contexts in which they work. This is of real importance for many Pacific and Pacific-rim countries where the teaching and learning of English can have implications for economic success, and the teaching and learning of indigenous languages can have implications for the very survival of these languages.

text: Does direct grammar instruction improve students’ performance on grammar-based tests of English as a foreign language? This paper reports the results of an experiment designed to test the hypothesis that direct grammar instruction has a positive impact on the test performance of learners of English as a foreign language. At first sight, the results appear to indicate that direct grammar instruction had a negligible effect overall on test performance. However, a more detailed examination of the results suggests that there was a marked positive effect in the case of some students. Furthermore, the test itself proved useful as a diagnostic tool and as a measure of student progress. Perhaps most significant is the fact that a comparison of the results of a pilot study and the experimental study itself raises issues about the significance, or otherwise, of research on teaching and learning second and foreign languages that is based on single experiments. Teachers of languages (international, community and indigenous) need to be sure that experimentally-based research is both robust and of direct relevance to the particular contexts in which they work. This is of real importance for many Pacific and Pacific-rim countries where the teaching and learning of English can have implications for economic success, and the teaching and learning of indigenous languages can have implications for the very survival of these languages.

year: 2004-09