title: The ecology of bivalves on Centre Bank, Tauranga Harbour

authors: Hull, Penelope Jane

subjects: Tauranga Harbour

abstract: An investigation into the ecology of bivalve molluscs on Centre Bank, the flood tidal delta of Tauranga Harbour was undertaken over the period December 1994 - March 1996. The primary purpose of which was to gather quantitative data on bivalve diversity, spatial patterns of distribution, abundance, and population size structure of bivalves present on Centre Bank. Experiments were conducted to assess the burrowing behaviour of the bivalve Paphies australis. It was intended that information obtained be such that it could be used as a base for future investigations into changes in the ecology of Centre Bank.
Two broad scale benthic surveys of 27 sites on Centre Bank, conducted 6 months apart resulted in a total of 31 bivalve taxa being identified. Temporal and spatial variation in abundance was prominent for all species. Three species Paphies australis, Tawera spissa and Ruditapes largillierti occurred in far greater abundances than any others. Distribution of bivalves in both surveys was patchy with some species showing strong associations with particular sites.
Small scale abundance patterns of P. australis was examined in detail by systematic sampling of a 50 m x 15 m grid. The grid was monitored at 2- monthly intervals from March 1995 to November 1995. Abundances at sites in the northern half of the grid were found to be very dense (up to 1400 m², mean shell length=55-65 mm), while densities at the southern end were noticeably lower. Through time densities across the grid appeared to decrease evenly in a constant north-west direction. The smothering effect of mobile sand ridges was speculated to be the cause of these density decreases.
Experiments examining the burrowing behaviour of the infaunal bivalve Paphies australis were conducted both in the field and in the laboratory. The ability of P. australis to bury into the sediment if left exposed on the sediment surface was examined in the field. It appeared that P. australis were able to bury relatively quickly with the majority of experimental animals reburying within 40 minutes. Laboratory experiments showed P. australis to be capable of burrowing to the sediment surface after being inundated with sediment to a depth of 10 cm.

text: The ecology of bivalves on Centre Bank, Tauranga Harbour An investigation into the ecology of bivalve molluscs on Centre Bank, the flood tidal delta of Tauranga Harbour was undertaken over the period December 1994 - March 1996. The primary purpose of which was to gather quantitative data on bivalve diversity, spatial patterns of distribution, abundance, and population size structure of bivalves present on Centre Bank. Experiments were conducted to assess the burrowing behaviour of the bivalve Paphies australis. It was intended that information obtained be such that it could be used as a base for future investigations into changes in the ecology of Centre Bank.
Two broad scale benthic surveys of 27 sites on Centre Bank, conducted 6 months apart resulted in a total of 31 bivalve taxa being identified. Temporal and spatial variation in abundance was prominent for all species. Three species Paphies australis, Tawera spissa and Ruditapes largillierti occurred in far greater abundances than any others. Distribution of bivalves in both surveys was patchy with some species showing strong associations with particular sites.
Small scale abundance patterns of P. australis was examined in detail by systematic sampling of a 50 m x 15 m grid. The grid was monitored at 2- monthly intervals from March 1995 to November 1995. Abundances at sites in the northern half of the grid were found to be very dense (up to 1400 m², mean shell length=55-65 mm), while densities at the southern end were noticeably lower. Through time densities across the grid appeared to decrease evenly in a constant north-west direction. The smothering effect of mobile sand ridges was speculated to be the cause of these density decreases.
Experiments examining the burrowing behaviour of the infaunal bivalve Paphies australis were conducted both in the field and in the laboratory. The ability of P. australis to bury into the sediment if left exposed on the sediment surface was examined in the field. It appeared that P. australis were able to bury relatively quickly with the majority of experimental animals reburying within 40 minutes. Laboratory experiments showed P. australis to be capable of burrowing to the sediment surface after being inundated with sediment to a depth of 10 cm.

year: 1996

title: Photosynthesis of lichens from lichen-dominated communities in the alpine/nival belt of the Alps – II: Laboratory and field measurements of CO₂ exchange and water relations

authors: Reiter, Robert

subjects: lichen

abstract: CO₂ exchange and water relations of selected lichen species were investigated in the field and also in the laboratory, at a height of 3106 m above sea level in the Austrian Alps, during the short snowless summer period from middle of July to the end of August. In the course of the field investigations, clear summer days were quite rare. Altogether 14 diurnal courses of CO₂ exchange were measured spanning a time of 255 h of measurements.
The air temperatures measured close to the ground ranged between −0.7 and 17.1 °C and their daily fluctuation was lower than 10.7 °C. Fog was present for more than one-third of the measuring period and relative humidity (RH) exceeded 90% in almost half of the time. Temperature optimum of net photosynthesis (NP) of Xanthoria elegans and Brodoa atrofusca determined in the laboratory increased with increasing photosynthetic photon flux density (PPFD) from 1.5 to 11.3 °C and the maximal CO₂ uptake was found to be at 10 °C. In the field the lichens were metabolically active at air temperatures between −0.7 and 12.8 °C. The light compensation points (LCP) of both lichen species ranged in the laboratory between 50 and 200 μmol m⁻² s⁻¹ PPFD (0–20 °C) and in the field between 22 and 56 μmol m⁻² s⁻¹ PPFD (3–8 °C). At 30 °C the NP of X. elegans surpassed the LCP, whereas B. atrofusca remained below the LCP. NP in X. elegans did not reach light saturation at 1500 μmol m−2 s−1 PPFD. NP in B. atrofusca reached light saturation at low temperatures (−5 to +5 °C). At higher temperatures light saturation was almost detectable. On sunny days the lichens in the field were metabolically active only for 3 h during the early morning. In this time they reached the maximal values or values close to their maximal CO₂ uptake in situ. Under dry weather conditions the lichens dried out to a minimal water content (WC) of 5–12% which is below the moisture compensation point (MCP) of 34–25%. The optimal WC was between 90% and 120% dry weight (DW) in B. atrofusca and Umbilicaria cylindrica, in X. elegans between 140% and 180% DW. Species specific differences in water-holding capacity, desiccation intensity and in the compensation points of temperature, light and moisture are responsible for differences in metabolic activity. The lichens were active during less than half of the observation time. Total time of NP of X. elegans was 24% of the measuring period, for U. cylindrica 22% and for B. atrofusca 16%.

text: Photosynthesis of lichens from lichen-dominated communities in the alpine/nival belt of the Alps – II: Laboratory and field measurements of CO₂ exchange and water relations CO₂ exchange and water relations of selected lichen species were investigated in the field and also in the laboratory, at a height of 3106 m above sea level in the Austrian Alps, during the short snowless summer period from middle of July to the end of August. In the course of the field investigations, clear summer days were quite rare. Altogether 14 diurnal courses of CO₂ exchange were measured spanning a time of 255 h of measurements.
The air temperatures measured close to the ground ranged between −0.7 and 17.1 °C and their daily fluctuation was lower than 10.7 °C. Fog was present for more than one-third of the measuring period and relative humidity (RH) exceeded 90% in almost half of the time. Temperature optimum of net photosynthesis (NP) of Xanthoria elegans and Brodoa atrofusca determined in the laboratory increased with increasing photosynthetic photon flux density (PPFD) from 1.5 to 11.3 °C and the maximal CO₂ uptake was found to be at 10 °C. In the field the lichens were metabolically active at air temperatures between −0.7 and 12.8 °C. The light compensation points (LCP) of both lichen species ranged in the laboratory between 50 and 200 μmol m⁻² s⁻¹ PPFD (0–20 °C) and in the field between 22 and 56 μmol m⁻² s⁻¹ PPFD (3–8 °C). At 30 °C the NP of X. elegans surpassed the LCP, whereas B. atrofusca remained below the LCP. NP in X. elegans did not reach light saturation at 1500 μmol m−2 s−1 PPFD. NP in B. atrofusca reached light saturation at low temperatures (−5 to +5 °C). At higher temperatures light saturation was almost detectable. On sunny days the lichens in the field were metabolically active only for 3 h during the early morning. In this time they reached the maximal values or values close to their maximal CO₂ uptake in situ. Under dry weather conditions the lichens dried out to a minimal water content (WC) of 5–12% which is below the moisture compensation point (MCP) of 34–25%. The optimal WC was between 90% and 120% dry weight (DW) in B. atrofusca and Umbilicaria cylindrica, in X. elegans between 140% and 180% DW. Species specific differences in water-holding capacity, desiccation intensity and in the compensation points of temperature, light and moisture are responsible for differences in metabolic activity. The lichens were active during less than half of the observation time. Total time of NP of X. elegans was 24% of the measuring period, for U. cylindrica 22% and for B. atrofusca 16%.

year: 2008

title: Colouring in the White Spaces: Reclaiming Cultural Identity in Whitestream Schools

authors: Milne, Beverley Ann

subjects: Maori education

abstract: If we look at a child’s colouring book, before it has any colour added to it, we think of the page as blank.  It’s actually not blank, it’s white.  That white background is just “there” and we don’t think much about it.  Not only is the background uniformly white, the lines are already in place and they dictate where the colour is allowed to go.  When children are young, they don’t care where they put the colours, but as they get older they colour in more and more cautiously. They learn about the place of colour and the importance of staying within the pre-determined boundaries and expectations. 

This thesis argues that this is the setting for our mainstream, or what I have called, whitestream New Zealand schools — that white background is the norm.   When we talk about multiculturalism and diversity what we are really referring to is the colour of the children, or their difference from that white norm, and how they don’t fit perfectly inside our lines.  If the colour of the space doesn’t change schools are still in the business of assimilation, relegating non-white children to the margins, no matter how many school reform initiatives, new curricula, strategic plans, or mandated standards we implement.  What the schools in this study have tried to do is change the colour of the space – so that the space fits the children and they don’t have to constantly adjust to fit in.  

New Zealand’s education system has been largely silent on the topic of whiteness and the Eurocentric nature of our schooling policy and practice. However, when I talk to senior Māori and Pasifika ‘warrior-scholars” in Te Whānau o Tupuranga and Clover Park Middle School about “white spaces” they have encountered in their schooling experience they can identify them all too easily.  “White spaces,” they explain, are anything you accept as “normal” for Māori – when it’s really not,  any situation that prevents, or works against you “being Māori” or who you are, and that requires you to “be” someone else and leave your beliefs behind. White spaces are spaces that allow you to require less of yourself and that reinforce stereotypes and negative ideas about Māori.  Most telling of all was the comment from a Māori student that goes straight to the root of the problem, “White spaces are everywhere,” she said, “even in your head.”

This thesis describes the 25 year journey of two schools and their community’s determination to resist and reject alienating school environments in favour of a relevant culturally-located, bilingual learning model based in a secure cultural identity, stable positive relationships, and aroha (authentic caring and love).  While the research design is a case study, in terms of western, “white space” academic tradition, it is also a story in terms of kaupapa Māori and critical race methodology. More importantly, it is a counter-story that chronicles the efforts of these two schools to step outside education’s “white spaces” to create new space.  This counter-story is juxtaposed against pervasive, deficit-driven whitestream explanations of “achievement gaps” and the “long tail” of Māori and Pasifika “under-achievement” in New Zealand schools.  In the process of this research the focus shifted from how could Māori and Pasifika learners develop secure cultural identities in mainstream schools, to examining what barriers exist in schools that prevent this from happening already?  As these issues became clear the language of the thesis shifted accordingly; “developing” a cultural identity was reframed as a reclamation of educational sovereignty — the absolute right to “be Māori” or “be Pasifika” in school — and “mainstream” schooling became better understood as the “whitestream.” 

The study hopes to contribute to the journey other schools might take to identify and name their own white spaces, and to make learning equitable for indigenous and minoritised learners.

text: Colouring in the White Spaces: Reclaiming Cultural Identity in Whitestream Schools If we look at a child’s colouring book, before it has any colour added to it, we think of the page as blank.  It’s actually not blank, it’s white.  That white background is just “there” and we don’t think much about it.  Not only is the background uniformly white, the lines are already in place and they dictate where the colour is allowed to go.  When children are young, they don’t care where they put the colours, but as they get older they colour in more and more cautiously. They learn about the place of colour and the importance of staying within the pre-determined boundaries and expectations. 

This thesis argues that this is the setting for our mainstream, or what I have called, whitestream New Zealand schools — that white background is the norm.   When we talk about multiculturalism and diversity what we are really referring to is the colour of the children, or their difference from that white norm, and how they don’t fit perfectly inside our lines.  If the colour of the space doesn’t change schools are still in the business of assimilation, relegating non-white children to the margins, no matter how many school reform initiatives, new curricula, strategic plans, or mandated standards we implement.  What the schools in this study have tried to do is change the colour of the space – so that the space fits the children and they don’t have to constantly adjust to fit in.  

New Zealand’s education system has been largely silent on the topic of whiteness and the Eurocentric nature of our schooling policy and practice. However, when I talk to senior Māori and Pasifika ‘warrior-scholars” in Te Whānau o Tupuranga and Clover Park Middle School about “white spaces” they have encountered in their schooling experience they can identify them all too easily.  “White spaces,” they explain, are anything you accept as “normal” for Māori – when it’s really not,  any situation that prevents, or works against you “being Māori” or who you are, and that requires you to “be” someone else and leave your beliefs behind. White spaces are spaces that allow you to require less of yourself and that reinforce stereotypes and negative ideas about Māori.  Most telling of all was the comment from a Māori student that goes straight to the root of the problem, “White spaces are everywhere,” she said, “even in your head.”

This thesis describes the 25 year journey of two schools and their community’s determination to resist and reject alienating school environments in favour of a relevant culturally-located, bilingual learning model based in a secure cultural identity, stable positive relationships, and aroha (authentic caring and love).  While the research design is a case study, in terms of western, “white space” academic tradition, it is also a story in terms of kaupapa Māori and critical race methodology. More importantly, it is a counter-story that chronicles the efforts of these two schools to step outside education’s “white spaces” to create new space.  This counter-story is juxtaposed against pervasive, deficit-driven whitestream explanations of “achievement gaps” and the “long tail” of Māori and Pasifika “under-achievement” in New Zealand schools.  In the process of this research the focus shifted from how could Māori and Pasifika learners develop secure cultural identities in mainstream schools, to examining what barriers exist in schools that prevent this from happening already?  As these issues became clear the language of the thesis shifted accordingly; “developing” a cultural identity was reframed as a reclamation of educational sovereignty — the absolute right to “be Māori” or “be Pasifika” in school — and “mainstream” schooling became better understood as the “whitestream.” 

The study hopes to contribute to the journey other schools might take to identify and name their own white spaces, and to make learning equitable for indigenous and minoritised learners.

year: 2013