title: Recent and historical sedimentation and sediment characteristics of Ōhiwa Harbour, New Zealand

authors: La Croix, Andrew D.

abstract: The Bay of Plenty Regional Council is seeking to understand historical and recent sedimentation in Ōhiwa Harbour, a barrier-enclosed lagoon, to help establish sediment accumulation rates and water quality limits in accordance with the Resource Management Act (1991) and the NZ Freshwater Policy Statement. To provide sedimentation data that is independent of sediment plate data already being collected by the Council, and to supplement other historical data, a series of nine vibracores, nine box cores, and 73 surface sediment samples were collected from across Ōhiwa Harbour.
Three key vibracores were analyzed for their radionuclide activity (²¹⁰Pb and ²²⁶Ra) in an attempt to determine their sediment accumulation rates. However, no rate could be established due to very low and irregular radionuclide activity through the cores. It is probable that the method did not work due to the combined effects of hydrodynamic mixing and bioturbation.
Sedimentological analysis was undertaken on all nine vibracores and box cores, which indicated that the intertidal sediments consist of five distinctive depositional units: clast supported calci-gravel, ripple to cross bedded sand, bioturbated sand, laminated to rippled silt, and bioturbated silt. Recognition and interpretation of these units will be useful for future workers interested in reconstructing the evolution of sedimentation within the harbour.
Grain size of core sediment and surficial sediment around the harbour was compared to historical surface sediment maps. They show clearly that Ōhiwa Harbour is becoming muddier through time, although in a non-linear and complex way with some parts of the harbour getting sandier. The perimeter of the harbour and the upper harbour are the main areas affected by a fining grain size trend.
Loss-on-ignition (LOI) of sediment indicates that organic carbon is more concentrated in fine-grained sediment than coarser sediment across the harbour. No clear stratigraphic pattern of LOI could be established. However, surface sediments display larger LOI along the perimeter of the harbour where the proportion of mud is greater.
Three recommendations are put forth based on the results of this study, as well as gaps in knowledge discovered during data collection and analysis. The first is that determining longer-term (decadesâ€“millennia) sediment accumulation rates may be achievable by carbondating the abundant shell material contained within cores. The second is that calculation of sediment compaction under its own weight ('autocompaction') may help determine the causes of sedimentation and erosion in the harbour. The third and final recommendation is for repeat surface sediment surveys to be undertaken regularly, at intervals no greater than every five years. These insights will together yield a more complete picture of past, present, and future sedimentation and its effects in Ōhiwa Harbour.

text: Recent and historical sedimentation and sediment characteristics of Ōhiwa Harbour, New Zealand The Bay of Plenty Regional Council is seeking to understand historical and recent sedimentation in Ōhiwa Harbour, a barrier-enclosed lagoon, to help establish sediment accumulation rates and water quality limits in accordance with the Resource Management Act (1991) and the NZ Freshwater Policy Statement. To provide sedimentation data that is independent of sediment plate data already being collected by the Council, and to supplement other historical data, a series of nine vibracores, nine box cores, and 73 surface sediment samples were collected from across Ōhiwa Harbour.
Three key vibracores were analyzed for their radionuclide activity (²¹⁰Pb and ²²⁶Ra) in an attempt to determine their sediment accumulation rates. However, no rate could be established due to very low and irregular radionuclide activity through the cores. It is probable that the method did not work due to the combined effects of hydrodynamic mixing and bioturbation.
Sedimentological analysis was undertaken on all nine vibracores and box cores, which indicated that the intertidal sediments consist of five distinctive depositional units: clast supported calci-gravel, ripple to cross bedded sand, bioturbated sand, laminated to rippled silt, and bioturbated silt. Recognition and interpretation of these units will be useful for future workers interested in reconstructing the evolution of sedimentation within the harbour.
Grain size of core sediment and surficial sediment around the harbour was compared to historical surface sediment maps. They show clearly that Ōhiwa Harbour is becoming muddier through time, although in a non-linear and complex way with some parts of the harbour getting sandier. The perimeter of the harbour and the upper harbour are the main areas affected by a fining grain size trend.
Loss-on-ignition (LOI) of sediment indicates that organic carbon is more concentrated in fine-grained sediment than coarser sediment across the harbour. No clear stratigraphic pattern of LOI could be established. However, surface sediments display larger LOI along the perimeter of the harbour where the proportion of mud is greater.
Three recommendations are put forth based on the results of this study, as well as gaps in knowledge discovered during data collection and analysis. The first is that determining longer-term (decadesâ€“millennia) sediment accumulation rates may be achievable by carbondating the abundant shell material contained within cores. The second is that calculation of sediment compaction under its own weight ('autocompaction') may help determine the causes of sedimentation and erosion in the harbour. The third and final recommendation is for repeat surface sediment surveys to be undertaken regularly, at intervals no greater than every five years. These insights will together yield a more complete picture of past, present, and future sedimentation and its effects in Ōhiwa Harbour.

year: 2022

title: An investigation of colour discrimination with horses (Equus caballus)

authors: Blackmore, Tania Louise

subjects: chromatic discrimination

abstract: The ability of four horses (Equus caballus) to discriminate coloured (three shades of blue, green, red, and yellow) from grey (neutral density) stimuli, produced by back projected lighting filters, was investigated in a two response forced-choice procedure. Pushes of the lever in front of a coloured screen were occasionally reinforced, pushes of the lever in front of a grey screen were never reinforced. Each colour shade was randomly paired with a grey that was brighter, one that was dimmer, and one that approximately matched the colour in terms of brightness. Each horse experienced the colours in a different order, a new colour was started after 85% correct responses over five consecutive sessions or if accuracy showed no trend over sessions. All horses reached the 85% correct with blue versus grey, three horses did so with both yellow and green versus grey. All were above chance with red versus grey but none reached criterion. Further analysis showed the wavelengths of the green stimuli used overlapped with the yellow. The results are consistent with histological and behavioural studies that suggest that horses are dichromatic. They differ from some earlier data in that they indicate horses can discriminate yellow and blue, but that they may have deficiencies in discriminating red and green.

text: An investigation of colour discrimination with horses (Equus caballus) The ability of four horses (Equus caballus) to discriminate coloured (three shades of blue, green, red, and yellow) from grey (neutral density) stimuli, produced by back projected lighting filters, was investigated in a two response forced-choice procedure. Pushes of the lever in front of a coloured screen were occasionally reinforced, pushes of the lever in front of a grey screen were never reinforced. Each colour shade was randomly paired with a grey that was brighter, one that was dimmer, and one that approximately matched the colour in terms of brightness. Each horse experienced the colours in a different order, a new colour was started after 85% correct responses over five consecutive sessions or if accuracy showed no trend over sessions. All horses reached the 85% correct with blue versus grey, three horses did so with both yellow and green versus grey. All were above chance with red versus grey but none reached criterion. Further analysis showed the wavelengths of the green stimuli used overlapped with the yellow. The results are consistent with histological and behavioural studies that suggest that horses are dichromatic. They differ from some earlier data in that they indicate horses can discriminate yellow and blue, but that they may have deficiencies in discriminating red and green.

year: 2008

title: A proposed hauora Māori clinical guide for psychologists: Using the hui process and meihana model in clinical assessment and formulation

authors: Pitama, Suzanne G.

subjects: Māori

abstract: This paper documents a joint initiative of clinical practice educators from four tertiary institutions and their engagement in the design and development of a proposed Hauora Māori Clinical Guide for Psychologists, which outlines how to apply the Hui Process and Meihana Model to applied psychology. It describes the ability for this proposed Hauora Maori Clinical Guide for Psychologists to assist clinicians, professional psychology training programmes and institutions in meeting the expectations of the Health Practitioners Act and The New Zealand Psychologists Board’s (NZPB) Standards and Procedures document. It presents how this proposed guide can support the implementation of clinical and cultural competence and the Code of Ethics for Psychologists Working in New Zealand. It also provides an opportunity for the psychology profession to demonstrate responsivity to Te Tiriti o Waitangi obligations.

text: A proposed hauora Māori clinical guide for psychologists: Using the hui process and meihana model in clinical assessment and formulation This paper documents a joint initiative of clinical practice educators from four tertiary institutions and their engagement in the design and development of a proposed Hauora Māori Clinical Guide for Psychologists, which outlines how to apply the Hui Process and Meihana Model to applied psychology. It describes the ability for this proposed Hauora Maori Clinical Guide for Psychologists to assist clinicians, professional psychology training programmes and institutions in meeting the expectations of the Health Practitioners Act and The New Zealand Psychologists Board’s (NZPB) Standards and Procedures document. It presents how this proposed guide can support the implementation of clinical and cultural competence and the Code of Ethics for Psychologists Working in New Zealand. It also provides an opportunity for the psychology profession to demonstrate responsivity to Te Tiriti o Waitangi obligations.

year: 2017