title: A summary of terminology used in tephra-related studies

authors: Lowe, David J.

subjects: tephra

abstract: The word ‘tephra’, derived from a Greek word for ash, is a collective term for all the unconsolidated, primary pyroclastic products of a volcanic eruption. We summarise here the meanings and applicability of this and related terms, including tephrostratigraphy, tephrochronology, tephrochronometry, tephrology, and cryptotephra. These and other tephra-based terms, some of which are erroneous or unnecessary, have been used in a wide range of stratigraphic and paleoenvironmental disciplines and in archaeology.

text: A summary of terminology used in tephra-related studies The word ‘tephra’, derived from a Greek word for ash, is a collective term for all the unconsolidated, primary pyroclastic products of a volcanic eruption. We summarise here the meanings and applicability of this and related terms, including tephrostratigraphy, tephrochronology, tephrochronometry, tephrology, and cryptotephra. These and other tephra-based terms, some of which are erroneous or unnecessary, have been used in a wide range of stratigraphic and paleoenvironmental disciplines and in archaeology.

year: 2001

title: Toxicological effects of MV Rena pollutants to New Zealand fish and lobster

authors: Webby, Ashley Jade

subjects: Oil spill

abstract: As part of the Rena Long Term Environmental Recovery Programme commissioned by the Ministry for the Environment in response to the grounding of the MV Rena on Astrolabe Reef (Otaiti), an experimental study of ecotoxicological effects was initiated to examine potential effects of major pollutants discharged from or associated with the Rena shipwreck. This project is one of the first examinations of ship wreck and oil spill pollution in New Zealand. Research will aid responses to future oil pollution events such as ship groundings and oil industry pollution.
The container ship MV Rena ran aground on Astrolabe Reef in the Bay of Plenty in October 2011 and discharged approximately 350 tonnes of heavy fuel oil (HFO). During the response HFO was treated with approximately 3 m³ of the oil dispersant Corexit 9500 at sea. Other pollutants associated with the Rena grounding included general cargo and other goods classified as environmentally hazardous, in particular, 560 tonnes of sodium hexafluoroaluminate or cryolite. Given the almost total absence of toxicity data relevant to HFOs, Corexit 9500 and other contaminant mixtures on New Zealand marine species, this project sought to assess the acute sublethal toxicity of these contaminants to a range of culturally, ecologically and commercially important species.
Sub-adult snapper (Pagrus auratus), spotted wrasse (Notolabrus celidotus) and red rock lobster (Jasus edwardsii) were exposed to 1:1000 cryolite, 1:10000 HFO (HFO WAF), 1:400000 Corexit 9500 and 1:40 HFO/Corexit 9500 combination (HFO CEWAF: 1:10000 HFO, 1:400000 Corexit 9500) for up to 96 h followed by recovery for up to 10 d. These concentrations and exposure durations were viewed as being environmentally realistic. Fish were necropsied and examined for haematology and accumulation of polycyclic aromatic hydrocarbons (PAHs).
Exposure to toxicants caused no lethality but did indicate sub-lethal effects. Measurements of blood parameters indicated two main effects in fish of erythrocyte swelling and haemoconcentration. The overall pattern of response in fish appeared to be a greater degree of erythrocyte swelling in response to the HFO WAF treatment. HFO WAF and HFO CEWAF treatments caused changes in leukocyte differential counts indicating negative responses of immunosuppression in fish. Corexit 9500 and cryolite exposure caused negligible/minimal changes in haematology in all species. Haematological assessment of Jasus edwardsii indicated immune effects of HFO WAF, HFO CEWAF and cryolite exposure as evident by changes in differential haemocyte counts.
Bile PAHs in fish and red rock lobster reached levels several orders of magnitude higher than controls. Corexit 9500 increased PAH body burden when combined with oil, however in fish it also appeared to accelerate depuration of PAHs during post-exposure recovery. Depuration was not as evident in red rock lobster. Exposure to HFO appeared to stimulate an increase in melanomacrophages in the spleen of Pagrus auratus. Overall HFO exposure with or without the addition of Corexit 9500 caused apparent sublethal changes in haematology that mostly recovered by 10 d post-exposure.

text: Toxicological effects of MV Rena pollutants to New Zealand fish and lobster As part of the Rena Long Term Environmental Recovery Programme commissioned by the Ministry for the Environment in response to the grounding of the MV Rena on Astrolabe Reef (Otaiti), an experimental study of ecotoxicological effects was initiated to examine potential effects of major pollutants discharged from or associated with the Rena shipwreck. This project is one of the first examinations of ship wreck and oil spill pollution in New Zealand. Research will aid responses to future oil pollution events such as ship groundings and oil industry pollution.
The container ship MV Rena ran aground on Astrolabe Reef in the Bay of Plenty in October 2011 and discharged approximately 350 tonnes of heavy fuel oil (HFO). During the response HFO was treated with approximately 3 m³ of the oil dispersant Corexit 9500 at sea. Other pollutants associated with the Rena grounding included general cargo and other goods classified as environmentally hazardous, in particular, 560 tonnes of sodium hexafluoroaluminate or cryolite. Given the almost total absence of toxicity data relevant to HFOs, Corexit 9500 and other contaminant mixtures on New Zealand marine species, this project sought to assess the acute sublethal toxicity of these contaminants to a range of culturally, ecologically and commercially important species.
Sub-adult snapper (Pagrus auratus), spotted wrasse (Notolabrus celidotus) and red rock lobster (Jasus edwardsii) were exposed to 1:1000 cryolite, 1:10000 HFO (HFO WAF), 1:400000 Corexit 9500 and 1:40 HFO/Corexit 9500 combination (HFO CEWAF: 1:10000 HFO, 1:400000 Corexit 9500) for up to 96 h followed by recovery for up to 10 d. These concentrations and exposure durations were viewed as being environmentally realistic. Fish were necropsied and examined for haematology and accumulation of polycyclic aromatic hydrocarbons (PAHs).
Exposure to toxicants caused no lethality but did indicate sub-lethal effects. Measurements of blood parameters indicated two main effects in fish of erythrocyte swelling and haemoconcentration. The overall pattern of response in fish appeared to be a greater degree of erythrocyte swelling in response to the HFO WAF treatment. HFO WAF and HFO CEWAF treatments caused changes in leukocyte differential counts indicating negative responses of immunosuppression in fish. Corexit 9500 and cryolite exposure caused negligible/minimal changes in haematology in all species. Haematological assessment of Jasus edwardsii indicated immune effects of HFO WAF, HFO CEWAF and cryolite exposure as evident by changes in differential haemocyte counts.
Bile PAHs in fish and red rock lobster reached levels several orders of magnitude higher than controls. Corexit 9500 increased PAH body burden when combined with oil, however in fish it also appeared to accelerate depuration of PAHs during post-exposure recovery. Depuration was not as evident in red rock lobster. Exposure to HFO appeared to stimulate an increase in melanomacrophages in the spleen of Pagrus auratus. Overall HFO exposure with or without the addition of Corexit 9500 caused apparent sublethal changes in haematology that mostly recovered by 10 d post-exposure.

year: 2014

title: Me ko Māui: Harnessing the sun to provide better outcomes for marae and communities

authors: Greensill, Waikauri

abstract: Marae are the cultural centres of Māori communities, providing a space for important gatherings both joyful and sad. With the advent of solar energy capture technologies and rising electricity bills, many marae are becoming interested in whether a solar powered system will be beneficial for them. However, marae have unique electricity demand profiles, distinct from commonly modelled building types such as residential or commercial buildings. It is thus difficult to estimate an appropriate solar and battery system size based on annual or even monthly electricity usage data, which may be the only data readily available, requiring more in-depth analysis at a highly site-specific level to find an answer. This thesis aims to increase understanding around how solar power could benefit marae, first by investigating the characteristic electricity demand profile of marae, then by observing how proposed system configurations meet the demand. The potential community benefits arising from such a system was also investigated. Using a year’s worth of half-hourly data from three marae, five characteristic day types were found in the analysis of the demand profile, namely a “Non-Event” profile that maintained a low baseload and accounted for 70% of the days in a year, a “1-Day Event” profile that lasted only a few hours, and for events spanning multiple days a “Start”, “Middle” and “End” day profile that varied greatly in demand magnitude. The demand profiles were then used to develop an annual demand profile for an average marae that was broadly representative of a wide range of marae. Different configurations of solar and battery powered systems were then applied to the annual demand and a technoeconomic analysis performed to determine whether a specific configuration met the needs of the average marae or not, which then produced a range of acceptable system sizes based on the needs specified. Not many solar and battery configurations resulted in positive economic returns for the marae alone, but widening the scope of the analysis to the surrounding community allows other interests such as local grid resilience to be considered, some of which may justify a marae’s decision to invest in a non-economic system to gain better community benefits. While investigating the use of peer-to-peer energy trading and community energy scenarios, sharing excess energy generated by a system with the wider community was also found to improve the economic outlook of solar for marae.

text: Me ko Māui: Harnessing the sun to provide better outcomes for marae and communities Marae are the cultural centres of Māori communities, providing a space for important gatherings both joyful and sad. With the advent of solar energy capture technologies and rising electricity bills, many marae are becoming interested in whether a solar powered system will be beneficial for them. However, marae have unique electricity demand profiles, distinct from commonly modelled building types such as residential or commercial buildings. It is thus difficult to estimate an appropriate solar and battery system size based on annual or even monthly electricity usage data, which may be the only data readily available, requiring more in-depth analysis at a highly site-specific level to find an answer. This thesis aims to increase understanding around how solar power could benefit marae, first by investigating the characteristic electricity demand profile of marae, then by observing how proposed system configurations meet the demand. The potential community benefits arising from such a system was also investigated. Using a year’s worth of half-hourly data from three marae, five characteristic day types were found in the analysis of the demand profile, namely a “Non-Event” profile that maintained a low baseload and accounted for 70% of the days in a year, a “1-Day Event” profile that lasted only a few hours, and for events spanning multiple days a “Start”, “Middle” and “End” day profile that varied greatly in demand magnitude. The demand profiles were then used to develop an annual demand profile for an average marae that was broadly representative of a wide range of marae. Different configurations of solar and battery powered systems were then applied to the annual demand and a technoeconomic analysis performed to determine whether a specific configuration met the needs of the average marae or not, which then produced a range of acceptable system sizes based on the needs specified. Not many solar and battery configurations resulted in positive economic returns for the marae alone, but widening the scope of the analysis to the surrounding community allows other interests such as local grid resilience to be considered, some of which may justify a marae’s decision to invest in a non-economic system to gain better community benefits. While investigating the use of peer-to-peer energy trading and community energy scenarios, sharing excess energy generated by a system with the wider community was also found to improve the economic outlook of solar for marae.

year: 2024