title: Subcanopy responses to human-induced disturbances: Astrolabe/Otāiti and Motiti Reefs under the MV Rena and climate change stressors

authors: Elizabeth , Thompson

abstract: Disturbances are recognised as key drivers of ecosystem change, yet there remains limited consensus on how different disturbance types interact, particularly across trophic levels and within subcanopy communities. Existing theories often overlook the nonlinear relationships between climate-driven stressors and species interactions, underscoring the need for system-specific studies to clarify recovery mechanisms. The grounding of the MV Rena on Astrolabe Reef/Otāiti in 2011 resulted in New Zealand’s worst maritime environmental disaster. Fourteen years later, this provides a rare opportunity to assess how legacy disturbance interacts with natural variability to influence subcanopy assemblages. This thesis investigated subcanopy dynamics at two Bay of Plenty locations: Astrolabe Reef, directly impacted by the MV Rena wreck, and Motiti Island, a nearby reef indirectly affected by the wreck, but directly affected by Cyclone Gabrielle, and both systems subject to fishing pressure, sedimentation, and other stressors. Biodiversity surveys, species inventories and Baited Remote Underwater Videos, were combined with manipulative clearance experiments to test environmental responses. At Astrolabe Reef, small-scale clearances were established in high and low impact zones, while at Motiti Island, large canopy removals in Carpophyllum spp and Ecklonia radiata transition zones simulated storm-driven disturbance. Quantitative assessments after eleven weeks of the clearances revealed rapid recolonisation but divergent trajectories. At Astrolabe Reef, sites nearer the wreck were dominated by turfing algae and urchins (Centrostephanus rodgersii), while more distant sites supported greater sponge richness and habitat heterogeneity. At Motiti Island, opportunists such as kina (Evechinus chloroticus) and turfing algae shifted into available space. Carpophyllum spp. recovered strongly and expanded downslope, contrasting with the weak recovery of Ecklonia radiata. These findings demonstrate that outward canopy recovery can mask deeper structural shifts in subcanopy communities. More broadly, they highlight how legacy disturbance, grazer dynamics, and climate-driven pressures interact to shape resilience pathways in temperate reefs.

text: Subcanopy responses to human-induced disturbances: Astrolabe/Otāiti and Motiti Reefs under the MV Rena and climate change stressors Disturbances are recognised as key drivers of ecosystem change, yet there remains limited consensus on how different disturbance types interact, particularly across trophic levels and within subcanopy communities. Existing theories often overlook the nonlinear relationships between climate-driven stressors and species interactions, underscoring the need for system-specific studies to clarify recovery mechanisms. The grounding of the MV Rena on Astrolabe Reef/Otāiti in 2011 resulted in New Zealand’s worst maritime environmental disaster. Fourteen years later, this provides a rare opportunity to assess how legacy disturbance interacts with natural variability to influence subcanopy assemblages. This thesis investigated subcanopy dynamics at two Bay of Plenty locations: Astrolabe Reef, directly impacted by the MV Rena wreck, and Motiti Island, a nearby reef indirectly affected by the wreck, but directly affected by Cyclone Gabrielle, and both systems subject to fishing pressure, sedimentation, and other stressors. Biodiversity surveys, species inventories and Baited Remote Underwater Videos, were combined with manipulative clearance experiments to test environmental responses. At Astrolabe Reef, small-scale clearances were established in high and low impact zones, while at Motiti Island, large canopy removals in Carpophyllum spp and Ecklonia radiata transition zones simulated storm-driven disturbance. Quantitative assessments after eleven weeks of the clearances revealed rapid recolonisation but divergent trajectories. At Astrolabe Reef, sites nearer the wreck were dominated by turfing algae and urchins (Centrostephanus rodgersii), while more distant sites supported greater sponge richness and habitat heterogeneity. At Motiti Island, opportunists such as kina (Evechinus chloroticus) and turfing algae shifted into available space. Carpophyllum spp. recovered strongly and expanded downslope, contrasting with the weak recovery of Ecklonia radiata. These findings demonstrate that outward canopy recovery can mask deeper structural shifts in subcanopy communities. More broadly, they highlight how legacy disturbance, grazer dynamics, and climate-driven pressures interact to shape resilience pathways in temperate reefs.

year: 2026-01-27

title: N- vs O-Coordination in cyclomanganation of 1,5-diaryl-3-(2-pyridyl)pentane-1,5-diones and 3-(2-pyridyl)chalcones; cyclomanganation at saturated carbon and the crystal structure of [1,5-diphenyl-κC2-3-(2-pyridyl- κN)pentan-2-yl-κC2-1,5-dione-κO1κO5]tetracarbonylmanganesetricarbonylmanganese

authors: Tully, Warren

subjects: Manganese

abstract: Reaction of 1,5-diphenyl-3-(2-pyridyl)pentane-1,5-dione (5a) with 2.5 moles of benzylpentacarbonylmanganese in petroleum spirit under reflux gives a small amount of the symmetric di-aryl-manganated product [1,5-diphenyl-κC2-3-(2-pyridyl)pentane-1,5-dione-κO1κO5]bis-(tetracarbonylmanganese) (7a), but mostly [1,5-diphenyl-κC2-3-(2-pyridyl-κN)pentan-2-yl- κC2-1,5-dione-κO1κO5]tetracarbonylmanganesetricarbonylmanganese (6a) which is manganated at only one aryl carbon [by Mn(CO)4] but also [by Mn(CO)3 with N and O coordination] at the methylene carbon adjacent to the Mn(CO)4-coordinated ketone carbonyl. The latter is a rare example of direct cyclomanganation at a saturated carbon and the only known case adjacent to a carbonyl group; the X-ray crystal structure of 6a is reported. With 3 moles of benzylpentacarbonylmanganese the yield of 6a remains unchanged but some trimanganation product [1,5-diphenyl-κC2′κC2 -3-(2-pyridyl-κN)pentan-2-yl-κC2-1,5-dione-κO1κO5]tris-(tetracarbonylmanganese) (8a) is formed, presumably from 7a. Routes to products are proposed and activating factors considered. 1,5-Di-(2-thienyl)-3-(2-pyridyl)pentane-1,5-dione (5b) and its 3-thienyl isomer (5c) similarly give 6a analogues [1,5-di-(2-thienyl-κC3)-3-(2-pyridyl-κN)pentan-2-yl-κC2-1,5-dione-κO1κO5]tetracarbonylmanganesetricarbonylmanganese (6b) and [1,5-di-(3-thienyl-κC2)-3-(2-pyridyl-κN)pentan-2-yl-κC2-1,5-dione-κO1κO5]tetracarbonylmanganesetricarbonylmanganese (6c).
Also reported are the mono-cyclomanganation product [1-(2,6-dimethoxyphenyl)-3-(2-pyridyl-κN)prop-2-en-2-yl-κC2-1-one]tetracarbonylmanganese (16) and dicyclomanganation product [1-(2,5-dimethyl-3-thienyl-κC4)-3-(2-pyridyl-κN)prop-2-en-2-yl- κC2-1-one-κO ]bis-(tetracarbonylmanganese) (17) from reaction of the respective (E)-1-aryl-3-(2-pyridyl)prop-2-en-1-ones (3-(2-pyridyl)chalcones), the first reported examples of enone metallation at the α-carbon via N-coordination by a β-2-pyridyl group.

text: N- vs O-Coordination in cyclomanganation of 1,5-diaryl-3-(2-pyridyl)pentane-1,5-diones and 3-(2-pyridyl)chalcones; cyclomanganation at saturated carbon and the crystal structure of [1,5-diphenyl-κC2-3-(2-pyridyl- κN)pentan-2-yl-κC2-1,5-dione-κO1κO5]tetracarbonylmanganesetricarbonylmanganese Reaction of 1,5-diphenyl-3-(2-pyridyl)pentane-1,5-dione (5a) with 2.5 moles of benzylpentacarbonylmanganese in petroleum spirit under reflux gives a small amount of the symmetric di-aryl-manganated product [1,5-diphenyl-κC2-3-(2-pyridyl)pentane-1,5-dione-κO1κO5]bis-(tetracarbonylmanganese) (7a), but mostly [1,5-diphenyl-κC2-3-(2-pyridyl-κN)pentan-2-yl- κC2-1,5-dione-κO1κO5]tetracarbonylmanganesetricarbonylmanganese (6a) which is manganated at only one aryl carbon [by Mn(CO)4] but also [by Mn(CO)3 with N and O coordination] at the methylene carbon adjacent to the Mn(CO)4-coordinated ketone carbonyl. The latter is a rare example of direct cyclomanganation at a saturated carbon and the only known case adjacent to a carbonyl group; the X-ray crystal structure of 6a is reported. With 3 moles of benzylpentacarbonylmanganese the yield of 6a remains unchanged but some trimanganation product [1,5-diphenyl-κC2′κC2 -3-(2-pyridyl-κN)pentan-2-yl-κC2-1,5-dione-κO1κO5]tris-(tetracarbonylmanganese) (8a) is formed, presumably from 7a. Routes to products are proposed and activating factors considered. 1,5-Di-(2-thienyl)-3-(2-pyridyl)pentane-1,5-dione (5b) and its 3-thienyl isomer (5c) similarly give 6a analogues [1,5-di-(2-thienyl-κC3)-3-(2-pyridyl-κN)pentan-2-yl-κC2-1,5-dione-κO1κO5]tetracarbonylmanganesetricarbonylmanganese (6b) and [1,5-di-(3-thienyl-κC2)-3-(2-pyridyl-κN)pentan-2-yl-κC2-1,5-dione-κO1κO5]tetracarbonylmanganesetricarbonylmanganese (6c).
Also reported are the mono-cyclomanganation product [1-(2,6-dimethoxyphenyl)-3-(2-pyridyl-κN)prop-2-en-2-yl-κC2-1-one]tetracarbonylmanganese (16) and dicyclomanganation product [1-(2,5-dimethyl-3-thienyl-κC4)-3-(2-pyridyl-κN)prop-2-en-2-yl- κC2-1-one-κO ]bis-(tetracarbonylmanganese) (17) from reaction of the respective (E)-1-aryl-3-(2-pyridyl)prop-2-en-1-ones (3-(2-pyridyl)chalcones), the first reported examples of enone metallation at the α-carbon via N-coordination by a β-2-pyridyl group.

year: 2005-07-01

title: Engaging and working with Maori? Effective practice for psychologists in education

authors: Glynn, Ted

subjects: New Zealand

abstract: I believe this whakatauki captures the reflective processes I am now engaged in, as I assess where I have come from and where I am going, as a second-generation pakeha of Irish descent, who completed postgraduate degrees in Psychology and Education in New Zealand and Canada, and who has been engaging and working with Māori in the field of education for many years.

text: Engaging and working with Maori? Effective practice for psychologists in education I believe this whakatauki captures the reflective processes I am now engaged in, as I assess where I have come from and where I am going, as a second-generation pakeha of Irish descent, who completed postgraduate degrees in Psychology and Education in New Zealand and Canada, and who has been engaging and working with Māori in the field of education for many years.

year: 2008