title: Comparing volcanic glass shards in unfertilized and fertilized Andisols derived from rhyolitic tephras, New Zealand: evidence for accelerated weathering and implications for land management

authors: Taylor, Matthew D.

abstract: Enhanced weathering associated with the use of phosphate fertilizers has already been identified in some of the major farming areas of New Zealand and there is need to evaluate its effects on soil properties and the implications for soil management. We assess changes in the character of volcanic glass shards in topsoils (010 cm depth) of two tephra-derived Andisols of differing ages (Udivitrands, Hapludands), and with and without long-term fertilization, to test if fertilizing accelerates the weathering of soil constituents. Using visual assessment based on scanning electron microscopy and electron microprobe analyses of glass shards from samples from paired sites, we show that the average sizes of the shards and the sharpness of the glass-shard edges (angularity) diminished with the age of the soil, and that these decreases were more marked in the soils that had been fertilized. Silica polymorphs were observed only in the older soil (Hapludand) that had been fertilized. We concluded that the addition of phosphate-containing fertilizer enhanced the dissolution of volcanic glass, consistent with phosphoric acid and F--induced dealumination and desilication, and thus soil weathering has been accelerated. The Al and Si may subsequently coprecipitate as secondary minerals, such as allophane. However, silica polymorphs may form where Al activity is low. The occurrence of neogenic silica in topsoils (despite high annual rainfall that should result in desilication of the topsoil and reprecipitation of silica deeper in the soil) is explained by the seasonality of fertilizer application and the spring-summer climate, where the soil remains moist for periods sufficiently long enough for the dissolution of volcanic glass (and possibly other aluminosilicates), the formation of Al-humus complexes, and the subsequent precipitation of silica in dry periods. Some implications of the accelerated weathering for soil management are discussed.

text: Comparing volcanic glass shards in unfertilized and fertilized Andisols derived from rhyolitic tephras, New Zealand: evidence for accelerated weathering and implications for land management Enhanced weathering associated with the use of phosphate fertilizers has already been identified in some of the major farming areas of New Zealand and there is need to evaluate its effects on soil properties and the implications for soil management. We assess changes in the character of volcanic glass shards in topsoils (010 cm depth) of two tephra-derived Andisols of differing ages (Udivitrands, Hapludands), and with and without long-term fertilization, to test if fertilizing accelerates the weathering of soil constituents. Using visual assessment based on scanning electron microscopy and electron microprobe analyses of glass shards from samples from paired sites, we show that the average sizes of the shards and the sharpness of the glass-shard edges (angularity) diminished with the age of the soil, and that these decreases were more marked in the soils that had been fertilized. Silica polymorphs were observed only in the older soil (Hapludand) that had been fertilized. We concluded that the addition of phosphate-containing fertilizer enhanced the dissolution of volcanic glass, consistent with phosphoric acid and F--induced dealumination and desilication, and thus soil weathering has been accelerated. The Al and Si may subsequently coprecipitate as secondary minerals, such as allophane. However, silica polymorphs may form where Al activity is low. The occurrence of neogenic silica in topsoils (despite high annual rainfall that should result in desilication of the topsoil and reprecipitation of silica deeper in the soil) is explained by the seasonality of fertilizer application and the spring-summer climate, where the soil remains moist for periods sufficiently long enough for the dissolution of volcanic glass (and possibly other aluminosilicates), the formation of Al-humus complexes, and the subsequent precipitation of silica in dry periods. Some implications of the accelerated weathering for soil management are discussed.

year: 2016

title: Navigating the noise: evaluating the occurence of vessels and cetaceans within tamatea/dusky sound

authors: Bassett, Oliver

subjects: marine acoustics

abstract: Vessel use associated with recreation and tourism is currently increasing without limits in Dusky Sound. Passive acoustic monitoring was used to investigate spatiotemporal presence and potential cooccurrence of vessels with the endangered resident subpopulation of Fiordland bottlenose dolphins (Tursiops truncatus) and migratory humpback whales (Megaptera novaeangliae) within Tamatea/Dusky Sound, Fiordland Marine Area (FMA). Hydrophones were deployed between February 2022 and November 2023 at three recording sites to collect soundscape data within Dusky Sound. The internal coastline of Five Fingers Peninsula, inside Taumoana Marine Reserve, was identified as a previously unrecognised area of significant usage for Fiordland bottlenose dolphins. Detected humpback whale presence coincided with peaks in migration, and though identified by previous visual surveying efforts, the extent of their presence in the area during their northward migration was previously unreported. Humpback whale presence was significantly higher in June compared with other months, which is consistent with their described increased vocalisation behaviour during the northward migration. 

Vessel presence detected by passive acoustic monitoring was primarily dictated by usage patterns of tourism and recreational vessels and was greatest in the channel south of Anchor Island, a highly utilised access into Dusky Sound from the outer coast. Monthly equivalent continuous sound levels (LEqs), produced using Automatic Identification System vessel records and sound propagation modelling, illustrated that sound exposure levels regularly reached ~150 dB re 1 µPa2.s within the study area. Cruise ship transits were the major contributor to these high levels, with noise levels exceeding the recommended behavioural exposure threshold for continuous sound in much of the area during the late spring and summer months. Proactive management strategies including vessel limits, speed restrictions (slowdowns) and exclusion zones (dolphin protection zones) are likely required in the future to protect these species before the potential impacts from increased tourism is seen in Tamatea/Dusky Sound.

text: Navigating the noise: evaluating the occurence of vessels and cetaceans within tamatea/dusky sound Vessel use associated with recreation and tourism is currently increasing without limits in Dusky Sound. Passive acoustic monitoring was used to investigate spatiotemporal presence and potential cooccurrence of vessels with the endangered resident subpopulation of Fiordland bottlenose dolphins (Tursiops truncatus) and migratory humpback whales (Megaptera novaeangliae) within Tamatea/Dusky Sound, Fiordland Marine Area (FMA). Hydrophones were deployed between February 2022 and November 2023 at three recording sites to collect soundscape data within Dusky Sound. The internal coastline of Five Fingers Peninsula, inside Taumoana Marine Reserve, was identified as a previously unrecognised area of significant usage for Fiordland bottlenose dolphins. Detected humpback whale presence coincided with peaks in migration, and though identified by previous visual surveying efforts, the extent of their presence in the area during their northward migration was previously unreported. Humpback whale presence was significantly higher in June compared with other months, which is consistent with their described increased vocalisation behaviour during the northward migration. 

Vessel presence detected by passive acoustic monitoring was primarily dictated by usage patterns of tourism and recreational vessels and was greatest in the channel south of Anchor Island, a highly utilised access into Dusky Sound from the outer coast. Monthly equivalent continuous sound levels (LEqs), produced using Automatic Identification System vessel records and sound propagation modelling, illustrated that sound exposure levels regularly reached ~150 dB re 1 µPa2.s within the study area. Cruise ship transits were the major contributor to these high levels, with noise levels exceeding the recommended behavioural exposure threshold for continuous sound in much of the area during the late spring and summer months. Proactive management strategies including vessel limits, speed restrictions (slowdowns) and exclusion zones (dolphin protection zones) are likely required in the future to protect these species before the potential impacts from increased tourism is seen in Tamatea/Dusky Sound.

year: 2024

title: He pakiriha

authors: Temara, Pou

subjects: Tikanga

abstract: Kua tae ki te wā hai kōrero i ētahi tikanga marae, ētahi tikanga kawa e kawa ana ki tā te mātanga titiro. Tērā ētahi tikanga e whakamahia ana e ngā kaumātua o nāianei e uru atu ana ki te pae o rorirori, ka mutu, e ai ki tā ngā kaumātua nei, ko te mutunga mai o te tika ā rātau i whakatau ai. Nā hei whakarāpopoto i te whakaaro whānui, i ētahi wā kāore ko te mea e tika ana ki ō tātau whakaaro te huarahi pai. Ko tā te tikanga he kimi i te huarahi e tika ana, kia kore ai e whara ngā whakaaro o te tangata. Ko te tikanga ehara i te mea i whakairotia ki te kōhatu, engari e taea ana te neke i ngā pae o te tikanga kia pai ai te whakahaere a te tangata i āna mahi, kia tau ai te rangimārie, kia mau tonu ai te mana o te tangata. E whakapae ana ahau e kūmea ana e ētahi kaumātua ētahi tikanga kia hāngai ki tā rātau i whakaaro ai kai te tika, kai te hē rānei. Mā ētahi tauira e mārama ai te kaipānui ki te kaupapa me te whakaaro o te kaituhi.

text: He pakiriha Kua tae ki te wā hai kōrero i ētahi tikanga marae, ētahi tikanga kawa e kawa ana ki tā te mātanga titiro. Tērā ētahi tikanga e whakamahia ana e ngā kaumātua o nāianei e uru atu ana ki te pae o rorirori, ka mutu, e ai ki tā ngā kaumātua nei, ko te mutunga mai o te tika ā rātau i whakatau ai. Nā hei whakarāpopoto i te whakaaro whānui, i ētahi wā kāore ko te mea e tika ana ki ō tātau whakaaro te huarahi pai. Ko tā te tikanga he kimi i te huarahi e tika ana, kia kore ai e whara ngā whakaaro o te tangata. Ko te tikanga ehara i te mea i whakairotia ki te kōhatu, engari e taea ana te neke i ngā pae o te tikanga kia pai ai te whakahaere a te tangata i āna mahi, kia tau ai te rangimārie, kia mau tonu ai te mana o te tangata. E whakapae ana ahau e kūmea ana e ētahi kaumātua ētahi tikanga kia hāngai ki tā rātau i whakaaro ai kai te tika, kai te hē rānei. Mā ētahi tauira e mārama ai te kaipānui ki te kaupapa me te whakaaro o te kaituhi.

year: 2017