ORCID Profile
0000-0003-0543-7212
Current Organisation
The University of Auckland
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Publisher: SAGE Publications
Date: 27-05-2022
DOI: 10.1177/15586898211014422
Abstract: With a rising world population and pressure on ecosystems due to development, researchers need sophisticated and integrated approaches for conducting sustainability research. We outline a mixed methods practical sustainability research framework, defined as an equal-priority social–ecological methodology, whereby both community engagement and integrated bio ersity assessments are constructed to identify sustainability trade-offs. We illustrate the framework’s use for investigating the social–ecological trade-offs between preserving and removing temperate mangroves in New Zealand. We used a multistage mixed methods design with three stages to generate knowledge and identify social–ecological trade-offs. Our case study illustrates an operational approach for local mangrove management and regional coastal sustainability. Working with communities affected by ecosystem change through participatory research proved key to knowledge exchange and colearning.
Publisher: MDPI AG
Date: 29-10-2021
Abstract: The New Zealand abalone industry relies mostly on the export of processed products to distant Asian markets, notably China. Over the past five years, live export of high quality abalone from New Zealand has proven successful. However, transport of live animals is associated with multiple stressors that affect survival and meat quality at the end of the transport phase. Better understanding of transport-derived stress is needed to improve transport conditions and recovery at destination to ensure high product quality and safety throughout the supply chain. To this end, we applied an untargeted GC–MS-based metabolomics approach to examine the changes in metabolite profiles of abalone after a 2-day transport event and subsequent water re-immersion for 2 days. The results revealed alterations of many metabolites in the haemolymph and muscle of post-transported abalone. Decreased concentrations of many amino acids suggest high energy demands for metabolism and stress responses of transported abalone, while increases of other amino acids may indicate active osmoregulation and/or protein degradation due to oxidative stress and apoptosis. The accumulation of citric acid cycle intermediates and anaerobic end-products are suggestive of hypoxia stress and a shift from aerobic to anaerobic metabolism (resulting from aerial exposure). Interestingly, some features in the metabolite profile of reimmersed abalone resembled those of pre-transported in iduals, suggesting progressive recovery after reimmersion in water. Evidence of recovery was observed in the reduction of some stress biomarkers (e.g., lactic acid, succinic acid) following reimmersion. This study revealed insights into the metabolic responses to transport stress in abalone and highlights the importance of reimmersion practices in the supply chain of live animal exports.
Publisher: Elsevier BV
Date: 11-2004
Publisher: Elsevier BV
Date: 02-2023
Publisher: Elsevier BV
Date: 06-2023
Publisher: Elsevier BV
Date: 2023
Publisher: Elsevier BV
Date: 09-2022
DOI: 10.1016/J.FSI.2022.08.015
Abstract: The New Zealand Greenshell™ mussel (Perna canaliculus) is an endemic bivalve species with cultural importance, that is harvested recreationally and commercially. However, production is currently h ered by increasing incidences of summer mortality in farmed and wild populations. While the causative factors for these mortality events are still unknown, it is believed that increasing seawater temperatures and pathogen loads are potentially at play. To improve our understanding of these processes, challenge experiments were conducted to investigate the combined effects of increased seawater temperature and Vibrio infection on the immune and metabolic responses of adult mussels. Biomarkers that measure the physiological response of mussels to multiple-stressors can be utilised to study resilience in a changing environment, and support efforts to strengthen biosecurity management. Mussels acclimated to two temperatures (16 °C and 24 °C) were injected with either autoclaved, filtered seawater (control) or Vibriosp. DO1 (infected). Then, haemolymph was s led 24 h post-injection and analysed to quantify haemocyte immune responses (via flow-cytometry), antioxidant capacity (measured electrochemically) and metabolic responses (via gas chromatography-mass spectrometry) to bacterial infection. Both seawater temperature and injection type significantly influenced the immune and metabolite status of mussels. A lack of interaction effects between temperature and injection type indicated that the effects of Vibrio sp. 24 h post-infection were similar between seawater temperatures. Infected mussels had a higher proportion of dead haemocytes and lower overall haemocyte counts than uninfected controls. The proportion of haemocytes showing evidence of apoptosis was higher in mussels held at 24 °C compared with those held at 16 °C. The proportion of haemocytes producing reactive oxygen species did not differ between temperatures or injection treatments. Mussels held at 24 °C exhibited elevated levels of metabolites linked to the glycolysis pathway to support energy production. The saccharopin-lysine pathway metabolites were also increased in these mussels, indicating the role of lysine metabolism. A decrease in metabolic activity (decreases in BCAAs, GABA, urea cycle metabolites, oxidative stress metabolites) was largely seen in mussels injected with Vibrio sp. Itaconate increased as seen in previous studies, suggesting that antimicrobial activity may have been activated in infected mussels. This study highlights the complex nature of immune and metabolic responses in mussels exposed to multiple stressors and gives an insight into Vibrio sp. infection mechanisms at different seawater temperatures.
Publisher: Elsevier BV
Date: 2022
Publisher: Springer Science and Business Media LLC
Date: 27-12-2022
DOI: 10.1007/S11306-021-01862-8
Abstract: Ocean temperatures have been consistently increasing due to climate change, and the frequency of heatwave events on shellfish quality is a growing concern worldwide. Typically, shellfish growing areas are in remote or difficult to access locations which makes in-field s ling and s le preservation of shellfish heat stress difficult. As such, there is a need to investigate in-field s ling approaches that facilitate the study of heat stress in shellfish. This study aims to apply a gas chromatography-mass spectrometry (GC-MS) based metabolomics approach to examine molecular mechanisms of heat stress responses in shellfish using abalone as a model, and compare the effects of different quenching protocols on abalone metabolic profiles. Twenty adult Haliotis iris abalone were exposed to two temperatures (14 °C and 24 °C) for 24 h. Then, haemolymph and muscle tissues of each animal were s led and quenched with 4 different protocols (liquid nitrogen, dry ice, cold methanol solution and normal ice) which were analyzed via GC-MS for central carbon metabolites. The effects of different quenching protocols were only observed in muscle tissues in which the cold methanol solution and normal ice caused some changes in the observed metabolic profiles, compared to dry ice and liquid nitrogen. Abalone muscle tissues were less affected by thermal stress than haemolymph. There were 10 and 46 compounds significantly influenced by thermal stress in muscle and haemolymph, respectively. The changes of these metabolite signatures indicate oxidative damage, disturbance of amino acid and fatty acid metabolism, and a shift from aerobic metabolism to anaerobic pathways. The study provided insights into the heat response of abalone, which could be useful for understanding the effects of marine heatwaves and summer mortality events on abalone. Dry ice appeared to be a suitable protocol, and safer in-field alternative to liquid nitrogen, for quenching of abalone tissues.
Location: United States of America
No related grants have been discovered for Andrea C. Alfaro.