ORCID Profile
0000-0002-1945-3750
Current Organisation
University of Tasmania
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Publisher: MDPI AG
Date: 23-11-2022
Abstract: The longspined sea urchin, Centrostephanus rodgersii, is a climate-driven pest species in south-eastern Australia. The harvest of this species is highly encouraged and in Tasmania, the existing fishery is expanding resulting in a large amount of waste that needs disposal. Research into use of waste products as inputs for organic or biodynamic farming systems can help reduce costs of disposal and keep the industry profitable by sustaining or incrementing sea urchin harvest the industry can assist in their control. In the current study, urchin waste was dried and finely ground to a powder and applied to tomato plants in a greenhouse to examine the effect on growth and productivity. Urchin waste powder (UWP) had a mineral composition of Ca (40 g 100 g−1), Mg (1.7 g 100 g−1), P (0.03 g 100 g−1), Fe (19.34 mg kg−1) and B (38 mg kg−1), a pH 8.06 in water and an Electrical Conductivity (EC) value of 7.64 dSm−1. Seven different treatment rates of UWP (0.3% 0.5% 0.8% 1% 2% 3% 5%), were added to 10 replicate pots containing 4 kg nutrient-poor potting mix planted with tomato (Variety K1) seedlings. Plant growth, yield, quality attributes and mineral content of tomato were measured under UWP treatments with comparison against a Hoagland solution control. UWP influenced tomato growth and productivity proportional to the quantity applied, however, the Hoagland solution control had a significantly greater yield. Potting mix pH increased from 6.8 to 7 and higher available P was detected in potting mix receiving higher rates of UWP. No phytotoxic effects were detected. The highest UWP treatment matched the Hoagland control in fruit quality and nutritional composition. Processing waste from the sea urchin fishery has potential as organic fertiliser or amendment providing plant-available Ca and some microelements such as Boron.
Publisher: Frontiers Media SA
Date: 06-03-2020
Publisher: Springer Science and Business Media LLC
Date: 10-03-2005
Publisher: Elsevier BV
Date: 12-1996
Publisher: Wiley
Date: 2009
Publisher: Springer Science and Business Media LLC
Date: 14-07-2017
DOI: 10.1038/NCOMMS16101
Abstract: The Tasman Sea off southeast Australia exhibited its longest and most intense marine heatwave ever recorded in 2015/16. Here we report on several inter-related aspects of this event: observed characteristics, physical drivers, ecological impacts and the role of climate change. This marine heatwave lasted for 251 days reaching a maximum intensity of 2.9 °C above climatology. The anomalous warming is dominated by anomalous convergence of heat linked to the southward flowing East Australian Current. Ecosystem impacts range from new disease outbreaks in farmed shellfish, mortality of wild molluscs and out-of-range species observations. Global climate models indicate it is very likely to be that the occurrence of an extreme warming event of this duration or intensity in this region is respectively ≥330 times and ≥6.8 times as likely to be due to the influence of anthropogenic climate change. Climate projections indicate that event likelihoods will increase in the future, due to increasing anthropogenic influences.
Publisher: Oxford University Press (OUP)
Date: 09-2023
Publisher: Wiley
Date: 2004
DOI: 10.1002/AQC.597
Publisher: Elsevier BV
Date: 02-2018
Publisher: Informa UK Limited
Date: 12-1992
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.
Publisher: National Shellfisheries Association
Date: 08-2005
Publisher: Wiley
Date: 31-05-2012
Publisher: Frontiers Media SA
Date: 23-09-2021
DOI: 10.3389/FMARS.2021.693695
Abstract: Macroalgae, with their various morphologies, are ubiquitous throughout the world’s oceans and provide ecosystem services to a multitude of organisms. Water motion is a fundamental physical parameter controlling the mass transfer of dissolved carbon and nutrients to and from the macroalgal surface, but measurements of flow speed and turbulence within and above macroalgal canopies are lacking. This information is becoming increasingly important as macroalgal canopies may act as refugia for calcifying organisms from ocean acidification (OA) and the extent to which they act as refugia is driven by water motion. Here we report on a field c aign to assess the flow speed and turbulence within and above natural macroalgal canopies at two depths (3 and 6 m) and two sites (Ninepin Point and Tinderbox) in Tasmania, Australia in relation to the canopy height and % cover of functional forms. Filamentous groups made up the greatest proportion (75%) at both sites and depth while foliose groups were more prevalent at 3 than at 6 m. Irrespective of background flows, depth or site, flow speeds within the canopies were & .03 m s –1 – a ∼90% reduction in flow speeds compared to above the canopy. Turbulent kinetic energy (TKE) within the canopies was up to two orders of magnitude lower (& .008 m 2 s –2 ) than above the canopies, with higher levels of TKE within the canopy at 3 compared to 6 m. The significant d ing effect of flow and turbulence by macroalgae highlights the potential of these ecosystems to provide a refugia for vulnerable calcifying species to OA.
Publisher: Inter-Research Science Center
Date: 2003
DOI: 10.3354/MEPS252289
Publisher: Informa UK Limited
Date: 10-2012
Publisher: Oxford University Press (OUP)
Date: 25-04-2019
Abstract: Laboratory studies that test the responses of coastal organisms to ocean acidification (OA) typically use constant pH regimes which do not reflect coastal systems, such as seaweed beds, where pH fluctuates on diel cycles. Seaweeds that use CO2 as their sole inorganic carbon source (non-carbon dioxide concentrating mechanism species) are predicted to benefit from OA as concentrations of dissolved CO2 increase, yet this prediction has rarely been tested, and no studies have tested the effect of pH fluctuations on non-CCM seaweeds. We conducted a laboratory experiment in which two ecologically dominant non-CCM red seaweeds (Callophyllis lambertii and Plocamium dilatatum) were exposed to four pH treatments: two static, pHT 8.0 and 7.7 and two fluctuating, pHT 8.0 ± 0.3 and 7.7 ± 0.3. Fluctuating pH reduced growth and net photosynthesis in C. lambertii, while P. dilatatum was unaffected. OA did not benefit P. dilatatum, while C. lambertii displayed elevated net photosynthetic rates. We provide evidence that carbon uptake strategy alone cannot be used as a predictor of seaweed responses to OA and highlight the importance of species-specific sensitivity to [H+]. We also emphasize the importance of including realistic pH fluctuations in experimental studies on coastal organisms.
Publisher: Elsevier
Date: 2023
Publisher: Elsevier BV
Date: 06-2023
Publisher: Springer Science and Business Media LLC
Date: 07-2003
Publisher: Springer Science and Business Media LLC
Date: 27-07-2000
Publisher: Wiley
Date: 10-2014
DOI: 10.1111/MEC.12914
Abstract: Hierarchical s ling and subsequent microsatellite genotyping of >2300 Haliotis laevigata (greenlip abalone) from 19 locations distributed across five biogeographic regions have substantially advanced our knowledge of population structure and connectivity in this commercially important species. The study has found key differences in stock structure of H. laevigata compared with the sympatric and congeneric Haliotis rubra (blacklip abalone) and yielded valuable insights into the management of fisheries targeting species characterized by spatial structure at small scales (i.e. S-fisheries). As with H. rubra, H. laevigata comprise a series of metapopulations with strong self-recruitment. However, the spatial extent of H. laevigata metapopulations (reefal areas around 30 km(2) distances of up to 135 km are effective barriers to larval dispersal) was substantially greater than that identified for H. rubra (Miller et al. 2009). Differences in the dynamics and scale of population processes, even between congeneric haliotids as made evident in this study, imply that for S-fisheries, it is difficult to generalize about the potential consequences of life history commonalities. Consequently, species-specific management reflective of the population structure of the target species remains particularly important. This will likely require integration of information about stock structure and connectivity with data on life history and population dynamics to determine the necessary input (e.g. number of fishers, fishing effort) and output (e.g. minimum legal size, total allowable catch) controls to underpin their sustainable management.
Publisher: Elsevier BV
Date: 05-1998
Publisher: Springer Science and Business Media LLC
Date: 22-10-2020
Publisher: Wiley
Date: 02-04-2020
DOI: 10.1111/GCB.15052
Publisher: CSIRO Publishing
Date: 2007
DOI: 10.1071/MF07015
Abstract: The scale over which populations exchange in iduals (migration) is central to ecology, and important for understanding recruitment and connectivity in commercial species. Field studies indicate that blacklip abalone (Haliotis rubra) have localised larval dispersal. However, genetic studies show differentiation only at large scales, suggesting dispersal over more than 100 km. Most genetic studies, however, have failed to test for sub ision at scales equivalent to field experiments. We used microsatellite DNA to investigate genetic structure at small scales (100 m to 10 km) in blacklip abalone in south-east Tasmania. We found significant sub ision (FST = 0.021 P 0.05) among sites, and hierarchical FST analysis indicated 64% of genetic variation was at the smallest scale, supporting field studies that concluded larval dispersal is less than 100m. We also tested if genetic differentiation varied predictably with wave exposure, but found no evidence that differences between adjacent sites in exposed locations varied from differences between adjacent sites in sheltered populations (mean FST = 0.016 and 0.017 respectively). Our results show the usefulness of microsatellites for abalone, but also identify s ling scales as critical in understanding gene flow and dispersal of abalone larvae in an ecologically relevant framework. Importantly, our results indicate that H. rubra populations are self-recruiting, which will be important for the management of this commercial species.
Publisher: Springer Science and Business Media LLC
Date: 12-02-2015
Publisher: Oxford University Press (OUP)
Date: 13-01-0088
Abstract: Climate change increases the need to control range-extending species, which adversely impact their recipient ecosystem. Increasing populations of resident predators may be effective to counter such range-extension, but only if they consume the novel invaders at sufficient rates. In South-East Australia, poleward range-extending Longspined Sea Urchins (Centrostephanus rodgersii) are causing catastrophic ecological habitat transition to extensive urchin barrens. Tasmanian native Southern Rock Lobster (Jasus edwardsii) is a potential predator that could control further urchin expansion. Experimental feeding trials showed that range-extending Longspined Sea Urchins are the least preferred prey choice for Southern Rock Lobsters (3.8% predation events), when compared to three local species: abalone, urchins, and snails (36.6, 32.6, and 27%). Interestingly, habitat origin and naivete of lobsters to urchins affected urchin consumption with 85% being consumed by lobsters originating from urchin barrens. Low predation rates on Longspined Sea Urchin suggest that resident lobsters are unlikely to control further barren expansion unless a behavioural shift occurs. Results imply that potential control of Longspined Sea Urchins by Southern Rock Lobsters has previously been overestimated. Additional control methods are needed to safeguard ecological communities and important commercial stocks from this climate change-induced, range-extending pest species.
Publisher: Inter-Research Science Center
Date: 1988
DOI: 10.3354/MEPS045095
Publisher: Oxford University Press (OUP)
Date: 11-11-2021
Abstract: Most research investigating how ocean warming and acidification will impact marine species has focused on visually dominant species, such as kelps and corals, while ignoring visually cryptic species such as crustose coralline algae (CCA). CCA are important keystone species that provide settlement cues for invertebrate larvae and can be highly sensitive to global ocean change. However, few studies have assessed how CCA respond to low emission scenarios or conditions. In a laboratory experiment, we examined the responses of temperate CCA assemblages to combined warming and acidification projected under low, medium, and high emissions. Net calcification and net photosynthesis significantly declined in all emissions scenarios, while significant reductions in relative growth rates and increases in percentage bleaching were observed in the highest emission scenario. The negative responses of CCA to both low and medium emissions suggest that they may be adversely impacted by combined warming and acidification by 2030 if current emissions are sustained. This will have far reaching consequences for commercially important invertebrates that rely on them to induce settlement of larvae. These findings highlight the need to take rapid action to preserve these critical keystone species and the valuable services they provide.
Publisher: Elsevier BV
Date: 2022
Publisher: Elsevier BV
Date: 05-2005
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: CSIRO Publishing
Date: 2016
DOI: 10.1071/MF14340
Abstract: Satellite sea-surface temperature (SST) is widely used for biological modelling and ecological studies, assuming it represents subsurface in situ temperature (IST). We tested this assumption at 32 coastal sites in southern Australia, spanning a wide geographic range. Annual IST regimes are described and were demonstrated to be highly correlated with SST. Mean annual daily temperature differences between SST and IST (DTD) were generally small, varying spatially and seasonally (range 0–1°C). No correlation between DTDs and a range of site attributes was found, indicating the importance of site-specific factors. Seasonal DTDs were not geographically consistent, being higher in South Australia during the summer (mean 1.4°C) than in Tasmania (mean 0.5°C). Generally, small annual mean DTDs justify using SST for broad-scale ecological and climate-change studies, although considerable DTDs at some sites suggest that using SST at smaller spatial and temporal scales is unlikely to be appropriate. In addition, SST data lack information on daily temperature fluctuation that may be biologically relevant. Excepting South Australia, where spatially consistent summer DTDs would allow a correction factor, this site-specific variation is hard to correct. In spite of this, studies that rely on SST should consider the implications of such variation on the level of certainty associated with temperature-based predictions.
Publisher: University of Chicago Press
Date: 04-1994
DOI: 10.2307/1542050
Abstract: The apparatus was designed to enable ers to obtain discrete replicate s les from known volumes of water. Relatively large volumes of water can be filtered without the need to maintain contact with or return to the surface. These attributes confer a high degree of flexibility in subsurface s ling situations. Although we used the equipment to s le the eggs of invertebrates, it could equally easily be used to s le other small, patchily distributed plankton.
Publisher: No publisher found
Date: 2016
Publisher: CSIRO Publishing
Date: 1992
DOI: 10.1071/MF9920525
Abstract: Gametogenesis and reproductive behaviour of Acanthaster planci were observed at Davies Reef between September 1990 and February 1991. Gonad development in females and males of A. planci peaked in early December 1991. Mean gonad volume then decreased by about 50% following a major spawning in which at least two-thirds of the population participated. Mean gonad volume recovered to near prespawning values by mid January, despite a further minor spawning that was observed in the population. Further spawnings are likely to have occurred in mid- to late January. Fertilization rates measured during natural spawnings of A. planci were highest (83%) in s les taken at the peak of a major spawning event and much lower (23%) in s les taken at the end of the same spawning event. Trials conducted with starfish artificially induced to spawn indicated that potential fertilization rates decreased relatively slowly as distances between female and male animals increased. Fertilization rates were 47% for animals separated by 32 m. For animals separated by more than 60 m, fertilization rates were 23%. The distances at which these fertilization rates were achieved were two orders of magnitude greater than those recorded for other marine organisms, most likely because of the large volumes of gametes that A. planci can release.
Publisher: Inter-Research Science Center
Date: 2000
DOI: 10.3354/MEPS198109
Publisher: Springer Science and Business Media LLC
Date: 16-05-2019
Publisher: University of Chicago Press
Date: 02-1994
DOI: 10.2307/1542033
Abstract: This study was undertaken to compare fertilization rates of the sea star Acanthaster planci that were predicted using sperm diffusion models with those that were determined under natural conditions in the field. During experimentally induced spawnings, measured fertilization rates for broadcast eggs were high. More than 70% of the eggs were fertilized at distances as great as 8 m downstream from a single spawning male starfish, and more than 20% were fertilized at separations of more than 60 m. Fertilization was still measurable, at 5.8%, 100 m downstream. Lateral diffusion of sperm away from the axis of flow produced fertilization rates of 13.8% at 8 m normal to the flow and 32 m downstream. The large volumes of sperm released by male A. planci are the primary cause of high rates of fertilization for eggs derived from widely spaced in iduals. Models of sperm diffusion using high sperm release rates such as those found in this starfish accurately confirmed the fertilization rates measured in situ for two populations of A. planci with widely differing rates of sperm release. We observed some changes in starfish density and degree of aggregation in the study population for spawning periods during two spawning seasons, though these were not striking. High levels of aggregation may not be necessary for fertilization success in this starfish, due to the potential for long-distance fertilization and the probability that, for any spawning starfish, the total number of zygotes formed will be greater at some distance from the point of spawning. Although fertilization rates in areas distant from the sperm source were relatively low, the total area for potential gamete encounters is much greater and may make a large contribution to net fertilization. We predict that other behaviors, such as migration to shallow water, commonly associated with spawning in A. planci and other marine invertebrates will have measurable impacts on fertilization success. The potential for high levels of fertilization in A. planci was realized during natural spawnings. Fertilization rates as high as 99% were recorded when levels of spawning synchrony were high.
Location: New Zealand
Start Date: 2008
End Date: 2008
Funder: Winifred Violet Scott Charitable Trust
View Funded ActivityStart Date: 2012
End Date: 2013
Funder: Dept of Climate Change, Energy & Efficiency and FRDC
View Funded ActivityStart Date: 2016
End Date: 2016
Funder: Fisheries Research & Development Corporation
View Funded ActivityStart Date: 2017
End Date: 2017
Funder: Donation via University of Tasmania Foundation
View Funded ActivityStart Date: 2006
End Date: 2010
Funder: Fisheries Research and Development Corporation
View Funded Activity