The topic of animal growth has been central to my research since my honours year at the University of Melbourne where I studied abalone feeding behaviour. For my PhD I investigated the effects of hyper-nutrification on coral growth. Since then I have conducted and supervised research on the growth of fishes, worms and, most recently, crustaceans. I teach undergraduate units of Coastal Marine Ecosystems and Fisheries Biology at Southern Cross University. My aim is to integrate my research with my teaching as much as possible.
ABSTRACT A preliminary study was conducted to assess the usefulness of calcified ossicles from th... more ABSTRACT A preliminary study was conducted to assess the usefulness of calcified ossicles from the gastric mills of decapod crustaceans for ageing, based on the application of a traditional fisheries biology method for the analysis of concentric growth marks in scales, bones and otoliths. Transverse cross sections of prepyloric, zygocardiac and pyloric ossicles of gastric mills from Cherax quadricarinatus, Euastacus valentulus, Ranina ranina, Scylla serrata and Thenus orientalis showed the presence of alternating translucent and opaque growth rings. Growth ring analysis indicated a growth record in two series, each likely representing different periodicities. Comparisons of growth ring counts showed close agreement between all gastric ossicles examined. Progressive sectioning of zygocardiac ossicles from C. quadricarinatus and S. serrata showed that growth ring counts varied along the length of these structures and demonstrated the need for species-specific assessment of gastric mill components. In conclusion, further empirical research is warranted to validate the periodicity of the gastric ossicle growth record to further elucidate its potential for ageing crustaceans.
Anecdotal reports from fishers in Southeast Queensland, Australia suggest that shark depredation ... more Anecdotal reports from fishers in Southeast Queensland, Australia suggest that shark depredation is a significant issue, however little is known about which species are responsible for depredating catches. This research aimed to identify depredating species in Southeast Queensland line based fisheries, by undertaking a genetic analysis of depredated samples collected by commercial, charter and recreational fishers. The genetic analysis successfully identified ten depredating sharks, all from the genus Carcharhinus (19.2% success). The species identified using mitochondrial DNA included five C. leucas (bull sharks), two C. plumbeus (sandbar sharks), one C. amboinensis (pigeye shark) , one C. brevipinna (spinner shark) and one unconfirmed C. plumbeus / C. altimus (bignose shark). While many species of Carcharhinus have been found to depredate catches in Australia, C. leucas has not been highlighted until this research as a potential problematic species. The optimised protocol allowed for the confident identification of shark species responsible for depredation in fisheries using frozen fish samples donated by fishers.
This research project stemmed from the principal investigator’s (J. Leland) pioneering crustacean... more This research project stemmed from the principal investigator’s (J. Leland) pioneering crustacean ageing research at Southern Cross University (see Leland et al., 2011), for which he was awarded the Department of Agriculture, Fisheries and Forestry 2013 Science and Innovation Award (Fisheries category). The associated Fisheries Research and Development Corporation (FRDC) funded grant initiated a one year research project into direct age-determination studies for two short-lived Australian crustaceans (i.e. the Mud Crab, Scylla serrata and Redclaw Crayfish, Cherax quadricarinatus). That project allowed J. Leland to refine his direct ageing protocols and resulted in one scientific publication (Leland et al., 2015) and an Honours thesis (Sarapuk, 2014) that demonstrated the methods applicability to short-lived subtropical decapods. During that time, co-investigator S. de Lestang was investigating the utility of direct methods for ageing Western Rock Lobster (Panulirus cygnus – see Rudd, 2013), while applying for FRDC funding (along with other co-investigators) to support further research. This project represents a combination of the two initiatives. Recognition of the value of developing direct methods for ageing crustaceans, while extending Australian leadership in this field has led to this collaborative effort. This project aligns with five FRDC Strategic Priority Areas: Program 1 (Environment), Program 2 (Industry), Program 3 (Communities), Program 4 (People) and Program 5 (Adoption)
The six chapters of this thesis demonstrate how data from reef monitoring, coral recruitment, and... more The six chapters of this thesis demonstrate how data from reef monitoring, coral recruitment, and larval dispersal models provide insights into the drivers of reef recovery and be used to support the conservation management of coral reefs. While 9-12 years was needed for coral reefs to recover from 1998-mass bleaching event, the recovery of the eastern outer reefs following typhoon disturbances is predicted to be slower due to overall low larval supply within this habitat. Following larval supply, high reef structural complexity, suitable substrata availability and high herbivory facilitated the recovery of dominant coral taxa following both types of disturbances.
Rising levels of atmospheric carbon dioxide are driving ocean warming and acidification. This cou... more Rising levels of atmospheric carbon dioxide are driving ocean warming and acidification. This could cause stress resulting in decreases in nutritional quality of marine species for human consumption, if environmental changes go beyond the optimal range for harvested species. To evaluate this, we used ambient and near-future elevated temperatures and pCO2 to assess impacts on the proximate nutritional composition (moisture, ash, protein, and lipids), fatty acids and trace elements of the foot tissue of Turbo militaris, a commercially harvested marine snail from south-eastern Australia. In a fully orthogonal design, the snails were exposed to ambient seawater conditions (22 ± 0.2 °C, pH 8.13 ± 0.01–450 μatm pCO2), ocean warming (25 ± 0.05 °C), pCO2 ocean acidification (pH 7.85 ± 0.02, ∼880 μatm pCO2) or a combination of both in controlled flow-through seawater mesocosms for 38 days. Moisture, ash, protein and total lipid content of the foot tissue in the turban snails was unaffected b...
Reef cryptofauna (animals inhabiting cracks and crevices) represent much of a reef’s biodiversity... more Reef cryptofauna (animals inhabiting cracks and crevices) represent much of a reef’s biodiversity yet are seldom studied owing to their inaccessibility. Subtidal rocky reefs off Brunswick Heads and Byron Bay in northern New South Wales, Australia support benthic communities ranging from coral-dominated offshore reefs to kelp beds of Ecklonia radiata on inshore reefs. It was hypothesised that differential exposure to river discharge and the East Australian Current, as well as proximity to other reef habitats, may produce differences in recruitment and persistence of cryptofauna between superficially similar reefs within a small geographical range. Artificial crevice habitats were deployed at similar depths on three inshore reefs supporting similar Ecklonia densities. Although the species richness of crevice fauna was similar at all reefs, the species composition differed significantly along with the assemblages recruited in different seasons and to different crevice sizes. Neither re...
Journal of University Teaching and Learning Practice
This paper builds on some ideas recently presented by Boyd et al. (2010). In that paper, the focu... more This paper builds on some ideas recently presented by Boyd et al. (2010). In that paper, the focus was on the ways in which experienced academic staff articulate the teaching-research nexus. By presenting six short case accounts, this paper describes how a reflective narrative activity enabled some ‘new to academe’ teachers to identify the teaching research nexus in their own work. For each of them, there was some particular reason or stimulus that led to them articulating the teaching-learning nexus in their work. Given the effectiveness of this method for enabling staff to consider the teaching-research nexus, this paper speculates on ways of drawing all academic staff to encounter the ‘concept’ of the teachingresearch nexus.
Rates of linear extension and changes in buoyant weight were measured for transplanted colonies o... more Rates of linear extension and changes in buoyant weight were measured for transplanted colonies of Acropora longicyathus exposed to elevated concentrations of ammonium and/or phosphate in the ENCORE experiment (One Tree Island, Great Barrier Reef). Linear extension was significantly faster in elevated phosphate treatments compared with controls. Rates of buoyant weight change were significantly increased by elevated ammonium on an annual basis, but significant reductions occurred in winter. Phosphate significantly increased the rate of buoyant weight change in some seasons but had no significant effect on an annual basis. Caution is therefore advised when extrapolating short-term growth data to represent annual trends. Chlorophyll a content of phosphate-treated corals was significantly higher than controls. Unlike other coral taxa in previous studies, elevated chlorophyll a content in Acropora longicyathus in this study did not correlate with reduced calcification. Growth of Acropor...
ABSTRACT A preliminary study was conducted to assess the usefulness of calcified ossicles from th... more ABSTRACT A preliminary study was conducted to assess the usefulness of calcified ossicles from the gastric mills of decapod crustaceans for ageing, based on the application of a traditional fisheries biology method for the analysis of concentric growth marks in scales, bones and otoliths. Transverse cross sections of prepyloric, zygocardiac and pyloric ossicles of gastric mills from Cherax quadricarinatus, Euastacus valentulus, Ranina ranina, Scylla serrata and Thenus orientalis showed the presence of alternating translucent and opaque growth rings. Growth ring analysis indicated a growth record in two series, each likely representing different periodicities. Comparisons of growth ring counts showed close agreement between all gastric ossicles examined. Progressive sectioning of zygocardiac ossicles from C. quadricarinatus and S. serrata showed that growth ring counts varied along the length of these structures and demonstrated the need for species-specific assessment of gastric mill components. In conclusion, further empirical research is warranted to validate the periodicity of the gastric ossicle growth record to further elucidate its potential for ageing crustaceans.
Anecdotal reports from fishers in Southeast Queensland, Australia suggest that shark depredation ... more Anecdotal reports from fishers in Southeast Queensland, Australia suggest that shark depredation is a significant issue, however little is known about which species are responsible for depredating catches. This research aimed to identify depredating species in Southeast Queensland line based fisheries, by undertaking a genetic analysis of depredated samples collected by commercial, charter and recreational fishers. The genetic analysis successfully identified ten depredating sharks, all from the genus Carcharhinus (19.2% success). The species identified using mitochondrial DNA included five C. leucas (bull sharks), two C. plumbeus (sandbar sharks), one C. amboinensis (pigeye shark) , one C. brevipinna (spinner shark) and one unconfirmed C. plumbeus / C. altimus (bignose shark). While many species of Carcharhinus have been found to depredate catches in Australia, C. leucas has not been highlighted until this research as a potential problematic species. The optimised protocol allowed for the confident identification of shark species responsible for depredation in fisheries using frozen fish samples donated by fishers.
This research project stemmed from the principal investigator’s (J. Leland) pioneering crustacean... more This research project stemmed from the principal investigator’s (J. Leland) pioneering crustacean ageing research at Southern Cross University (see Leland et al., 2011), for which he was awarded the Department of Agriculture, Fisheries and Forestry 2013 Science and Innovation Award (Fisheries category). The associated Fisheries Research and Development Corporation (FRDC) funded grant initiated a one year research project into direct age-determination studies for two short-lived Australian crustaceans (i.e. the Mud Crab, Scylla serrata and Redclaw Crayfish, Cherax quadricarinatus). That project allowed J. Leland to refine his direct ageing protocols and resulted in one scientific publication (Leland et al., 2015) and an Honours thesis (Sarapuk, 2014) that demonstrated the methods applicability to short-lived subtropical decapods. During that time, co-investigator S. de Lestang was investigating the utility of direct methods for ageing Western Rock Lobster (Panulirus cygnus – see Rudd, 2013), while applying for FRDC funding (along with other co-investigators) to support further research. This project represents a combination of the two initiatives. Recognition of the value of developing direct methods for ageing crustaceans, while extending Australian leadership in this field has led to this collaborative effort. This project aligns with five FRDC Strategic Priority Areas: Program 1 (Environment), Program 2 (Industry), Program 3 (Communities), Program 4 (People) and Program 5 (Adoption)
The six chapters of this thesis demonstrate how data from reef monitoring, coral recruitment, and... more The six chapters of this thesis demonstrate how data from reef monitoring, coral recruitment, and larval dispersal models provide insights into the drivers of reef recovery and be used to support the conservation management of coral reefs. While 9-12 years was needed for coral reefs to recover from 1998-mass bleaching event, the recovery of the eastern outer reefs following typhoon disturbances is predicted to be slower due to overall low larval supply within this habitat. Following larval supply, high reef structural complexity, suitable substrata availability and high herbivory facilitated the recovery of dominant coral taxa following both types of disturbances.
Rising levels of atmospheric carbon dioxide are driving ocean warming and acidification. This cou... more Rising levels of atmospheric carbon dioxide are driving ocean warming and acidification. This could cause stress resulting in decreases in nutritional quality of marine species for human consumption, if environmental changes go beyond the optimal range for harvested species. To evaluate this, we used ambient and near-future elevated temperatures and pCO2 to assess impacts on the proximate nutritional composition (moisture, ash, protein, and lipids), fatty acids and trace elements of the foot tissue of Turbo militaris, a commercially harvested marine snail from south-eastern Australia. In a fully orthogonal design, the snails were exposed to ambient seawater conditions (22 ± 0.2 °C, pH 8.13 ± 0.01–450 μatm pCO2), ocean warming (25 ± 0.05 °C), pCO2 ocean acidification (pH 7.85 ± 0.02, ∼880 μatm pCO2) or a combination of both in controlled flow-through seawater mesocosms for 38 days. Moisture, ash, protein and total lipid content of the foot tissue in the turban snails was unaffected b...
Reef cryptofauna (animals inhabiting cracks and crevices) represent much of a reef’s biodiversity... more Reef cryptofauna (animals inhabiting cracks and crevices) represent much of a reef’s biodiversity yet are seldom studied owing to their inaccessibility. Subtidal rocky reefs off Brunswick Heads and Byron Bay in northern New South Wales, Australia support benthic communities ranging from coral-dominated offshore reefs to kelp beds of Ecklonia radiata on inshore reefs. It was hypothesised that differential exposure to river discharge and the East Australian Current, as well as proximity to other reef habitats, may produce differences in recruitment and persistence of cryptofauna between superficially similar reefs within a small geographical range. Artificial crevice habitats were deployed at similar depths on three inshore reefs supporting similar Ecklonia densities. Although the species richness of crevice fauna was similar at all reefs, the species composition differed significantly along with the assemblages recruited in different seasons and to different crevice sizes. Neither re...
Journal of University Teaching and Learning Practice
This paper builds on some ideas recently presented by Boyd et al. (2010). In that paper, the focu... more This paper builds on some ideas recently presented by Boyd et al. (2010). In that paper, the focus was on the ways in which experienced academic staff articulate the teaching-research nexus. By presenting six short case accounts, this paper describes how a reflective narrative activity enabled some ‘new to academe’ teachers to identify the teaching research nexus in their own work. For each of them, there was some particular reason or stimulus that led to them articulating the teaching-learning nexus in their work. Given the effectiveness of this method for enabling staff to consider the teaching-research nexus, this paper speculates on ways of drawing all academic staff to encounter the ‘concept’ of the teachingresearch nexus.
Rates of linear extension and changes in buoyant weight were measured for transplanted colonies o... more Rates of linear extension and changes in buoyant weight were measured for transplanted colonies of Acropora longicyathus exposed to elevated concentrations of ammonium and/or phosphate in the ENCORE experiment (One Tree Island, Great Barrier Reef). Linear extension was significantly faster in elevated phosphate treatments compared with controls. Rates of buoyant weight change were significantly increased by elevated ammonium on an annual basis, but significant reductions occurred in winter. Phosphate significantly increased the rate of buoyant weight change in some seasons but had no significant effect on an annual basis. Caution is therefore advised when extrapolating short-term growth data to represent annual trends. Chlorophyll a content of phosphate-treated corals was significantly higher than controls. Unlike other coral taxa in previous studies, elevated chlorophyll a content in Acropora longicyathus in this study did not correlate with reduced calcification. Growth of Acropor...
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