I began my career in environmental science by completing a Bachelor of Science in Marine Biology, then a Bachelor of Environmental Science (Honours) at the University of Technology Sydney (UTS). I then moved into industry working in a variety of positions including a laboratory technician in the biofuels industry, an environmental representative in the oil and gas industry, a marine researcher for a Not-for-profit Organisation and a researcher for the ecotoxicology department of state government. I then returned to UTS to complete a Doctorate of Philosophy with the Climate Change Cluster (C3) and Coastal Oceanography and Algal reSearch Team (COAST) investigating the toxicology an ecology of Gambierdiscus, the dinoflagellate genus associated with the human illness Ciguatera Fish Poisoning.
I am now continuing with the Climate Change Cluster (C3) and have started a Postdoctoral Research Associate Position investigating the evolution of biological bet-hedging strategies in a variable ocean.
Scholarships and Awards
2018 Staff Conference Travel Grant, UTS.
2018 Training and Travel Grant, British Ecological Society (BES).
2017 Travel Grant, Indo-Pacific Fish Conference (IPFC).
2017 Charles Boyden Research Award, Estuarine and Coastal Sciences Association (ECSA).
2016 Student Travel Grant, Ecological Society of Australia (ESA).
2016 Science Faculty Higher Degree Research Student Conference Travel Fund Award, UTS.
2016 Vice Chancellor Conference Fund Award, UTS.
2016 Student Bursary, British Phycological Society (BPS).
2016 Travel Award, International Society for the Study of Harmful Algae (ISSHA).
2016 Research Grant, PADI Foundation.
2015 Student Travel Award, Australasian Society for Phycology and Aquatic Botany (ASPAB).
2015 Best Student Presentation, 29th ASPAB Conference, Hobart.
2015 William Macleay Microbiology Research Fund Award, Linnean Society of NSW.
2014 Science Faculty Higher Degree Research Student Conference Travel Fund Award, UTS.
2014 Research Excellence Scholarship, UTS.
2014 Australian Postgraduate Award (APA).
2009 Deans Merit Award for Academic Excellence, UTS.
2009 Climate Change Cluster Research Scholarship, UTS.
Can supervise: YES
91107 The Biosphere
91157 Marine Communities
91167 Introduction to Oceanography
Ajani, PA, Larsson, ME, Woodcock, S, Rubio, A, Farrell, H, Brett, S & Murray, SA 2020, 'Fifteen years of Pseudo-nitzschia in an Australian estuary, including the first potentially toxic P. delicatissima bloom in the southern hemisphere', Estuarine, Coastal and Shelf Science, vol. 236, pp. 106651-106651.View/Download from: Publisher's site
Murray, JS, Nishimura, T, Finch, SC, Rhodes, LL, Puddick, J, Harwood, DT, Larsson, ME, Doblin, MA, Leung, P, Yan, M, Rise, F, Wilkins, AL & Prinsep, MR 2020, 'The role of 44-methylgambierone in ciguatera fish poisoning: Acute toxicity, production by marine microalgae and its potential as a biomarker for Gambierdiscus spp.', Harmful Algae, vol. 97.View/Download from: Publisher's site
© 2020 The Author(s) Ciguatera fish poisoning (CFP) is prevalent around the tropical and sub-tropical latitudes of the world and impacts many Pacific island communities intrinsically linked to the reef system for sustenance and trade. While the genus Gambierdiscus has been linked with CFP, it is commonly found on tropical reef systems in microalgal assemblages with other genera of toxin-producing, epiphytic and/or benthic dinoflagellates – Amphidinium, Coolia, Fukuyoa, Ostreopsis and Prorocentrum. Identifying a biomarker compound that can be used for the early detection of Gambierdiscus blooms, specifically in a mixed microalgal community, is paramount in enabling the development of management and mitigation strategies. Following on from the recent structural elucidation of 44-methylgambierone, its potential to contribute to CFP intoxication events and applicability as a biomarker compound for Gambierdiscus spp. was investigated. The acute toxicity of this secondary metabolite was determined by intraperitoneal injection using mice, which showed it to be of low toxicity, with an LD50 between 20 and 38 mg kg−1. The production of 44-methylgambierone by 252 marine microalgal isolates consisting of 90 species from 32 genera across seven classes, was assessed by liquid chromatography-tandem mass spectrometry. It was discovered that the production of this secondary metabolite was ubiquitous to the eight Gambierdiscus species tested, however not all isolates of G. carpenteri, and some species/isolates of Coolia and Fukuyoa.
Kretzschmar, AL, Larsson, ME, Hoppenrath, M, Doblin, MA & Murray, SA 2019, 'Characterisation of Two Toxic Gambierdiscus spp. (Gonyaulacales, Dinophyceae) from the Great Barrier Reef (Australia): G. lewisii sp. nov. and G. holmesii sp. nov', PROTIST, vol. 170, no. 6.View/Download from: Publisher's site
Larsson, ME, Harwood, TD, Lewis, RJ, Himaya, SWA & Doblin, MA 2019, 'Toxicological characterization of Fukuyoa paulensis (Dinophyceae) from temperate Australia', Phycological Research, vol. 67, no. 1, pp. 65-71.View/Download from: Publisher's site
© 2018 Japanese Society of Phycology Dinoflagellates of the genus Gambierdiscus are known to produce neurotoxins that cause the human illness ciguatera, a tropical and sub-tropical fish poisoning. Some species from the Gambierdiscus genus were recently re-classified into a new genus, Fukuyoa based on their phylogenetic and morphological divergence, however, little is known about their distribution, ecology and toxicology. Here we report the first occurrence of F. paulensis in the temperate coastal waters of eastern Australia and characterize its toxicology. Liquid chromatography–tandem mass spectrometry (LC–MS/MS) did not detect the presence of ciguatoxins, however, a putative maitotoxin congener (MTX-3) was present. Similarly, high maitotoxin-like activity was detected in High Performance Liquid Chromatography (HPLC) fractionated cell extracts using a Ca2+ influx bioassay on a Fluorescent Imaging Plate Reader (FLIPR), but no ciguatoxin-like activity was detected.
Larsson, ME, Smith, KF & Doblin, MA 2019, 'First description of the environmental niche of the epibenthic dinoflagellate species Coolia palmyrensis, C. malayensis, and C. tropicalis (Dinophyceae) from Eastern Australia.', Journal of phycology, vol. 55, no. 3, pp. 565-577.View/Download from: Publisher's site
Environmental variables such as temperature, salinity, and irradiance are significant drivers of microalgal growth and distribution. Therefore, understanding how these variables influence fitness of potentially toxic microalgal species is particularly important. In this study, strains of the potentially harmful epibenthic dinoflagellate species Coolia palmyrensis, C. malayensis, and C. tropicalis were isolated from coastal shallow water habitats on the east coast of Australia and identified using the D1-D3 region of the large subunit (LSU) ribosomal DNA (rDNA). To determine the environmental niche of each taxon, growth was measured across a gradient of temperature (15-30°C), salinity (20-38), and irradiance (10-200 μmol photons · m-2 · s-1 ). Specific growth rates of Coolia tropicalis were highest under warm temperatures (27°C), low salinities (ca. 23), and intermediate irradiance levels (150 μmol photons · m-2 · s-1 ), while C. malayensis showed the highest growth at moderate temperatures (24°C) and irradiance levels (150 μmol photons · m-2 · s-1 ) and growth rates were consistent across the range of salinity levels tested (20-38). Coolia palmyrensis had the highest growth rate of all species tested and favored moderate temperatures (24°C), oceanic salinity (35), and high irradiance (>200 μmol photons · m-2 · s-1 ). This is the first study to characterize the environmental niche of species from the benthic harmful algal bloom genus Coolia and provides important information to help define species distributions and inform risk management.
McInnes, AS, Laczka, OF, Baker, KG, Larsson, ME, Robinson, CM, Clark, JS, Laiolo, L, Alvarez, M, Laverock, B, Kremer, CT, van Sebille, E & Doblin, MA 2019, 'Live cell analysis at sea reveals divergent thermal performance between photosynthetic ocean microbial eukaryote populations.', The ISME journal, vol. 13, no. 5, pp. 1374-1378.View/Download from: Publisher's site
Experimentation at sea provides insight into which traits of ocean microbes are linked to performance in situ. Here we show distinct patterns in thermal tolerance of microbial phototrophs from adjacent water masses sampled in the south-west Pacific Ocean, determined using a fluorescent marker for reactive oxygen species (ROS). ROS content of pico-eukaryotes was assessed after 1, 5 and 25 h of incubation along a temperature gradient (15.6-32.1 °C). Pico-eukaryotes from the East Australian Current (EAC) had relatively constant ROS and showed greatest mortality after 25 h at 7 °C below ambient, whereas those from the Tasman Sea had elevated ROS in both warm and cool temperature extremes and greatest mortality at temperatures 6-10 °C above ambient, interpreted as the outcome of thermal stress. Tracking of water masses within an oceanographic circulation model showed populations had distinct thermal histories, with EAC pico-eukaryotes experiencing higher average temperatures for at least 1 week prior to sampling. While acclimatization and community assembly could both influence biological responses, this study clearly demonstrates that phenotypic divergence occurs along planktonic drift trajectories.
Ajani, PA, Larsson, M, Woodcock, S, Rubio, A, Farrell, H, Brett, S & Murray, S 2018, 'Bloom drivers of the potentially harmful dinoflagellate Prorocentrum minimum (Pavillard) Schiller in a south eastern temperate Australian estuary', Estuarine, Coastal and Shelf Science, vol. 215.View/Download from: Publisher's site
Larsson, M, Laczka, O, Suthers, I, Ajani, PA & Doblin, M 2018, 'Hitchhiking in the East Australian Current: rafting as a dispersal mechanism for harmful epibenthic dinoflagellates', Marine Ecology Progress Series.View/Download from: Publisher's site
Larsson, ME, Laczka, OF, Harwood, DT, Lewis, RJ, Himaya, SWA, Murray, SA & Doblin, MA 2018, 'Toxicology of Gambierdiscus spp. (Dinophyceae) from Tropical and Temperate Australian Waters.', Marine drugs, vol. 16, no. 1.View/Download from: Publisher's site
Ciguatera Fish Poisoning (CFP) is a human illness caused by the consumption of marine fish contaminated with ciguatoxins (CTX) and possibly maitotoxins (MTX), produced by species from the benthic dinoflagellate genus Gambierdiscus. Here, we describe the identity and toxicology of Gambierdiscus spp. isolated from the tropical and temperate waters of eastern Australia. Based on newly cultured strains, we found that four Gambierdiscus species were present at the tropical location, including G. carpenteri, G. lapillus and two others which were not genetically identical to other currently described species within the genus, and may represent new species. Only G. carpenteri was identified from the temperate location. Using LC-MS/MS analysis we did not find any characterized microalgal CTXs (P-CTX-3B, P-CTX-3C, P-CTX-4A and P-CTX-4B) or MTX-1; however, putative maitotoxin-3 (MTX-3) was detected in all species except for the temperate population of G. carpenteri. Using the Ca2+ influx SH-SY5Y cell Fluorescent Imaging Plate Reader (FLIPR) bioassay we found CTX-like activity in extracts of the unidentified Gambierdiscus strains and trace level activity in strains of G. lapillus. While no detectable CTX-like activity was observed in tropical or temperate strains of G. carpenteri, all species showed strong maitotoxin-like activity. This study, which represents the most comprehensive analyses of the toxicology of Gambierdiscus strains isolated from Australia to date, suggests that CFP in this region may be caused by currently undescribed ciguatoxins and maitotoxins.
Larsson, M, Ajani, PA, Rubio, AM, Guise, K, MacPherson, RG, Brett, SJ, Davies, KP & Doblin, M 2017, 'Long-term perspective on the relationship between phytoplankton and nutrient concentrations in a southeastern Australian estuary', Marine Pollution Bulletin, vol. 114, no. 1, pp. 227-238.View/Download from: Publisher's site
Munday, R, Murray, S, Rhodes, LL, Larsson, ME & Harwood, DT 2017, 'Ciguatoxins and Maitotoxins in Extracts of Sixteen Gambierdiscus Isolates and One Fukuyoa Isolate from the South Pacific and Their Toxicity to Mice by Intraperitoneal and Oral Administration', MARINE DRUGS, vol. 15, no. 7.View/Download from: Publisher's site
Ajani, PA, Larsson, M, Rubio, A, Bush, S, Brett, S & Farrell, H 2016, 'Modelling bloom formation of the toxic dinoflagellates Dinophysis acuminata and Dinophysis caudata in a highly modified estuary, south eastern Australia', Estuarine, Coastal and Shelf Science, vol. 183, pp. 95-106.View/Download from: Publisher's site
Dinoflagellates belonging to the toxigenic genus Dinophysis are increasing in abundance in the Hawkesbury River, south-eastern Australia. This study investigates a twelve year time series of abundance and physico-chemical data to model these blooms. Four species were reported over the sampling campaign - Dinophysis acuminata, Dinophysis caudata, Dinophysis fortii and Dinophysis tripos-with D. acuminata and D. caudata being most abundant. Highest abundance of D. acuminata occurred in the austral spring (max. abundance 4500 cells l−1), whilst highest D. caudata occurred in the summer to autumn (max. 12,000 cells l−1). Generalised additive models revealed abundance of D. acuminata was significantly linked to season, thermal stratification and nutrients, whilst D. caudata was associated with nutrients, salinity and dissolved oxygen. The models' predictive capability was up to 60% for D. acuminata and 53% for D. caudata. Altering sampling strategies during blooms accompanied with in situ high resolution monitoring will further improve Dinophysis bloom prediction capability