Professor Emma Johnston
BSc (Hons) Melb., PhD Melb.
Field of Research: 
Subtidal ecology and ecotoxicology, marine bioinvasion
Contact details:
+61 2 9385 1825

Room 544B
Biological Sciences Building (D26)
UNSW, Kensington 2052

Head of the Applied Marine and Estuarine Ecology Lab (AMEE)

For general lab and student enquiries, please contact a.bugnot@unsw.edu.au

Research & Current Projects


My research group investigate human disturbances in marine communities. We approach this research from both an ecological and ecotoxicological perspective using field experimentation wherever possible.

Current Projects

Transient Disturbance Events

This program investigates the potential for the timing, frequency and intensity of disturbance events to change the nature of their impact. Estimates of recovery times are made along with investigations of disturbance effects on competitive and trophic interactions.

Marine Biological Invasions

This program aims to determine the major drivers of marine bioinvasions. We investigate whether disturbance events facilitate the colonisation, persistence and spread of non-native species and how initial assemblage diversity modifies this response.

Antarctic Marine Communities

Antarctica is no longer considered a pristine environment and the impact of human activity is likely to increase in coming years. This project compares the vulnerability of Antarctic assemblages to those of other regions and provides information on the responses of individuals, populations and communities to environmental stressors.

Estuarine Health

Estuaries are widely considered the most impacted of all marine habitats, and more than half of Australian estuaries are disturbed by anthropogenic activities to some degree. Most are subject to combinations of stressors from industry, agriculture, urbanisation and coastal development. This program aims to identify processes and interactions that drive impacts in an effort to develop targeted and effective management strategies to conserve biodiversity in these systems.

In her element - Professor Emma Johnston


 Professor Johnston is a co-presenter for the Foxtel/BBC television series "Coast Australia". Here she does a story on whale sharks in Ningaloo:

Coast Australia CLIP - Whale Sharks




Johnston EL, Mayer Pinto M (2015) Pollution: effects of chemical contaminants and debris. In ‘Marine Ecosystems: Human Impacts on Biodiversity, Functioning and Services’ ed. by T Crowe, C Frid, M Austen. Cambridge University Press, Cambridge.

Johnston EL (2011) Tolerance to contaminants: Evidence from chronically-exposed populations of aquatic organisms. In ‘Tolerance to Environmental Contaminants’ ed. by C. Amiard-Triquet, PS Rainbow, M Romeo. CRC Press. Boca Raton pp. 25-46.

Johnston EL, Piola R, Clark G (2008) The role of propagule pressure in marine invasions. In 'Marine Bioinvasions: Ecology, Conservation, and Management Perspectives' ed. by G. Rilov, J. Crooks. Springer-Verlag.




Tan E, Mayer Pinto M, Johnston E, Dafforn KA (2015) Differences in intertidal microbial assemblages on urban structures and natural rocky reef. Frontiers in Microbiology doi:10.3389/fmicb.2015.01276

Mayer Pinto M, Johnston E, Hutchings P, Marzinelli E, Ahyong S, Birch G, Booth D, Creese B, Doblin M, Figuera W, Gribben P, Pritchard T, Roughan M, Steinberg P, Hedge L (accepted 2/10/2015) Sydney Harbour: A review of anthropogenic impacts on the biodiversity and ecosystem function of one of the world’s largest natural harbours. Marine and Freshwater Research

Johnston E, Mayer Pinto M, Hutchings P, Marzinelli E, Ahyong S, Birch G, Booth D, Creese B, Doblin M, Figuera W, Gribben P, Pritchard T, Roughan M, Steinberg P, Hedge L (accepted 31/08/2015) Sydney Harbour: What we do and don't know about a highly diverse estuary. Marine and Freshwater Research

Sim VXY, Dafforn KA, Simpson SL, Kelaher BP, Johnston EL (2015) Sediment Contaminants and Infauna Associated with Recreational Boating Structures in a Multi-Use Marine Park. Plos One 10: e0130537

Baird DJ, Van den Brink PJ, Chariton AA, Dafforn KA, Johnston EL (accepted 31/08/15) Editorial: New diagnostics for multiply stressed marine and freshwater ecosystems: integrating models, ecoinformatics and Big Data. Marine and Freshwater Research

Dafforn KA, Johnston EL, Ferguson A, Humphrey C, Monk W, Nichols S, Simpson S, Tulbure M, Baird D (accepted 20/07/15) Big Data Opportunities and Challenges for Assessing Multiple Stressors across Scales in Aquatic Ecosystems. Marine and Freshwater Research

Byers J, Smith R, Pringle J, Clark G, Gribben P, Hewitt C, Inglis G, Johnston EL, Ruiz G, Stachowicz J, Bishop M (2015) Invasion Expansion: Time since introduction best predicts global ranges of marine invaders. Scientific Reports 5:12436

Clark GF, Marzinelli EM, Fogwill CJ, Turner CSM, Johnston EL (2015) Effects of sea-ice cover on marine benthic communities: A natural experiment in Commonwealth Bay, East Antarctica. Polar Biology 38: 1213-1222

Johnston EL, Mayer-Pinto M, Crowe T (2015) Chemical contaminant effects on marine ecosystem functioning. Journal of Applied Ecology 52:140-149

Edge KJ, Dafforn KA, Simpson SL, Ringwood A, Johnston EL (2015) Re-suspended contaminated sediments cause sub-lethal stress to oysters: a biomarker differentiates TSS and contaminant effects. Environmental Toxicology and Chemistry 34: 1345–1353

Clark G, Raymond B, Riddle M, Stark J, Johnston EL (2015) Vulnerability of Antarctic shallow invertebrate-dominated ecosystems. Austral Ecology 40: 482–491

Clark G, Kelaher BP, Dafforn KA, Coleman MA, Knott NA, Marzinelli EM, Johnston EL (2015) What does impacted look like? High diversity and abundance of epibiota in modified estuaries. Environmental Pollution 196: 12-20

Dafforn KA, Glasby TM, Airoldi L, Rivero NK, Mayer-Pinto M, Johnston EL (2015) Marine urban sprawl: an ecological framework to inform the design of multifunctional artificial structures. Frontiers in Ecology and the Environment 13:82-90



Dafforn KA, Baird DJ, Chariton AA, Sun MY, Brown M, Simpson SL, Kelaher BP, Johnston EL (in press 12/09/2014) Higher, faster and stronger? The pros and cons of molecular faunal data for assessing ecosystem condition. Advances in Ecological Research [Top 7% in Ecology]

Edge KJ, Dafforn KDSimpson SL, Ringwood A, Johnston EL (in press 28/11/2014) Re-suspended contaminated sediments cause sub-lethal stress to oysters: biomarkers differentiate TSS and contaminant effects. Environmental Toxicology and Chemistry [Top 24% in Environmental Sciences]

Johnston EL, Mayer-Pinto M, Crowe T (2014) Chemical contaminant effects on marine ecosystem functioning. Journal of Applied Ecology doi: 10.1111/1365-2664.12355 [Top 14% in Ecology]

Hook SE, Johnston EL, Nair S, Roach AC, Moncuquet P, Twine NA, Raftos DA. (2014) Next generation sequence analysis of the transcriptome of Sydney rock oysters (Saccostrea glomerata) exposed to a range of environmental stressors. Marine Genomics doi:10.1016/j.margen.2014.08.003 [Top 67% in Genetics and Heredity]

Smith RS, Johnston EL, Clark GF (2014) The Role of Habitat Complexity in Community Development Is Mediated by Resource Availability. Plos One 9: e102920 [Top 15% in Multidisciplinary Sciences]

Lavender JT, Dafforn KA, Johnston EL (2014) Meso-predators: A confounding variable in consumer exclusion studies. Journal of Experimental Marine Biology and Ecology 456: 26-33 [Top 20% in Marine and Freshwater Biology]

Hedge LH, Leung B, O’Connor WA, Johnston EL (2014) The interacting effects of diversity and propagule pressure on early colonisation and population size. Journal of Animal Ecology 83 (1), 168-175 [Top 1% of Zoology]

Edge KJ, Dafforn KDSimpson SL, Roach AC, Johnston EL (2014) A biomarker of contaminant exposure is effective in large scale assessment of ten estuaries. Chemosphere100: 16–26 [Top 15% in Environmental Sciences]

Hedge LHO’Connor WA, Johnston EL (2014) Colonisation of the non-indigenous Pacific oyster Crassostrea gigas determined by predation, size and initial settlement densities. PLoS ONE DOI: 10.1371/journal.pone.0090621 [Top 15% in Multidisciplinary Sciences]



Sun, MY, Dafforn KD, Johnston EL, Brown MV (2013) Core sediment bacteria drive community response to anthropogenic contamination over multiple environmental gradients. Environmental Microbiology 15: 2517-2531.[Top 11% of Microbiology]

Clark GF, Stark JS, Johnston EL, Runcie JW, Goldsworthy PM, Raymond B, Riddle MJ (2013) Light-driven tipping points in polar ecosystems Global Change Biology 19 (12), 3749-3761 [Top 2% of Environmental Sciences]

Clark GF, Johnston EL, Leung B (2013) Intrinsic time-dependence in the diversity-invasibility relationship. Ecology 94(1), 2013, pp. 25–31 [Top 12% of Ecology]

Rivero NKDafforn KA, Coleman MA, Johnston EL (2013) Environmental and ecological changes associated with a marina. Biofouling 29: 803-815 [Top 4% of Marine and Freshwater Ecology]

Dafforn KD Simpson SL, Kelaher, B, Hutchings P, Johnston EL (2013) Polychaete richness and abundance enhanced in anthropogenically modified estuaries despite high concentrations of toxic contaminants. PLoS ONE. 8(9): e77018. [Top 15% of Multidisciplinary Sciences]

Hill NA, Simpson SL, Johnston EL (2013) Beyond the bed: Effects of metal contamination on recruitment to bedded sediments and overlying substrata. Environmental Pollution 173:182-191[Top 10% of Environmental Sciences]

Ritchie EG, Bradshaw CJA, Dickman CR, Hobbs R, Johnson CN, Johnston EL, Laurance WF, Lindenmayer D, McCarthy MA, Nimmo DG, Possingham HH, Pressey RL, Watson DM, Woinar J (2013) Continental-Scale Governance and the Hastening of Loss of Australia’s Biodiversity Conservation Biology27 (6), 1133-1135 [Top 8% of Environmental Sciences]

Gall MLHolmes SP, Dafforn KA, Johnston EL (2013) Differential tolerance to copper, but no evidence of population-level genetic differences in a widely-dispersing native barnacle. Ecotoxicology 22: 929-937 [Top 33% of Environmental Sciences]

Durant H, Clark GF, Dworjanyn SA, Byrne M, Johnston EL (2013) Seasonal variation in the effects of ocean warming and acidification on a native bryozoan. Marine Biology 160: 1903-1911 [Top 21% in Marine and Freshwater Biology]



McKenzie LA, Brooks R, Johnston EL (2012) A widespread contaminant enhances invasion success of a marine invertebrate. Journal of Applied Ecology 49: 767-773. [Top 14% in Ecology]

Dafforn KA, Glasby TM, Johnston EL (2012) Comparing the invasibility of experimental “reef” with field observations of natural reef and artificial structures. PLoS One 7: e38124. [Top 15% in Multidisciplinary Sciences]

Hedge LH, WA O’Connor, Johnston EL (2012) The intrinsic parameters of invasive propagule pressure: arrival frequency, not size, increases invader colonisation. Ecosphere 3: Article 48 [Top 36% in Ecology]

McKinley AC, Taylor MD, Johnston EL (2012) Relationships between body burdens of trace metals and the relative size of small tooth flounder (Pseudorhombus jenynsii). Science of the Total Environment 423: 84-94 [Top 19% in Environmental Sciences]

Dafforn KA, Simpson SL, Kelaher, B, Komyakova V, Wong CK, Clark GF, Johnston EL (2012) The challenge of choosing environmental indicators of anthropogenic impacts in estuaries. Environmental Pollution 163: 207-217 [Top 10% in Environmental Sciences]

Sun MY, Dafforn KA, Brown MV, Johnston EL (2012) Bacterial communities are sensitive indicators of contaminant stress. Marine Pollution Bulletin 64: 1029-1038 [Top 12% in Marine and Freshwater Biology]

McKenzie LA, Johnston EL, Brooks R (2012) Using clones and copper to resolve the genetic architecture of metal tolerance in a marine invader. Ecology and Evolution 2: 1319-1329 [Top 60% in Ecology]

Edge K, Johnston EL, Roach A, Ringwood A (2012) Indicators of environmental stress: Cellular biomarkers and reproductive responses in the Sydney rock oyster (Saccostrea glomerata). Ecotoxicology21:1415–1425 [Top 33% in Environmental Sciences]

Hedge LH, Johnston EL (2012) Propagule pressure determines recruitment from a commercial shipping pier. Biofouling 28: 73-85 [Top 4% in Marine and Freshwater Ecology]

Gall ML, Poore AG, Johnston EL (2012) A biomonitor as a measure of ecologically-significant fraction of metals in an industrialised harbour. Journal of Environmental Monitoring 14: 830-838 [Top 40% in Environmental Sciences]

Birdsey E, Johnston EL, Poore AG (2012) Diversity and cover of a sessile animal assemblage does not predict its associated mobile fauna. Marine Biology 159: 551–560 [Top 21% in Marine and Freshwater Biology]



Clark GF, Johnston EL (2011) Temporal change in the diversity-invasibility relationship in the presence of a disturbance regime. Ecology Letters 14: 52–57 [Top 1% in Ecology]

McKinley AC, Taylor MD, Miskiewiecz A, Johnston EL (2011) High levels of sediment contamination have little influence on estuarine beach fish communities. PLoS One 6: e26353 [Top 15% in Multidisciplinary Sciences]

Johnston EL, Marzinelli E, Wood C, Speranze D, Bishop JDD (2011) Bearing the burden of boat harbours: heavy contaminant and fouling loads in a native habitat-forming alga. Marine Pollution Bulletin62: 2137-2144 [Top 12% in Marine and Freshwater Biology]

Hill NA, Johnston EL, King CK, Simpson S (2011) Physico-chemical changes in metal spiked sediments deployed in the field: Implications for the interpretation of in situ studies. Chemosphere 83: 400-408 [Top 15% in Environmental Sciences]

McKinley AC, Coleman M, Knott N, Clark GF, Taylor MD, Ryan L, Johnston EL (2011) Putting marine sanctuaries into context: A comparison of estuary fish assemblages over multiple levels of protection and modification. Aquatic Conservation 21(7): 636-648 [Top 40% in Marine and Freshwater Biology]

McKenzie LA, Brooks R, Johnston EL (2011) Heritable pollution tolerance in a marine invader. Environmental Research 111: 926-932 [Top 10% in Environmental Sciences]

Dafforn KA, Lewis JA, Johnston EL (2011) Antifouling strategies: History and regulation, ecological impacts and mitigation. Marine Pollution Bulletin 62: 453-465 [Top 12% in Marine and Freshwater Biology]

Clark GF, Stark JS, Hill NA, Perrett LA, Johnston EL (2011) Algal canopy as a proxy for the disturbance history of understorey communities in East Antarctica. Polar Biology 34: 781-790 [Top 47% in Ecology]

McKinley AC, Miskiewiecz A, Taylor MD, Johnston EL (2011) Strong links between metal contamination, habitat modification and estuarine larval fish distributions. Environmental Pollution 159: 1499-1509 [Top 10% in Environmental Sciences]



Roberts DA, Johnston EL, Knott NA (2010) Impacts of desalination plants on the marine environment: a critical review of published studies. Water Research 44: 5117-5128 [Top 4% in Environmental Sciences]

Pease C, Johnston EL, Poore AGB (2010) Genetic variability in tolerance to copper contamination in a herbivorous marine invertebrate. Aquatic Toxicology 99: 10-16 [Top 6% in Marine and Freshwater Biology]

Burton GA, Johnston EL (2010) Assessing contaminated sediments in the context of multiple stressors. Environmental Toxicology and Chemistry 29:2625-2643 [Top 24% in Environmental Sciences]

McKinley A, Johnston EL (2010) Impacts of contaminant sources on marine fish abundance and species richness: A review and meta-analysis of evidence from the field. Marine Ecology Progress Series420:175-191 [Top 15% in Marine and Freshwater Biology]


Research in the Media

ABC Catalyst - "Attack of the heavy metal invaders" 23rd October 2008

ABC Catalyst - "Toxic sediments" 3rd June 2010

Respect the Science campaign video for Science and Technology Australia

Respect the Science

SIMS Sydney Harbour Research Program

UTSpeaks: Our Priceless Harbour



Dr Katherine Dafforn

Room 624, Biological Sciences Building

9385 8701



Dr Graeme Clark

Room 624, Biological Science Building (D26)

9385 8701



Dr Mariana Mayer Pinto

Room 624, Biological Science Building (D26)

9385 8701


Dr Luke Hedge

Room 515, Biological Science Building (D26)


Dr Ana Bugnot

9385 3664


Dr Mark Browne


Research Students


Simone Birrer (PhD candidate) (with Dr Katherine Dafforn, UNSW)

Damon Bolton (PhD candidate) – Indirect effects of marine sanctuary zones (with Dr Coleman, Batemans’s Marine Park).

Sally Bracewell (PhD candidate) – Species traits and community dynamics across a latitudinal gradient (with Dr Graeme Clark, UNSW).

Kingsley Griffin (PhD candidate) Mapping distribution and stress effects in Sydney Harbour marine habitat (with Dr Luke Hedge, UNSW).

James Lavender (PhD candidate) – Marine bioinvasions in a changing climate (with Dr Dafforn, UNSW and Dr Bishop Macquarie University).

Aria Lee (PhD candidate) – Gametogenesis and larval settlement of the invasive fanworm, Sabella spallanzanii

Vivian Sim (PhD candidate) – Potential Influences of Anthropogenic Boating Structures on Estuarine Health

Melanie Sun (PhD candidate) – Developing ecogenomic signatures of ecosystem health from marine sediments (with Dr Brown, UNSW & Dr Chariton, CSIRO).

Jess Merrett (PhD candidate) – Distribution and impacts of marine debris in a complex, urbanized estuary: Sydney Harbour

Nina Schaefer (PhD candidate) – Eco-engineering in urban seascapes

Asunta Macolino (Honours candidate)


Photo: Lab Group End of Year Party - December 2012

Photo: Lab Group at SIMS



Katelyn Edge (PhD 2013) – Do cellular biomarkers in the Sydney Rock Oyster reflect ecological impacts of contaminants within estuaries?

Andrew McKinley (PhD 2012) Assessing and understanding ecological changes to fish communities in highly disturbed estuaries (with Dr Miskiewiecz & Dr Taylor, UNSW).

Luke Hedge (PhD 2012) Propagule pressure and invasion success (with Dr Wayne O’Connor, DPI).

Carol Sukhn (PhD 2011) Bioaccumulation of toxicants from complex effluents (with Imad Saoud, AUB).

Emma Birdsey (PhD 2011) Habitat mediated changes to marine biodiversity (with A/P Poore, UNSW).

Louise McKenzie (PhD 2010) Reaping the benefits of an anthropogenic contaminant: the evolution of copper tolerance in a marine invader (with Professor Brooks, UNSW).

Graeme Clark (PhD 2010) - Disturbance, diversity and invasion in marine systems.

Katherine Dafforn (PhD 2009) Anthropogenic modification of estuaries: disturbance and artificial structures influence marine invasion (with Dr Glasby NSW I&I).

Nicole Hill (PhD 2009) - Contaminated sediments and hard-substrate marine communities (with Dr Simpson, CSIRO).

David Roberts (PhD 2008) - Responses of algal epifauna to pulsed and chronic contamination of temperate algae beds (with A/P Poore, UNSW).

Richard Piola (PhD 2008) - Differential tolerance of introduced and native marine invertebrates to heavy metal pollution.

Mailie Gall (MSc. 2010) Tolerance and the assessment of heavy metal pollution in sessile invertebrates.

Ka-Man Lee (MSc. 2006) - Taxonomy and ecology of predatory marine flatworms (Platyhelminthes: Polycladida) in Botany Bay, New South Wales, Australia.


Jaz Lawes (PhD candidate) - Development of tools for health assessment of estuaries. (with Dr Graeme Clark, UNSW and Associate Professor Alistair Poore, UNSW)

Ceiwen Pease (PhD candidate) - Chemical arms races: the use of pharmacology to explain diet choices and responses to contaminants in marine herbivores (with Associate Professor Poore, UNSW).

Kate Reeds (Masters candidate) - Sydney Offshore Artificial Reef - Benthic Gradient Study (with Professor Iain Suthers, UNSW)

Shinjiro Ushiama (Masters candidate) - Productivity, diversity and predation in rocky reef invertebrate communities (with Professor Iain Suthers, UNSW).