Dr Perran Cook - Researcher Profile

Perran Cook

Address

School of Chemistry
Building 19, Clayton

Biography

Discovering the perfect bloom

In early 2011, Dr Perran Cook found the perfect bloom. It was no garden-variety bloom, but Perran is no simple gardener. He’s an environmental scientist, investigating the threat from algal blooms to life in Victoria’s estuaries, especially the Gippsland Lakes, a major centre of tourism and farming about 200 kilometres east of Melbourne. 

Perran’s interest in algal blooms was triggered in 1987, when he saw his first outbreak as a boy, growing up around the Gippsland Lakes – the largest estuary in eastern Australia with a surface area of some 360 square kilometres.

The lakes are largely protected along their southern edge from the mighty seas of Bass Strait by a thin yellow line of sand, known as the Ninety-mile Beach. But this delicately balanced ecosystem, where freshwater meets seawater, suffers from periodic blooms of toxic algae.

Six of Victoria’s biggest rivers flow through the lakes’ catchment area – about 10 per cent of the state – collecting nutrient-rich runoff from farms and urban areas along the way.

It’s these nutrients – mainly nitrogen and phosphorous – that cause algal blooms, which occur periodically but are very hard to predict.

Major blooms have a devastating impact on tourism and fishing. They turn healthy water into a stinking, toxic cesspool that kills aquatic life and makes swimming dangerous.

The blue-green bloom that Perran investigated in the summer of early 2011 was perfect, not because it was big – like the one in 1987 – but because it confirmed the predictive power of key indicators that he and fellow researchers, Dr Daryl Holland and Professor John Beardall, had indentified. 

“It was the perfect bloom in the sense that it told us that we understood what was going on; we had predicted it. What stopped it getting humungous was the fact that it was a wet, windy summer. The missing ingredients were a high level of sunlight and calm conditions because it was so overcast.” 

Freshwater, seawater, low nitrogen, high phosphorous, heat and sunlight are the necessary ingredients for a devastating bloom. Being able to predict when the mix is right for a major event is the great value of Perran and his colleagues’ research.

In estuaries, such as the Gippsland Lakes, regular freshwater runoff after rain adds more and more phosphorous to the system. It builds up in the sediment over time – waiting to turn normal levels of the cyanobacteria Nodularia into a toxic bloom under the right conditions. 

Conditions are almost right when a lot of fresh water is added after a flood. A large influx of fresh water sits on top of denser seawater “like a lid on a fish tank”, according to Perran, sucking oxygen from the seawater and allowing the release of phosphorous from the sediment.

Conditions become perfect when a long period of summer heat and sunlight triggers algae growth in huge numbers thanks to the high phosphorous levels. 

And things quickly get worse as short-lived algae – an organism, known as cyanobacteria because it has features of bacteria – die, consuming oxygen and releasing toxins into the system. 

The thick mat that forms on the surface in an algal bloom adds to the problem as it prevents sunlight reaching the lake bed, which kills sea grass and allows the release of more phosphorous.

The presence of all these factors feed concern that a healthy estuary could suddenly flip over into a toxic state from which it might never recover, which is why Perran and his colleagues’ predictive model has implications for the successful management of estuaries all along eastern Australia.

Perran says understanding complex environmental systems to control algal growth requires close collaboration with other researchers to identify exactly how nutrients interact with biological and physical factors.

Victoria’s Department of Sustainability and Environment, the Environment Protection Authority, Parks Victoria, Melbourne Water and the Australian Research Council all support Perran’s work.

Keywords

carbon, nitrogen, phosphorus, aquatic environments, eutrophication

Qualifications

DOCTOR OF PHILOSOPHY
Institution: University of Tasmania
Year awarded: 2006
BACHELOR OF APPLIED SCIENCE (HONOURS)
Institution: RMIT
Year awarded: 1998

Publications

Book Chapters

Joye, S.B., De Beer, D., Cook, P., 2009, Biogeochemical dynamics of coastal tidal flats, in Coastal Wetlands: an integrated ecosystem approach, eds Gerardo Perillo, Eric Wolanski, Donald Cahoon & Mark Brinson, Elsevier, Netherlands, pp. 345-374.

Journal Articles

Evrard, V., Glud, R.N., Cook, P., 2013, The kinetics of denitrification in permeable sediments, Biogeochemistry [P], vol 1, Springer Netherlands, Netherlands, pp. 1-12.

Holland, D.P., van Erp, I., Beardall, J., Cook, P., 2012, Environmental controls on the nitrogen-fixing cyanobacterium Nodularia spumigena in a temperate lagoon system in SE Australia, Marine Ecology-Progress Series [P], vol 461, Inter-Research, Oldendorf Luhe Germany, pp. 47-57.

Roberts, K.L., Eate, V., Eyre, B.D., Holland, D.P., Cook, P., 2012, Hypoxic events stimulate nitrogen recycling in a shallow salt-wedge estuary: the Yarra river estuary, Australia, Limnology and Oceanography [P], vol 57, issue 5, American Society Limnology Oceanography, Waco TX USA, pp. 1427-1442.

Evrard, V., Huettel, M., Cook, P., Soetaert, K., Heip, C.H., Middelburg, J.J., 2012, Importance of phytodetritus and microphytobenthos for heterotrophs in a shallow subtidal sandy sediment, Marine Ecology-Progress Series [P], vol 455, Inter-Research, Germany, pp. 13-31.

Cook, P., Holland, D.P., 2012, Long term nutrient loads and chlorophyll dynamics in a large temperate Australian lagoon system affected by recurring blooms of cyanobacteria, Biogeochemistry [P], vol 107, issue 1-3, Springer, Dordrecht Netherlands, pp. 261-274.

Kessler, A.J., Glud, R.N., Cardenas, M.R., Larsen, M., Bourke, M., Cook, P., 2012, Quantifying denitrification in rippled permeable sands through combined flume experiments and modeling, Limnology and Oceanography [P], vol 57, issue 4, American Society of Limnology and Oceanography, Waco TX USA, pp. 1217-1232.

Khoshmanesh, A., Cook, P., Wood, B.R., 2012, Quantitative determination of polyphosphate in sediments using Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy and partial least squares regression, Analyst [P], vol 137, issue 16, Royal Society of Chemistry, Cambs England, pp. 3704-3709.

Grant, S.B., Saphores, J., Feldman, D.L., Hamilton, A.J., Fletcher, T.D., Cook, P., Stewardson, M., Sanders, B.F., Levin, L.A., Ambrose, R.F., Deletic, A., Brown, R.R., Jiang, S.C., Rosso, D., Cooper, W.J., Marusic, I., 2012, Taking the "waste" out of "wastewater" for human water security and ecosystem sustainability, Science [E], vol 337, issue 6095, American Association for the Advancement of Science, Washington DC USA, pp. 681-686.

Santos, I.R., Cook, P., Rogers, L., de Weys, J., Eyre, B.D., 2012, The "salt wedge pump": convection-driven pore-water exchange as a source of dissolved organic and inorganic carbon and nitrogen to an estuary, Limnology and Oceanography [P], vol 57, issue 5, American Society Limnology Oceanography, Waco Texas United States of America, pp. 1415-1426.

Faber, P.A., Kessler, A.J., Bull, J., McKelvie, I., Meysman, F.J.R., Cook, P., 2012, The role of alkalinity generation in controlling the fluxes of CO2 during exposure and inundation on tidal flats, Biogeosciences [P], vol 9, issue 10, Copernicus Gesellschaft MBH, Gottingen Germany, pp. 4087-4097.

Pencharee, S., Faber, P.A., Ellis, P.S., Cook, P., Intaraprasert, J., Grudpan, K., McKelvie, I., 2012, Underway determination of dissolved inorganic carbon in estuarine waters by gas-diffusion flow analysis with C4D detection, Analytical Methods: Advancing Methods and Applications [P], vol 4, issue 5, Royal Society of Chemistry, England, pp. 1278-1283.

Faber, P., Cook, P., McKelvie, I., Ellis, P., 2011, Development of a gas diffusion probe for the rapid measurement of pCO2 in aquatic samples, Analytica Chimica Acta [P], vol 691, issue 1-2, Elsevier BV, Netherlands, pp. 1-5.

Shimeta, J., Cook, P., 2011, Testing assumptions of the eukaryotic inhibitor method for investigating interactions between aquatic protozoa and bacteria, applied to marine sediment, Limnology and Oceanography: Methods [P], vol 9, American Society of Limnology and Oceanography, Inc., United States, pp. 288-295.

Cook, P.L.M., Holland, D.P., Longmore, A.R., 2010, Effect of a flood event on the dynamics of phytoplankton and biogeochemistry in a large temperate Australian lagoon, Limnology and Oceanography [P], vol 55, issue 3, American Society of Limnology and Oceanography, USA, pp. 1123-1133.

Cook, P., Aldridge, K., Lamontagne, S., Brookes, J., 2010, Retention of nitrogen, phosphorus and silicon in a large semi-arid riverine lake system, Biogeochemistry [P], vol 99, Springer Netherlands, Netherlands, pp. 49-63.

Cook, P.L.M., Van Oevelen, D., Soetaert, K., Middelburg, J.J., 2009, Carbon and nitrogen cycling on intertidal mudflats of a temperate Australian estuary. IV. Inverse model analysis and synthesis., Marine Ecology-Progress Series [P], vol 394, Inter Research, Germany, pp. 35-48.

Bissett, A., Cook, P., Macleod, C., Bowman, J.P., Burke, C., 2009, Effects of organic perturbation on marine sediment betaproteobacterial ammonia oxidizers and on benthic nitrogen biogeochemistry, Marine Ecology-Progress Series [P], vol 392, Inter-Research, Germany, pp. 17-32.

Morgan, K.E., Burton, E.D., Cook, P., Raven, M.D., Fitzpatrick, R.W., Bush, R., Sullivan, L.A., Hocking, R.K., 2009, Fe and S K-edge XAS determination of iron-sulfur species present in a range of acid sulfate soils: Effects of particle size and concentration on quantitative XANES determinations, Journal of Physics: Conference Series [P], vol 190, Institute of Physics Publishing Ltd, United Kingdom, pp. 1-4.

Cardenas, M.R., Cook, P., Jiang, H., Traykovski, P., 2008, Constraining denitrification in permeable wave-influenced marine sediment using linked hydrodynamic and biogeochemical modeling, Earth and Planetary Science Letters, vol 275, issue 1-2, Elsevier, Netherlands, pp. 127-137.

Evrard, V., Cook, P., Veuger, B., Huettel, M., Middelburg, J.J., 2008, Tracing carbon and nitrogen incorporation and pathways in the microbial community of a photic subtidal sand, Aquatic Microbial Ecology [P], vol 53, Inter-Research, Germany, pp. 257-269.

Bissett, A., Burke, C., Cook, P., Bowman, J.P., 2007, Bacterial community shifts in organically perturbed sediments, Environmental Microbiology, vol 9, Wiley-Blackwell Publishing, UK, pp. 46-60.

Cook, P., Wenzhofer, F., Glud, R.N., Janssen, F., Huettel, M., 2007, Benthic solute exchange and carbon mineralization in two shallow subtidal sandy sediments: Effect of advective pore-water exchange, Limnology and Oceanography, vol 52, American Society of Limnology and Oceanography Inc, USA, pp. 1943-1963.

Cook, P., Veuger, B., Boer, S., Middleburg, J.J., 2007, Effect of nutrient availability on carbon and nitrogen incorporation and flows through benthic algae and bacteria in near-shore sandy sediment, Aquatic Microbial Ecology, vol 49, Inter-Research, Germany, pp. 165-180.

Meysman, F.J.R., Galaktionov, O.S., Cook, P., Janssen, F., Huettel, M., Middleburg, J.J., 2007, Quantifying biologically and physically induced flow and tracer dynamics in permeable sediments, Biogeosciences, vol 4, Copernicus GmbH, Germany, pp. 627-646.

Huettel, M., Cook, P., Janssen, F., Lavik, G., Middleburg, J.J., 2007, Transport and degradation of a dinoflagellate bloom in permeable sublittoral sediment, Marine Ecology - Progress Series, vol 340, Inter-Research, Germany, pp. 139-153.

Cook, P., Roy, H., 2006, Advective relief of CO2 limitation in microphytobenthos in highly productive sandy sediments, Limnology and Oceanography, vol 51, issue 4, American Society of Limnology and Oceanography, Inc, USA, pp. 1594-1601.

Cook, P., Wenzhofer, F., Rysgaard, S., Galaktionov, O.S., Meysman, F.J.R., Eyre, B.D., Cornwall, J.C., Heuttel, M., Glud, R.N., 2006, Quantification of denitrification in permeable sediments: Insights from a two-dimensional simulation analysis and experimental data, Limnology and Oceanography - Methods, vol 4, American Society of Limnology and Oceanography Inc, USA, pp. 294-307.

Wild, C., Rasheed, M., Jantzen, C., Cook, P., Struck, U., Boetius, A., Huettel, M., 2005, Benthic metabolism and degradation of natural particulate organic matter in carbonate and silicate reef sands of the northern Red Sea, Marine Ecology Progress Series, vol 298, Inter-Research, Germany, pp. 69-78.

Cook, P.L.M., Eyre, B.D., Leeming, R., Butler, E.C.V., 2004, Benthic fluxes of nitrogen in the tidal reaches of a turbid, high-nitrate sub-tropical river, Estuarine Coastal and Shelf Science, vol 59, Academic Press, U K, pp. 675-685.

Cook, P., Butler, E.C.V., Eyre, B.D., 2004, Carbon and nitrogen cycling on intertidal mudflats of a temperate Australian estuary. I. Benthic metabolism, Marine Ecology Progress Series, vol 280, Inter-Research, Germany, pp. 25-38.

Cook, P., Revill, A.T., Butler, E.C.V., Eyre, B.D., 2004, Carbon and nitrogen cycling on intertidal mudflats of a temperate Australian estuary. II. Nitrogen cycling, Marine Ecology Progress Series, vol 280, Inter-Research, Germany, pp. 39-54.

Cook, P., Revill, A.T., Clementson, L.A., Volkman, J.K., 2004, Carbon and nitrogen cycling on intertidal mudflats of a temperate Australian estuary. III. Sources of organic matter, Marine Ecology Progress Series, vol 280, Inter-Research, Germany, pp. 55-72.

Conference Proceedings

Schang, C.M., Osborne, C., Deletic, A., Cook, P., McCarthy, D.T., 2012, Survival of pathogenic and faecal indicator bacteria in the bed and bank sediments of the Yarra River estuary, Australia, Proceedings of the 7th International Conference on Water Sensitive Urban Design, 21 February 2012 to 23 February 2012, Centre for Water Sensitive Cities, Melbourne Vic Australia, pp. 1-8.

Pham, T., Payne, E.G.I., Fletcher, T.D., Cook, P., Deletic, A., Hatt, B.E., 2012, The influence of vegetation in stormwater biofilters on infiltration and nitrogen removal: preliminary findings, Proceedings of the 7th International Conference on Water Sensitive Urban Design, 21 February 2012 to 23 February 2012, Centre for Water Sensitive Cities, Melbourne Vic Australia, pp. 145-153.

Postgraduate Research Supervisions

Current Supervision

Program of Study:
(DOCTORATE BY RESEARCH).
Supervisors:
Hatt, B (Main), Cook, P (Associate), Fletcher, T (Associate).
Program of Study:
(DOCTORATE BY RESEARCH).
Thesis Title:
Biogeochemistry of Nitrate in the Weribee Estuary: Applications of Isotopic Identification of Nitrate Sources, Sinks and Transformations.
Supervisors:
Cook, P (Joint), Grace, M (Joint-co), Cartwright, I (Associate).
Program of Study:
(DOCTORATE BY RESEARCH).
Thesis Title:
Coupled Hydrodynamic Biogeochemical Ecological Model for the Gippsland Lakes.
Supervisors:
Cook, P (Main), Beardall, J (Associate).
Program of Study:
(DOCTORATE BY RESEARCH).
Thesis Title:
DIC dynamics in coastal systems from new methods and modelling..
Supervisors:
Cook, P (Main).
Program of Study:
(DOCTORATE BY RESEARCH).
Thesis Title:
Identification of photostable dyes for simultaneous analysis of compounds in 2D planar optodes..
Supervisors:
Cook, P (Main), Grace, M (Associate).
Program of Study:
(DOCTORATE BY RESEARCH).
Thesis Title:
Investigation on the biogeochemical processes affecting transformation and delivery of nutrients through low order streams of Poowong East catchments area..
Supervisors:
Cook, P (Joint), Grace, M (Joint-co).
Program of Study:
(DOCTORATE BY RESEARCH).
Thesis Title:
Phosphorus and biogeochemical cycling of nutrients in estuarine sediments..
Supervisors:
Cook, P (Joint-co), Grace, M (Joint).
Program of Study:
(DOCTORATE BY RESEARCH).
Thesis Title:
Quantification of denitrification in permeable sediments.
Supervisors:
Cook, P (Main).
Program of Study:
(DOCTORATE BY RESEARCH).
Thesis Title:
Unravelling the nitrogen cycle in a periodically anoxic estuary..
Supervisors:
Cook, P (Main), Grace, M (Associate).
Program of Study:
(DOCTORATE BY RESEARCH).
Thesis Title:
Use of vegetation in biofilters to remove nitrogen from stromwater.
Supervisors:
Hatt, B (Main), Cook, P (Associate), Fletcher, T (Associate).
Program of Study:
(DOCTORATE BY RESEARCH).
Thesis Title:
biogeochemistry of phosphorus in freshwater ecosystems where algal blooms occur.
Supervisors:
Cook, P (Joint), Grace, M (Joint-co).