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Dr Jeremy (Jay) Piggott


Phone +64-3-479-5855

Research Fellow, University of Otago, New Zealand
JSPS Invited Fellow, Kyoto University, Japan
Trimble Visiting Fellow, Imperial College London, UK
NZC Visiting Fellow, Peking University, China

ExStream Research
Associate Editor, Journal of Applied Ecology and the journal Limnology
Lead Author (Asia-Pacific Regional Assessment), IPBES
Executive Committee, New Zealand Freshwater Sciences Society
Advisor, EU MARS Project

Research Interests

  • Climate change and multiple stressor threats to freshwater ecosystems
  • Advancing multiple stressor theory
  • Linking biodiversity-ecosystem function
  • Parasites, invasive species and ecosystem functioning
  • Environmental flows and multiple stressors
  • Genetic connectivity in response to stressors

Current Projects

Climate change and multiple stressor threats to freshwater ecosystems

Climate change and its impacts are likely to be the dominant driver of biodiversity loss and changes in ecosystem functioning by the end of this century. But how the various drivers of climate change will interact with multiple stressors already impacting ecosystems remains the largest uncertainty in projections of future biodiversity change. Of potential concern is whether the drivers of climate change will interact with existing or impending stressors to create ‘ecological surprises’ in the form of synergisms (amplified effects) or antagonisms (reduced effects), in comparison to what would be expected based on knowledge of individual effects. My research employs a combination of experimental and theoretical approaches to investigate climate-change and multiple-stressor impacts on stream ecosystems across multiple levels of organization from genes to ecosystem. (MBIE/NIWA funded Research Fellow with Dr. Christoph Matthaei and Prof. Colin Townsend)

Genetic connectivity of freshwater species in response to multiple stressors (Japan)

Investigating the genetic connectivity of freshwater invertebrate species and biofilms along a longitudinal gradient in multiply stressed streams in Japan. Combining stream surveys with next generation sequencing techniques to gain novel insights into the ecological and genetic responses of freshwater invertebrates, algae and bacteria to natural and man made stressors. 

  • Collaborators at Kyoto University, Japan include, Professor Shin-ichi Nakano (Director of the Center for Ecological Research), Professor Tsutomu Hikida (Chief of Laboratory of Systematic Zoology) and Mr Yuma Shirakawa (Laboratory of Systematic Zoology, Graduate School of Kyoto University).
  • Collaborator at the Research Institute for Humanity and Nature, A/Prof Noboru Okuda.
  • Collaborators at the University of Bochum, Germany include Professor Ralph Tollrian, Dr Florian Leese and PhD student Jan Macher (genetic diversity of freshwater invertebrates). 

The Effects of DiCyanDiamide (DCD) on aquatic environments (New Zealand)

This is the first detailed evaluation of the impact of the nitrification inhibitor dicyandiamide (DCD) on aquatic ecosystems. Our approach combines correlative stream surveys from regions where farming intensity and DCD use are high with manipulative studies using the Experimental Stream Channel system (ExStream System). 

  • Collaborators at the University of Otago include, Project leader and freshwater ecologist Dr Christoph Matthaei, Dr Tina Summerfield, an expert in cyanobacteria, Postdoctoral researcher Dr Andreas Bruder, Romana Salis (PhD student) and Katie Blakemore (BSc Hons student).
  • Collaborators at the University of Bochum, Germany include Professor Ralph Tollrian, Dr Florian Leese and PhD student Jan Macher (genetic diversity of cyanobacteria/algae and invertebrates.
  • Collaborators at the University of Mississippi, USA include with Dr Todd Mlsna (establishing a sensitive and reproducible DCD detection technique).

Environmental flows and multiple stressors (New Zealand)

Investigating the relationship between environmental flows and multiple stressor impacts using survey and reach-scale experiments in tributaries varying in terms of the stress of water abstraction and other abiotic stressors. 

  • Collaborators at the University of Otago include, Principle Investigators Dr Christoph Matthaei and Professor Colin Townsend and Katharina Lange (PhD Student).
  • Collaborating institutions include the Cawthron Institute and the National Institute of Water and Atmospheric Research (NIWA), New Zealand.

The GeneStream project (Germany)

Within the GeneStream project, we investigate the biodiversity of freshwater ecosystems on different levels.

Combining traditional and novel methodological approaches are:

  • Characterizing the gene flow and genetic diversity within species across habitats and anthropogenic barriers using population genomic approaches.
  • Using traditional taxonomic and DNA Barcoding approaches to characterize the macrozoobenthic species diversity of the Breitenbach (Hesse, Germany) and other freshwater systems. Developing high-throughput sequencing protocols that build upon the Barcode databases with the aim to facilitate and improve freshwater ecosystem assessments using such metabarcoding approaches. 
  • Using an innovative stream mesocosm system (the ExStream System) developed by Dr Jeremy Piggott and Dr Christoph Matthaei (University of Otago, New Zealand), we are investigating effects of single and multiple anthropogenic stressors on freshwater communities. This outdoor experimental setup is statistically powerful and tightly controlled, yet highly realistic (because it allows natural immigration and emigration of stream organisms).
  • The GeneStream project is funded for three years (2013-2015) by the Kurt-Eberhard-Bode Foundation to Dr. Florian Leese, Ruhr University of Bochum, Germany.
  • Project video at:
  • Website:

Selected Publications

  • Jackson, M.C., Weyl, O.L.F., Altermatt, F., Durance, I.6, Friberg, N., Dumbrell, A.J., Piggott, J.J., Tiegs, S., Tockner, K., Lehmann, A., Narwani, A.J.T., Krug, C., Leadley, P. & Woodward, G. (2016) Recommendations for the next generation of global freshwater biomonitoring tools. Advances in Ecological Research. DOI: 10.1016/bs.aecr.2016.08.008
  • Taniwaki R., Piggott J.J., de Barros Ferraz S.F. & Matthaei C.D. (2016) Climate change and multiple stressors in small tropical streams. Hydrobiologia. DOI: 10.1007/s10750-016-2907-3
  • Piggott J.J. (2016). Project Report: IPBES Regional Assessment of Biodiversity and Ecosystem Services for Asia and the Pacific. Towards the Zero Order Draft (ZOD). Journal of Integrated Creative Studies, No.2016-009-e. DOI: 10.14989/214433.
  • Elbrecht V., Beermann A.J., Goessler G., Neumann J., Tollrian R.,, Wagner R., Wlecklik A., Piggott J.J., Matthaei C.D. & Leese F. (2016). Multiple-stressor effects on stream invertebrates: a mesocosm experiment manipulating nutrients, fine sediment and flow velocity. Freshwater Biology. 61, 362-375.
  • Magbanua F.S., Townsend C.R., Hageman K.J., Piggott J.J. & Matthaei C.D. (2015). Individual and combined effects of fine sediment and glyphosate herbicide on invertebrate drift and insect emergence: a stream mesocosm experiment. Freshwater Science. DOI: 10.1086/684363. 
  • Piggott J.J., Niyogi D.K., Townsend C.R. & Matthaei C.D. (2015). Multiple stressors and stream ecosystem functioning: climate warming and agricultural stressors interact to affect processing of organic matter. Journal of Applied Ecology. DOI: 10.1111/1365-2664.12480.
  • Piggott J.J., Townsend C.R. & Matthaei C.D. (2015). Re-conceptualizing synergism and antagonism among multiple stressors. Ecology & Evolution. 5: 1538-1547.
  • Piggott J.J., Townsend C.R. & Matthaei C.D. (2015). Climate warming and agricultural stressors interact to determine stream macroinvertebrate community dynamics. Global Change Biology. 21: 1887-1906.
  • Piggott J.J., Salis R., Lear G., Townsend C.R. & Matthaei C.D. (2015). Climate warming and agricultural stressors interact to determine stream periphyton community composition. Global Change Biology. 21: 206-222. 
  • Piggott J.J., Lange K., Townsend C.R. & Matthaei C.D. (2012). Multiple Stressors in Agricultural Streams: A Mesocosm Study of Interactions among Raised Water Temperature, Sediment Addition and Nutrient Enrichment. PLoS ONE, 7, e49873.
  • Lange K., Liess A., Piggott J.J., Townsend C.R. & Matthaei C.D. (2011). Light, nutrients and grazing interact to determine stream diatom community composition and functional group structure. Freshwater Biology, 56, 264-278.
  • Matthaei C.D., Piggott J.J. & Townsend C.R. (2010). Multiple stressors in agricultural streams: interactions among sediment addition, nutrient enrichment and water abstraction. Journal of Applied Ecology, 47, 639-649.
  • Liess A., Lange K., Schulz F., Piggott J.J., Matthaei C.D. & Townsend C.R. (2009). Light, nutrients and grazing interact to determine diatom species richness via changes to productivity, nutrient state and grazer activity. Journal of Ecology, 97, 326-336. 
  • Mark A.F., Porter S., Piggott J.J., Michel P., Maeglp T. & Dickinson K.J.M. (2008). Altitudinal patterns of vegetation, flora, life forms, and environments in the alpine zone of the Fiord Ecological Region, New Zealand. New Zealand Journal of Botany, 46, 205-237.