Freshwaters provide essential services to humans but are one of the World’s most degraded and threatened ecosystems. Climate change and its impacts are likely to become the dominant driver of biodiversity loss and changes in ecosystem functioning by the end of this century, but how the drivers of climate change will interact with the multiple stressors that already impact ecosystems remains one of the largest uncertainties in projections of future biodiversity change. By understanding the underlying mechanisms driving these interactions and connecting science and policy we will be in a better position to be able to manage, conserve, or even restore, damaged ecosystems in the face of global change.
Piggott Lab Projects
·ExStream: Freshwater Ecosystems under Global Change (2018-2022). ExStream seeks to understand the relationships among biodiversity, ecosystem functioning and the key drivers of climate change in streams and rivers. Funded by the IRC Laureate Award.
·IMPACT: Innovative monitoring to prioritise contaminants of emerging concern for Ireland (2018-2022). IMPACT will detect, monitor and risk assess contaminants of emerging concern, in particular pesticides, low level pharmaceuticals and personal care and cosmetic products. Funded by EPA Ireland.
·SNET: Managing the small stream network for improved water quality, and biodiversity and ecosystem services protection (2018-2022). SSNET will advance knowledge on the role of small streams in water quality, biodiversity and ecosystem services protection so as to inform policy, measures and management options to meet the WFD objectives and other regulatory targets. Funded by EPA Ireland.
·HydroMussel: Hydrological requirements of the freshwater pearl mussel Margaritifera margaritifera (2018-2022). Funded by the TCD Provost PhD Award and a private donation
·Land2Sea: Integrated modelling of consequences of terrestrial activities and climate change for freshwater and coastal marine biodiversity and ecosystem services (2019-2022).Funded by Belmont Forum and BiodivERsA.
·ESDecide: From Ecosystem Services Framework to Application for Integrated Freshwater Resources Management (2019-2022). Funded by EPA Ireland.
·Woodward et al: A Novel Framework for Predicting Emerging Chemical Stressor Impacts in Complex Ecosystems (2019-2022). Funded by NERC, UK.
Fig. 1. The ExStream System and collaborating institutions. See Piggott et al. (2015, Global Change Biology 21: 206-222) for more details.
My past research has focused on: (i) understanding how climate and/or land-use related stressors interact to affect biodiversity and ecosystem function in freshwaters, (ii) prioritizing managementinterventionsfor multiple stressors in freshwaters, and (iii) advancing multiple-stressor theory. I have combined multi-scale survey and experimental approaches to disentangle the individual and combined effects of multiple stressors in running waters. The latter includes the development of the experimental stream mesocosm system (ExStream System; Fig. 1), a powerful field research facility comprising 128 circular stream mesocosms offering the rare combination of strict control of experimental variables, excellent statistical power and a high degree of realism.
Using the ExStream System, I have pioneered the first empirical investigations into how climate warming and multiple agricultural stressors interact to determine the structure (Piggott et al. 2015a, Global Change Biology), function (Piggott et al. 2015, Journal of Applied Ecology) and behavioural/assembly dynamics (Piggott et al. 2015b, Global Change Biology) of stream communities. Collectively, my research demonstrates how the magnitude and complexity of interactions between climate and/or agricultural stressors are magnified or suppressed among trophic levels (algal producers, invertebrate consumers and microbial decomposers) and levels of biological organization (populations, communities and ecosystem), with important implications for our understanding and management of freshwaters in the face of global change.
My work has also made novel conceptual advances in the determination of synergism (amplified effects) and antagonism (reduced effects) among multiple stressors (Piggott et al. 2015, Ecology and Evolution), and more recently, to describe and understand behavioural responses to multiple stressors (Hale et al. 2016). Furthermore, the ExStream System has attracted considerable attention among international aquatic ecologists who then sought research collaborations, leading to an NZ registered spin-off company (ExStream Systems Ltd) and the construction of ExStream Systems in Germany in 2013 (Elbrecht et al. 2016 Freshwater Biology) and Ireland in 2016, with funding secured to establish ExStream Systems in China and Japan to facilitate distributed experiments on a global scale (Fig. 1).