EU network of mesocosms facilities for research on marine and freshwater ecosystems open for global collaboration.

Silwood Mesocosm Facility (SMF)

Gene-to-Ecosystem effects of warming in freshwater ecosystems

Project lead: Prof. Guy Woodward

Timing of the Imperial Silwood Ponds experiment: This is an ongoing long-term experiment – heating started in summer 2018.

We encourage a wide range of Transnational Access (TA) users to apply: You may come from public authorities, technological partners, and research or teaching institutions. As we plan to observe whole-ecosystem responses, everyone with expertise or interest in freshwater ecosystems is welcome to apply. A total of at ca. 100 person days will be allocated to external users through Transnational Access provided under AQUACOSM for 2019.

If you are interested, please contact us (,, well before the application deadline, so we can advice you about possible options.

Introduction to the project: The impacts of climate change on natural ecosystems remain poorly understood as complex interactions between biological systems add emergent properties that can only be understood using an interdisciplinary and holistic approach. We use artificial ponds (mesocosms) at Silwood Park to assess the impacts of warming in freshwater systems by studying multiple levels of biological organisation, from genes to food webs and whole ecosystems.

We are studying the impacts of warming and extreme temperature events using an array of 96 pond mesocosms. In summer 2018 we started heating the ponds, with treatments that match climate projections, including constant warming at 2 or 4oC above ambient temperature and events of periodic extreme warming that mimic heat waves. This experiment is part of a NERC-funded project that integrates information generated from a global collection of naturally warmed freshwater habitats across a circumpolar ring of geothermal activity, hundreds of large-scale artificial streams and ponds (mesocosms) in the field, and thousands of robotically-assembled microbial communities in the laboratory (microcosms). 

More information on the overall project:

Measurements: Each mesocosm is equipped with a temperature logger and re regularly measure conductivity, oxygen, pH, turbidity and total Chl a. We also take samples seasonally to characterise benthic and pelagic microbial and invertebrate communities, using both traditional and molecular methods. We plan to measure greenhouse gas fluxes and insect emergence. We are particularly interested in applicants with expertise in identifying algae and measuring ecosystem processes.

Long term climate change warming experiment and warming drought and flooding experiment. Project lead: Michelle Jackson. 01/01-31/12 2018

Imperial College Silwood Park plans specific experiments in 2018-2020 related to climate change open for AQUACOSM Transnational Access:

Experiment: 96 mesocosms in a long-term climate warming experiment with treatments including ambient conditions, gradients of warming (+1.5oC to +10oC) and extreme warming events. Warming will start in October 2017.

Experiment: 32 mesocosms with 4 treatments replicated 8 times each: ambient, warming (+4oC), drought and flooding (using the same experiment design as the Iberian ponds in the AQUACOSM network). Treatment application will start in summer 2018.

Timing: Experiments are running all year around with preference given to alignment with our peak sampling in the growing season – further details on request for alignment of research.

Specific expertise: Freshwater plankton identification, general viral work (and virome characterisation specifically), fungal diversity work, measures of nitrogen fixation, multiple stressor ecology.

Transnational Access: 234 person days to be divided in responsive mode. A minimum of 4 visiting scientists of AQUACOSM TA approved users over 26 days are welcome to join ongoing experiments.

Silwood Mesocosm Facility (SMF)
Legal name of organisation
Imperial College London
United Kingdom
Organisation address

Silwood Park Campus, Imperial College London, Ascot, UK

Primary contact information (PI)

Prof. Guy Woodward, Please login or register to view contact information.

Dr. Michelle Jackson, Please login or register to view contact information.;

Dr. Emma Ransome, Please login or register to view contact information.

Years of Mesocosm Experiments
Started 2016
Description of Facility

96 freshwater mesocosms, 32 more coming in 2017

Controlled Parameters

Temperature, drought

Research Topics

Climate change, Food webs, Biochemistry, Microbial Ecology

Facility location(s)
Primary interests
Specialist areas
Source of Information
Photos of experiments/installations


Infrastructure (short name)
Silwood Mesocosm Facility (SMF)
Installation (short name)

Silwood Park Campus, Imperial College London, Ascot, UK

Coordinates / (routes, areas if non-static)
Water / environmental conditions
Depths / bottom / surface

The Silwood Mesocosms are 96 freshwater ponds, each 0.70 m deep and 1.85 m in diameter (Fig. 6.17.1), identical to the mesocosms of the Iberian Pond Network (see above). The Silwood ponds were first filled with degassed tap water in summer 2015. Sand and gravel was added to 5 cm depth in October 2015. After this initial establishment phase, the ponds were seeded with organisms and propagules collected from local surface waters to establish standardised communities before starting experiments. The ponds are wide and shallow enough to mix naturally. Instrumentation will be installed in late 2016 in all experimental units to facilitate long-term high-frequency monitoring of temperature and oxygen. Less frequent monitoring of chlorophyll concentrations will be manual. Samples for eDNA and traditional analyses of benthic and planktonic organisms will be taken at the same time. Funding for these activities is secured through a NERC Large Grant (2015-2019), which will address impacts of warming and nutrients on community structure and ecosystem functioning in freshwater food webs. Experimental treatments in the mesocosms, which are part of this project, will be applied from late 2016 onwards. The mesocosm facility is complemented by a variety of facilities, including a microscopy lab, culture/live laboratory, constant temperature rooms (new rooms currently under construction and due for commission in 2017), several general-purpose labs and a -80°C freezer.

Fig. 6.17.1. Silwood Mesocosm Facility established in 2015 and consisting of 96 ponds and associated research facilities on the Silwood Park Campus near London, UK. Photos: G. Woodward.

Instruments / sensors / equipment
Modality of access

At least 234 person-days in total will be allocated to external users supported by an AQUACOSM TA activity in years 2-4. A minimum of 4 visiting scientists over 26 days per year are welcome to join ongoing experiments. Recently started long-term studies using the mesocosm facility focus on the impacts of warming and nutrients on aquatic community structure and ecosystem functioning.

Unit of access
What is available and when
What service and support facilities are available

Services currently offered by the infrastructure: Users are given access to the mesocosms and associated laboratories and equipment. Visiting scientists are encouraged to cooperate with local scientists and integrate their research activities with ongoing mesocosm experiments to take full advantage of synergies and local expertise. The current priority for using the Silwood Mesocosm Facility are experiments underpinning the NERC Large Grant described above, which will form the basis for developing additional experiments on site and co-ordinated experiments with sister set-ups elsewhere.

Support offered under AQUACOSM: Imperial College offers open access to all infrastructures at Silwood Park for accepted visiting scientists. However, scientific cooperation with Silwood scientists facilitates using the facilities and instruments and receiving advice from experienced local staff. During mesocosm experiments one person at the SMF is dedicated to ensuring smooth operation of the mesocosms. This includes a try-out of operational procedures, surveillance and maintenance of the facility before starting and during an experiment. One scientist will be available for issues relating to the scientific and practical coordination of experiments, and one or more persons will be responsible for conducting chemical and biological analyses of samples, the results of which may be purchased for a particular project.


Accommodation is on site in private rooms with shared kitchen facilities. Silwood Park is close to Sunningdale which has shops and rail station with direct links to central London.

Special rules