Cumulative impacts of multiple stressors: improving temporal and biological realism

Lead Research Organisation: University of Oxford
Department Name: Biology

Abstract

In our changing world there is an increasing urgency to understand interactions among multiple environmental stressors, such as pollution and warming. Much of the concern surrounding multiple stressors is due to their potential to interact, creating more severe impacts than they would do independently. Freshwater ecosystems are particularly vulnerable and freshwater biodiversity is the most threatened across the globe: a recent report estimated average population declines of >80% among freshwater vertebrate species compared to <40% in terrestrial and marine species (since 1970; WWF Living Planet Report, 2018). Although the combined impacts of multiple stressors has started to receive more attention, our knowledge on their interactive effects still remains almost non-existent.

In reality, stressors are unlikely to occur in the same space at exactly the same time, yet studies that measure the combined effects of multiple stressors often assume this to be the case. In other words, they lack temporal realism. Most of these studies also lack biological realism by quantifying the effects of stressors on model species at lower levels of organisation (e.g. range shifts, survival, abundance) and ignoring feeding interactions. Here, we will consider how the order, or sequence, of stressor events alters individual-to-ecosystem responses of freshwaters, with a focus on food web interactions. Ecosystems will have multiple responses to the multiple stressors they face, including changes in diversity, abundance, body size and feeding behaviour. Even minor alterations to any of these can shift food web structure, with implications for the effects of future stressors, yet these critically important interactions have been largely ignored to date. This leaves us with little or no predictive ability about the consequences of future change in natural systems. Therefore, here we will use mesocosm experiments to quantify the combined effects of staggered nutrient pollution and warming events (i.e. previous exposure) on freshwater ecosystems, and scale our results up to the catchment level by adapting a suite of dynamic water quality models. Our experimental results will be used to parameterize temperature and nutrient controlled population sizes and growth rates, and to simulate how these changed rates will alter food web structure at the larger river system scale.

This interdisciplinary study will generate an unprecedented breadth and depth of data: from individual changes in fitness and population shifts in size structure to food web complexity. We will show how the order of multiple stressor events (i.e. previous exposure) affects community resistance and resilience to change. These unique data sets will allow us to ask numerous novel questions in pure and applied ecology, and to characterise the little known multiple impacts of multiple stressors on freshwater food webs. Such a comprehensive coverage of responses has never been attempted before and this study will address this glaring gap in our knowledge of stressor impacts.

Planned Impact

The proposed project has the potential to have huge impacts on both the academic (see Academic Beneficiaries) and non- academic communities. Here we address non-academic beneficiaries while the approaches we will take to maximise the likelihood of the identified benefits being achieved is in the Pathways to Impact attachment.

Non-academic beneficiaries:

The long-term impacts of pollution and warming, which can be both direct and indirect, are poorly understood in natural systems, especially when they interact in complex ways in time and space. In particular, the interactive effect of two or more stressors on biodiversity and economically valuable ecosystem services (water purification; productivity; iconic species) remains unknown. Our research addresses this major knowledge gap and will have implications for policy and management through both national and international legislative bodies, so it will be of significant benefit to many stakeholders. The research will help prioritise management and regulation of stressors with direct application for conservation managers and governmental bodies both in the UK and on a more global scale.

The main beneficiaries of this research among the stakeholder communities include the major UK environmental/conservation agencies (Department of Environment Food & Rural Affairs (Defra), Environment Agency (EA), Natural England (NE), Centre for Ecology & Hydrology (CEH), Centre for Environment, Fisheries and Aquaculture Science (CEFAS)), for whom understanding, predicting and mitigating the impacts of stressors in natural ecosystems is an essential remit. These agencies will benefit from our data, especially as we will be measuring responses of whole food webs and ecosystem processes, which will complement their traditional structural metrics focused on taxonomy. Other beneficiaries include commercial bodies (e.g., Thames Water; Wessex Water, Cambridge Environmental Assesements) who will benefit from the new framework we will develop to assess stressor impacts, such as those that are linked to statutory requirements they must meet. Our work will also benefit conservation bodies and learned societies who we are actively engaged with, including those with a freshwater focus (e.g., Freshwater Habitats Trust; Freshwater Biological Association; British Ecological Society) and those with a wider remit (e.g., EarthWatch, World Wildlife Fund for Nature). Although our research is focused in freshwater ecosystems, many insects rely on these as larvae and so the research will also have implications for terrestrial ecosystem management.

Through the proposed stakeholder and public engagement events (see Pathways to Impact), we will engage with all of these groups to bridge the science-policy gap and promote conservation of freshwater ecosystems.

Publications

10 25 50
 
Description Evidence to parliament
Geographic Reach National 
Policy Influence Type Contribution to a national consultation/review
Impact In its 25 Year Environment Plan the Government promised to deliver cleaner inland water to protect biodiversity and human health. This aim is threatened by multiple anthropogenic stressors, including agricultural pollution, sewage and wastewater, and run-off from urban areas. This enquiry looked into the sources of pollution, potential solutions, and suggested policy changes. The aim is to improve water quality to allow safe human use of this resource for recreation.
URL https://committees.parliament.uk/work/891/water-quality-in-rivers/publications/
 
Description Reviewer for the IPBES report: "Thematic assessment of the interlinkages among biodiversity, water, food and health (nexus assessment)"
Geographic Reach Multiple continents/international 
Policy Influence Type Contribution to a national consultation/review
 
Description Food webs in the Antropocene: a stable isotope synthesis to understand the global response of freshwater ecosystems
Amount € 500,000 (EUR)
Organisation National Center for Scientific Research (Centre National de la Recherche Scientifique CNRS) 
Sector Academic/University
Country France
Start 07/2023 
End 08/2026
 
Description PAthways of Chemcials Into Freshwaters and their ecological ImpaCts (PACIFIC)
Amount £2,000,000 (GBP)
Funding ID NE/X015874/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 11/2022 
End 11/2025
 
Title Supplementary information for Local stressors can mask the effects of warming in freshwater ecosystems 
Description Data associated with paper 
Type Of Material Database/Collection of data 
Year Produced 2022 
Provided To Others? Yes  
Impact Free to use for further analysis, including code for null models. 
URL https://figshare.com/collections/Supplementary_information_for_Local_stressors_can_mask_the_effects_...
 
Description Collaboration with CEH on water quality 
Organisation UK Centre for Ecology & Hydrology
Country United Kingdom 
Sector Public 
PI Contribution Co-I on new NERC grant on water quality
Collaborator Contribution We co-wrote the grant and will run WP3 - mesocosm experiments
Impact Awarded NERC funding
Start Year 2022
 
Description Collaboration with School of Geography at University of Oxford on ecological forecasts 
Organisation University of Oxford
Department School of Geography and the Environment
Country United Kingdom 
Sector Academic/University 
PI Contribution Dr. Michelle Jackson and I are collaborating with Dr. Gianbattista Bussi, Dr. Paul G. Whitehead, Dr. Jocelyne M.R. Hughes from the School of Geography at the University of Oxford on a project entitled: "Predicting if local management practices can offset the future impacts of climate change on freshwater macroinvertebrate communities". We provide ecological (macro invertebrate community) and multiple-stressor interaction expertise.
Collaborator Contribution Dr. Gianbattista Bussi and Dr. Paul G. Whitehead provide expertise in catchment-scale hydrology and water quality modelling. Dr. Jocelyne M.R. Hughes is providing expertise in water quality assessments and biomonitoring.
Impact A manuscript is currently being prepared for submission to a journal.
Start Year 2022
 
Description Collaboration with various Norwegian institutes on polar research cruise 
Organisation University Centre in Svalbard
Country Norway 
Sector Academic/University 
PI Contribution Member of the "Closing the Gap" two-week research cruise in Svalbard funded by the Nansen Legacy Project. The project focused on polar cod populations and arctic food webs in the western Svalbard fjords with a team of 30 scientists from various Norwegian institutes. I was on the zooplankton team - we performed global change multiple-stressor experiments on board with marine copepods and we also did sample collection to contribute to long-term biomonitoring datasets.
Collaborator Contribution Other members of the team worked on eco acoustics, fish monitoring, shark monitoring, water chemistry, and geology. Several datasets were formed and numerous papers will be published. See details in report: http://dx.doi.org/10.7557/nlrs.6944
Impact http://dx.doi.org/10.7557/nlrs.6944
Start Year 2022
 
Description Collaboration with various Norwegian institutes on polar research cruise 
Organisation University of Bergen
Country Norway 
Sector Academic/University 
PI Contribution Member of the "Closing the Gap" two-week research cruise in Svalbard funded by the Nansen Legacy Project. The project focused on polar cod populations and arctic food webs in the western Svalbard fjords with a team of 30 scientists from various Norwegian institutes. I was on the zooplankton team - we performed global change multiple-stressor experiments on board with marine copepods and we also did sample collection to contribute to long-term biomonitoring datasets.
Collaborator Contribution Other members of the team worked on eco acoustics, fish monitoring, shark monitoring, water chemistry, and geology. Several datasets were formed and numerous papers will be published. See details in report: http://dx.doi.org/10.7557/nlrs.6944
Impact http://dx.doi.org/10.7557/nlrs.6944
Start Year 2022
 
Description Collaboration with various Norwegian institutes on polar research cruise 
Organisation University of Oslo
Country Norway 
Sector Academic/University 
PI Contribution Member of the "Closing the Gap" two-week research cruise in Svalbard funded by the Nansen Legacy Project. The project focused on polar cod populations and arctic food webs in the western Svalbard fjords with a team of 30 scientists from various Norwegian institutes. I was on the zooplankton team - we performed global change multiple-stressor experiments on board with marine copepods and we also did sample collection to contribute to long-term biomonitoring datasets.
Collaborator Contribution Other members of the team worked on eco acoustics, fish monitoring, shark monitoring, water chemistry, and geology. Several datasets were formed and numerous papers will be published. See details in report: http://dx.doi.org/10.7557/nlrs.6944
Impact http://dx.doi.org/10.7557/nlrs.6944
Start Year 2022
 
Description Collaboration with various Norwegian institutes on polar research cruise 
Organisation University of Tromso
Country Norway 
Sector Academic/University 
PI Contribution Member of the "Closing the Gap" two-week research cruise in Svalbard funded by the Nansen Legacy Project. The project focused on polar cod populations and arctic food webs in the western Svalbard fjords with a team of 30 scientists from various Norwegian institutes. I was on the zooplankton team - we performed global change multiple-stressor experiments on board with marine copepods and we also did sample collection to contribute to long-term biomonitoring datasets.
Collaborator Contribution Other members of the team worked on eco acoustics, fish monitoring, shark monitoring, water chemistry, and geology. Several datasets were formed and numerous papers will be published. See details in report: http://dx.doi.org/10.7557/nlrs.6944
Impact http://dx.doi.org/10.7557/nlrs.6944
Start Year 2022
 
Description Food-webs in the Anthropocene : a stable isotope synthesis to understand the global response of freshwater ecosystems 
Organisation National Center for Scientific Research (Centre National de la Recherche Scientifique CNRS)
Country France 
Sector Academic/University 
PI Contribution We have a new project with Julien Cucherousset funded by CNRS on which Michelle Jackson is a Co-I (co-wrote the project). The project asks how food-web architecture in freshwater ecosystems is affected by human activities?
Collaborator Contribution Michelle Jackson is the Co-I and will be involved with all aspects of this large synthesis project.
Impact Grant funding
Start Year 2023
 
Description Wessex Water Sewage Impacts - Multiple Stressors 
Organisation Wessex Water
Country United Kingdom 
Sector Private 
PI Contribution Our NERC grant has lead to a strong collaboration with Wessex Water. We are working together to determine the impact of wastewater and other stressors on river communities.
Collaborator Contribution Wessex Water have provided site access, funding, and intellectual input to this project.
Impact In prep
Start Year 2021
 
Description Keynote at Food Web Workshop, Portugal 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Food web workshop on global change and bio-monitoring techniques
Year(s) Of Engagement Activity 2023
 
Description Talk at University of Sheffield 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Invited seminar
Year(s) Of Engagement Activity 2022
 
Description Talk for Environment Agency 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Talk to community ecology group at the Environment Agency on multiple stressors
Year(s) Of Engagement Activity 2022
 
Description Talk for University of Calgary 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Postgraduate students
Results and Impact Invited speaker for the University of Calgary Ecology and Evolutionary Biology seminar series. I spoke about global change as a complex system of interacting stressors with a focus on temporal dynamics.
Year(s) Of Engagement Activity 2023
 
Description Talk for the British Ecological Society's Aquatic Group Meeting 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact I was invited to give a talk based on an early career researcher prize. I spoke about global change being a complex system of interacting stressors with a focus on temporal dynamics and freshwater ecosystems.
Year(s) Of Engagement Activity 2022
 
Description Talk for the University of Oslo 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact I was invited to give a seminar to the ecotoxicology research unit at the University of Oslo. I spoke about adaptation to multiple stressors and temporal dynamics.
Year(s) Of Engagement Activity 2022
 
Description Talk for the Water Security Alliance at the University of Exeter 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact I was invited to give a seminar to the "Water Security Alliance". I spoke about multiple stressors in freshwater ecosystems with a focus on interactions between stressors.
Year(s) Of Engagement Activity 2022