Does the discharge of chemicals to the environment harm wildlife populations?

Lead Research Organisation: Zoological Soc London Inst of Zoology
Department Name: Insitute of Zoology


Traditional chemical risk assessment relies on undertaking laboratory ecotoxicity studies, but can only assume what the population or ecosystem functioning consequences might be. We aim to move beyond these current limitations by interrogating wildlife population data (terrestrial, freshwater and marine) in the context of chemical exposure in a way that will progress the field.

Our high-level aim is to identify which populations and environments are doing well under the current chemical regime and which are not. This will allow the UK to focus its research where the greatest wildlife declines are occurring and bring clarity to the issue of chemical risk in the environment that continues to cause great uncertainty.

Only a few studies have exploited Britain's long-term wildlife population data with regards to the influence of chemical exposure. Chemical exposures we will examine will include pesticides in the terrestrial and freshwater environments, the chemical mixture in sewage effluent, metals and persistent organic pollutants. We will be looking at macroinvertebrates and fishes in our rivers, invertebrates and sparrowhawks on land and cetaceans (dolphins and killer whales) off our coasts. These environments and species represent current concerns across the natural environment for both diffuse and point source pollution. We will focus on species and taxa that are either core providers of ES or represent aspects of native biodiversity identified by the public as important to societal wellbeing. There are many stressors and compensating factors other than chemicals that can influence wildlife populations. We will incorporate such factors into our analyses to assess their role and significance and thus also address the research question: How important are chemical stressors in relation to other pressures in the environment? By comparing long-term and spatially explicit trends in natural populations, with the response predicted by classical ecotoxicity as reported in the literature, we will evaluate whether such tests are indicative of impacts in the wild. This is essential to assess to what extent traditional risk assessments, typical of those used in the Water Framework and similar Directives, are predictive of outcomes for wildlife populations in terrestrial, freshwater or marine environments.

Planned Impact

Through the examination of population monitoring data, we will inform the regulatory approach to chemicals by evaluating whether the current approach protects wildlife populations and their ecosystem services (ES). Our aim is to identify which populations and environments are doing well under the current chemical regime and which are not. This is tied closely with our regulatory and operational stakeholders' aims. Thus, evaluating the population response to chemical exposure will provide vital information for a wide range of stakeholders and they will be able to focus on chemicals and environments where the greatest declines in native wildlife are occurring. The pathways for engaging and promoting these impacts are detailed in the Pathways to Impact section.

Regulators and Government such as the EA and Defra welcome this proposal. Our research will complement laboratory studies on the impact of a chemical on an organism and provide knowledge on the true impact on wildlife populations over time in the real environment, something that cannot be replicated in the laboratory. The EA are keen to know if there are population impacts occurring despite regulation and we are responding to the Defra Group ARI. We will meet their needs to 'a more effective use of observations to better understand risk' and 'to provide a better understanding of how chemical pollution may be changing the environment'.

The Chemicals Industry including pharmaceuticals, personal care and agrochemicals, are aware that a proportion of their products enter the environment following sewage treatment or agricultural application. Our industry partners (Johnson & Johnson, Bayer, Pfizer, Roche) are all giving strong support to this proposal. They believe this project will greatly help their industry by opening a new line of evidence on the true impact of their chemicals on wildlife. It will give greater confidence and allow decisions to be based on evidence rather than assumptions. This research will improve regulator-industry relationships by giving regulators greater certainty regarding where to show caution and put further controls on products and where the burden of an overly cautious approach may be reduced.

The Water Industry have argued that the risks from chemicals, particularly pharmaceuticals, which escape in wastewater are not well understood We will determine the impact of chemicals released in wastewater both on macroinvertebrates and fish populations over recent decades. If no population consequences are occurring in waters receiving wastewater then we can argue that such costly expenditure and additional energy requirement is unnecessary; the current UK bill for stringent tertiary treatment is an estimated £30 billion. We have close support from Thames Water for our freshwater work.

The Recreation Industry such as Angling, are important stakeholders. They can place considerable pressure on politicians and industry when ill-informed speculation on chemical impacts takes off. Our NGO contacts have expressed great interest in the outcome of our proposal. We will help this sector to better understand chemical pressure and where to focus conservation efforts to mitigate it. Environmental NGOs will recognise the value of our work on assessing population-level impacts of chemicals to address their concerns.

Wider Dissemination and Building Capacity
Incorporating population studies routinely in the way we examine the impact of chemicals, or indeed other human activities, will be a paradigm shift. As well as through publications, we will influence other stakeholders by hosting a web-based training resource to reveal our sources and approach. Showing how publically available monitoring data can be used will democratise the access to science and the power it can provide. It will help grow a new generation of scientists using this approach.
Description Contaminant analysis of tissue samples 
Organisation Centre For Environment, Fisheries And Aquaculture Science
Country United Kingdom 
Sector Public 
PI Contribution My team collected cetacean tissue samples and submitted to CEFAS for contaminant analysis.
Collaborator Contribution CEFAS analysed cetacean tissue samples for specific contaminants
Impact No outputs yet from this collaboration since the current NERC grant started.
Description Cornwall Wildlife Trust Marine Strandings Network 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact The Cornwall Wildlife Trust Marine Strandings Network (CWTMSN) held its annual volunteer's forum on 26th January 2019. Over 70 volunteers attended and Paul Jepson gave an update on the current science and policy aspects of PCBs, especially at the higher trophic levels.
Year(s) Of Engagement Activity 2019
Description MSc marine mammal course, London 
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 ZSL organised and ran a two-day marine mammal specific component of the joint ZSL-RVC (Royal Veterinary College) MSc course over 28th February-1st March. A series of lectures on our cetacean strandings investigation work in the UK, a variety of cetacean threats and on response to live strandings and marine mammal medicine were given by Paul Jepson and Rob Deaville (ZSL) and Frances Gulland (University California, Davis and The Marine Mammal Centre).
Year(s) Of Engagement Activity 2019
Description Science Media Centre press briefing 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Media (as a channel to the public)
Results and Impact Paul Jepson took part in a joint press briefing at the Science Media Centre in Central London on 26th February with Sir Charles Godfrey (Oxford Uni) and Prof John Sumpter (Brunel Uni) to discuss the Oxford Martin position statement on endocrine disrupting chemicals published in Proceedings of the Royal Society B (Godfray et al 2019).
Year(s) Of Engagement Activity 2019