Keynote lectures

The Sea: What’s in it for me?

Emeritus Professor Michael Depledge

European Centre for Environment and Human Health, University of Exeter Medical School, United Kingdom.

The seas and oceans provide more than 99% of the space in which organisms can survive and flourish on Earth. Regrettably, they are also receptacles into which vast amounts of anthropogenic waste have been discharged, accidentally or intentionally, over centuries. This, together with the long-term, ruthless exploitation of marine biota, has led to a decline in biodiversity and, in some cases, ecosystem collapse. To try to address this dire situation the United Nations have designated the period from 2021-2030, the “Ocean Decade”. Objectives include achieving a clean ocean, with healthy and resilient ecosystems that are safe and accessible for humans, while also providing inspiration and engagement. This initiative echoes of many earlier national and international efforts directed to similar goals, but clearly, they have achieved only limited success. How then can we improve our approach to make greater progress?

In this presentation, the situation will be reframed. Attention will be paid to how we arrived at this juncture and how we might alter future human interactions with seas and oceans worldwide. There is much in our seas that directly or indirectly threatens our lives, but equally, marine ecosystems contain a wealth of resources that foster human health and wellbeing. Potential changes in the management of environmental chemicals and microbial pollution will be discussed in the context of a rapidly changing climate. The importance of ocean literacy and the vital role of coastal communities in tackling the “wicked problems” we face, will be explored. In particular, the case will be made for the further developing the meta-discipline of “Oceans and Human Health” to transform the way we think about our relationship with the marine environment and embrace the intimate interconnections between human health, wellbeing and the seas around us.

Tracking complex mixtures in the environment and wildlife with in vitro bioassays

Professor Beate I Escher,

1 Helmholtz Centre for Environmental Research – UFZ, Department of Cell Toxicology, Permoserstr. 15, 04318 Leipzig, Germany
2 Eberhard Karls University Tübingen, Environmental Toxicology, Center for Applied Geoscience, 72076 Tübingen, Germany

An overwhelming number and diversity of organic chemicals are in daily use and enter the environment during or after use and disposal. Chemical pollution is an increasing threat to our environment, to wildlife and to people. The impact of chemical pollution will be amplified by population growth and climate change. However, conventional chemical monitoring programs have been criticized on the basis that they cannot include the full range of chemical pollutants that could occur in the environment including transformation products, and they do not account for the combined effects of mixtures of chemicals. Bioanalytical tools may therefore complement chemical analysis for cost-efficient and comprehensive (bio)monitoring. Bioanalytical tools are in vitro cell-based bioassays that target specific mechanisms of toxicity and give a measure of the toxicity of mixtures of known and unknown chemicals, such as persistent organic pollutants, pesticides, industrial chemicals, pharmaceuticals and their transformation products. Bioanalytical tools provide measures of the cumulative effects of mixtures of chemicals that exhibit the same mode of toxic action, for which the selected bioassays are indicative plus they can give a measure of the cytotoxicity of all chemicals acting together in an environmental sample. One of the biggest challenges for the application of in vitro bioassays is the comprehensive extraction of organic chemicals from complex and often also organic matrices. A smart combination of passive equilibrium sampling for hydrophobic pollutants together with solid-phase extraction for more hydrophilic and ionizable organic chemicals leads to a defined extraction without changing mixture composition. Using case studies on water quality monitoring and biomonitoring of marine wildlife I will illustrate how a combination of chemical analysis and bioanalytical tools in conjunction with mixture modelling can help to understand which fractions of the chemical pollution are known and which are unknown. Improved detection of the presence of mixtures of chemicals in environmental matrices, such as water or sediment but also in biota informs chemical risk assessment and management options.

Just how toxic is microplastic and nanoplastic?

Dr Andy M. Booth

SINTEF Ocean, Norway

Is the increasing societal acceptance that microplastic and nanoplastic (MNP) represent an environmental and human health risk based on proven scientific fact? This presentation aims to provide a status on the known risks associated with MNP and highlight how we can improve risk assessment going forward. Microplastic is prevalent in the environment, and we have good tools for determining environmental and human exposure levels (>10 µm). Yet hazard assessment has not been able to keep pace with exposure assessment. A key issue is the lack of environmentally relevant MP reference materials that replicate the irregular shaped, partially degraded MP, comprising a continuum of sizes, a wide range of polymer types and a vast range of plastic-associated chemicals, that are found in the environment. There are also no representative NP reference materials and we have even less knowledge to work with from an exposure perspective. With just a handful of studies attempting to quantify environmental concentrations of NP, the extraction and analysis techniques are not validated, meaning we may easily be over or underestimating levels. NP is thought to present a greater risk than microplastic given that its small size could permit transfer across biological barriers and lead to accumulation in organisms. The result is many MNP toxicity studies employ spherical particles of a single size or narrow size distribution, comprised of a single polymer type; making it extremely difficult to extrapolate results to the complex mixture of particles and associated chemicals found in the environment. There is often no link between determined environmental levels and the exposure concentrations used in the toxicity studies. Limited physicochemical characterisation of MNP used in toxicity studies means that the properties driving observed toxicological impacts are poorly understood and the mechanisms of toxicity are rarely investigated. To conduct meaningful risk assessment, it is critical to identify and use the most relevant species, life stages and toxicological endpoints. With an increasing body of published MNP research available, we will take a brief look at the new FARE Toolbox for assessing the quality of MP studies for use in risk assessment. We conclude with a look at the new UNEA5 plastics treaty and what this might mean for the micro- and nanoplastic research fields.

Upstream changes, downstream impacts: 

How terrestrial inputs shape contaminant cycling and fate in northern freshwater and coastal ecosystems

Dr Amanda E. Poste1,2

1Norwegian Institute for Water Research, Oslo, Norway

2UiT The Arctic University of Norway, Tromsø, Norway

Climate change is resulting in permafrost thaw, melting glaciers, and changes to precipitation and runoff patterns, leading to altered inputs of freshwater and terrigenous material (sediments, nutrients, organic matter (OM), and contaminants) from land to northern freshwater and coastal ecosystems. Recent research has indicated that substantial amounts of mercury (Hg) are stored in Arctic permafrost soils, while other studies have documented substantial pools of previously deposited persistent organic pollutants (POPs) in glaciers and surface soils. As such, ongoing thawing of the cryosphere and increased precipitation and runoff, has the potential to lead to strong increases in the mobilization and transport of contaminants from northern permafrost, glaciers and surface soils from land to rivers, lakes and–eventually–to the sea. However, little is known about fluxes of terrestrially-derived contaminants to northern freshwater and marine ecosystems, and even less is known about the fate of these contaminants in the aquatic environment, despite the potential for increased mobilization of and downstream transport of ‘legacy’ POPs and permafrost associated-Hg to lead to increased contamination of aquatic food webs.

This presentation will focus on how terrestrial inputs to northern freshwater and marine ecosystems shape contaminant cycling and food web accumulation, with examples drawn from research on Hg and POPs in northern lakes, rivers and coastal systems. In particular, I will provide examples related to: 1) climate change impacts on inputs of contaminants from land to downstream freshwater and coastal ecosystems; 2) the role of terrestrial OM and particulate matter in shaping the fate of contaminants in the aquatic environment; 3) indirect effects of terrestrial inputs on contaminant uptake and food web transfer via changes in food web structure; and 4) potential implications of expected increases in Arctic terrestrial-aquatic (including land-ocean) inputs.