Ecotoxicology

New Challenges and New Approaches

Elisabeth Gross, Jeanne Garric

• Publisher: ISTE Press - Elsevier
• Year: 2019
• Print ISBN: 9781785483141
• eBook ISBN: 9780128212417
• Topic: Biological Sciences
• Subtopic: Environmental Science
• Index: Biological Sciences

Ecotoxicology, New Challenges and New Approaches provides the latest in new challenges for research in ecotoxicology. In six comprehensive chapters, the book deals with the long term effect of stressors on biological communities, the effect of pollutants on the chemical communication among organisms, the impact of multiple stressors and of emerging pollutants (microplastics), and at the use of new technologies (omics) in ecotoxicology.- Addresses "emerging issues" that pose new challenges for ecotoxicology research- Resolves several topics, such as the long-term effect of stressors on biological communities and the effect of pollutants on chemical communication between organisms- Analyzes the impact of multiple stressors and emerging pollutants (microplastics)- Explains new technologies (omics) in ecotoxicology

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Chemical Ecology and Ecotoxicology

Elisabeth Gross

Abstract

The main aim of this book is to show new options and challenges in ecotoxicology. One big challenge is the better inclusion of ecological relevance in ecotoxicological tests, and another is the incorporation of other possible stressors and disturbances into risk evaluation. The aim of this chapter is to show how concepts in chemical ecology can help answer these questions. In fact, chemical ecology and ecotoxicology are two research fields which have much in common.

Keywords

Biocides; Chemical Ecology; Chemical fingerprints; Infodisruptors; Kairomone perception; Pesticides; Pheromone perception; Synthetic organic pollutants; Terrestrial habitats

1.1 Introduction

The main aim of this book is to show new options and challenges in ecotoxicology. One big challenge is the better inclusion of ecological relevance in ecotoxicological tests, and another is the incorporation of other possible stressors and disturbances into risk evaluation. The aim of this chapter is to show how concepts in chemical ecology can help answer these questions. In fact, chemical ecology and ecotoxicology are two research fields which have much in common.

Ecotoxicology is a relatively young field resulting from a series of pollution accidents affecting humans and the environment in the 1950s (Vasseur 2018). The birth of the concept of chemical ecology also happened during the late 1950s (Whittaker and Feeny 1971, Hartmann 2008). Thus, the terms “ecotoxicology” and “chemical ecology” emerged almost at the same time, reflecting a new view of and new approaches to emerging challenges. Both fields have a somewhat different focus, yet they have more in common than just the prefix “eco”. Both look at the impact of compounds on organisms; while ecotoxicology focuses mainly on anthropogenic pollutants, chemical ecology concentrates on natural metabolites produced by certain species and affecting others. I propose to take a close look at chemical ecology and assess its utility within ecotoxicology. In the following, I will outline several research fields within chemical ecology that are of interest for ecotoxicology. This cannot be a comprehensive overview of these topics, but will rather be a spotlight on findings and research questions that in the future can be stimulating for both fields. Ultimately, this should allow interested researchers to discover and explore new approaches, which might lead to a better understanding of ecological interactions in a world of multiple stressors.

Chemical ecology came into the focus of the broader scientific community in the late 1950s. At that time, the essential role of plant secondary metabolites for plant–insect interactions became apparent, and evolutionary scientists suggested that their diversity evolved under the selection pressure of herbivory (Hartmann 2008). Ecotoxicology started out with a closer look at the whole food web in order to understand the observed effects of biomagnification or bioamplification of pollutants, and effects on top predators, based on the observations made, for example, in the Bay of Minamata (Japan) and in Clear Lake (USA) (Vasseur 2018, Wiener and Suchanek 2008). Thus, both fields emerged in the context of studies focusing on trophic links between consumers and their food source.

Chemical ecology focused in the beginning mainly on the first trophic levels, looking at the chemical communication between primary producers and their herbivores. The chemical quality of the host plants determines the amount of herbivory, specifically the content and type of defensive secondary metabolites. So-called specialized herbivores are adapted to feed on host plants bearing many toxic secondary metabolites and often have a tight link with their host plants so that they are specialized only on one species or genus of plants. Generalist herbivores instead eat a large variety of different plants with no or low concentrations of deterrent plant secondary metabolites. Usually, host plants through volatile compounds attract herbivores (Dicke and Baldwin 2010). An intriguing idea was to test the use of such volatiles to attract pest insect species to traps and thus minimize herbivore damage on cultured plants such as crops, fruit orchards or commercial timberland (Witzgall et al. 2010, Pickett et al. 1997, Cook et al. 2007). The field is now extremely large, including all types of (secondary) metabolite-related allelochemical interactions within the plant and animal kingdom, and with microorganisms such as fungi and bacteria (Watson 2003, Pawlik 1992, Lenoir et al. 2001, Kusari et al. 2012, Hay 1996, Ferrari et al. 2010, Cembella 2003, Dobretsov et al. 2013, Iason et al. 2012).

The abovementioned different initial viewpoints in ecotoxicology (focusing on top predators and effects of the trophic transfer of pollutants) and chemical ecology (focusing on plant–herbivore interactions and thus the lower trophic levels) might suggest substantial conceptual differences in focus between both fields (Figure 1.1). Yet, there is a common base, and this is to explore relevant trophic links within an ecosystem and to identify which factors influence these trophic links. The amount of ecological studies focusing on different trophic links within ecotoxicology has been increasing over the last 30 years (Relyea and Hoverman 2006), enhancing our knowledge of direct and indirect effects of pollutants on biotic interactions, and including the fact that there are interactions between pollutants and chemical cues, with ultimate effects on trophic links.

Figure 1.1 Conceptual framework for trophic interactions considered in ecotoxicology and chemical ecology. Red arrows describe top-down and bottom-up links in a typical four-level food chain (simplified). Ecotoxicology (yellow arrows) focuses mainly on trophic transfer by bioamplification or biomagnification. Chemical ecology focuses on the role of allelochemicals in trophic links: both top-down and bottom-up (green arrows). Allelochemical interactions can thus modify the strength of a given trophic link and will thus ultimately affect the strength of the trophic transfer of pollutants. For more details, please see the text. For a color version of this figure, see www.iste.co.uk/gross/ecotoxicology.zip

The aim of this chapter is to highlight several topics where ecotoxicology and chemical ecology strongly interact. Section 1.2 focuses on the main questions asked in the chemical ecology of aquatic and terrestrial habitats, and outlines similarities and differences of so-called allelochemical interactions between these habitats. Section 1.3 describes the impact of selected pollutants on allelochemical interactions. Most, but not all, examples will be from aquatic habitats and describe the impact of different groups of inorganic and organic pollutants on the so-called “infodisruption” (Lurling and Scheffer 2007, Lurling 2012), i.e. the disturbance of normal chemical communication or allelochemical interactions. Section 1.4 outlines current knowledge in the chemical ecology of natural biocides. A large range of plant or microbial secondary metabolites with different modes of action have been identified as potential natural pesticides (section 1.4.1). They offer interesting alternatives to synthetic pesticides, yet they might also have ecotoxicological effects. Quite a range of natural fouling compounds have been isolated from various organisms based on chemical ecology studies (section 1.4.2); however, only a few of those are commercially available. Finally, section 1.5 outlines how response factors commonly used in chemical ecology can help in interpreting ecologically relevant effects of pollutants on biotic interactions. This includes a closer look at the impact of pollutants on the production of plant secondary metabolites.

1.2 Chemical ecology in aquatic and terrestrial habitats

In our daily life, m...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Preface
• 1: Chemical Ecology and Ecotoxicology
• 2: Pollution Tolerance in Aquatic Animals: From Fundamental Biological Mechanisms to Ecological Consequences
• 3: Strategies and Consequences of Indigenous and Invasive Freshwater Mussels Living in Cyanobacterial and Anthropogenic Impacted Waters
• 4: Anthropogenic Stressor and Parasite Interactions in Aquatic Environments
• 5: Microplastic in Aquatic Environments
• 6: New Challenges: Omics Technologies in Ecotoxicology
• List of Authors
• Index