Research program

The overarching goal of my research is to understand how human-induced environmental change impacts ecological and evolutionary processes in wild animal populations. In particular, I am interested in investigating whether and how emerging forms of chemical pollution disrupt complex traits and behavioural processes in wildlife, and what implications this may have for individuals, populations, and communities inhabiting contaminated ecosystems.

Emerging contaminants

All environments on Earth are now impacted by chemical pollution from human activities. In fact, release of novel synthetic chemicals into the environment is amongst the fastest-growing agents of global change. This jeopardises human health, drives wildlife declines and species extinctions, and degrades and destroys ecosystems. While wildlife population crashes are a relatively obvious warning sign of the presence of these contaminants at toxic levels, it is far more common for ecosystems to be exposed to a cocktail of chemicals at sublethal levels. These relatively low concentrations may be insufficient to cause direct mortality but can nevertheless have significant negative impacts on wildlife, including via alterations to behaviour. A large part of my research to date has focussed on uncovering how exposure to emerging forms of pollution (e.g. neuroactive pharmaceuticals, endocrine disruptors) influences fitness-related traits and behaviours in wildlife, and how these impacts might affect population- and community-level outcomes. By investigating these questions, my research both highlights the complex environmental hazards posed by biologically active pollution and provides information to enable effective regulation of these contaminants, which is currently severely lacking in the majority of countries worldwide.

SELECTED Publications

Bertram, M.G., Tomkins, P., Saaristo, M., Martin, J.M., Michelangeli, M., Tomkins, R.B., Wong, B.B.M., 2020. Disruption of male mating strategies in a chemically compromised environment. Sci. Total Environ. 703, 134991.

Bertram, M.G., Martin, J.M., Saaristo, M., Ecker, T., Michelangeli, M., Deal, N.D.S., Lim, S.L., O’Bryan, M.K., Wong, B.B.M., 2019. Context-specific behavioural changes induced by exposure to an androgenic endocrine disruptor. Sci. Total Environ. 664, 177–187.

Bertram, M.G., Saaristo, M., Martin, J.M., Ecker, T.E., Michelangeli, M., Johnstone, C.P., Wong, B.B.M., 2018. Field-realistic exposure to the androgenic endocrine disruptor 17β-trenbolone alters ecologically important behaviours in female fish across multiple contexts. Environ. Pollut. 243, 900–911.

Upscaling behavioural ecotoxicology

Animal behaviour can be remarkably sensitive to disruption by chemical pollution. In this regard, given that behaviour is the link between an organism’s physiological processes and its environment, contaminant-induced behavioural changes can have dire implications for ecological and evolutionary processes in wildlife. However, conventional approaches used to assess impacts of chemical pollution on behaviour are largely insufficient to understand the true effects of these contaminants in highly complex, interconnected, and dynamic natural systems. Because of this, I am particularly interested in harnessing recent experimental and technological advancements to increase mechanistic understanding and environmental realism in the field of behavioural ecotoxicology. This includes, for example, examining impacts of chronic multigenerational contaminant exposure, conducting large-scale field exposures and tracking animal behaviour using acoustic telemetry techniques, and testing impacts of exposure on collective behaviour and social interactions within animal groups. These relatively new approaches are capable of capturing contaminant-induced effects that would otherwise be overlooked with more conventional methods, and can therefore provide unparalleled insights into how pollution affects animal behaviour in the wild.

SELECTED Publications

Tan, H., Polverino, G., Martin, J.M., Bertram, M.G., Wiles, S.C., Palacios, M.M., Bywater, C.L., White, C.R., Wong, B.B.M. 2020. Chronic exposure to a pervasive pharmaceutical pollutant erodes among-individual phenotypic variation in a fish. Environ. Pollut. 263, 114450.

Martin, J.M., Saaristo, M., Tan, H., Bertram, M.G., Nagarajan-Radha, V., Dowling, D.K., Wong, B.B.M., 2019. Field-realistic antidepressant exposure disrupts group foraging dynamics in mosquitofish. Biol. Lett. 15, 20190615.

Saaristo, M., Brodin, T., Balshine, S., Bertram, M.G., Brooks, B.W., Ehlman, S.M., McCallum, E.S., Sih, A., Sundin, J., Wong, B.B.M., Arnold, K.E., 2018. Direct and indirect effects of chemical contaminants on the behaviour, ecology and evolution of wildlife. Proc. R. Soc. Lond., B, Biol. Sci. 20181297.

Sexual selection and mating systems

Environmental contaminants can affect reproduction across all biological levels. This includes the development of reproductive organs and production of gametes, release and regulation of sex hormones, and the development and maintenance of secondary sex characteristics. However, despite the fact that appropriate production of mating behaviour is contingent on a variety of physiological systems that are vulnerable to disruption by pollution, whether and how environmental contaminants influence processes of mate choice and sexual selection has received surprisingly little attention. This is cause for concern given that sexual selection has important consequences for reproductive success, population dynamics, and broader evolutionary processes. I am therefore interested in uncovering how sexual selection processes can be disturbed by chemical pollution, and what evolutionary implications this could have for contaminated populations. To date, my research in this area has spanned both pre-copulatory (e.g. female and male mate choice, male-male competition) and post-copulatory (e.g. sperm production and performance) modes of sexual selection, which have both proven to be highly sensitive to pollution exposure. Given that these processes can directly influence the quality and quantity of offspring produced, greater understanding of such contaminant-induced perturbations of sexual selection processes can greatly help to inform environmental conservation and management practices.

SELECTED Publications

Bertram, M.G., Saaristo, M., Ecker, T.E., Baumgartner, J.B., Wong, B.B.M., 2018. An androgenic endocrine disruptor alters male mating behavior in the guppy (Poecilia reticulata). Behav. Ecol. 29, 1255–1263.

Bertram, M.G., Ecker, T.E., Wong, B.B.M., O’Bryan, M.K., Baumgartner, J.B., Martin, J.M., Saaristo, M., 2018. The antidepressant fluoxetine alters mechanisms of pre- and post-copulatory sexual selection in the eastern mosquitofish (Gambusia holbrooki). Environ. Pollut. 238, 238–247.

Bertram, M.G., Saaristo, M., Baumgartner, J.B., Johnstone, C.P., Allinson, M., Allinson, G., Wong, B.B.M., 2015. Sex in troubled waters: widespread agricultural contaminant disrupts reproductive behaviour in fish. Horm. Behav. 70, 85–91.