Behavioural responses of fishes to anthropogenic disturbances: Adaptive value and ecological consequences

Abstract

Aquatic ecosystems are changing at an accelerating rate because of human activities. The changes alter the abundance and distribution of fishes, with potential consequences for ecosystem structure and function. Behavioural responses often underlie these changes in population dynamics, such as altered habitat choice or foraging activity. Here, we present a framework for understanding how and why behaviour is affected by human activities and how the behavioural responses in turn influence higher ecological levels. We further review the literature to assess the present state of the field and identify gaps in our knowledge. We begin with discussing the factors that determine how an individual responds to a change in the environment and whether the response is adaptive or not. In particular, we explain the importance of the evolutionary history of the species. We then search the literature to assess our current knowledge of the impact of human disturbances on the behaviour of fishes and the consequences for ecosystems. The search reveals that much attention has been directed to the impact of human activities on the behaviour of fishes, but that worryingly little is known about the consequences of these responses for populations, communities and ecosystems. Yet, behavioural responses can have profound ecological consequences given that behaviour underly many, if not most, species interactions. Thus, more attention should be paid to the mechanisms and pathways through which behavioural responses influence higher ecological levels. Such information is needed if we are to determine the ultimate effects of human activities on biodiversity and the function and stability of aquatic ecosystems.

Parental thermal conditions affect the brain activity response to alarm cue in larval zebrafish

“…However, this effect can be compensated through parental anticipatory effects, suggesting that the impact of near-future predicted thermal conditions may be limited owing to exposure to the parents' environment. 15 Nevertheless, the adaptive value of such parental conditioning effects conferred to the offspring is not clear, and it is often difficult to assess whether the response to parental environments is adaptive (Donelson et al, 2018;Candolin and Rahman, 2023), where changing one's phenotype can buffer against effects of environmental change. Although elevated temperature experienced as embryos was shown to have persistent positive effects on performance at elevated temperature for zebrafish adults (Scott and Johnston, 2012), such developmental temperature acclimation cannot always be expected as beneficial (Leroi, Bennett and Lenski, 1994;Huey et al, 1999).…”

The challenges faced by fish in a dynamic world

“…Tim Lamont (Lancaster, UK) captivated the audience with a superb talk on his work on ocean soundscapes and how our developing understanding of the ecology of underwater sound can be used to help rejuvenate coral reef ecosystems following bleaching events. Plenaries delivered by Ulrika Candolin (Helsinki, Finland) and Ben Geffroy (Montpellier, France) focused on fish behavior in a changing world (Candolin, 2023) and how climate change can alter the sex ratio of fish in natural and managed aquaculture populations were equally informative and instructive.…”

Ecological uncertainty and antipredator behaviour: an integrative perspective

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