Impacts of artificial light at night in marine ecosystems—A review

Abstract

The globally widespread adoption of Artificial Light at Night (ALAN) began in the mid‐20th century. Yet, it is only in the last decade that a renewed research focus has emerged into its impacts on ecological and biological processes in the marine environment that are guided by natural intensities, moon phase, natural light and dark cycles and daily light spectra alterations. The field has diversified rapidly from one restricted to impacts on a handful of vertebrates, to one in which impacts have been quantified across a broad array of marine and coastal habitats and species. Here, we review the current understanding of ALAN impacts in diverse marine ecosystems. The review presents the current state of knowledge across key marine and coastal ecosystems (sandy and rocky shores, coral reefs and pelagic) and taxa (birds and sea turtles), introducing how ALAN can mask seabird and sea turtle navigation, cause changes in animals predation patterns and failure of coral spawning synchronization, as well as inhibition of zooplankton Diel Vertical Migration. Mitigation measures are recommended, however, while strategies for mitigation were easily identified, barriers to implementation are poorly understood. Finally, we point out knowledge gaps that if addressed would aid in the prediction and mitigation of ALAN impacts in the marine realm.

Plasticity and seasonality of the vertical migration behaviour of Antarctic krill using acoustic data from fishing vessels

“…A potentially important aspect that we were not able to take into account in this study is the effect of artificial light emitted from the ship on the observed krill behaviour, especially on days with short photoperiods in autumn and winter. Recent studies have shown that artificial light can strongly alter the vertical migration behaviour of pelagic organisms [89][90][91]. Quantifying the magnitude and persistence of this effect is highly important, as it could have strong implications for almost all vessel-based observations in behavioural studies of pelagic organisms conducted to date.…”

Toward a decade of ocean science for sustainable development through acoustic animal tracking

“…The effects of anthropogenic sound pollution (an emergent pollutant) in marine organisms have not yet been extensively studied (Duarte et al, 2021). It is known that certain marine species are attracted or repulsed by artificial light sources constituting a type of pollution (Marangoni et al, in press). More research is needed to understand the ecological implications of such behavioral changes (Nightingale et al, 2006).…”

Urban-industrial seascapes can be abundant and dynamic fish habitat

“…The diel foraging movements of fish has been well documented on coral reefs, where some species migrate away from reefs at night to feeding areas (Francis and Cote, 2018). One possible cause of this higher nocturnal abundance is the attraction of fish to these structures because of the proliferation of artificial light at night, which can alter fish community behaviour (Marangoni et al, 2022) including providing optimal conditions for predators (Becker et al, 2013). These emerging patterns highlight the importance of undertaking diel fish distribution and abundance surveys, so that we can begin to tackle some of the most basic questions about how these areas are used by mobile marine fauna, which has important implications for the optimal design and construction of coastal urbanindustrial structures.…”