Impacts of artificial light at night on the early life history of two ecosystem engineers

Abstract

Sessile marine invertebrates play a vital role as ecosystem engineers and in benthic–pelagic coupling. Most benthic fauna develop through larval stages and the importance of natural light cycles for larval biology and ecology is long-established. Natural light–dark cycles regulate two of the largest ocean-scale processes that are fundamental to larvae's life cycle: the timing of broadcast spawning for successful fertilization and diel vertical migration for foraging and predator avoidance. Given the reliance on light and the ecological role of larvae, surprisingly little is known about the impacts of artificial light at night (ALAN) on the early life history of habitat-forming species. We quantified ALAN impacts on larval performance (survival, growth, development) of two cosmopolitan ecosystem engineers in temperate marine ecosystems, the mussel Mytilus edulis and the barnacle Austrominius modestus . Higher ALAN irradiance reduced survival in both species (57% and 13%, respectively). ALAN effects on development and growth were small overall, and different between species, time-points and parentage. Our results show that ALAN adversely affects larval survival and reiterates the importance of paternal influence on offspring performance. ALAN impacts on the early life stages of ecosystem engineering species have implications not only for population viability but also the ecological communities that these species support. This article is part of the theme issue ‘Light pollution in complex ecological systems’.

Evaluation of the effect of agroclimatic variables on the probability and timing of olive fruit fly attack

“…The Julian day of occurrence of the first attacks was evaluated by means of linear mixed-effects models ( Burnham and Anderson, 2002 ; Rondoni et al., 2012 ), excluding from the final analysis the data from 2017, due to the limited number of infestation outbreaks. For both types of models, the relevance of the fixed and random structure was evaluated by means of the likelihood ratio test (LRT) and Akaike information criteria (AIC) ( Pinheiro and Bates, 2006 ; Jacobs et al., 2022 ; Tidau et al., 2023 ). The best-fitted models, i.e., retaining the minimum number of explanatory variables, were selected using LRT ( Burnham and Anderson, 2002 ; Ferracini et al., 2023 ).…”

Light pollution in complex ecological systems

“…R. Soc. B 378: 20220351 [52], plant production [34], soil respiration [36] and movement activity and space use [35,38]. Such changes in processes and functions can have strong consequences for species interactions and ecological networks that constitute entire communities [53].…”

“…The chosen light levels might not fully capture the complexity of the relationship between light and organisms, especially when considering the possibility of nonlinear and intricate relationships. In this theme issue, for example, research by Tidau et al [52] illustrates nonlinear relationships between irradiance and barnacle survival rate. Also, Dyer et al [35] demonstrate a saturating relationship with a steep increase in invertebrate movement activity with light intensity, emphasizing that more than 50% of the change observed in their study already occurred at illuminance levels that were below that of a maximum full moon.…”

“…Notably, alterations in both physiology and behaviour can exert significant influence on fundamental ecological processes and functions [ 39 ]. Research in this issue reveals significant effects on growth and development of marine invertebrates [ 52 ], plant production [ 34 ], soil respiration [ 36 ] and movement activity and space use [ 35 , 38 ]. Such changes in processes and functions can have strong consequences for species interactions and ecological networks that constitute entire communities [ 53 ].…”

“…In this theme issue, for example, research by Tidau et al . [ 52 ] illustrates nonlinear relationships between irradiance and barnacle survival rate. Also, Dyer et al .…”