Ocean warming and acidification adjust inter- and intra-specific variability in the functional trait expression of polar invertebrates

Abstract

Climate change is known to affect the distribution and composition of species, but concomitant alterations to functionally important aspects of behaviour and species-environment relations are poorly constrained. Here, we examine the ecosystem ramifications of changes in sediment-dwelling invertebrate bioturbation behaviour—a key process mediating nutrient cycling—associated with near-future environmental conditions (+ 1.5 °C, 550 ppm [pCO2]) for species from polar regions experiencing rapid rates of climate change. We find that responses to warming and acidification vary between species and lead to a reduction in intra-specific variability in behavioural trait expression that adjusts the magnitude and direction of nutrient concentrations. Our analyses also indicate that species behaviour is not predetermined, but can be dependent on local variations in environmental history that set population capacities for phenotypic plasticity. We provide evidence that certain, but subtle, aspects of inter- and intra-specific variation in behavioural trait expression, rather than the presence or proportional representation of species per se, is an important and under-appreciated determinant of benthic biogeochemical responses to climate change. Such changes in species behaviour may act as an early warning for impending ecological transitions associated with progressive climate forcing.

Dilute concentrations of maritime fuel can modify sediment reworking activity of high‐latitude marine invertebrates

“…Moreover, communities with diverse response capacities have higher probabilities of including organisms that persist under specific environmental conditions and functionally compensate following species loss (Bernhardt & Leslie, 2013;Thomsen et al, 2017Thomsen et al, , 2019, minimising the impact on linked ecosystem services when environmental conditions fluctuate over time (Truchy et al, 2015). Although the effects of the conservative contamination event simulated here were relatively subtle, we did note a change in intra-specific variation of sediment reworking activity akin to other studies on responses to pressures in high-latitude marine invertebrates (Williams et al, 2024). Intra-specific variation in trait 1.…”