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.

The skeletons of long-lived bamboo coral (Family Keratoisididae) are promising archives for deep-water palaeoceanographic reconstructions as they can record environmental variation at sub-decadal resolution in locations where in-situ measurements lack temporal coverage. Yet, detailed three dimensional (3D) characterisations of bamboo coral skeletal architecture are not routinely available and non-destructive investigations into microscale variations in calcification are rare. Here, we provide high-resolution micro-focus computed tomography (µCT) data of skeletal density for two species of bamboo coral (Acanella arbuscula: 5 specimens, voxel size, 15 µm (central branch scans) and 50 µm (complete structure scan); Keratoisis sp.: 4 specimens, voxel size, 15 µm) collected from the Labrador Sea and Baffin Bay deep-water basins, Eastern Canadian Arctic. These data provide reference models useful for developing methods to assess structural integrity and other fine-scale complexities in many biological, geological, and industrial systems. This will be of wider value to those investigating structural composition, arrangement and/or composition of complex architecture within the fields and subdisciplines of biology, ecology, medicine, environmental geology, and structural engineering.

The rapid expansion of human activity in coastal and shelf seas provides impetus to investigate increased risks to ocean health and social-ecological resilience, but progress in understanding the role and relative importance of associated pressures is frustrated by a lack of a routinely available set of processed geospatial information. Here, we pool 337 standardised geospatial layers derived from 35 sources, including anthropogenic activities, ecological and geoscience assets and features, and met-ocean conditions for the exclusive economic zone surrounding the United Kingdom. Our compilation has undergone pre-processing: spatial interpolation, density estimation, data resampling and extraction, and harmonisation to populate ~10 km ² grids. We provide source version history, an open-access interactive portal, and the details of the spatial processes we used to create each layer, including data quality and uncertainties for layers generated by interpolation/density estimation. Our motivation is to provide reference information and spatio-temporal context, encourage the exploration and inclusion of any inter-dependencies between layers when determining system response, improve mechanistic understanding of observed patterns, and enable better parameterisation of models for those tasked with assessing the compound and cumulative effects of anthropogenic activity.

Multiple expressions of climate change, in particular warming‐induced reductions in the type, extent and thickness of sea ice, are opening access and providing new viable development opportunities in high‐latitude regions. Coastal margins are facing these challenges, but the vulnerability of species and ecosystems to the effects of fuel contamination associated with increased maritime traffic is largely unknown. Here, we show that low concentrations of the water‐accommodated fraction of marine fuel oil, representative of a dilute fuel oil spill, can alter functionally important aspects of the behaviour of sediment‐dwelling invertebrates. We find that the response to contamination is species specific, but that the range in response among individuals is modified by increasing fuel concentrations. Our study provides evidence that species responses to novel and/or unprecedented levels of anthropogenic activity associated with the opening up of high‐latitude regions can have substantive ecological effects, even when human impacts are at, or below, commonly accepted safe thresholds. These secondary responses are often overlooked in broad‐scale environmental assessments and marine planning yet, critically, they may act as an early warning signal for impending and more pronounced ecological transitions.

Consensus has been reached that the sequential loss of biodiversity leads to a non‐linear and accelerating decline in ecosystem properties. The form of this relationship, however, is based on theory and empirically derived observations that do not include species co‐extinctions. Here, we use data from marine benthic invertebrate communities to parameterise trait‐based extinction models that adjust the probability of species extirpation and compensation by including the dependencies between different species across a gradient of climate‐driven environmental change. Our simulations reveal that the inclusion of static co‐extinctions leads to more pronounced declines in the trajectories of sediment bioturbation—a process of great importance to the functioning of marine ecosystems—than those observed with sequential losses of single species. Compensatory mechanisms and the allowance of the formation of new interactions derived from local and regional species pools moderate the compounding influence of co‐extinction but introduce additional variability in community response depending on the composition and functional role of incoming and outgoing species. Our observations emphasise the importance of accounting for local and regional community dynamics, especially in highly connected systems that are prone to extinction cascades when projecting the ecosystem consequences of altered biodiversity.