Spatio‐temporal turnover and drivers of bentho‐demersal community and food web structure in a high‐latitude marine ecosystem

Abstract

Aim: Assess the spatial and temporal turnover of bentho-demersal marine fauna by integrating ecological metrics at the community and food web levels and evaluate their main environmental and anthropogenic drivers.Location: Barents Sea. Method:We analysed data of benthic and bentho-pelagic fish and megabenthic invertebrates caught in the Barents Sea ecosystem survey in August-September 2009-2017 to characterize the spatial and temporal variability of bentho-demersal communities and food webs. We used a trait dataset and highly resolved benthodemersal food web to calculate community and food web metrics in space and time.We spatially clustered the community and food web based on their properties using archetypal analysis and investigated their co-variation with environmental and fishing pressure using (hierarchical) redundancy analysis. Result:The community and food web metrics partitioned the Barents Sea into four sub-regions where different pressures act on the bentho-demersal fauna, such as sea ice loss and fisheries. Multiple community metrics (e.g. mean body length and trophic level) varied along an environmental gradient of annual mean sea bottom temperature, trawling intensity and ice-cover, whereas multiple food web metrics (e.g. nestedness and connectance) varied along an environmental gradient of depth and sediment composition. Communities had higher biomass-weighted variability in body size and omnivory values in areas where the Atlantic and Arctic water masses mix. Several food web and community metrics co-varied (e.g. food chain length and mean trophic level). We found no clear temporal trends in the ecological metrics in any of the four sub-regions, but the metrics had large inter-annual variability with some local minima or maxima coinciding with high sea temperature and ice-cover anomalies. Conclusion:Analyses at the community and food web level are seldom integrated in ecological studies, while this integration gives complementary information to assess patterns and drivers of ecosystem state and to better prioritize conservation efforts.

Viruses may facilitate the cyanobacterial blooming during summer bloom succession in Xiangxi Bay of Three Gorges Reservoir, China

“…This study found that the variation of phytoplankton communities during summer bloom successions was closely associated with the changes in abiotic environmental factors (i.e., T, TN, and PO 4 3− ) and viral factors (i.e., VA, VLP, FLP, and VLB; Table 2 ; Figures 6 , 7 ). Hierarchical partitioning method has been widely used to estimate the individual importance of each explanatory variable ( Li et al, 2022 ; Pecuchet et al, 2022 ). Based on the hierarchical partitioning analysis, the viral variables still have a marked effect on the dynamics of phytoplankton community, although the environmental attributes were the major factors ( Table 2 ).…”

Over 20% of marine fishes shifting in the North and Barents Seas, but not in the Norwegian Sea

“…Understanding how geographic shifts affect marine communities at a finer geographic scale within the study areas considered here remains a present and future challenge. Even though very recent studies report no clear sub-regional temporal community trends across the Barents Sea, these could be hard to detect due to interannual variability in community composition at smaller scales ( Pecuchet et al, 2022 ). Moreover, our results contain surveys from only one season in each study region, which could be partially influenced by seasonal changes in species abundance and biomass, as observed in other marine ecosystems ( Lloret-Lloret et al, 2021 ; Vilas et al, 2020 ).…”

Polar biocenosis cumulative response to environmental stressors reveals who benefits from marine ice loss

“…Weakening of the pelagic-benthic coupling through the decrease in vertical export efficiency and amount of sinking labile organic matter will have repercussions on arctic deep-sea ecosystems. Indeed, benthic biomass and diversity were found to be higher in the seasonally ice-covered areas (Pecuchet et al 2022) with a shorter but with higher modularity food web. Modelling results indicate that climate-related changes in phytodetrital inputs can lead to important shifts in benthic biomass, community structure, and functional diversity, with loss of various common taxa (Lovvorn et al 2016).…”