Sensitivity of a cold‐water coral reef to interannual variability in regional oceanography

Aim We assessed the effects of regional oceanographic shifts on macrofaunal biodiversity and biogeography cold-water coral reefs (CWCRs). CWCRs are often hotspots ecosystem services in frontline exposure to multiple human pressures climate change. Almost nothing is known about how large-scale atmospheric variability affects structure CWCRs’ communities over ecological timescales, this hinders their efficient conservation. This knowledge gap especially evident for species-rich macrofauna, a key component functioning. Location The Mingulay Reef Complex, protected biogenic northeast Atlantic (120–190 m). Methods A unique time series (2003–2011) at 79 stations was used make first assessment interannual changes biodiversity, functional traits. quantified impacts North Oscillation Index (NAOI)—the major mode Atlantic, bottom temperature salinity alongside static variables seafloor terrain hydrography. Results Environmental gradients explained significant amount community composition ( = 26.7%, p < .01) with temperature, NAOI explaining nearly twice as much than or observed differences composition, diversity traits but not species richness across temperature. In warmer years, biogeographic shifted more towards temperate subtropical affinity. Main Conclusions Our findings highlight necessity thorough investigations faunal they may be sensitive oceanography. Considering scientific consensus substantial warming by 2100, we recommend establishment programmes monitoring CWCRs. will support an advanced understanding environmental status serve conservation future.