Environmental stability and long-term variability of harpacticoid copepod assemblages

Harpacticoid copepods of the Chernaya Bay (White Sea) intertidal zone were collected in 45 surveys carried out from spring to autumn over a 25-year period (1996–2020) at three sites that differed sediment properties. There no significant long-term trends or seasonal cycles total abundance. Regarding species composition, differences between most important source variability whole while fine-scale (within-habitat) was low. Epibenthic prevailed fine silty sand, both burrowing and epibenthic medium interstitial coarse sand. A comparison data on harpacticoid assemblages number geographically remote loci corroborated generality this pattern. In temporal dimension, structure each community stable until early 2000s, when proportion epibenthic, changed following changes properties (increasing siltation sandy decreasing site). At site, there an increasing trend diversity (both richness expected number). This increase particularly apparent because appearance species. We suggest composition is key factor determining space time. The “ecomorphological profile”, i.e., with different lifestyle morphological traits, useful informative indicator for describing typifying these assemblages.