Community variability and ecological functioning: 40 years of change in the North Sea benthos

• Published in: Marine environmental research Vol. 107; no. C; pp. 24 - 34
• Main Authors: Clare, D.S., Robinson, L.A., Frid, C.L.J.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2015; Elsevier
• Subjects: Alterations; Animals; benthic organisms; Biodiversity; Biological traits analysis; Carbon - metabolism; Communities; Compensation; Density; ecological function; Ecology; Ecosystem; Ecosystem function; effect traits; Feeding Behavior; fisheries; Functional compensation; life history; Marine; Marine biodiversity; North Sea; Population Dynamics; Regime shift; Stations; Temporal change; Time; Time series; Trawls; North Sea; ANE, North Sea; Temporal change; Functional compensation; Marine biodiversity; Ecosystem function; Time series; Regime shift; effect traits; Biological traits analysis
• ISSN: 0141-1136; 1879-0291; 1879-0291
• DOI: 10.1016/j.marenvres.2015.03.012

Using established associations between species traits (life history, morphological and behavioural characteristics) and key ecological functions, we applied biological traits analysis (BTA) to investigate the consequences of 40 years of change in two North Sea benthic communities. Ecological functioning (trait composition) was found to be statistically indistinguishable across periods that differed significantly in taxonomic composition. A temporary alteration to functioning was, however, inferred at both sampling stations; coinciding with the North Sea regime shift of the 1980s. Trait composition recovered after 1 year at the station located inside the grounds of a trawl fishery, whereas the station located outside the main area of fishing activity underwent a six-year period of significantly altered, and temporally unstable, trait composition. A further alteration to functioning was inferred at the fished station, when the population of a newly established species rapidly increased in numbers. The results suggest that density compensation by characteristically similar (redundant) taxa acts to buffer changes to ecological functioning over time, but that functional stability is subject to aperiodic disruption due to substitutions of dissimilar taxa or uncompensated population fluctuations. The rate at which ecological functioning stabilises and recovers appears to be dependent on environmental context; e.g. disturbance regime. •Two infaunal assemblages experienced long-term changes in taxonomic composition.•Substitutions of redundant taxa buffered changes to trait composition.•Population fluctuations caused trait composition to temporarily change.•Benthic functioning may show long-term stability, but with temporary disruptions.