title: Assigning environmental variables to observed biological changes.
abstract: A method for assigning environmental variables to observed biological changes in benthic communities is proposed. The approach requires biological and environmental sampling at the same sites. Additionally, a biological gradient or trend such as a change in observed species or a significant change in their relative abundances is necessary in order to connect the biological observations to the environmental measurements. Whether there is a statistical significant correspondence between the environmental measurements and the biological changes is tested after quantifying the biological changes by using the community disturbance index (CDI). Finally, the environmental variables that are most strongly associated with the biological changes are identified, and it is proposed that these are strong candidates as the pollutants responsible for the biological changes observed. However, this cannot be confirmed using the monitored data only. The approach is tested on data collected in monitoring surveys at the Ekofisk oil field in the North Sea. The results indicate the method is feasible for assigning environmental variables to observed biological changes.
authors.affiliation: Department of Chemistry, University of Bergen, Allègaten 41, 5007, Bergen, Norway.
authors.forename: Geir Rune
authors.initials: GR
authors.lastname: Flåten
authors.forename: Helge
authors.initials: H
authors.lastname: Botnen
authors.forename: Bjørn
authors.initials: B
authors.lastname: Grung
authors.forename: Olav M
authors.initials: OM
authors.lastname: Kvalheim
mesh_terms: D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000032:analysis; D019015:Geologic Sediments / Q000737:chemistry; D016018:Least-Squares Analysis; D009659:North Sea; D010578:Petroleum; D013997:Time Factors
chemical_list: D004785:Environmental Pollutants; D010578:Petroleum