Calculation of species sensitivity values and their precision in marine benthic faunal quality indices.
A challenging aspect of benthic quality indices used for assessing the marine environment has been to compile reliable measures of the species' sensitivity to disturbances. Sensitivity values and their uncertainties can be calculated, but a problem to cope with is that the results may depend on the actual proportion of samples from disturbed and undisturbed environments. Here we calculated sensitivity values for each species along an artificial disturbance gradient created by bootstrapping varying numbers of samples from disturbed and undisturbed environments. The values were increasing, decreasing, or more or less constant along this gradient. The lowest value with the lowest uncertainty was adopted as the species sensitivity value. Analyses of the uncertainties indicated that the accuracy rather than the precision might be a concern. We suggest a method to exclude species for which the uncertainty is outside predefined limits as a precaution to reduce bias in the environmental status classification.
Department of Wildlife, Fish, and Environmental Studies, Swedish University of Agricultural Sciences, SE-901 83 Umeå, Sweden. Electronic address: Kjell.Leonardsson@slu.se.
Kjell
K
Leonardsson
Hafok AB, SE-179 61 Stenhamra, Sweden.
Mats
M
Blomqvist
Marine Monitoring AB, Strandvägen 9, SE-453 30 Lysekil, Sweden.
Marina
M
Magnusson
Marine Monitoring AB, Strandvägen 9, SE-453 30 Lysekil, Sweden.
Andreas
A
Wikström
Marine Monitoring AB, Strandvägen 9, SE-453 30 Lysekil, Sweden; Department of Biology and Environmental Science - Kristineberg, University of Gothenburg, SE-451 78 Fiskebäckskil, Sweden.
Rutger
R
Rosenberg
D000818:Animals; D059001:Aquatic Organisms / Q000145:classification / Q000502:physiology; D004777:Environment; D004784:Environmental Monitoring / Q000379:methods* / Q000592:standards; D007448:Invertebrates / Q000145:classification / Q000502:physiology; D012623:Seawater / Q000737:chemistry; D012680:Sensitivity and Specificity
Benthic invertebrates; Disturbance; Kattegat; Marine Strategy Framework Directive; Skagerrak; Water Framework Directive