Species classification
Species classification was performed by a random forest (RF) model using
the R package randomForest (Liaw & Wiener, 2002) using 2000 trees and
the square root of peak number as randomly sampled variables at each
split. To avoid overrepresentation of most abundant species, the number
of specimens per species in each tree was limited to the abundance of
the least abundant species, respectively. The species classification RF
model was applied to all specimens from these 27 species: Acartia
(Acanthacartia) bifilosa (N=5), A. (Acanthacartia) tonsa (N=34),
A. (Acartiura) clausi (N=48), A. (Acartiura) longiremis
( N=81), A. (Acartia) danae (N=18), A. (Acartia) negligens(N=6), Anomalocera patersonii (N=9), Calanus finmarchicus(N=77), C. helgolandicus (N=29), C. glacialis(N=10), C. hyperboreus (N=29), Centropages bradyi(N=4), C. typicus (N=47), C. hamatus (N=53), C.
chierchiae (N=6), Ditrichocorycaeus anglicus(N=10), Eurytemora affinis affinis (N=12), Limnocalanus
macrurus macrurus (N=12), Metridia longa (N=13), M.
lucens (N=24), Microcalanus sp. (N=12), Nannocalanus
minor (N=24), Paraeuchaeta norvegica (N=10), Pseudocalanus
elongatus (N=16), P. moultoni (N=15), Temora longicornis(N=91) and T. sytlifera (N=16). Please note that these are the
taxa names accepted as valid by the World Register of Marine Species,
but for simplification we will use genus and species name only from here
on.