PELAGIC BIOGEOGRAPHY AND FRONTS

Fronts, in their world-wide occurrence in the oceans at all space and time scales, exert a wide range of effects on the distribution of pela gic organisms including boundary effects, mixing, concentration, taxon omic and ontogenetic selection, enhanced production, initiation of suc cessions, vertical export, and horizontal transport; a list which is n ot exhaustive. Moreover, at any given time two or more may be interact ing to determine distribution patterns. Thus fronts are hydrological s tructures which have to be given full consideration in biogeographical studies, even if some of their effects are still poorly understood.