title: High olfactory sensitivity for dimethyl sulphide in harbour seals.
abstract: Productive areas are patchily distributed at sea and represent important feeding grounds for many marine organisms. Although pinnipeds are known to travel on direct routes and return regularly to particular feeding sites, the environmental information seals use to perform this navigation is as yet unknown. As atmospheric dimethyl sulphide (DMS) has been demonstrated to be a reliable indicator for profitable foraging areas, we tested seals for their ability to smell DMS at concentrations typical for the marine environment. Using a go/no-go response paradigm we determined the DMS detection threshold in two harbour seals (Phoca vitulina vitulina). DMS stimuli from 8.05 x 108 to 8 pmol (DMS)m(-3)(air) were tested against a control stimulus using a custom-made olfactometer. DMS-thresholds determined for both seals (20 and 13 pmol m(-3)) indicate that seals can detect ambient concentrations associated with high primary productivity, e.g. in the North Atlantic. Thus, seals possess an extraordinarily high olfactory sensitivity for DMS, which could provide a sensory basis for identifying or orienting to profitable foraging grounds.
authors.affiliation: Department of General Zoology & Neurobiology, University of Bochum, ND 6/33, 44780 Bochum, Germany.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Kowalewsky
authors.forename: Martin
authors.initials: M
authors.lastname: Dambach
authors.forename: Björn
authors.initials: B
authors.lastname: Mauck
authors.forename: Guido
authors.initials: G
authors.lastname: Dehnhardt
mesh_terms: D025041:Animal Migration; D000818:Animals; D005247:Feeding Behavior; D046049:Phoca / Q000502:physiology*; D012684:Sensory Thresholds; D012903:Smell / Q000502:physiology*; D013440:Sulfides / Q000032:analysis*
chemical_list: D013440:Sulfides; C004784:dimethyl sulfide