title: Seasonal migration of the starry smooth-hound shark Mustelus asterias as revealed from tag-recapture data of an angler-led tagging programme.
abstract: The primary aim of this long-term angler-led tagging programme was to gain information about seasonal changes in distribution of the starry smooth-hound shark Mustelus asterias, along the Dutch coast for management and conservation purposes. Between 2011 and 2014, M. asterias comprised 92·6% (n = 2418) of the total elasmobranch catch (n = 2612) by the licenced group of taggers within the Dutch Delta of which 2244 M. asterias were fin-tagged with plastic rototags. Sex and total length (LT ) composition inside the eastern tidal basin (Oosterschelde) were significantly different, i.e. more females and larger individuals, than outside indicating a pupping ground, which was confirmed by the capture of 30 newborn pups (≤32 cm). The distribution pattern of reported recaptured M. asterias (return-rate 3·6%, n = 80) showed a circannual migration between summering in the southern North Sea and wintering in the English Channel and the Bay of Biscay, and suggests that M. asterias is philopatric. The Dutch angling season for M. asterias runs from approximately mid-May to mid-October when the water temperature is above 13° C. Recaptures of eight mature females, but no males in the Bay of Biscay, indicate partial spatial segregation by sex, where mature females migrate over larger distances than immature females and males. These observations, with the absence of recaptures in other known summering areas (i.e. the Irish Sea and Bristol Channel), suggest that the southern North Sea is used by a separate population. Implications for management and recommendations to improve and expand the study approach are discussed.
authors.affiliation: Sportvisserij Nederland, Leijenseweg 115, 3721 BC, Bilthoven, the Netherlands.
authors.forename: N W P
authors.initials: NW
authors.lastname: Brevé
authors.affiliation: IMARES, Wageningen UR, Haringkade 1, 1976 CP, IJmuiden, the Netherlands.
authors.forename: H V
authors.initials: HV
authors.lastname: Winter
authors.affiliation: IMARES, Wageningen UR, Haringkade 1, 1976 CP, IJmuiden, the Netherlands.
authors.forename: H M J
authors.initials: HM
authors.lastname: Van Overzee
authors.affiliation: School of Biology & Environmental Science, Science Centre West, University College Dublin, Belfield, Dublin, 4, Ireland.
authors.forename: E D
authors.initials: ED
authors.lastname: Farrell
authors.affiliation: Van Hall Larenstein University of Applied Sciences, Agora 1, 8934 CJ, Leeuwarden, the Netherlands.|Dutch Elasmobranch Society, Hobbemakade 118-hs, 1071 XW, Amsterdam, the Netherlands.
authors.forename: P A
authors.initials: PA
authors.lastname: Walker
mesh_terms: D063147:Animal Distribution; D000823:Animal Identification Systems; D025041:Animal Migration / Q000502:physiology*; D000818:Animals; D005260:Female; D005398:Fisheries; D008297:Male; D009659:North Sea; D012621:Seasons; D012754:Sharks / Q000502:physiology*; D013696:Temperature
keywords: EU action plan on sharks; Triakidae; rototag; seasonal migration; shark angling