GerdKrausJohann Heinrich von Thünen-Institut (Institut für Seefischerei, Hamburg)

GerdKrausassociatedParty2013-01-17The German Small-scale Bottom Trawl Survey (GSBTS) was initiated in 1987. Over the last 20 years, the initial number of 4 survey areas (10 x 10 nautical miles; "Boxes") has been increased to 12, which are distributed over the entire North Sea. Samples were taken with two fishing gears (Grande Ouverture Verticale and cod hopper). All samples were taken in summer (July/August). Box A was additionally sampled in winter (January). Abundance, biomass and length measurements of demersal fish species were recorded.Permissions via Hermann Neumann. Hermann Neumann is contact person for data request, NOT Gerd Krauss! Obtain permission from data set owner(s)North Sea (Box A: 54 degree 17 min N to 54 degree 27 min N, 06 degree 58 min E to 07 degree 15 min E; Box B: 55 degree 16 min N to 55 degree 26 min N, 00 degree 18 min W to 00 degree 00 min W; Box C: 56 degree 33 min N to 56 degree 43 min N, 05 degree 10 min E to 05 degree 28 min E; Box D: 57 degree 48 min N to 57 degree 58 min N, 00 degree 44 min W to 01 degree 04 min W; Box E: 53 degree 50 min N to 54 degree 00 min N, 04 degree 40 min E to 04 degree 57 min E; Box F: 52 degree 23 min N to 52 degree 33 min N, 02 degree 25 min E to 02 degree 41 min E; Box H: 56 degree 20 min N to 56 degree 30 min N, 02 degree 20 min E to 02 degree 38 min E; Box K: 55 degree 25 min N to 55 degree 35 min N, 06 degree 18 min E to 06 degree 36 min E; Box L: 58 degree 40 min N to 58 degree 50 min N, 02 degree 23 min E to 02 degree 43 min E; Box M: 60 degree 17 min N to 60 degree 27 min N, 02 degree 22 min E to 02 degree 42 min E; Box N: 54 degree 43 min N to 54 degree 53 min N, 07 degree 30 min E to 07 degree 48 min E; Box P: 55 degree 10 min N to 55 degree 20 min N, 04 degree 40 min E to 04 degree 58 min E)6.96677.2554.4554.28311987demersal fish (ca. 100 species)Species Leveldemersal fishHermannNeumannSenckenberg / BiK-F

hneumann@senckenberg.de

The total number of hauls per Box and year varied betweeen 20 and 30. The standard towing time of the gears (GOV and KJH) is 30 minutes. Aboard normally the entire catch is sorted according to species, which are weighed, counted and measured. Sub-samples are taken of the abundant species. From the abundant species representative sub-samples of at least 100 individuals depending on variability in size are taken for length measurements. More details on the whole fishing procedure are given in the attached reference

attached_fileNot authorized to access resourceOther timeseries yearly Lusitanean, boreal Mobility, Habitat, Feeding type, Food type, Size, Adult longevity, Age at sexual maturity, Reproduction technique, Reproduction frequency, Reproduction season, Dissemination, Fertilization type Weekly sea surface temperature data (southern North Sea/German Bight). Yearly temperature anomalies from stations near Box D, L and M Temperature and salinity profiles taken during the surveys.