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Fishing effort distribution of small beam trawlers in 2011

File Identifier: 65EAFC76-D747-4D1C-8B6E-2B1114ADE28D
Metadata Language: English
Resource Type: Service
Responsible Party:
Organisation Name: Thünen Institut
Role: Point Of Contact
Contact Info:
E-Mail Address: rabea.diekmann@ti.bund.de
Metadata Date: 2014-10-29
Metadata Standard Name: INSPIRE Metadata Implementing Rules: Technical Guidelines based on EN ISO 19115 and EN ISO 19119
Metadata Standard Version: V. 1.2
Service Identification
Abstract: International fishing effort distribution in 2011 was calculated for small beam trawlers (<221kW, <24m) in the German EEZ of the North Sea. It was quantified as swept area ratio, which is the ratio between the trawled area over one year and the size of the respective grid cell. Thus, a swept area ratio of 1 means that an area equivalent to the size of the grid cell was fished over one year. The swept area was calculated from data from Vessel monitoring by satellite (VMS) using the approximate width of the first gear of the ship, taken from the European Fleet register. Cell sizes were assigned using the nested grid approach following Gerritsen et al. 2013 (ICES J. Mar. Sci. 70: 523-531), with approximately 3552km² (corresponding to a resolution of 1°x0.5° at 55°N) as the coarsest and approximately 3.5km² as the finest resolution of grid cells, whereas the resolution depends on the amount of information (GPS data from fishing vessels) within a spatial grid.
Browse Graphic: https://coastmap.hzg.de/server/rest/directories/thumbs/Nestedgrid_smallTBB_2011_Clip.jpg
Browse Graphic Type: JPG
Browse Graphic Caption: Fishing effort distribution of small beam trawlers in 2011
Title: Fishing effort distribution of small beam trawlers in 2011
Date: 2014-11-11
Date Type: Creation Date
Identifier: 65EAFC76-D747-4D1C-8B6E-2B1114ADE28D-D
Point Of Contact:
Organisation Name: Thünen Institut
Role: Point Of Contact
Contact Info:
E-Mail Address: rabea.diekmann@ti.bund.de
Keyword Collection:
Keyword: infoMapAccessService
Associated Thesaurus: ISO 19119 service taxonomy
Keyword: NOAH
Keyword: Fishing effort distribution
Keyword: pressureKey5
Keyword: TI
Keyword: Live Data and Maps
Associated Thesaurus: Thematic
Service Type: view
West Bounding Longitude: 3.5
East Bounding Longitude: 9.980012
North Bounding Latitude: 56
South Bounding Latitude: 53.077597
Operation Name: HTTPGet
DCP: WebServices
URL: https://coastmap.hzg.de/server/services/NOAH_geoDB/TI_nestedgrid_smallTBB_2011/MapServer/WMSServer?
Constraints: The swept area ratio can only be an approximate value to quantify the impact on the seafloor. First of all, calculations were based on the assumption that all vessels use exclusively their primary gear listed in the Fleet register. Further, gear types are usually further broken down into fishing métiers, specifying gear parameters and target species. Here, we could only distinguish between small and large beam trawlers. Small beam trawler represent to a large degree the coastal shrimp fishery. Effort in offshore areas is probably associated to plaice fishery. Large beam trawlers represent the flatfish fishery, mainly but not exclusively the fishery targeting sole.Because gear designs differ not only in their size, which is considered as gear width, but also in their bottom contact (e.g. by tickler chains), the physical trawling impact is not equivalent to the swept area ratio. Further, the swept area is not equivalent to the proportion of the cell that was impacted by the gear (unless fishing tracks do not overlap at all). The nested grid approach gives swept area ratios for each grid cell, which are however not equivalent in size. Locally the swept area ratio may be even larger when grid cells would be further broken down. However, this can be only done to a resolution of approximately 3.5km² because position data are usually only exact to 0.01°. Further, the VMS system sends position data approximately every 2 hours, and the track of the ship in between cannot be estimated with a high precision.
Legal Constraints:
Access Constraints: Other Restrictions
Other Constraints: (e) intellectual property rights;
Distribution Format:
Format Name: ArcGIS Service
Format Version: 10.2.1
Transfer Options:
URL: https://coastmap.hzg.de/server/rest/services/NOAH_geoDB/TI_nestedgrid_smallTBB_2011/MapServer
Function: Information
Transfer Options:
URL: https://coastmap.hzg.de/server/services/NOAH_geoDB/TI_nestedgrid_smallTBB_2011/MapServer/WMSServer?
Function: Information
Scope: Service
Conformance Result:
Validation Performed: true
Explanation: NOAH Project
Title: INSPIRE Directive 2007/2/EC
Date: 2015-02-11
Date Type: Publication Date
Lineage: Trawlers data and data from Vessel monitoring by satellite (VMS)
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