Fishing effort in the Wadden Sea Difficult estimates in dendritic landscapes

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1 Fishing effort in the Wadden Sea Difficult estimates in dendritic landscapes Dr. Torsten Schulze, Katharina Schulte Thünen Institut für Seefischerei, Hamburg Hamburg, Dr. Torsten Schulze, Katharina Schulte 8 9 January 2015 Conservation Management of Fish Populations in the Wadden Sea

2 Conservation aims vs avaiable data Conservation aims and claims of environmental NGOs often area related 50+ percent of National Park shall be undisturbed Need to define size of undisturbed areas Undisturbed areas == non fished areas?? Seite 2

3 Estimate of fishing effort Aivailable data Logbook data (vessel ID, fishing trip, gear, mesh size) Landing data (species, weight, revenue) Vessel Monitoring System (VMS) data (position, speed, heading) Seite 3

4 From ping to route to area Vessel Monitoring System (VMS) Data from ping to route identity, date & time, posistion, heading, speed; every 2 hours cubic Hermite Spline interpolation (Hintzen et al. 2010) (Hintzen et al. VMS tools course material) Seite 4

5 From ping to route to area Vessel Monitoring System (VMS) Data from route to area (Verändert nach Hintzen et al. 2010) Seite 5

6 From ping to route to area Vessel Monitoring System (VMS) Data from route to area (Verändert nach Hintzen et al. 2010) Seite 6

7 From ping to route to area Vessel Monitoring System (VMS) Data from route to area (Verändert nach Hintzen et al. 2010) Seite 7

8 Fishing effort German and Dutch Vessels using beam trawls 2010 Targeting brown shrimp (TBS) Sole, plaice & Co. (TBB) D3.2: Schulze et al Seite 8 Dr. Torsten Schulze, Katharina Schulte Conservation Management of Fish Populations in the Wadden Sea

9 Estimats in coastal waters To be continued?? Seite 9

10 Difficult estimates in dendritic landscapes Raster green: 1,5 sm x 3 sm Raster Fishing effort Wadden Sea (right): 110 m x 65 m Seite 10

11 Difficult estimates in dendritic landscapes (110 m x 65 m) Seite 11 Dr. Torsten Schulze, Katharina Schulte Conservation Management of Fish Populations in the Wadden Sea

12 From ping to route to area Vessel Monitoring System (VMS) Data (Where?) from route to area (Verändert nach Hintzen et al. 2010) Seite 12

13 Vom Ping zur Strecke zur Fläche Estimate of area fished depends on the size of raster used! (Verändert nach Hintzen et al. 2010) Seite 13

14 Think about: Estimation of area via gear width (Hintzen et al. VMS tools course material) Seite 14

15 How to deal with uncertainty? (Hintzen et al. 2010) (Hintzen et al. VMS tools course material) Seite 15

16 Difficult estimates in dendritic landscapes Current raster too coarse to analyse Wadden Sea landscape Problem: The smaller the cell size the larger the unfished area The larger the cell size the larger the fished area Can we interpolate the routes correctly? Seite 16

17 Difficult estimates in dendritic landscapes Interpolation of routes? Keep topography in mind Remember uncertainty Alternatives? Dialog Increase VMS ping intervals, use of AIS data...? Raster: 110 m x 65 m Seite 17 Dr. Torsten Schulze, Katharina Schulte Conservation Management of Fish Populations in the Wadden Sea

18 Thank YOU! and Deliverable 3.2: Report on economic analysis in coastal fisheries on the basis of revenue for individual profession and fishing trips Seite 18