Obstacles to Fish Passage (SEPA WMS) contains information on the location of barriers on the river network, whether they are natural or man-made and whether they are impassable or passable to fish under certain conditions. The legend accompanying the WMS displays Barrier Type.
The initial dataset was received by SEPA in January 2008 from Fisheries Research Services (which became Scottish Government Marine Scotland in April 2009). The dataset has undergone some error checking and correction with help from FRS / MS. Additional information on obstructions was provided to SEPA by the Fisheries Trusts and Boards between January and March 2009. Workshops with participants from SEPA and Fisheries Trusts were held in late 2010 and early 2011 to correct and add to the dataset. The dataset is updated on an on-going basis by SEPA with information collected by SEPA staff or information collected by third parties and validated by SEPA fisheries ecologists.
The initial barriers were created during the update in 2007 of the 1986 Salmon map transferring salmon distribution information to GIS format on the 1:50000 Digital Rivers Network (DRN). More detail about the initial data is available in the NASCO report at http://www.nasco.int/pdf/far_habitat/HabitatFAR_Scotland.pdf and Figure 2. Map showing the estimated distribution of salmon in Scotland, based on a 2007 update of the original Map of the Distribution in Scottish Rivers of the Atlantic Salmon, Salmo salarL. (Gardiner and Egglishaw, 1986).