Scottish Marine and Freshwater Science Volume 5 Number 6: Collation of Available Datasets on Smolt Populations in Scotland to Assess Migration Run Times

2. Methods

At the project outset in December 2013, the aim, background, context, methodology and funding procedures were outlined in a notification letter detailed in appendix A,1. At this stage organisations were asked to notify the SFCC if they either did not collect smolt data, or did collect smolt data. If an organisation identified that it did collect smolt data it was requested to fill in a brief meta-data questionnaire for each monitoring site as detailed in Appendix A.1. At this initial stage it was made clear that all data provided should be considered to be in the public domain and subject to Freedom of Information Scotland Act ( FOISA) and Environmental Information Regulations ( EIR) considerations.

Table 1. Project timescales adapted from Appendix A.1. Initial Notification Letter.

All meta-data identified through this process was then collated into a standardised meta data format and presented to MSS. During January 2014 all outstanding regions were contacted and final metadata responses collated. The SFCC met with MSS on Monday the 3 ^rd of February to discuss and agree the raw datasets which would be requested in full. A standard format for data submission was also discussed and agreed with MSS during the week of the 3 ^rd of February. At this meeting an inventory of adult fish counters and traps in Scotland as detailed in Simpson (2003) was also provided by MSS whichdrew attention to a further two smolt monitoring locations that had not been identified in the original request process. On the 12 ^th of February confirmation letters ( Appendix A.2. Confirmation Letter) were sent out to 13 organisations with smolt data deemed to be relevant to the aims of this project. MSS also suggested that the SFCC circulate a second metadata questionnaire to provide additional information along with the provision of trap installation photographs.

Each organisation was subsequently contacted by phone to outline data format requirements as detailed in the standard data format spread sheet provided by the SFCC. A deadline of 14 days (February the 26 ^th) was set for raw data submission with extensions awarded to several organisations due either to time constraints or to the scale of work involved to collate data from multiple sites and over long timescales. All raw data was provided to the SFCC by March the 7 ^th. Each dataset was then audited to ensure continuity and compatibility within the standard format.

Count level datasets were identified as highly relevant in the context of assessing the potential to quantify migration run-timings, and in order to assess the capability of salmon and sea trout smolts to carry acoustic tags, MSS requested individual fish measurement data if available. 18 datasets were supplied featuring individual fish measurements at a resolution of either 1mm individual fish observation, 5mm category count or 10mm category count. Datasets were collated into the following 4 formats dependent upon the methodology applied by the data collector;

• Individual fish length (1mm)
• Individual fish length (5mm)
• Individual fish length (10mm)
• Fish count level data

It should be noted that multiple organisations collected length data as a subset of total fish counts. Thus, data in these cases was provided in both count and length formats. An extensive meta-data summary ( Table 4) is included with the raw data provided and is detailed in the results section.