1412S- Mackerel acoustic survey North Sea -Scotia cruise 1412S dataset https://portal.medin.org.uk/portal/start.php?tpc=012_Marine_Scotland_FishDAC_1720 Daily folders (6) of Simrad format (.raw) acoustic data. SH80 sonar data. pdf biological data sheets for 5 pelagic hauls. All biological data available in FSS database. CTD data for 4 vertical dips. Continual Thermosalinograph data. Continual AGDS data. Objectives: • To obtain in-situ target strength data and biological samples from dispersed individuals and schools of mackerel to verify target strength models. • To obtain echosounder and sonar data from mackerel schools to determine numerical density and abundance. • To obtain hydrographic data from vertical CTD casts Specific Objectives 1. Obtain individual in-situ TS measurements of mackerel 2. Obtain sonar recordings of mackerel schools 3. Obtain echosounder recordings of mackerel schools 4. Obtain biological samples of mackerel from schools (trawl) 5. Obtain biological samples of mackerel from dispersed single targets (rod and line) 6. Calibrate Sv and TS gains on the Simrad EK60 7. Obtain and freeze a length stratified sample of mackerel for analysis on the laboratory 8. Obtain biological samples of spurdog 9. Obtain echosounder recordings of spurdog 20160405