Annex 7: Analysis of Fishing Activity Data: Detailed Methodology
Data used in fisheries analysis was obtained from IFISH, the UK fisheries data warehouse. IFISH provides information on sea fishing activity, landings and sales.
Voyage and landing information is supplied by skippers. Vessels over 10 metres are required to maintain logbooks or e-logbooks and provide landings declarations under European Union ( EU) legislation. Vessels of 10 metres and under are not required to provide this information under EU legislation but in Scotland, these vessels provide the information on FISH1 forms whereas in the rest of the UK, the data is submitted voluntarily by the skippers and is supplemented with sales data from the Register of Buyers and Sellers.
Data on Nephrops, king and queen scallop, landings into Scottish ports by UK vessels apportioned equally to where the fishing activity was declared within ICES area VI.a and rectangles 38E4, 38E5 and 38E6 in ICES area VIIa (see figure 2) were analysed for this report. This area of fishing grounds was analysed as it is associated with the majority of MPAs on the West Coast and Nephrops, king and queen scallops, were thought to be the landings most likely to be affected by management measures. It is, important to note that the queen scallop fishery can fluctuate naturally so changes observed in the data may be due to natural variations in that fishery.
The number of effort days and the number of voyages were analysed to see if there was any difference in fishing patterns since management measures were implemented. The number of effort days for UK vessels are calculated using voyage data from logbooks to determine the time spent fishing with each gear type and in each ICES rectangle. Landings are apportioned to each rectangle based on the number of fishing days declared in each, and as such, landings by ICES rectangle may not be a true reflection of what was actually caught in each rectangle. Furthermore, ICES rectangles are self-declared and hence subject to errors.
ICES rectangles are 30 square nautical miles and much larger than the area of an MPA. The rectangles that are estimated to be affected by MPA management measures were determined from information in two Marine Scotland reports:
The analysis of fishing data covered years 2015 and 2016. The data on effort days, number of voyages and live weight of landings was analysed by month of landing, the ICES rectangle fishing activity was declared in gear type. Fishing gears were grouped into five main categories for analyses; mobile trawls, mobile dredges, mobile other, static traps and static other. When making comparisons between the years, only the data from January to September for each year was analysed as 2016 is not a complete year.
It is important to note that 2016 data is not officially published at the time of this report and has not been finalised. Data for 2016 has not been through the full quality check process to ensure its accuracy and therefore is subject to change. The main issue for the quality of the statistics is the completeness of information in the administrative system. The entry of information into the relevant administrative data base for catches of fish species not subject to quota can often take months and for this reason 2016 data is not complete. A further issues is that information was supplied by the fishermen on their activity and catch and has not been subject to quality checks. In conclusion, information on fisheries data analysed in connection with this report should be considered indicative at best and defining conclusions or policy decisions should not presently be based on this analysis.