Technical Guidelines - Timeline of ICES advice

The production of ICES advice on fishing opportunities can be separated into four distinct temporal phases (Figure 12.4.4.1):

• The first phase is the assembly of data up to 31 December of the year preceding the assessment year. For stocks where data from surveys conducted in the assessment year is available before the assessment is conducted ICES includes these data in the assessment. For a few stocks ICES is also able to include catch data from the first half of the assessment year in the assessments.

• The second phase is the assessment of the state of the stock at 1 January of the assessment year. This phase is looking at the past only and dealing with the stock status and level of exploitation.

• The third phase between the assessment and the forecast is the assessment (interim) year. As incomplete data are available for this year (the year is not over yet), ICES has to make a number of assumptions on the fishery and biology. Some of these so-called interim year assumptions can significantly influence the catch forecast for the next year. If these assumptions prove to be markedly different from reality in subsequent assessments, stock status may be different than that forecasted.

• The fourth phase is the prognosis (forecast) on catch options to be taken next year (the year for which advice is given) and the state of the stock resulting from the different options).