For several stocks, international management plans and agreements exist that stipulate suitable harvest control rules (and hence exploitation rates and appropriate removals). In many cases the exploitation rates align closely with MSY principles. If these stocks also have accepted age-structured assessments based on catch and survey data, then these are used to determine the advice. Examples include North sea herring or saithe. Maximum sustainable yield (MSY) Where no agreed international management plan exists, the default ICES position for stocks with full accepted assessments is to base advice on a fishing mortality rate (known as FMSY) that is expected to generate the MSY for the participating fleets: that is, the highest possible catch that can be maintained indefinitely. Examples include the haddock stock (IIIa, IV and VIa). This approach has superseded the precautionary approach (PA), although PA biomass reference points are still in use for some stocks and PA advice is still listed. The biomass reference point is used as a ‘trigger’ - if the stock drops below this size, then F is adjusted downwards below FMSY. MSY (or, more specifically, FMSY) can be very difficult to estimate, and proxies to it are often used. It may be different in single-species and multi-species contexts, but it is generally the case that FMSY is less than the historical fishing mortality rate experienced by a stock. Hence a requirement to fish at or around FMSY usually leads to a reduction in fishing mortality, and a concomitant increase in sustainability. ‘Data-poor’ stocks For all other stocks, the form of the ICES advice is principally determined by the requirements of the advice customer, which for ICES is often the European Commission (EC). In an attempt to force member states to monitor and submit detailed data on all their fisheries, in 2011 the EC decided that only stocks with full, age-structured analytic assessments could be managed according to management plans or MSY considerations. All other stocks, including those with only (for example) research-vessel survey data, would be managed according to advice based on the following table. While the intention to improve data provision is laudable, questions need to be asked about whether a rigid approach to the type of assessments that are acceptable is appropriate. Robust assessments using different approaches also need to be considered. For now, the consequences of the consistent application of the table are that many stocks for which reasonable indicators of stock abundance exist are subject to quota cuts because these data do not fit a particular paradigm. Examples include Northern Shelf monkfish.