EU/UK request to ICES on roundnose grenadier apportion

ICES has examined the proposed methods for apportioning ICES advice among the existing management areas. Relevant background information regarding stock structure, historic fisheries, and management measures for roundnose grenadier in the northeast Atlantic are presented. 

While studies suggest the existence of population structure within roundnose grenadier from subareas 5, 6, 7, and 12, available results are insufficient to delineate alternative stock boundaries to those currently used in the northeast Atlantic. 

The bulk of the biomass of roundnose grenadier in the Atlantic basin occurs at depths below 800 m. As a result, most roundnose grenadier are no longer accessible to commercial fishing, as bottom trawling is not permitted at depths below 800 m and gillnetting is not permitted below 600 m in EU and UK waters. Landings have decreased in all areas during the past decade, reflecting the overall decrease in fleets engaged in deep-water bottom trawling. Total catches since 2016 have been very low in relation to the sum of advised catches.

There are limited fisheries-independent data and a lack of stock assessments for these stocks. In the absence of analytical models, it is not currently possible to undertake any scenario testing to quantify long-term sustainability. Therefore, using the available landings information, as is done for both proposed methods, is the best available basis to determine splits of advice by area. It is recommended to use the latest ICES working group estimates of landings by area in the apportioning methods. Given that landings proportions by area are very changeable, it is recommended that a rolling window of years be used to estimate proportions by area each time the TACs are set. The interannual variability in landings also means that this window should not be too short, so as to be representative of expected landings by area in the coming years (e.g. the most recent five years).

Both methods take some account of third-country catches (countries to which the EU–UK TAC does not apply), method A more so that method B. Method A is relatively complex compared to method B; otherwise, there is little difference in the fundamentals of the two methods. There is no analytical stock assessment undertaken on these stocks and, therefore, no indication of stock status in relation to reference points. However, provided the existing deep-sea fisheries regulations restricting the depth of operation of deep-sea fishing remain in place, neither of the two proposed apportionment approaches seems likely to bring the stock to the point of conservation concern. 

ICES will continue to monitor catches and available information about these roundnose grenadier stocks. The conservation status of these stocks will be reviewed as and when new information becomes available.