Last updated on 12 June 2017
An XSA model is used in the assessment, with catch data and the results of two international acoustic surveys (ICES 2015) . Natural mortality is derived using a multi-species model which incorporates predation; particularly Cod (ICES 2015).
The current assessment method has historically resulted in an under estimation of SSB and an over-estimation of F in the most recent year. This pattern however was not seen with the 2016 update (ICES 2016)(ICES 2017) .
Last updated on 3 July 2017
The most recent assessment and advice (ICES 2017) considers that the central Baltic herring are caught inside and outside the central Baltic Sea area. Quotas are advised for all herring caught in the central Baltic management area, which includes also a small amount of Gulf of Riga herring caught in the central Baltic Sea. As such the Herring quota for 2017 in the central Baltic area is based on advice for both Central Baltic and Gulf of Riga stocks. From (ICES 2017)
The TAC value proposed for the central Baltic area is based on the advised catch for the central Baltic herring stock, plus the assumed catch of the Gulf of Riga herring taken in the central Baltic, minus the assumed catch of herring from the central Baltic stock taken in the Gulf of Riga. The values of the two latter are given by the average over the last five years.
- Central Baltic herring assumed to be taken in the Gulf of Riga in 2018 (Subdivision 28.1) is 4340 t (average 2012–2016);
- Gulf of Riga herring assumed to be taken in Subdivision 28.2 in 2018 is 260 t (average 2012–2016).
As an example, following the ICES MSY approach (here identical to the MAP FMSY), catches from the central Baltic herring stock in 2018 should be no more than 267 745 t. The corresponding TAC in the central Baltic management area for 2018 would be calculated as 267 745 t + 260 t – 4340 t = 263 665 t.
It should be noted that catch of Central Baltic herring in the Western Baltic area are not included in this assesment.
Last updated on 03 Jul 2017
ICES reviewed the harvest control rule and reference points for this stock in 2015 (ICES 2015). Currently F at FMSY is the management target. A target biomass reference point of MSY Btrigger= 600 kt is set while a Blim of 430 kt is also set (ICES 2016). The harvest control rule linearly reduces F from FMSY to zero as the stock moves from MSY Btrigger to Blim (ICES 2015).
Last updated on 12 June 2017
According to the most recent ICES update assessment (ICES 2017) the stock’s SSB is currently at approximately 1.3 million tons and is well above Blim (430 kt) and MSY Btrigger (600 kt). Likewise current F at 0.195 is below FMSY (0.22). Recruitment in 2016 while lower than the record high 2015 recruitment event, is above average.
Last updated on 12 Jun 2017
According to the most recent ICES update assessment (ICES 2016) stock biomass has been increasing since 2001. F declined from 2001 to 2006 then stayed stable until 2010, when it started to fall again. Both F and catch have recently increased, with the increase in F somewhat above historical low levels in 2013. With the most recent update, F is now closer to FMSY then it has been over the last few years (ICES 2017)