Report of the striped red mullet (Mullus surmuletus) and red mullet (Mullus barbatus) Exchange 2016

In September 2015, the Working Group on Biological Parameters (WGBIOP) recommended an otolith exchange for Mullus surmuletus and Mullus barbatus in 2016 (Otolith Exchanges proposals for 2016/2017; ICES, 2015). Kélig Mahe (IFREMER, France) was decided to be the responsible to organise this otolith exchange. Two otolith exchanges (2008, 2011), and two age reading workshops (ICES, 2009; 2012), have been taken place until now (Mahé et al., 2012). A total of 13 readers from 5 countries (France, Spain, Italy, Cyprus and Greece) participated at the exchange of 2016. The otoliths of 465 individuals (345 M. barbatus & 120 M. surmuletus), sampled from 2011 to 2014 in the Mediterranean Sea (Central Adriatic Sea, Cyprus, Levantine Spain coasts, Balearic Islands) were used for this exchange. For both Mullus species, the precision values were very low, the PA ranged between 56 and 67% the CV ranged from 32 to 64% and the APE ranged from 1.9 to 3.6%. The results by area and species showed the same trend with the first age groups presenting the higher CV values and in some cases lower PA values. These results could be explained by the position of the first growth increment and the two different approaches of reading interpretation used by the readers (ICES, 2012).

Report of the pollack (Pollachius pollachius) Exchange 2016

In September 2015, the Working Group on Biological Parameters (WGBIOP) recommended the first otolith exchange for Pollachius pollachius in 2016 (Otolith Exchanges proposals for 2016/2017; ICES, 2015). Kélig Mahe (IFREMER, France) was decided to be the responsible to organise this otolith exchange. A total of 5 readers from 2 countries (France & Spain) participated at the exchange of 2016. The otoliths of 314 individuals sampled from 2011 to 2015 in Southern stock (ICES area: IXa; n=99) and in (ICES areas: IVc, VIId, VIIe, VIIj-h; n=215) were used for this exchange. For the Northern stock, the precision values for both stocks were very high but the value for Northern stock (PA=91.6%, CV=3.8%; APE= 0.8%) was higher than this for Southern stock (PA=74.5%, CV=14.9%; APE= 1.9%). There were some differences between readers but there were no difference between Northern stock readers and between Southern stock readers.