Aq Res State Trend
In overexploitation, with relatively intermediate biomass.
[The GFCM methodology to provide stock status and management advice is described in the Appendix F of the Sixteenth Session of the Scientific Advisory Committee Report. See the Bibliography section.]
Habitat Bio
Climatic Zone: Temperate. Bottom Type: Soft bottom; Hard bottom. Depth Zone: Shelf (50 m - 200 m); Slope (200 m - 1000 m). Horizontal Dist: Neritic. Vertical Dist: Demersal/Benthic.
Aq Res Struct
Biological Stock: No
Stock assessment in the GFCM area of application is often conducted by management units, based on GSAs. This method does not ensure that the whole stock is assessed, since stocks may cover several different management units. In some cases, when there is scientific evidence of a stock spreading through different GSAs, as well as information on species from different GSAs, existing information is combined across GSAs. This is then defined as a “joint stock assessment of a shared stock”. The GFCM recommends that when scientific evidence of shared stocks exists, joint stock assessments should be attempted. A number of activities aimed at achieving a better definition of stock boundaries are currently being conducted at the GFCM level. [The State of Mediterranean and Black Sea Fisheries, 2016]
Exploit
In the Balearic Islands, commercial bottom trawlers develop up to four different fishing tactics, which are associated with the shallow shelf, deep shelf, upper slope and middle slope, mainly targeting: i) picarel (
Spicara smaris), striped red mullet, common octopus (
Octopus vulgaris) and a mixed fish category on the shallow shelf (50-80 m); ii) European hake,
Mullus spp., John dory (
Zeus faber) and a mixed fish category on the deep shelf (80-250 m); iii) Norway lobster, but with an important bycatch of big European hake,
Lepidorhombus spp.,
Lophius spp. and blue whiting (
Micromesistius poutassou) on the upper slope (350-600 m); and iv) blue and red shrimp on the middle slope (600-750 m). European hake is a target species for this fishery, mainly exploited on the deep shelf and upper slope, with annual landings oscillating between 50 tonnes and 190 tonnes during recent decades. All European hake catches from this area come exclusively from bottom trawlers.
Bio Assess
Data
Size composition of commercial trawl catches and official landings (1980-2019) and catch per unit effort (CPUE) data come from bottom trawl surveys (2001-2019) and from the commercial fleet (2000-2019). Growth parameters come from Mellon Duval et al. (2010), maturity ogive from Spanish National Data Collection Programme, and M vector from PRODBIOM.
Assess Models
Type: Age-structured
a4a
Both XSA and a4a were used. The final advice came from a4a. Additionally, Y/R analysis and short-term forecast analysis were carried out. The assessment is an update from the previous year.
Results
Stock abundance, stock biomass and recruitment showed oscillations for the entire data series, without any clear trend.
Sci Advice
Reduce fishing mortality. STF available.
Sources
FAO. 2021. General Fisheries Commission for the Mediterranean. Report of the twenty-second session of the Scientific Advisory Committee on Fisheries, online, 22–25 June 2021. FAO Fisheries and Aquaculture Report No. 1347. Rome.
https://www.fao.org/3/cb7622en/cb7622en.pdfReport of the Working Group on Stock Assessment of Demersal Species (WGSAD). Online, 18–23 January 2021.
https://www.fao.org/gfcm/technical-meetings/detail/en/c/1412431/ Bibliography
FAO. 2020. The State of Mediterranean and Black Sea Fisheries 2020. General Fisheries Commission for the Mediterranean. Rome.
https://www.fao.org/3/cb2427en/cb2427en.pdfFAO. 2016. The State of Mediterranean and Black Sea Fisheries. General Fisheries Commission for the Mediterranean. Rome, Italy.
https://www.fao.org/3/i5496e/i5496e.pdfFAO General Fisheries Commission for the Mediterranean/Commission générale des pêches pour la Méditerranée. Report of the sixteenth session of the Scientific Advisory Committee. St. Julian’s, Malta, 17–20 March 2014/Rapport de la seizième session du Comité scientifique consultatif. Saint Julien, Malte, Malte, 17-20 mars 2014. FAO Fisheries and Aquaculture Report/FAO Rapport sur les pêches et l’aquaculture. No. R1102. Rome. 2015. 250 pp.
https://www.fao.org/3/i4381b/i4381b.pdf