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| Marine Resource Fact Sheet |
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| Red shrimp - Balearic Islands, 2008 |
 | Aristeus antennatus - Balearic Islands |
| | Owned by | General Fisheries Commission for the Mediterranean (GFCM)
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| Main Descriptors | Considered a single stock: Yes
Spatial Scale: Sub-Regional
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| Considered a single stock: A group of individuals in a species occupying a well defined spatial range independent of other stocks of the same species. It can be affected by random dispersal movements and directed migrations due to seasonal or reproductive activity. |
| Spatial Scale: Spatial scale contains a standard term such as Global, Regional (e.g. for the whole Atlantic), sub-regional (e.g. for a part of the Atlantic), national, local (for sub-national levels). |
| Considered a management unit: An aquatic resource or fishery is
declared as [Fishery] Management Unit if it is
effectively the focus for the application of selected
management methods and measures, within the broader
framework of a management system. According to the FAO
Glossary for Responsible Fishing, "a Fishery Management
Unit (FMU) is a fishery or a portion of a fishery
identified in a Fishery Management Plan (FMP) relevant
to the FMP's management objectives." FMU's may be
organised around fisheries biological, geographic,
economic, technical, social or ecological dimensions ,
and the makeup and attribute of a fishery management
unit depends mainly on the FMP's management
objectives. |
| Jurisdictional distribution: Jurisdictional qualifier (e.g.
"shared", "shared - highly migratory") of the aquatic
resource related with its spatial distribution. |
| Environmental group: Classification of the aquatic
resource according to the environmental group (e.g.
pelagic invertebrate, or demersal fish) to which the
species belong. |
| | | | | | Habitat and Biology Climatic zone: Temperate. Bottom type: Soft bottom. Depth zone: Slope 200 1000m. Horizontal distribution: Neritic. Vertical distribution: Demersal/Benthic. Geographical Distribution Jurisdictional distribution: Straddling between High Seas and EEZ Water Area Overview Spatial Scale: Sub-Regional Balearic IslandsGeo References  | | Distribution of Red shrimp - Balearic Islands
| GFCM geographical sub-areas | 5: Balearic Islands |
| | | | | | Other georeferences
| FAO Fishing Statistical Division Areas | 37.1.1: Balearic |
| | | | | | Intersecting Major FAO areas and LME areas |
The following area codes have been found as intersecting the distribution of Red shrimp - Balearic Islands Resource Structure Considered a single stock: Yes Exploitation In the Balearic Islands (GSA 05) trawl vessels are between 12-24 meters length. The general gear is a bottom trawl with a vertical opening of 1-3 meters, and diamond mesh codend size of 40 mm diameter until the year 2007. This general model can be modified with small technical adaptations. Red shimps species fleet segment correspond to those vessels that perform their activity for fishing red shrimps in the slope up to 500 m depth. Vessel perform daily trips, and use to do a haul by trip . The number of total annual trips by vessels are variable between 79 and 190 (xmean=183 days). The fishings activivity are developed during the year and there is no fishing closure regulation in the area. The present trawl fleet is performed by 46 vessels; it split their fishing effort between the shelf and slope, about 50% of the fleet (22~24 vessels) fish regularly in the slope. The target species is the red shrimp (Aristeus antennatus), total discards was estimated of 33% in 2005 DCR discards data assessment. Discards for the target species (red shrimp) are considered nul (below 0.001%). Information on Operational Units exploiting this resource will be soon available at the following link: GSA 05 Red Shrimp (Aristeus antennatus)Assessment Data Quality of data and inputs: Length frequency data for landings are available on a monthly basis. It was run a single VPA of males and females combined, using VPA package. Effort series used in days is considered representative of the effort for the whole fleet, however must be considered as rough estimates of the effort, since the effort data and landings are estimated from the Mallorca Island where most of the fleet fish. The male and female length distributions for year (1992-2007) were split using L2Age, slincing ICES package to ages . The catch-at-age for the two sexes were then summed to combined input file for separable VPA and XSA. Catch weights-at-age were averages weighted by numbers -at-age for each sex. Tuning data series was made using the Palma harbour reference fleet. and BALAR_MEDITS Surveys Assessment Model Type: Size-structured Length cohort analysis (LCA), Yield per recruit analysis (Y/R) Assessment Model Virtual population analysis (VPA), Extended survivors analysis (XSA) Overall Assessment Results The XSA model shows a fit of the catchability model for at least the youngest and intermediate ages suitable. Results The XSA model shows similar results to those obtained with the Separable VPA, and the analysis improved our perception of the fishery and it was considered suitable. The assessment of age based by combined sex are suitable and results in a more easily understable assessment in order to apply management measures. Abundance and yield fluctuated between years and it seems quite stable. The fishery is considered as fully exploited, under this premise we consider fishing effort should not increase beyond the current levels. Scientific Advice For management considerationsThe recommendation proposed is not to increase the fishing effort Management Management Advice Scientific advices for management consideration formulated by SCSA have been adopted by SAC. Biological State and Trend Exploitation state: OverexploitedExploitation rate: Moderate fishing mortality
Abundance level: Intermediate abundance Source of information “Assessment of red shrimp (Aristeus antennatus) exploited by the Spanish trawl fishery (1992-2005) in the Geographical Sub-Area 05 (Balearic Islands). In: Report of the 11th session of the Sub-Commitee on Stock Assessment (SCSA)” . Carbonell, A., Guijarro, B., Gaza, M., Valls, M., Ordines, F. FAO-GFCM Malaga, Spain, 30 November - 3 December 2009 2009 FAO  . “General Fisheries Commission for the Mediterranean. Thirthy-fourth Session. Management of Mediterranean Fisheries.” FAO-GFCM Athens, Greece, 14-17 April 2010 2010 FAO  . |
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