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Anchovy - Southern Adriatic Sea
Marine Resource  Fact Sheet
Stock status report 2011
Anchovy - Southern Adriatic Sea
Fact Sheet Citation  
Engraulis encrasicolus – Southern Adriatic Sea
Owned byGeneral Fisheries Commission for the Mediterranean (GFCM) – More
Monitoring periodThis marine resource is reported in FIRMS up to 2012. Subsequently monitored as: Anchovy - Adriatic Sea
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Related observationsLocate in inventorydisplay tree map
 
Species:
FAO Names: en - European anchovy, fr - Anchois, es - Boquerón, ru - Анчоус европейский
Geographic extent of Anchovy - Southern Adriatic Sea
Main Descriptors
Considered a single stock: Yes        Spatial Scale: Sub-Regional
Reference year: 2010
 
 
Biological State and Trend
State & Trend Descriptors
PartnerFIRMS
Exploitation rateModerate fishing mortalityModerate fishing mortality
Abundance levelIntermediate abundanceIntermediate abundance
Aq Res State Trend
Exploitation stateModerately exploited
Habitat and Biology
Climatic zone: Temperate.   Depth zone: Coastal (0 m - 50 m); Shelf (50 m - 200 m).   Horizontal distribution: Neritic.   Vertical distribution: Pelagic.  

Geographical Distribution
Jurisdictional distribution: Straddling between High Seas and EEZ

Water Area Overview
Spatial Scale: Sub-Regional


Southern Adriatic Sea
Geo References
Resource Structure
Considered a single stock: Yes
Exploitation
 

Italy

Anchovy (Engraulis encrasicolus) is exploited by pelagic trawl, purse seine and to a lower level by bottom trawl (bycatch of small pelagics). Highest landings in weight are those of pelagic trawling followed by purse seine. Fishing is carried out five days a week. Exploitation is mainly based on age classes 1 and 2. Purse seiners during most of the fishing season operate in GSA17 (Northern Adriatic Sea). From official data, the pelagic trawl and purse seine fleet of the geographical sub-area 18 (South-Western Adriatic Sea) is made up by 41 boats, but not all of them are operating all over the year.

Montenegro

Since 2004 there was no commercial catching of small pelagic fishes in Montenegro so it wasn’t possible to estimate biomass or MSY from commercial landings data. At present time, there is only one active vessel (purse seine) that is exploiting these resources in Montenegro but the catches are poor, probably because of lack of experience of the crew and some technical problems. Even when catches are accomplished there is a big problem in its sale because of unorganized market. As for the case of sardine, anchovy is targeted mostly by small-scale fisheries. Fishing grounds are located along the coast, and also in the Boka Kotorska Bay. In small-scale fishery almost all types of nets are used (gillnet, purse seines, trammel net etc. and long lines). With this type of fishery, a lot of economically important fishes are caught but there are no precise data about their amounts.

Albania

At present there are 4 pelagic vessels in Albania, which are active for 3-5 months during the year. There are three main exploitation areas: Shengjin, Durres and Valona. The catch goes to market or is used by the local conservation industry. There are three conservation industries in Shengjin; most of the product for these industries is imported.
Assessment
 
Data

Data concerning Italian official commercial landings come from ISTAT (1987-2003) and IREPA (2004-2010). Anchovy biomass was assessed by two direct methods, acoustics and DEPM (Daily Egg Production Method), in the frameworks of MEDIAS and AdriaMed project in both sides of GSA18. Survey period was July. Reproductive parameters of adult population were processed directly onboard (total length, weight with and without gonads, sex ratio and maturity stages), while relative batch fecundity (Frb) and spawning frequencies (f) were analysed in lab. Plankton samples were processed in lab using methodology given by Regner (1985). Developmental time from fertilization to hatching (D) was analyzed and also instantaneous mortality rates of eggs, average and total daily egg production and spawning areas. Biomass estimate is derived from the elaboration of acoustic data logged at three frequencies (38, 120 and 200 kHz) to calculate raw density of small pelagic fish in the study area converted into biomass per species on the base of percentage in weight of the different species and their mean size from the outcome of pelagic trawls made during the survey. Biomass per age class is also estimated using age length keys derived by biological samples collected during the survey.
Assessment Model
Type:  Biomass-aggregated
Acoustic Biomass estimates
Methodology

Direct method.
Results

Western GSA18

The average value of anchovy biomass density estimations for the studied period (1987-2010) is 26.7 t/nm2. From the very low levels of abundance at the beginning of the historical series we assist to a recovery since 1994; after that the stock maintained good levels of abundance from 1997 to 2002. In these last years anchovy biomass in this area presents strong fluctuations with two minima (2005, 2008) and two maxima (2006, 2009). In 2010 biomass density was estimated in 20.2 t/nm2 equal to 50 692 t for an area of 2 510 nm2, a value slightly below the mean.

Eastern GSA18

Apart from the first surveys that took place in Montenegro waters only, the results of two surveys covering the whole area (Montenegro and Albania) are available by now. While in 2008 anchovy biomass was 31 606 t, in 2010 it resulted only 13 081 t over an area of 2 597 nm2.
Assessment Model
Type:  Others
Daily Egg Production Method (DEPM)
Methodology

Direct method.
Results

Western GSA18

The only estimate available is for 2010, biomass resulted 81 904 t. This estimation resulted higher than the acoustic one but comparing the estimates in SW GSA18 with those of SE GSA18 they are in agreement seeing much lower biomasses in SE. Using the historical series of biomass estimates by acoustics and the relative landings from ISTAT & IREPA the harvest rate was estimated. Using the mean value for the last 4 years and considering it in good approximation equal to fishing mortality F the exploitation rate E was calculated assuming natural mortality M equal to 0.82. The value of natural mortality used refers to that indicated in the stock assessment of GSA17 for age class 1, being this age class the most represented in 2009 and 2010 in survey samples. The value of E resulted 0.17, well below the reference point of 0.4.

Eastern GSA18

The available estimates for the whole area made in 2008 and 2010 gave respectively 21 524 t and 18 448 t.
Overall Assessment Results

In 2008 acoustic estimation was higher while in 2010 it was lower than DEPM one; anyway the decrease in anchovy biomass from 2008 to 2010 is seen by both methods even if at different extents. The stock in GSA18 shows a decrease respect to 2009 in the western side and also respect to 2008 in the eastern side (no survey here in 2009). Due to the fact that the biomass in the western side is at an intermediate level looking at the historical series and that the fishing effort is not entirely directed in GSA18 the stock could be considered moderately exploited. Moreover the exploitation rate estimated with western side data gave a value of 0.17, well below the Patterson’s Reference Point of 0.4. For what concerns the eastern side even if anchovy biomass resulted at a low level the fishing effort is very low, so the stock could be considered moderately exploited.
Scientific Advice

For scientific research

There is the need to keep investigation of all GSA18 using two independent methods simultaneously. Another suggestion is to try to improve the quality and availability of landings data.

For management consideration

Eastern GSA18

Due to the fact that there is a lack of consistent fishery effort here the stock could be considered moderately exploited. In any case if an increase in fishing effort is foreseen in eastern GSA18 for a precautionary approach it has to be introduced slowly and step by step, also due to the fact that biomass estimations through two direct methods indicated a decrease for anchovy stock in 2010.

Western GSA18

Anchovy is targeted mainly by purse seiners and pelagic trawls; fishing effort is bigger than in the eastern side. The exploitation rate E estimated through the harvest rate over the historical series of biomass estimates by acoustics and the landings data resulted 0.17 (0.4 Patterson’s Reference Point), then the stock could be considered moderately exploited also due to the fact that part of the fleet operates in GSA17.
Source of information
 
Report of the Working Group on Stock Assessment of Small Pelagic Species. FAO-GFCM Chania, Crete (Greece) 24-29 October 2011. 2011 FAO Click to openhttp://151.1.154.86/GfcmWebSite/SAC/SCSA/WG_Small_Pelagics/2011/WGSA_Small-Pelagic-Greece-Report.pdf
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