Stock boundaries for fisheries assessment and management in the Mediterranean: the Balearic Islands as a case study


  • Antoni Quetglas Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears
  • Beatriz Guijarro Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears
  • Francesc Ordines Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears
  • Enric Massutí Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears



stock boundary, fishery assessment and management, General Fisheries Commission for the Mediterranean (GFCM), Balearic Islands, Mediterranean Sea


The stock concept plays a pivotal role in fisheries assessment and management. Stocks are defined according to biological, geographical, economic or socio-political factors. The General Fisheries Commission for the Mediterranean (GFCM) has established thirty management geographical sub-areas (GSAs) based on political and statistical considerations rather than biological or economic factors. Here, we present our view on the main biological and ecological aspects that should be considered for delineating different management units in the Mediterranean. We focus on the Balearic Islands (GSA05) as a case study highlighting its specificities compared to the adjacent coast of the Iberian Peninsula (GSA06), but the approach could be generalized to the problem of identifying stock boundaries in other areas. The work is based on published information from different marine disciplines such as geomorphology, ecology and fisheries, combined with the analysis of new data coming from official fishery statistics and scientific surveys. This approach avoids the important drawbacks (inconclusive results, high costs) of other time-consuming techniques used in stock identification, such as genetics. According to the information presented, we conclude that GSA05 should be maintained as an individualized area for assessment and management purposes in the western Mediterranean.


Download data is not yet available.


Abaunza P. 2008. Horse mackerel: Identification of stocks: Foreword. Fish. Res. 89: 101-103.

Abaunza P., Murta A.G., Campbell N., Cimmaruta R., Comesana A.S., Dahle G., Santamaria M.T.G., Gordo L.S., Iversen S.A., MacKenzie K., Magoulas A., Mattiucci S., Molloy J., Nascetti G., Pinto A.L., Quinta R., Rarnos P., Sanjuan A., Santos A.T., Stransky C., Zimmermann C. 2008. Stock identity of horse mackerel (Trachurus trachurus) in the Northeast Atlantic and Mediterranean Sea: Integrating the results from different stock identification approaches. Fish. Res. 89: 196-209.

Acosta J., Canals M., López-Martínez J., Muñoz A., Herranz P., Urgeles R., Palomo C., Casamor J.L. 2002. The Balearic Promontory geomorphology (western Mediterranean): morphostructure and active processes. Geomorphology 49: 177-204.

Ardizzone GD. 2006. An introduction to Sensitive and Essential Fish Habitats identification and protection in the Mediterranean Sea. Working Document to the STECF/ SGMED-06-01 sub-group meeting on Sensitive and Essential Fish Habitats in the Mediterranean, Rome, March 2006.

Ballesteros E. 1988. Composición y estructura de los fondos de maërl de Tossa de Mar (Girona, España). Collect. Bot. (Barcelona) 17: 161-182.

Ballesteros E. 1994. The deep-water Peyssonnelia beds from the Balearic Islands (Western Mediterranean). Mar. Ecol.-Pubbl. Staz. Zool. Napoli I 15: 233-253.

Begg G.A., Friedland K.D., Pearce J.B. 1999. Stock identification and its role in stock assessment and fisheries management: an overview. Fish. Res. 43: 1-8.

Begg G.A., Waldman J.R. 1999. An holistic approach to fish stock identification. Fish. Res. 43: 35-44.

Berntson E.A., Moran P. 2009. The utility and limitations of genetic data for stock identification and management of North Pacific rockfish (Sebastes spp.). Rev. Fish Biol. Fisher. 19: 233-247.

Bertrand J.A., Gil de Sola L., Papaconstantinou C., Relini G., Souplet A. 2000. Contribution on the distribution of elasmobranchs in the Mediterranean (from the MEDITS surveys). Biol. Mar. Mediterr. 7: 1-15.

Bertrand J.A., Gil de Sola L., Papaconstantinou C., Relini G., Souplet A. 2002. The general specifications of the MEDITS surveys. Sci. Mar. 66(Suppl. 2): 9-17.

BIOMAERL Team, 2003. Conservation and management of NE Atlantic and Mediterranean maerl beds. Aquat. Conserv. 13: S65–S76.

Bordehore C., Ramos-Esplá A.A., Riosmena-Rodríguez R. 2003. Comparative study of two maërl beds with different otter trawling history, southeast Iberian Peninsula. Aquat. Conserv. 13: 43-54.

Brown B.E., Darcy G.H., Overholtz W. 1987. Stocks assessment/stock identification: an interactive process. In: Kumpf H.E., Vaught R.N., Grimes C.B. (eds.), Proceedings of the stock identification workshop. US Department of Commerce, Washington, D.C.

Cadrin S.X., Friedland K.D.,Waldman J.R. (eds.) 2005. Stock identification methods. Applications in fishery science. Elsevier, Amsterdam, 736 pp.

Canals M., Ballesteros E. 1997. Production of carbonate particles by phytobenthic communities on the Mallorca-Menorca shelf, northwestern Mediterranean Sea. Deep Sea Res. Pt II 44: 611-629.

Colloca F., Cardinale M., Belluscio A., Ardizzone G. 2003. Pattern of distribution and diversity of demersal assemblages in the central Mediterranean sea. Est. Coast. Shelf Sci. 56: 469-480.

Cope J.M., Punt A.E. 2009. Drawing the lines: resolving fishery management units with simple fisheries data. Can. J. Fish. Aquat. Sci. 66: 1256-1273.

Danovaro R., Company J., Corinaldesi C., D’Onghia G., Galil B., Gambi C., Gooday A.J., Lampadariou N., Luna G.M., Morigi C., Olu K., Polymenakou P., Ramirez-Llodra E., Sabbatini A., Sarda F., Sibuet M., Tselepides A. 2010. Deep-sea biodiversity in the Mediterranean Sea: The known, the unknown, and the unknowable. PloS One 5(8): e11832. PMid:20689848    PMCid:2914020

Estrada M. 1996. Primary production in the northwestern Mediterranean. Sci. Mar. 60(2): 55-64.

EU 2006. Council Regulation (EC) No 1967/2006 of 21 December 2006 concerning management measures for the sustainable exploitation of fishery resources in the Mediterranean Sea. Official Journal of the European Union, L 409/11-85.

Fernández A.M. 2010. Stock assessment of red mullet in GSA06. Sub-Committee on Stock Assessment, Istanbul, Turkey, 18-23 October 2010.

Fornós J.J, Ballesteros E., Massutí C., Rodríguez-Perea A. 1988. Red algae sediments in the Balearic Shelf. Rapp. Comm. int. Mer Médit. 31: 2.

Frank K.T., Brickman D. 2000. Allee effects and compensatory population dynamics within a stock complex. Can. J. Fish. Aquat. Sci. 57: 513-517.

García-Rodríguez M., Esteban A. 1999. On the biology and fishery of Aristeus antennatus (Risso, 1816), (Decapoda, Dendrobranchiata) in the Ibiza Channel (Balearic Islands, Spain). Sci. Mar. 63: 27-37.

García-Rodríguez M., Esteban A., Gil J.L.P. 2000. Considerations on the biology of Plesionika edwardsi (Brandt, 1851) (Decapoda, Caridea, Pandalidae) from experimental trap catches in the Spanish western Mediterranean Sea. Sci. Mar. 64: 369-379.

GFCM 2010a. Report of the 12th session of the scientific advisory committee (SAC). Budva, Montenegro, 25-29 January 2010. GFCM: XXXIV/2010/Inf.9, 212 pp.

GFCM 2010b. Report of the SCSA working group on stock assessment of demersal species. Istanbul, Turkey, 18-23 October 2010. GFCM: SAC13/2011/Inf.19, 91 pp.

Haddon M. 2001. Modelling and quantitative methods in fisheries. Chapman & Hall/CRC, Florida, 424 pp.

Ihssen P.E., Booke H.E., Casselman J.M., McGlade J.M., Payne N.R., Utter F.M. 1981. Stock identification: materials and methods. Can. J. Fish. Aquat. Sci. 38: 1838-1855.

Lleonart J., Maynou F. 2003. Fish stock assessments in the Mediterranean: state of the art. Sci. Mar. 67: 37-49.

Lombarte A., Recasens L., González M., Gil de Sola L. 2000. Spatial segregation of two species of Mullidae (Mullus surmuletus and M. barbatus) in relation to habitat. Mar. Ecol. Progr. Ser. 206: 239-249.

Massutí E., Guijarro B. 2004. Recursos demersales en los fondos de arrastre de la plataforma y el talud de Mallorca y Menorca (Illes Balears). Resultados de las campañas BALAR0401 y BALAR0901. Inf. Tec. Inst. Esp. Oceanogr. 182, 132 pp.

Massutí E., Moranta J. 2003. Demersal assemblages and depth distribution of elasmobranchs from the continental shelf and slope off the Balearic Islands (western Mediterranean). ICES J. Mar. Sci. 60(4): 753-766.

Massutí E., Reñones O. 2005. Demersal resource assemblages in the trawl fishing grounds off the Balearic Islands (western Mediterranean). Sci. Mar. 69: 167-181.

Massutí E., García-Rodríguez M., Gil de Sola L., Guijarro B., Ordines F., García C., Ponce R. 2008. Informe campaña MEDITS_ ES_2008. Instituto Español de Oceanografía, 219 pp.

Ordines F., Massutí E. 2009. Relationships between macro-epibenthic communities and fish on the shelf grounds of the western Mediterranean. Aquat. Conserv. 19: 370-383.

Ordines F., Massutí E., Guijarro B., Mas R. 2006. Diamond vs. square mesh codend in a multi-species trawl fishery of the western Mediterranean: effects on catch composition, yield, size selectivity and discards. Aquat. Living Resour. 19: 329-338.

Ordines F., Quetglas A., Massutí E., Moranta J. 2009. Habitat preferences and life history of the red scorpion fish, Scorpaena notata, in the Mediterranean. Est. Coast. Shelf Sci. 85(4): 537-546.

Palmer M., Quetglas A., Guijarro B., Moranta J., Ordines F., Massutí E. 2009. Performance of artificial neural networks and discriminant analysis in predicting fishing tactics from multispecific fisheries. Can. J. Fish. Aquat. Sci. 66: 224-237.

Pelletier D., Ferraris J. 2000. A multivariate approach for defining fishing tactics from commercial catch and effort data. Can. J. Fish. Aquat. Sci.57: 51-65.

Piet G.J., van Hal R., Greenstreet S.P.R. 2009. Modelling the direct impact of bottom trawling on the North Sea fish community to derive estimates of fishing mortality for non-target fish species. ICES J. Mar. Sci. 66(9): 1985-1998.

Reiss H., Hoarau G., Dickey-Collas M., Wolff W.J. 2009. Genetic population structure of marine fish: mismatch between biological and fisheries management units. Fish Fish. 10: 361-395.

Sampedro P., Saínza M., TrujilloV. 2005. A simple tool to calculate biological parameter’s uncertainty. Working Document in Workshop on Sampling Design for Fisheries Data. ICES CM 2005/ACFM:11, Pasajes (Spain), 82 pp.

Sánchez P., Demestre M., Martín P. 2004. Characterisation of the discards generated by bottom trawling in the northwestern Mediterranean. Fish. Res. 67: 71-80.

Shaklee J.B., Currens K.P. 2003. Genetic stock identification and risk assessment. In: Hallerman E.M. (ed.), Population genetics: Principles and applications for fisheries scientists. American Fisheries Society, Bethesda, pp. 291-328.

Stevens J.D., Bonfil R., Dulvy N.K., Walker P.A. 2000. The effects of fishing on sharks, rays, and chimaeras (chondrichthyans), and the implications for marine ecosystems. ICES J. Mar. Sci. 57(3): 476-494.

Taylor B.L., Dizon A.E. 1999. First policy then science: why a management unit based solely on genetic criteria cannot work. Mol. Ecol. 8: S11-S16. PMid:10703548

Thresher R.E. 1999. Elemental composition of otoliths as a stock delineator in fishes. Fish. Res. 43: 165-204.

Tserpes G., Fiorentino F., Levi D., Cau A., Murenu M., Zamboni A., Papaconstantinou C. 2002. Distribution of Mullus barbatus and M. surmuletus (Osteichthyes : Perciformes) in the Mediterranean continental shelf: implications for management. Sci. Mar. 66: 39-54.

Waldman J.R. 2005. Definition of stocks: an evolving concept. In: Cadrin S.X., Friedland K.D., Waldman J.R. (eds.), Stock Identification methods. Applications in fishery science. Elsevier, Academic Press, Amsterdam, pp. 7-16.


Darby C.D, Flatman S. 1994. Virtual Population Análisis: version 3.1 (Windows/DOS) user guide. Info. Tech. Ser., MAFF Direct. Fish. Res., Lowestoft, Nº 1, 85 pp.

Lleonart J., Salat J. 1997. VIT: Software for fishery analysis. User’s manual. FAO Computerized Information Series (Fisheries), Nº 11, Rome, FAO, 105 pp.

Sardà F., Lleonart J., Cartes J.E. 1998. An analysis of the population dynamics of Nephrops norvegicus (L.) in the Mediterranean Sea. Sci. Mar. 62(Supl. 1): 135-143.




How to Cite

Quetglas A, Guijarro B, Ordines F, Massutí E. Stock boundaries for fisheries assessment and management in the Mediterranean: the Balearic Islands as a case study. Sci. mar. [Internet]. 2012Mar.30 [cited 2024May26];76(1):17-28. Available from:




Most read articles by the same author(s)

<< < 1 2 3 4 > >>