Linking trawl fleet dynamics and the spatial distribution of exploited species can help to avoid unwanted catches: the case of the NW Mediterranean fishing grounds




unwanted catches, northwestern Mediterranean, trawl fishery, discard, VMS, MCRS


With the full implementation of the landing obligation on 1 January 2019, In European waters it will become mandatory for the trawling fleet to land at port all catches of certain species because, according to Article 15 of the new European Common Fisheries Policy, the species subject to the minimum conservation reference size (MCRS) cannot be discarded. Additionally, since 2005, trawlers over 15 m in length are required to carry an onboard vessel monitoring system (VMS), which generates information on fleet dynamics. The objective of this work was to provide a tool for avoiding unwanted catches by integrating the catch study of trawlers operating in the port of Blanes together with VMS data. To achieve this objective, the catches of 40 hauls were monitored, sampled and analysed together with VMS data for the years 2012-2014 integrated in a geographical information system. The results show that specimens below the MCRS were often captured in crinoid aggregation habitats, bottoms with maërl and muddy bottoms that were identified as nursery habitats of commercial species, e.g. Merluccius merluccius, Pagellus spp. and Mullus spp. VMS data showed considerable fishing pressure on areas with maërl and muddy habitats during the recruitment periods of these and other commercially relevant species. Implementing spatial or seasonal closures in habitats where species regulated by the MCRS are subject to catches could be a useful tool for preventing unwanted catches.


Download data is not yet available.


Barberá C., Bordehore C., Borg J.A., et al. 2003. Conservation and management of northeast Atlantic and Mediterranean maerl beds. Aquat. Conserv. Mar. Freshw. Ecosyst. 13: 65-76.

Barberá C., Moranta J., Ordines F., et al. 2012. Biodiversity and habitat mapping of Menorca Channel (western Mediterranean): implications for conservation. Biodiversity Conserv. 21: 701-728.

Basso D. 1996. Adaptative strategies and convergent morphologies in some Mediterranean coralline algae. in Cherchi, A. (ed.), Autecology of selected fossil organisms: Achievement and problems. Boll. Soc. Paleon. Ital. Special Vol. 3: 1-8.

Bellido J.M., Santos M.B., Pennino M.G., et al. 2011. Fishery discards and bycatch: solutions for an ecosystem approach to fisheries management? Hydrobiologia 670: 317-333.

Bellido J.M., Garcia-Rodriguez M., Garcia-Jimenez T., et al. 2017. Could the obligation to land undersized individuals increase the black market for juveniles: evidence from the Mediterranean? Fish Fish. 18: 185-194.

Campos A., Fonseca P., Pilar-Fonseca T., et al. 2015. Survival of trawl-caught Norway lobster (Nephrops norvegicus L.) after capture and release-Potential effect of codend mesh type on survival. Fish. Res. 172: 415-422.

Carbonara P., Intini S., Modugno E., et al. 2015. Reproductive biology characteristics of red mullet (Mullus barbatus L., 1758) in Southern Adriatic Sea and management implications. Aquat. Living Resour. 28: 21-31.

Carbonell A., Alemany F., Merella P., et al. 2003. The by-catch of sharks in the western Mediterranean (Balearic Islands) trawl fishery. Fish. Res. 61: 7-18.

Clarke K.R., Gorley R.N. 2006. PRIMER v6: User Manual/Tutorial. PRIMER-E. Plymouth. 192 pp.

Colloca F., Carpentieri P., Balestri E., et al. 2004. A critical habitat for Mediterranean fish resources: shelf-break areas with Leptometra phalangium (Echinodermata: Crinoidea). Mar. Biol. 145: 1129-1142.

Damalas D. 2015. Mission impossible: Discard management plans for the EU Mediterranean fisheries under the reformed Common Fisheries Policy. Fish. Res. 165: 96-99.

De Juan S., Lo Iacono C., Demestre M. 2013. Benthic habitat characterisation of soft-bottom continental shelves: Integration of acoustic surveys, benthic samples and trawling disturbance intensity. Estuar. Coast. Shelf Sci. 117: 199-209.

Demestre M., Sanchez P., Abello P. 2000. Demersal fish assemblages and habitat characteristics on the continental shelf and upper slope of the north-western Mediterranean. J. Mar. Biol. Assoc. U.K. 80: 981-988.

Demestre M., Muntadas A., de Juan S., et al. 2015. The need for fine-scale assessment of trawl fishing effort to inform on an ecosystem approach to fisheries: Exploring three data sources in Mediterranean trawling grounds. Mar. Policy 62: 134-143.

Demestre M., Muntadas A., Sanchez P., et al. 2017. Bio and anthropogenic disturbance on maërl communities in subaqueous dunes of the Mar Menor shelf (SW Mediterranean). In: Guillén J., Acosta J., Chiocci F., et al. (eds), Atlas of bedforms in western Mediterranean. Springer, Cham, pp. 215-219

Durell S., Stillman R.A., Triplet P., et al. 2008. Using an individual-based model to inform estuary management in the Baie de Somme, France. Oryx 42: 265-277.

Garcia-de-Vinuesa A. 2012. Estudio de las comunidades bentónicas afectadas por la pesca de arrastre de la plataforma continental de Palamós. MSc thesis, Univ. Barcelona.

Garcia-de-Vinuesa A., Breen M., Benoit H., et al. 2017. Survival of discarded Nephrops norvegicus from the Catalan sea bottom trawl fishery. Study as part of Science, Technology, and Society Initiative to Minimize Unwanted Catches in European Fisheries. (MINOUW Project). PMCid:PMC5452635

Generalitat de Catalunya, Departament d'Agricultura, Ramaderia, Pesca i Alimentació Direcció General de Pesca i Afers Marítims. 2015. Talles mínimes autoritzades de peix i marisc. Espècies procedents del calador Mediterrani Reglamentació europea, nacional i autonòmica. calador_mediterrani/dar_talles_minimes_autoritzades/.

Gorelli G., Blanco M., Sarda F., et al. 2016. Spatio-temporal variability of discards in the fishery of the deep-sea red shrimp Aristeus antennatus in the northwestern Mediterranean Sea: implications for management. Sci. Mar. 80: 79-88.

Hall-Spencer J.M., Grall J., Moore P.G., et al. 2003. Bivalve fishing and maerl-bed conservation in France and the UK - retrospect and prospect. Aquat. Conserv. Mar. Freshw. Ecosyst. 13: 33-41.

Hinz H., Murray L.G., Lambert G.I., et al. 2013. Confidentiality over fishing effort data threatens science and management progress. Fish Fish. 14: 110-117.

Mangano M.C., Porporato E., de Domenico F., et al. 2010. Leptometra phalangium (J. Mueller, 1841) fields from the southern Tyrrhenian Sea: preliminary data on the associated fauna. Biol. Mar. Mediterr. 17: 304-305.

Martín P., Muntadas A., de Juan S., et al. 2014. Performance of a northwestern Mediterranean bottom trawl fleet: How the integration of landings and VMS data can contribute to the implementation of ecosystem-based fisheries management. Mar. Policy 43: 112-121.

Maynou F., Cartes J. 2000. Community structure of bathyal decapod crustaceans off south-west Balearic Islands (western Mediterranean): seasonality and regional patterns in zonation. J. Mar. Biol. Ass. U.K. 80: 789-798.

Méhault S., Morandeau F., Kopp D. 2016. Survival of discarded Nephrops norvegicus after trawling in the Bay of Biscay. Fish. Res. 183: 396-400.

QGIS Development Team. 2015. QGIS Geographic Information System. Open Source Geospatial Foundation.

R Core Team. 2017. R: A language and environment for statistical. R Foundation for Statistical Computing. Vienna, Austria.

Reale B., Sartor P., Ligas A., et al. 2005. Demersal species assemblage on the Leptometra phalangium (J. Mueller, 1841) (Echinodermata: Crinoidea) bottoms of the northern Tyrrhenian Sea. Biol. Mar. Medit. 12: 571-574.

Recasens L., Chiericoni V., Belcari P. 2008. Spawning pattern and batch fecundity of the European hake (Merluccius merluccius (Linnaeus, 1758)) in the western Mediterranean. Sci. Mar. 72: 721-732.

Salas S., Gaertner D. 2004. The behavioural dynamics of fishers: management implications. Fish Fish. 5: 153-167.

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

Sommer M. 2005. Pesca de arrastre. Aniquilación silenciosa. Rev. Elect. Vet. REDVET 4.

Steller D.L., Riosmena-Rodriiguez R., Foster M.S., et al. 2003. Rhodolith bed diversity in the Gulf of California: the importance of rhodolith structure and consequences of disturbance. Aquat. Conserv. Mar. Freshw. Ecosyst. 13: 5-20.

Tsagarakis K., Palialexis A., Vassilopoulou V. 2014. Mediterranean fishery discards: review of the existing knowledge. ICES J. Mar. Sci. 71: 1219-1234.

Tsikliras A.C., Stergiou K.I. 2014. Size at maturity of Mediterranean marine fishes. Rev. Fish. Biol. Fish. 24: 219-268.

Vilela R., Bellido J.M. 2015. Fishing suitability maps: helping fishermen reduce discards. Can. J. Fish. Aquat. Sci. 72: 1191-1201.



How to Cite

Garcia-de-Vinuesa A, Sola I, Quattrocchi F, Maynou F, Demes M. Linking trawl fleet dynamics and the spatial distribution of exploited species can help to avoid unwanted catches: the case of the NW Mediterranean fishing grounds. scimar [Internet]. 2018Dec.30 [cited 2023Oct.4];82(S1):165-74. Available from:




Most read articles by the same author(s)

1 2 3 > >>