Scientia Marina, Vol 76, No 1 (2012)

Inter- and intra-annual trends and status indicators of nektobenthic elasmobranchs off the Balearic Islands (northwestern Mediterranean)

Beatriz Guijarro
Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears , Spain

Antoni Quetglas
Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears , Spain

Joan Moranta
Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears , Spain

Francesc Ordines
Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears , Spain

Maria Valls
Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears , Spain

Natalia González
Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears , Spain

Enric Massutí
Instituto Español de Oceanografía, Centre Oceanogràfic de les Balears , Spain


We assessed the elasmobranch communities exploited by the bottom trawl fishery off the Balearic Islands (northwestern Mediterranean) by analysing two time series containing information with different levels of detail: 1) a long-term series containing the abundance indices of the whole elasmobranch community landed from 1965 to 2009; and 2) a shorter time series from 2000 to 2009 from two different data sources (daily sales records: 2000-2009; bottom trawl surveys: 2001-2009), with information that allowed the shelf and slope to be analysed separately and different community parameters and abundance indices to be studied. Temporal trends of all these variables were used as ecological status indicators and tested with generalized additive models and analysis of variance. They were finally summarised using the Traffic Light methodology. The long-term series showed two marked trends, an inter-annual decreasing trend that would be a consequence of the large increase in fishing effort, and an intra-annual trend with a clear peak in May in accordance with the seasonal biological cycle of these species. However, data from the last ten years revealed differences between the shelf and slope, as some parameters increased significantly over time on the shelf but did not follow any trend on the slope. The Traffic Light methodology captured these differences well, demonstrating its usefulness for interpreting ecological transitions at a glance.


elasmobranchs; assessment; Traffic Light method; indicators; fishing effort; Balearic Islands

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Aldebert Y. 1997. Demersal resources of the Gulf of Lions (Mediterranean). Impact on fish diversity. Vie Milieu 47: 275-284.

Baeta F., Batista M., Maia A., Costa M.J., Cabral H. 2010. Elasmobranch bycatch in a trammel net fishery in the Portuguese west coast. Fish. Res. 102(1-2): 123-129.

Bertrand J.A., Aldebert Y., Souplet A. 1998. Temporal variability of demersal species in the Gulf of Lions from trawl surveys (1983-1997). IFREMER Actes des Colloques 26: 153-164.

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. Medit. 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.

Browman H.I., Stergiou K.I. 2004. Perspectives on ecosystem-based approaches to the management of marine resources. Mar. Ecol. Prog. Ser. 274: 269-270.

Caddy J.F. 1998. A short review of precautionary reference points and some proposals for their use in data-poor situations. FAO Fisheries Technical Paper. No. 379, Rome, 30 pp.

Caddy J.F. 1999. Deciding on precautionary management measures for a stock based on a suite of Limit Reference Points (LRPs) as abasis for a multi-LRP harvest law. NAFO Sci. Council Stud. 32: 55-68.

Caddy J.F. 2002. Limit reference points, traffic lights, and holistic approaches to fisheries management with minimal stock assessment input. Fish. Res. 56(2): 133-137.

Caddy J.F., Wade E., Surette T., Hebert M., Moriyasu M. 2005. Using an empirical traffic light procedure for monitoring and forecasting in the Gulf of St. Lawrence fishery for the snow crab, Chionoecetes opilio. Fish. Res. 76(1): 123-145.

Capape C., Tomasini J.A., Quignard J.P. 2000. The Pleurotremate Elasmobranchs from the Languedoc coast (Southern France): biological and demographic observations. Vie Milieu 50(2): 123-133.

Carbonell A., Alemany F., Merella P., Quetglas A., Roman E. 2003. The by-catch of sharks in the western Mediterranean (Balearic Islands) trawl fishery. Fish. Res. 61(1-3): 7-18.

Casey J.M., Myers R.A. 1998. Near extinction of a large, widely distributed fish. Science 281(5377): 690-692. PMid:9685260

Cavanagh R.D., Gibson C. 2007. Overview of the conservation status of cartilaginous fishes (Condrichthyans) in the Mediterranean Sea. IUCN, Gland, Switzerland and Málaga, Spain, 42 pp.

Ceriola L., Accadia P., Mannini P., Massa F., Milone N., Ungaro N. 2008. A bio-economic indicators suite for the appraisal of the demersal trawl fishery in the Southern Adriatic Sea (Central Mediterranean). Fish. Res. 92(2-3): 255-267.

Ceriola L., Ungaro N., Toteda F. 2007. A “Traffic” Light approach for the assessment of the Broadtail shortfin squid Illex coindetii Verany, 1839 in the Southern Adriatic Sea (Central Mediterranean). Rev. Fish Biol. Fish. 17(2-3): 145-157.

Chen Q.X., Chan K.S., Lekve K., Torstensen E., Gjosaeter J., Ottersen

G., Stenseth N.C. 2005. Population dynamics of cod Gadus morhua in the North Sea region: biological density-dependent and climatic density-independent effects. Mar. Ecol. Prog. Ser. 302: 219-232.

Ciannelli L., Chan K.S., Bailey K.M., Stenseth N.C. 2004. Nonadditive effects of the environment on the survival of a large marine fish population. Ecology 85(12): 3418-3427.

Coelho R., Erzini K. 2008. Effects of fishing methods on deep water shark species caught as by-catch off southern Portugal. Hydrobiologia 606: 187-193.

Damalas D., Katsanevakis S., Maravelias C.D., Karageorgis A.P., Anagnostou C., Tsitsika E., Papaconstantinou C. 2009. Habitat preferences and spatiotemporal distribution of four benthic skates in the Eastern Mediterranean Sea. 9th Symposium on Oceanography and Fisheries - Proceedings, Volume II: 771-776.

DFO. 2005. Northern Shrimp on the Eastern Scotial Shelf (SFA 13-15). DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2005/060.

Dulvy N.K., Baum J.K., Clarke S., Compagno L.J.V., Cortes E., Domingo A., Fordham S., Fowler S., Francis M.P., Gibson C., Martinez J., Musick J.A., Soldo A., Stevens J.D., Valenti S. 2008. You can swim but you can’t hide: the global status and conservation of oceanic pelagic sharks and rays. Aquat. Conserv. 18(5): 459-482.

Dulvy N.K., Metcalfe J.D., Glanville J., Pawson M.G., Reynolds J.D. 2000. Fishery stability, local extinctions, and shifts in community structure in skates. Conserv. Biol. 14(1): 283-293.

Ellis J., Dulvy N.K., Jennings S., Parker-Humphreys M., Rogers S.I. 2005. Assessing the status of demersal elasmobranchs in UK waters: a review. J. Mar. Biol. Ass. U.K. 85(5): 1025-1047.

Garofalo G., Gristina M., Fiorentino F., Fulgosi F.C., Norrito G., Sinacori G. 2003. Distributional pattern of rays (Pisces, Rajidae) in the Strait of Sicily in relation to fishing pressure. Hydrobiologia 503(1-3): 245-250.

Gouraguine A., Hidalgo M., Moranta J., Bailey D.M., Ordines F., Guijarro B., Valls M., Barberá C., Quetglas A., De Mesa A. 2011. Spatial segregation between deep water elasmobranch species related to biological and environmental factors. Sci. Mar., 75(4): 653-664.

Guijarro B., Massutí E. 2006. Selectivity of diamond- and square-mesh codends in the deepwater crustacean trawl fishery off the Balearic Islands (western Mediterranean). ICES J. Mar. Sci. 63(1): 52-67.

Guijarro B., Massutí E., Moranta J., Díaz P. 2008. Population dynamics of the red shrimp Aristeus antennatus in the Balearic Islands (western Mediterranean): Short spatio-temporal differences and influence of environmental factors. J. Mar. Syst. 71: 385-402.

Guijarro B., Tserpes G., Moranta J., Massutí E. 2011. Assessment of the deep water trawl fishery off the Balearic Islands (western Mediterranean): from single to multi-species approach. Hydrobiologia, 670: 67-85.

Halliday R.G., Fanning L.P., Mohn R.K. 2001. Use of the Traffic Light Method in Fishery Management Planning. 2001/108 ISSN 1480-4883: 1-41.

Hastie T.J., Tibshirani R.J. 1990. Generalized Additive Models. Chapman and Hall, New York, 335 pp.

Hidalgo M., Massutí E., Guijarro B., Moranta J., Ciannelli L., Lloret J., Oliver P., Stenseth N.C. 2009. Population effects and changes in life history traits in relation to phase transitions induced by long-term fishery harvesting: European hake (Merluccius merluccius) off the Balearic Islands. Can. J. Fish. Aquat. Sci. 66: 1355-1370

Jennings S. 2005. Indicators to support an ecosystem approach to fisheries. Fish and Fisheries 6(3): 212-232.

Koeller P., Savard L., Parsons D.G., Fu C. 2000. A precautionary approach to assessment and management of shrimp stocks in the Northwest Atlantic. J. Northwest Atl. Fish. Soc. 27: 235-246.

Massutí E., Monserrat S., Oliver P., Moranta J., López-Jurado J.L., Marcos M., Hidalgo M., Guijarro B., Carbonell A., Pereda P. 2008. The influence of oceanographic scenarios on the population dynamics of demersal resources in the western Mediterranean: Hypothesis for hake and red shrimp off Balearic Islands. J. Mar. Syst. 71: 421-438.

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.

Moranta J., Quetglas A., Massutí E., Guijarro B., Hidalgo M., Díaz P. 2008. Spatio-temporal variations in deep-sea demersal communities off the Balearic Islands (western Mediterranean). J. Mar. Syst. 71(3-4): 346-366.

Morey G., Moranta J., Riera F., Grau A.M., Morales-Nin B. 2006. Elasmobranchs in trammel net fishery associated to marine reserves in the Balearic Islands (NW Mediterranean). Cybium 30(4): 125-132.

Morey G., Navarro O. 2010. Monitoring of elasmobranchs landings in Mallorca (Balearic Islands, NW Mediterranean). Identification at species level and understanding of the official statistics. In: Book of abstracts of the 14th European Elasmobranch Association Conference. 10th-12th November 2010. Galway, Ireland.

Mouffok S., Massutí E., Boutiba Z., Guijarro B., Ordines F., Fliti K. 2008. Ecology and Fishery of the Deep-Water Shrimp, Aristeus Antennatus (Risso, 1816) Off Algeria (South-Western Mediterranean). Crustaceana 81(10): 1177-1199.

Ordines F., Massutí E. 2009. Relationships between macro-epibenthic communities and fish on the shelf grounds of the western Mediterranean. Aquat. Conserv. 19(4): 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(4): 329-338.

Ordines F., Massutí E., Moranta J., Quetglas A., Guijarro B., Fliti K. 2011. Balearic Islands vs Algeria: two nearby western Mediterranean elasmobranchs populations with different oceanographic scenarios and fishing histories. Sci. Mar. 75(4): 707-717.

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. Earth Sci. 66(2): 224-237.

Relini G., Biagi F., Serena F., Belluscio A., Spedicato M.T., Rinelli P., Follesa M.C., Piccinetti C., Ungaro N., Sion L., Levi D. 2000. I Selaci pescati con lo strascico nei mari italiani. Biol. Mar. Medit. 7: 347-384.

Rochet M.J., Trenkel V.M. 2003. Which community indicators can measure the impact of fishing? A review and proposals. Can. J. Earth Sci. 60(1): 86-99.

Rogers S.I., Maxwell D., Rijnsdorp A.D., Damm U., Vanhee W. 1999. Fishing effects in northeast Atlantic shelf seas: patterns in fishing effort, diversity and community structure. IV. Can comparisons of species diversity be used to assess human impacts on demersal fish faunas? Fish. Res. 40(2): 135-152.

Serena F., Papaconstantinou C., Relini G., Gil de Sola L., Bertrand J.A. 2009. Distribution and abundance of spiny dogfish in the Mediterranean Sea based on the Mediterranean International Trawl Survey Program. In: Gallucci V.F., Mcfarlane G.A., Bargmann G.G. (eds.), Biology and management of Dogfish Sharks. American Fisheries Society, pp. 139-149.

Smith S.E., Au D.W., Show C. 1998. Intrinsic rebound potentials of 26 species of Pacific sharks. Mar. Freshw. Res. 49(7): 663-678.

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.

Walker T.I. 1998. Can shark resources be harvested sustainably? A question revisited with a review, of shark fisheries. Mar. Freshw. Res. 49(7): 553-572.

Wood S.N. 2004. Stable and efficient multiple smoothing parameter estimation for generalized additive models. J. Am. Stat. Ass. 99: 673-686.

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