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The trawlfauna of the Mauritanian shelf (Northwest Africa): density, species composition, and biomass

  • G. C. A. Duineveld
  • M. S. S. Lavaleye
  • G. J. van Noort
Conference paper
Part of the Developments in Hydrobiology 86 book series (DIHY, volume 86)

Abstract

In May 1988, epifaunal trawlsamples were collected at 17 stations on the Mauritanian shelf off the Banc d’Arguin. The species composition and biomass of the invertebrates and demersal fish were analysed. On the basis of species abundances, three station groups could be distinguished each corresponding to a subregion of the shelf: an inner shelf, a midshelf and an outer shelf station group. The average depth increased from 20 m for the inner to more than 100 m for the outer shelf stations. The biomass of mobile epifauna and fish was lowest on the inner shelf stations where the trawlfauna was dominated by large sessile filterfeeders. The trawlfaunas of the mid- and outer shelf were more similar in species composition. Demersal fish and crustaceans appeared to be more abundant on the outer shelf. The increase in density and biomass from inner to outer shelf is discussed in relation to the distribution of the infauna and the hydrographical conditions on the Mauritanian shelf. Being a demersal fishing area, density and biomass of the epifauna on the shelf are compared with that of the demersal fishing grounds in the southern North Sea. The result of this comparison shows that, except for echinoderms, all taxa attain higher densities and biomasses at the Mauritanian shelf.

Key words

trawlfauna Mauritanian shelf 

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References

  1. Ansa-Emmim, M., 1982. Fisheries in the CINECA region. Rapp. P.-v. Réun. Cons. int. Explor. Mer 180: 405–422.Google Scholar
  2. Boely, T., 1982. Les ressources en poissons pélagiques des côtes ouest-africaines entre la Mauritanie et le fleuve Congo. Rapp. P.-v. Réun. Cons. int. Explor. Mer 180: 423–431.Google Scholar
  3. Bonnet, M., J. Duclerc & P. Pichot, 1971. Nouvelle étude sur les fonds de pêche du Banc d’Arguin et de ses abords. Campagne de la Thalassa’, janvier-février 1971. Science et Pêche, Bull. Inst. Pêches marit. 203: 1–15.Google Scholar
  4. Brulhet, J., J. Maigret & Sy Moussa Arouna, 1974. Résultats de la campagne de chalutage expérimental autour du Banc d’Arguin. Bull. Lab. Pêches de Nouadhibou 3: 71–111.Google Scholar
  5. Bravo de-Laguna, J., 1982. Distribution and abundance of demersal resources of the CINECA region. Rapp. P.-v. Réun. Cons. int. Explor. Mer 180: 432–446.Google Scholar
  6. Collignon, J., 1971. Les poissons benthiques du plateau continental Marocain; 2eme note: le peuplement des sables coders. Bull. Inst. Pêches marit. 18: 37–69.Google Scholar
  7. Creutzberg, F., G. C. A. Duineveld & G. J. van Noort, 1987. The effect of different numbers of tickler chains on beamtrawl catches. J. Cons. int. Explor. Mer 43: 159–168.Google Scholar
  8. Duineveld, G. C. A. & G. J. van Noort, 1990. Geographical variation in the epifauna of the southern North Sea and adjacent regions. ICES paper CM. 1990/Mini:9: 1–11.Google Scholar
  9. Duineveld, G. C. A., P. A. W. J. de Wilde & A. Kok, 1990. A synopsis of the macrobenthic assemblages and benthic ETS activity in the Dutch Sector of the North Sea. Neth. J. Sea Res. 26: 125–138.CrossRefGoogle Scholar
  10. Duineveld, G. C. A., P. A. W. J. de Wilde, E. M. Berghuis & A. Kok, 1993. The benthic infauna and benthic respiration off the Banc d’Arguin (Mauritania, Northwest Africa). Hydrobiologia 258: 107–117.CrossRefGoogle Scholar
  11. Hill, M. O., 1979a. TWINSPAN — a FORTRAN program for arranging multivariate data in an ordered two-way table by classification of the individuals and their attributes. Ithaca, Cornell University, New York, 90 pp.Google Scholar
  12. Hill, M. O., 1979b. DECORANA — a FORTRAN program for detrended correspondence analysis and reciprocal averaging. Ithaca, Cornell University, New York, 52 pp.Google Scholar
  13. Huntsman, S. A. & R. T. Barber, 1977. Primary production off northwest Africa: the relationship to wind and nutrient conditions. Deep Sea Res. 24: 25–33.CrossRefGoogle Scholar
  14. Maurin, C. & M. Bonnet, 1969. Le chalutage au large des côtes nord-ouest africaines. Résultats des campagnes de la ‘Thalassa’. Science et Pêche, Bull. Inst. Pêches marit. 177: 1–17.Google Scholar
  15. Minas, H. J., L. A. Cospidoti & R. C. Dugdale, 1982. Nutrients and primary production in the upwelling region off Northwest Africa. Rapp. P.-v. Réun. Cons. int. Explor. Mer 180: 148–183.Google Scholar
  16. Pihl, L., S. P. Baden & R. J. Diaz, 1991. Effects of periodic hypoxia on distribution of demersal fish and crustaceans. Mar. Biol. 108: 349–360.CrossRefGoogle Scholar
  17. Rumohr, H., T. Brey & S. Ankar, 1987. A compilation of biometric conversion factors for benthic invertebrates of the Baltic Sea. The Baltic Marine Biologists Publication 9: 1–56.Google Scholar
  18. Thiel, H., 1982. Zoobenthos of the CINECA area and other upwelling regions. Rapp. P.v. Réun. Cons. int. Explor. Mer 180: 323–334.Google Scholar
  19. Van der Knaap, M., 1985. Preliminary annotated inventory of the scientific expeditions and resource surveys carried out in the CECAF area. CECAF/TECH/85/64, Dakar: 50 pp.Google Scholar
  20. Weichart, G., 1974. Meereschemische Untersuchungen im nordwestafrikanischen Auftriebsgebiet 1968. ‘Meteor’ Forsch.-Ergebnisse A 14: 33–70.Google Scholar
  21. Zijlstra, J. J., 1988. The North Sea ecosystem. In H. Postma & J. J. Zijlstra (eds), Continental shelves. Elsevier Scientific Publishers, London: 231–277.Google Scholar

Copyright information

© Springer Science+Business Media Dordrecht 1993

Authors and Affiliations

  • G. C. A. Duineveld
    • 1
  • M. S. S. Lavaleye
    • 1
  • G. J. van Noort
    • 1
  1. 1.Netherlands Institute for Sea ResearchDen BurgThe Netherlands

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