Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Selective foraging behaviour of basking sharks on zooplankton in a small-scale front


The basking shark Cetorhinus maximus is the second largest fish species, attaining lengths of up to 11 m. During summer months in temperate coastal waters circumglobally, these sharks filter-feed on surface zooplankton1,2,3,4 near water-mass boundaries (fronts)5,6; however, little else is known about their biology1. Their foraging behaviour has not been investigated until now, although they have been described2 as indiscriminate planktivores that are unlikely to orientate to specific plankton-rich waters. We have now tracked basking sharks responding to zooplankton gradients. We show that they are selective filter-feeders that choose the richest, most profitable plankton patches. They forage along thermal fronts and actively select areas that contain high densities of large zooplankton above a threshold density. They remain for up to 27 hours in rich patches that are transported by tidal currents and move between patches over periods of 1–2 days. We mapped feeding locations of these sharks in two years; the maps show that these sharks indicate broad shifts in front-located secondary production. Foraging behaviour of basking sharks therefore indicates the distribution, density and characteristics of zooplankton directly. This makes these sharks unique biological ‘plankton recorders’, with potential use as detectors of trends in abundance of zooplankton species that are influenced by climatic fluctuations of the North Atlantic Oscillation7.

This is a preview of subscription content

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Distribution of surface-foraging basking sharks and changes in summer SST.
Figure 2: Feeding behaviour of basking sharks in relation to zooplankton density.
Figure 3: Movements of a feeding group of basking sharks over two consecutive days (3 June 1996, filled circles, and 4 June 1996, open circles).


  1. Sims, D. W., Fox, A. M. & Merrett, D. A. Basking shark occurrence off south-west England in relation to zooplankton abundance. J. Fish Biol. 51, 436–440 (1997).

    Article  Google Scholar 

  2. Matthews, L. H. & Parker, H. W. Notes on the anatomy and biology of the basking shark (Cetorhinus maximus (Gunner). Proc. Zool. Soc. Lond. 120, 535–576 (1950).

    Article  Google Scholar 

  3. Kenney, R. D., Owen, R. E. & Winn, H. E. Shark distributions off the northeast United States from marine mammal surveys. Copeia 1985, 220–223 (1985).

    Article  Google Scholar 

  4. Berrow, S. D. & Heardman, C. The basking shark Cetorhinus maximus (Gunnerus) in Irish waters—patterns of distribution and abundance. Proc. R. Irish Acad. B 94, 101–107 (1994).

    Google Scholar 

  5. Priede, I. G. Abasking shark (Cetorhinus maximus) tracked by satellite together with simultaneous remote sensing. Fish. Res. 2, 201–216 (1984).

    Article  Google Scholar 

  6. Choy, B. K. & Adams, D. H. An observation of a basking shark, Cetorhinus maximus, feeding along a thermal front off the east-central coast of Florida. Florida Sci. 58, 313–319 (1995).

    Google Scholar 

  7. Fromentin, J.-M. & Planque, B. Calanus and environment in the eastern North Atlantic. II. Influence of the North Atlantic Oscillation on C. finmarchicus and C. helgolandicus. Mar. Ecol. Prog. Ser. 134, 111–118 (1996).

    Article  ADS  Google Scholar 

  8. Harvey, H. W., Cooper, L. H. N., Lebour, M. V. & Russell, F. S. Plankton production and its control. J. Mar. Biol. Assoc. UK 20, 407–441 (1935).

    Article  Google Scholar 

  9. Southward, A. J. On changes of sea temperature in the English Channel. J. Mar. Biol. Assoc. UK 39, 449–458 (1960).

    Article  Google Scholar 

  10. Armstrong, F. A. J., Butler, E. I. & Boalch, G. T. Hydrographic and nutrient chemistry surveys in the western English Channel during 1963 and 1964. J. Mar. Biol. Assoc. UK 52, 915–930 (1972).

    Article  Google Scholar 

  11. Southward, A. J. & Butler, E. I. Anote on further changes of sea temperature in the Plymouth area. J. Mar. Biol. Assoc. UK 52, 931–937 (1972).

    Article  Google Scholar 

  12. Southward, A. J. & Demir, N. The abundance and distribution of eggs and larvae of some teleost fishes off Plymouth in 1969 and 1970. J. Mar. Biol. Assoc. UK 52, 987–996 (1972).

    Article  Google Scholar 

  13. Southward, A. J. The western English Channel—an inconstant ecosystem? Nature 285, 361–366 (1980).

    Article  ADS  Google Scholar 

  14. Southward, A. J. Fluctuations in the ‘indicator’ chaetognaths Sagitta elegans and Sagitta setosa in the western Channel. Oceanol. Acta 7, 229–239 (1984).

    Google Scholar 

  15. Robinson, I. S. Satellite Oceanography(Wiley, Chichester, 1994).

    Google Scholar 

  16. Wolanski, E. & Hamner, W. M. Topographically controlled fronts in the ocean and their biological significance. Science 241, 177–181 (1988).

    CAS  Article  ADS  Google Scholar 

  17. Kingsford, M. J., Wolanski, E. & Choat, J. H. Influence of tidally induced fronts and Langmuir circulations on distribution and movements of presettlement fishes around a coral reef. Mar. Biol. 109, 167–180 (1991).

    Article  Google Scholar 

  18. Le Fèvre, J. Aspects of the biology of frontal systems. Adv. Mar. Biol. 23, 163–299 (1986).

    Article  Google Scholar 

  19. Sims, D. W. & Merrett, D. A. Determination of zooplankton characteristics in the presence of surface feeding basking sharks, Cetorhinus maximus. Mar. Ecol. Prog. Ser. 158, 297–302 (1997).

    Article  ADS  Google Scholar 

  20. Kalmijn, A. J. Electric and magnetic field detection in elasmobranch fishes. Science 218, 916–918 (1982).

    CAS  Article  ADS  Google Scholar 

  21. Nevitt, G. A., Veit, R. R. & Kareiva, P. Dimethyl sulphide as a foraging cue for Antarctic Procellariiform seabirds. Nature 376, 680–682 (1995).

    CAS  Article  ADS  Google Scholar 

  22. Cramp, S. et al. Handbook of the Birds of Europe the Middle East and North Africa: The Birds of the Western Palearctic Vol. 1(Oxford Univ. Press, Oxford, 1977).

    Google Scholar 

  23. Pingree, R. D., Pugh, P. R., Holligan, P. M. & Forster, G. R. Summer phytoplankton blooms and red tides along tidal fronts in the approaches to the English Channel. Nature 258, 672–677 (1975).

    Article  ADS  Google Scholar 

  24. Yoder, J. A. et al. Aline in the sea. Nature 371, 689–692 (1994).

    Article  ADS  Google Scholar 

  25. Fiedler, P. C., Smith, G. B. & Laurs, R. M. Fisheries applications of satellite data in the eastern north Pacific. Mar. Fish. Rev. 46, 1–13 (1984).

    Google Scholar 

  26. Southwell, K. Oceanography: Shades of the sea. Nature 389, 444 (1997).

    CAS  Article  ADS  Google Scholar 

  27. Zar, J. H. Biostatistical Analysis(Prentice-Hall, Englewood Cliffs, 1984).

    Google Scholar 

Download references


The research programme was supported by the Nature Conservancy Council for England (English Nature) and the Plymouth Environmental Research Centre. We thank A. Fox, B.Broughton, D. Murphy, A. Giles, D. Uren, R. Harris, P. Ede and R. Hopgood for their assistance in research at sea; D. Merrett for help in zooplankton analysis; and the late F. Carey and D. Nelson, whose work helped to inspire the principal investigator (D.W.S.) to begin these studies. Satellite images of SST were supplied by the NERC Satellite Receiving Station.

Author information

Authors and Affiliations


Corresponding author

Correspondence to David W. Sims.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Sims, D., Quayle, V. Selective foraging behaviour of basking sharks on zooplankton in a small-scale front. Nature 393, 460–464 (1998).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing